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* [PATCH v3 00/59] irqchip: KVM: Add support for GICv4
@ 2017-07-31 17:25 Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 01/59] genirq: Let irq_set_vcpu_affinity() iterate over hierarchy Marc Zyngier
                   ` (58 more replies)
  0 siblings, 59 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm
  Cc: Christoffer Dall, Thomas Gleixner, Jason Cooper, Eric Auger,
	Shanker Donthineni, Mark Rutland, Shameerali Kolothum Thodi

This (monster of a) series implements full support for GICv4, bringing
direct injection of MSIs to KVM on arm and arm64, assuming you have
the right hardware (which is quite unlikely).

To get an idea of the design, I'd recommend you start with patches #33
and #57, which try to shed some light on the approach that I've
taken. And before that, please digest some of the GICv3/GICv4
architecture documentation[1] (less than 800 pages!). Once you feel
reasonably insane, you'll be in the right mood to read the code.

The structure of the series is fairly simple. The initial 35 patches
add some generic support for GICv4, while the rest of the code plugs
KVM into it. This series relies on Eric Auger's irq-bypass series[2],
which is a prerequisite for this work, as well as a KVM fix by
Shanker. The last two patches add a quirk for the Huawei D05 box on
which I tested this code, and which is added here for completeness and
for people to test.

The stack has been *very lightly* tested on an arm64 model, with a PCI
virtio block device passed from the host to a guest (using kvmtool and
Jean-Philippe Brucker's excellent VFIO support patches[3]), as well as
the Huawei D05 box I mentionend above using an Intel I350 Ethernet
card and passing a VF into the guest. I expect things to be (not so)
subtly broken, so go forward and test if you can, though I'm mostly
interested in people reviewing the code at the moment.

I've pushed out a branch based on 4.13-rc3 containing the dependencies:

git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git kvm-arm64/gicv4-kvm

* From v2:

  - Lots of fixes all over the map (the doorbell code was amazingly
    wrong, both at the GICv4 level and in KVM)
  - KVM GICv4 enablement is now gated by a command-line option and
    defaults to off
  - Now properly deals with ordering of vITS creation
  - Some debugging features
  - More documentation so that I can forget what this is all about
  - Huawei D05 quirks

* From v1:
  - The bulk of the 30-something initial patches have seen countless
    bugs being fixed, and some key data structures have been subtly
    tweaked (or killed altogether). They are still quite similar to
    what I had in v1 though.
  - The whole KVM code is brand new and as I said above, only lightly
    tested.
  - Collected a bunch a R-bs from Thomas and Eric (many thanks, guys).

[1] https://static.docs.arm.com/ihi0069/c/IHI0069C_gic_architecture_specification.pfd
[2] http://www.spinics.net/lists/kvm/msg151463.html
[3] http://www.spinics.net/lists/kvm/msg151823.html

Marc Zyngier (59):
  genirq: Let irq_set_vcpu_affinity() iterate over hierarchy
  irqchip/gic-v3: Add redistributor iterator
  irqchip/gic-v3: Add VLPI/DirectLPI discovery
  irqchip/gic-v3-its: Move LPI definitions around
  irqchip/gic-v3-its: Add probing for VLPI properties
  irqchip/gic-v3-its: Macro-ize its_send_single_command
  irqchip/gic-v3-its: Implement irq_set_irqchip_state for pending state
  irqchip/gic-v3-its: Split out property table allocation
  irqchip/gic-v3-its: Allow use of indirect VCPU tables
  irqchip/gic-v3-its: Split out pending table allocation
  irqchip/gic-v3-its: Rework LPI freeing
  irqchip/gic-v3-its: Generalize device table allocation
  irqchip/gic-v3-its: Generalize LPI configuration
  irqchip/gic-v4: Add management structure definitions
  irqchip/gic-v3-its: Add GICv4 ITS command definitions
  irqchip/gic-v3-its: Add VLPI configuration hook
  irqchip/gic-v3-its: Add VLPI map/unmap operations
  irqchip/gic-v3-its: Add VLPI configuration handling
  irqchip/gic-v3-its: Add VPE domain infrastructure
  irqchip/gic-v3-its: Add VPE irq domain allocation/teardown
  irqchip/gic-v3-its: Add VPE irq domain [de]activation
  irqchip/gic-v3-its: Add VPENDBASER/VPROPBASER accessors
  irqchip/gic-v3-its: Add VPE scheduling
  irqchip/gic-v3-its: Add VPE invalidation hook
  irqchip/gic-v3-its: Add VPE affinity changes
  irqchip/gic-v3-its: Add VPE interrupt masking
  irqchip/gic-v3-its: Support VPE doorbell invalidation even when
    !DirectLPI
  irqchip/gic-v3-its: Allow doorbell interrupts to be injected/cleared
  irqchip/gic-v3-its: Set implementation defined bit to enable VLPIs
  irqchip/gic-v4: Add per-VM VPE domain creation
  irqchip/gic-v4: Add VPE command interface
  irqchip/gic-v4: Add VLPI configuration interface
  irqchip/gic-v4: Add some basic documentation
  irqchip/gic-v4: Enable low-level GICv4 operations
  irqchip/gic-v3: Advertise GICv4 support to KVM
  KVM: arm: Select ARM_GIC_V3 and ARM_GIC_V3_ITS
  KVM: arm/arm64: vgic: Move kvm_vgic_destroy call around
  KVM: arm/arm64: vITS: Add MSI translation helpers
  KVM: arm/arm64: GICv4: Add property field and per-VM predicate
  KVM: arm/arm64: GICv4: Add init/teardown of the per-VM vPE irq domain
  KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq
    bypass
  KVM: arm/arm64: GICv4: Handle INT command applied to a VLPI
  KVM: arm/arm64: GICv4: Unmap VLPI when freeing an LPI
  KVM: arm/arm64: GICv4: Handle MOVI applied to a VLPI
  KVM: arm/arm64: GICv4: Handle CLEAR applied to a VLPI
  KVM: arm/arm64: GICv4: Handle MOVALL applied to a vPE
  KVM: arm/arm64: GICv4: Propagate property updates to VLPIs
  KVM: arm/arm64: GICv4: Handle INVALL applied to a vPE
  KVM: arm/arm64: GICv4: Propagate VLPI properties at map time
  KVM: arm/arm64: GICv4: Use pending_last as a scheduling hint
  KVM: arm/arm64: GICv4: Add doorbell interrupt handling
  KVM: arm/arm64: GICv4: Use the doorbell interrupt as an unblocking
    source
  KVM: arm/arm64: GICv4: Hook vPE scheduling into vgic flush/sync
  KVM: arm/arm64: GICv4: Enable virtual cpuif if VLPIs can be delivered
  KVM: arm/arm64: GICv4: Enable VLPI support
  KVM: arm/arm64: GICv4: Prevent heterogenous systems from using GICv4
  KVM: arm/arm64: GICv4: Theory of operations
  irqchip/gic-v3-its: Pass its_node pointer to each command bulder
  irqchip/gic-v3-its: Workaround Huawei D05 redistributor addressing

 Documentation/admin-guide/kernel-parameters.txt |    4 +
 arch/arm/include/asm/arch_gicv3.h               |   33 +
 arch/arm/kvm/Kconfig                            |    2 +
 arch/arm/kvm/Makefile                           |    1 +
 arch/arm64/include/asm/arch_gicv3.h             |    6 +
 arch/arm64/kvm/Makefile                         |    1 +
 drivers/irqchip/Makefile                        |    2 +-
 drivers/irqchip/irq-gic-v3-its.c                | 1421 +++++++++++++++++++++--
 drivers/irqchip/irq-gic-v3.c                    |   95 +-
 drivers/irqchip/irq-gic-v4.c                    |  224 ++++
 include/kvm/arm_vgic.h                          |   22 +
 include/linux/irqchip/arm-gic-common.h          |    2 +
 include/linux/irqchip/arm-gic-v3.h              |   86 ++
 include/linux/irqchip/arm-gic-v4.h              |  103 ++
 kernel/irq/manage.c                             |   14 +-
 virt/kvm/arm/arm.c                              |   33 +-
 virt/kvm/arm/hyp/vgic-v3-sr.c                   |    9 +-
 virt/kvm/arm/vgic/vgic-init.c                   |    9 +
 virt/kvm/arm/vgic/vgic-its.c                    |  173 ++-
 virt/kvm/arm/vgic/vgic-mmio-v3.c                |    5 +
 virt/kvm/arm/vgic/vgic-v3.c                     |   34 +
 virt/kvm/arm/vgic/vgic-v4.c                     |  335 ++++++
 virt/kvm/arm/vgic/vgic.c                        |    7 +
 virt/kvm/arm/vgic/vgic.h                        |   11 +
 24 files changed, 2419 insertions(+), 213 deletions(-)
 create mode 100644 drivers/irqchip/irq-gic-v4.c
 create mode 100644 include/linux/irqchip/arm-gic-v4.h
 create mode 100644 virt/kvm/arm/vgic/vgic-v4.c

-- 
2.11.0

^ permalink raw reply	[flat|nested] 118+ messages in thread

* [PATCH v3 01/59] genirq: Let irq_set_vcpu_affinity() iterate over hierarchy
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 02/59] irqchip/gic-v3: Add redistributor iterator Marc Zyngier
                   ` (57 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

When assigning an interrupt to a vcpu, it is not unlikely that
the level of the hierarchy implementing irq_set_vcpu_affinity
is not the top level (think a generic MSI domain on top of a
virtualization aware interrupt controller).

In such a case, let's iterate over the hierarchy until we find
an irqchip implementing it.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 kernel/irq/manage.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 1d1a5b945ab4..573dc52b0806 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -400,8 +400,18 @@ int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
 		return -EINVAL;
 
 	data = irq_desc_get_irq_data(desc);
-	chip = irq_data_get_irq_chip(data);
-	if (chip && chip->irq_set_vcpu_affinity)
+	do {
+		chip = irq_data_get_irq_chip(data);
+		if (chip && chip->irq_set_vcpu_affinity)
+			break;
+#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
+		data = data->parent_data;
+#else
+		data = NULL;
+#endif
+	} while (data);
+
+	if (data)
 		ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
 	irq_put_desc_unlock(desc, flags);
 
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 02/59] irqchip/gic-v3: Add redistributor iterator
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 01/59] genirq: Let irq_set_vcpu_affinity() iterate over hierarchy Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 03/59] irqchip/gic-v3: Add VLPI/DirectLPI discovery Marc Zyngier
                   ` (56 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

In order to discover the VLPI properties, we need to iterate over
the redistributor regions. As we already have code that does this,
let's factor it out and make it slightly more generic.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3.c | 69 ++++++++++++++++++++++++++++++--------------
 1 file changed, 47 insertions(+), 22 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index dbffb7ab6203..640f621c7f75 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -421,24 +421,14 @@ static void __init gic_dist_init(void)
 		gic_write_irouter(affinity, base + GICD_IROUTER + i * 8);
 }
 
-static int gic_populate_rdist(void)
+static int gic_iterate_rdists(int (*fn)(struct redist_region *, void __iomem *))
 {
-	unsigned long mpidr = cpu_logical_map(smp_processor_id());
-	u64 typer;
-	u32 aff;
+	int ret = -ENODEV;
 	int i;
 
-	/*
-	 * Convert affinity to a 32bit value that can be matched to
-	 * GICR_TYPER bits [63:32].
-	 */
-	aff = (MPIDR_AFFINITY_LEVEL(mpidr, 3) << 24 |
-	       MPIDR_AFFINITY_LEVEL(mpidr, 2) << 16 |
-	       MPIDR_AFFINITY_LEVEL(mpidr, 1) << 8 |
-	       MPIDR_AFFINITY_LEVEL(mpidr, 0));
-
 	for (i = 0; i < gic_data.nr_redist_regions; i++) {
 		void __iomem *ptr = gic_data.redist_regions[i].redist_base;
+		u64 typer;
 		u32 reg;
 
 		reg = readl_relaxed(ptr + GICR_PIDR2) & GIC_PIDR2_ARCH_MASK;
@@ -450,15 +440,9 @@ static int gic_populate_rdist(void)
 
 		do {
 			typer = gic_read_typer(ptr + GICR_TYPER);
-			if ((typer >> 32) == aff) {
-				u64 offset = ptr - gic_data.redist_regions[i].redist_base;
-				gic_data_rdist_rd_base() = ptr;
-				gic_data_rdist()->phys_base = gic_data.redist_regions[i].phys_base + offset;
-				pr_info("CPU%d: found redistributor %lx region %d:%pa\n",
-					smp_processor_id(), mpidr, i,
-					&gic_data_rdist()->phys_base);
+			ret = fn(gic_data.redist_regions + i, ptr);
+			if (!ret)
 				return 0;
-			}
 
 			if (gic_data.redist_regions[i].single_redist)
 				break;
@@ -473,9 +457,50 @@ static int gic_populate_rdist(void)
 		} while (!(typer & GICR_TYPER_LAST));
 	}
 
+	return ret ? -ENODEV : 0;
+}
+
+static int __gic_populate_rdist(struct redist_region *region, void __iomem *ptr)
+{
+	unsigned long mpidr = cpu_logical_map(smp_processor_id());
+	u64 typer;
+	u32 aff;
+
+	/*
+	 * Convert affinity to a 32bit value that can be matched to
+	 * GICR_TYPER bits [63:32].
+	 */
+	aff = (MPIDR_AFFINITY_LEVEL(mpidr, 3) << 24 |
+	       MPIDR_AFFINITY_LEVEL(mpidr, 2) << 16 |
+	       MPIDR_AFFINITY_LEVEL(mpidr, 1) << 8 |
+	       MPIDR_AFFINITY_LEVEL(mpidr, 0));
+
+	typer = gic_read_typer(ptr + GICR_TYPER);
+	if ((typer >> 32) == aff) {
+		u64 offset = ptr - region->redist_base;
+		gic_data_rdist_rd_base() = ptr;
+		gic_data_rdist()->phys_base = region->phys_base + offset;
+
+		pr_info("CPU%d: found redistributor %lx region %d:%pa\n",
+			smp_processor_id(), mpidr,
+			(int)(region - gic_data.redist_regions),
+			&gic_data_rdist()->phys_base);
+		return 0;
+	}
+
+	/* Try next one */
+	return 1;
+}
+
+static int gic_populate_rdist(void)
+{
+	if (gic_iterate_rdists(__gic_populate_rdist) == 0)
+		return 0;
+
 	/* We couldn't even deal with ourselves... */
 	WARN(true, "CPU%d: mpidr %lx has no re-distributor!\n",
-	     smp_processor_id(), mpidr);
+	     smp_processor_id(),
+	     (unsigned long)cpu_logical_map(smp_processor_id()));
 	return -ENODEV;
 }
 
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 03/59] irqchip/gic-v3: Add VLPI/DirectLPI discovery
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 01/59] genirq: Let irq_set_vcpu_affinity() iterate over hierarchy Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 02/59] irqchip/gic-v3: Add redistributor iterator Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 04/59] irqchip/gic-v3-its: Move LPI definitions around Marc Zyngier
                   ` (55 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Add helper functions that probe for VLPI and DirectLPI properties.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3.c       | 24 +++++++++++++++++++++++-
 include/linux/irqchip/arm-gic-v3.h |  3 +++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 640f621c7f75..17f0ad41864f 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013, 2014 ARM Limited, All Rights Reserved.
+ * Copyright (C) 2013-2017 ARM Limited, All Rights Reserved.
  * Author: Marc Zyngier <marc.zyngier@arm.com>
  *
  * This program is free software; you can redistribute it and/or modify
@@ -504,6 +504,24 @@ static int gic_populate_rdist(void)
 	return -ENODEV;
 }
 
+static int __gic_update_vlpi_properties(struct redist_region *region,
+					void __iomem *ptr)
+{
+	u64 typer = gic_read_typer(ptr + GICR_TYPER);
+	gic_data.rdists.has_vlpis &= !!(typer & GICR_TYPER_VLPIS);
+	gic_data.rdists.has_direct_lpi &= !!(typer & GICR_TYPER_DirectLPIS);
+
+	return 1;
+}
+
+static void gic_update_vlpi_properties(void)
+{
+	gic_iterate_rdists(__gic_update_vlpi_properties);
+	pr_info("%sVLPI support, %sdirect LPI support\n",
+		!gic_data.rdists.has_vlpis ? "no " : "",
+		!gic_data.rdists.has_direct_lpi ? "no " : "");
+}
+
 static void gic_cpu_sys_reg_init(void)
 {
 	/*
@@ -968,6 +986,8 @@ static int __init gic_init_bases(void __iomem *dist_base,
 	gic_data.domain = irq_domain_create_tree(handle, &gic_irq_domain_ops,
 						 &gic_data);
 	gic_data.rdists.rdist = alloc_percpu(typeof(*gic_data.rdists.rdist));
+	gic_data.rdists.has_vlpis = true;
+	gic_data.rdists.has_direct_lpi = true;
 
 	if (WARN_ON(!gic_data.domain) || WARN_ON(!gic_data.rdists.rdist)) {
 		err = -ENOMEM;
@@ -976,6 +996,8 @@ static int __init gic_init_bases(void __iomem *dist_base,
 
 	set_handle_irq(gic_handle_irq);
 
+	gic_update_vlpi_properties();
+
 	if (IS_ENABLED(CONFIG_ARM_GIC_V3_ITS) && gic_dist_supports_lpis())
 		its_init(handle, &gic_data.rdists, gic_data.domain);
 
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index 6a1f87ff94e2..20a553423ac7 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -204,6 +204,7 @@
 
 #define GICR_TYPER_PLPIS		(1U << 0)
 #define GICR_TYPER_VLPIS		(1U << 1)
+#define GICR_TYPER_DirectLPIS		(1U << 3)
 #define GICR_TYPER_LAST			(1U << 4)
 
 #define GIC_V3_REDIST_SIZE		0x20000
@@ -487,6 +488,8 @@ struct rdists {
 	struct page		*prop_page;
 	int			id_bits;
 	u64			flags;
+	bool			has_vlpis;
+	bool			has_direct_lpi;
 };
 
 struct irq_domain;
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 04/59] irqchip/gic-v3-its: Move LPI definitions around
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (2 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 03/59] irqchip/gic-v3: Add VLPI/DirectLPI discovery Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 05/59] irqchip/gic-v3-its: Add probing for VLPI properties Marc Zyngier
                   ` (54 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

The various LPI definitions are in the middle of the code, and
would be better placed at the beginning, given that we're going
to use some of them much earlier.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 68932873eebc..ae6b2cee09fa 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -48,6 +48,19 @@
 
 #define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING	(1 << 0)
 
+static u32 lpi_id_bits;
+
+/*
+ * We allocate memory for PROPBASE to cover 2 ^ lpi_id_bits LPIs to
+ * deal with (one configuration byte per interrupt). PENDBASE has to
+ * be 64kB aligned (one bit per LPI, plus 8192 bits for SPI/PPI/SGI).
+ */
+#define LPI_NRBITS		lpi_id_bits
+#define LPI_PROPBASE_SZ		ALIGN(BIT(LPI_NRBITS), SZ_64K)
+#define LPI_PENDBASE_SZ		ALIGN(BIT(LPI_NRBITS) / 8, SZ_64K)
+
+#define LPI_PROP_DEFAULT_PRIO	0xa0
+
 /*
  * Collection structure - just an ID, and a redistributor address to
  * ping. We use one per CPU as a bag of interrupts assigned to this
@@ -695,7 +708,6 @@ static struct irq_chip its_irq_chip = {
 
 static unsigned long *lpi_bitmap;
 static u32 lpi_chunks;
-static u32 lpi_id_bits;
 static DEFINE_SPINLOCK(lpi_lock);
 
 static int its_lpi_to_chunk(int lpi)
@@ -790,17 +802,6 @@ static void its_lpi_free(struct event_lpi_map *map)
 	kfree(map->col_map);
 }
 
-/*
- * We allocate memory for PROPBASE to cover 2 ^ lpi_id_bits LPIs to
- * deal with (one configuration byte per interrupt). PENDBASE has to
- * be 64kB aligned (one bit per LPI, plus 8192 bits for SPI/PPI/SGI).
- */
-#define LPI_NRBITS		lpi_id_bits
-#define LPI_PROPBASE_SZ		ALIGN(BIT(LPI_NRBITS), SZ_64K)
-#define LPI_PENDBASE_SZ		ALIGN(BIT(LPI_NRBITS) / 8, SZ_64K)
-
-#define LPI_PROP_DEFAULT_PRIO	0xa0
-
 static int __init its_alloc_lpi_tables(void)
 {
 	phys_addr_t paddr;
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 05/59] irqchip/gic-v3-its: Add probing for VLPI properties
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (3 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 04/59] irqchip/gic-v3-its: Move LPI definitions around Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 06/59] irqchip/gic-v3-its: Macro-ize its_send_single_command Marc Zyngier
                   ` (53 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Add the probing code for the ITS VLPI support. This includes
configuring the ITS number if not supporting the single VMOVP
command feature.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c   | 71 +++++++++++++++++++++++++++++++++++---
 include/linux/irqchip/arm-gic-v3.h |  5 +++
 2 files changed, 72 insertions(+), 4 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index ae6b2cee09fa..e7a7dc9ad585 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -101,6 +101,7 @@ struct its_node {
 	u32			ite_size;
 	u32			device_ids;
 	int			numa_node;
+	bool			is_v4;
 };
 
 #define ITS_ITT_ALIGN		SZ_256
@@ -133,6 +134,14 @@ static DEFINE_SPINLOCK(its_lock);
 static struct rdists *gic_rdists;
 static struct irq_domain *its_parent;
 
+/*
+ * We have a maximum number of 16 ITSs in the whole system if we're
+ * using the ITSList mechanism
+ */
+#define ITS_LIST_MAX		16
+
+static unsigned long its_list_map;
+
 #define gic_data_rdist()		(raw_cpu_ptr(gic_rdists->rdist))
 #define gic_data_rdist_rd_base()	(gic_data_rdist()->rd_base)
 
@@ -1673,13 +1682,51 @@ static int its_init_domain(struct fwnode_handle *handle, struct its_node *its)
 	return 0;
 }
 
+static int __init its_compute_its_list_map(struct resource *res,
+					   void __iomem *its_base)
+{
+	int its_number;
+	u32 ctlr;
+
+	/*
+	 * This is assumed to be done early enough that we're
+	 * guaranteed to be single-threaded, hence no
+	 * locking. Should this change, we should address
+	 * this.
+	 */
+	its_number = find_first_zero_bit(&its_list_map, ITS_LIST_MAX);
+	if (its_number >= ITS_LIST_MAX) {
+		pr_err("ITS@%pa: No ITSList entry available!\n",
+		       &res->start);
+		return -EINVAL;
+	}
+
+	ctlr = readl_relaxed(its_base + GITS_CTLR);
+	ctlr &= ~GITS_CTLR_ITS_NUMBER;
+	ctlr |= its_number << GITS_CTLR_ITS_NUMBER_SHIFT;
+	writel_relaxed(ctlr, its_base + GITS_CTLR);
+	ctlr = readl_relaxed(its_base + GITS_CTLR);
+	if ((ctlr & GITS_CTLR_ITS_NUMBER) != (its_number << GITS_CTLR_ITS_NUMBER_SHIFT)) {
+		its_number = ctlr & GITS_CTLR_ITS_NUMBER;
+		its_number >>= GITS_CTLR_ITS_NUMBER_SHIFT;
+	}
+
+	if (test_and_set_bit(its_number, &its_list_map)) {
+		pr_err("ITS@%pa: Duplicate ITSList entry %d\n",
+		       &res->start, its_number);
+		return -EINVAL;
+	}
+
+	return its_number;
+}
+
 static int __init its_probe_one(struct resource *res,
 				struct fwnode_handle *handle, int numa_node)
 {
 	struct its_node *its;
 	void __iomem *its_base;
-	u32 val;
-	u64 baser, tmp;
+	u32 val, ctlr;
+	u64 baser, tmp, typer;
 	int err;
 
 	its_base = ioremap(res->start, resource_size(res));
@@ -1712,9 +1759,24 @@ static int __init its_probe_one(struct resource *res,
 	raw_spin_lock_init(&its->lock);
 	INIT_LIST_HEAD(&its->entry);
 	INIT_LIST_HEAD(&its->its_device_list);
+	typer = gic_read_typer(its_base + GITS_TYPER);
 	its->base = its_base;
 	its->phys_base = res->start;
-	its->ite_size = ((gic_read_typer(its_base + GITS_TYPER) >> 4) & 0xf) + 1;
+	its->ite_size = GITS_TYPER_ITT_ENTRY_SIZE(typer);
+	its->is_v4 = !!(typer & GITS_TYPER_VLPIS);
+	if (its->is_v4) {
+		if (!(typer & GITS_TYPER_VMOVP)) {
+			err = its_compute_its_list_map(res, its_base);
+			if (err < 0)
+				goto out_free_its;
+
+			pr_info("ITS@%pa: Using ITS number %d\n",
+				&res->start, err);
+		} else {
+			pr_info("ITS@%pa: Single VMOVP capable\n", &res->start);
+		}
+	}
+
 	its->numa_node = numa_node;
 
 	its->cmd_base = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
@@ -1761,7 +1823,8 @@ static int __init its_probe_one(struct resource *res,
 	}
 
 	gits_write_cwriter(0, its->base + GITS_CWRITER);
-	writel_relaxed(GITS_CTLR_ENABLE, its->base + GITS_CTLR);
+	ctlr = readl_relaxed(its->base + GITS_CTLR);
+	writel_relaxed(ctlr | GITS_CTLR_ENABLE, its->base + GITS_CTLR);
 
 	err = its_init_domain(handle, its);
 	if (err)
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index 20a553423ac7..af8c55105fc2 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -235,15 +235,20 @@
 #define GITS_TRANSLATER			0x10040
 
 #define GITS_CTLR_ENABLE		(1U << 0)
+#define	GITS_CTLR_ITS_NUMBER_SHIFT	4
+#define	GITS_CTLR_ITS_NUMBER		(0xFU << GITS_CTLR_ITS_NUMBER_SHIFT)
 #define GITS_CTLR_QUIESCENT		(1U << 31)
 
 #define GITS_TYPER_PLPIS		(1UL << 0)
+#define GITS_TYPER_VLPIS		(1UL << 1)
 #define GITS_TYPER_ITT_ENTRY_SIZE_SHIFT	4
+#define GITS_TYPER_ITT_ENTRY_SIZE(r)	((((r) >> GITS_TYPER_ITT_ENTRY_SIZE_SHIFT) & 0x1f) + 1)
 #define GITS_TYPER_IDBITS_SHIFT		8
 #define GITS_TYPER_DEVBITS_SHIFT	13
 #define GITS_TYPER_DEVBITS(r)		((((r) >> GITS_TYPER_DEVBITS_SHIFT) & 0x1f) + 1)
 #define GITS_TYPER_PTA			(1UL << 19)
 #define GITS_TYPER_HWCOLLCNT_SHIFT	24
+#define GITS_TYPER_VMOVP		(1ULL << 37)
 
 #define GITS_IIDR_REV_SHIFT		12
 #define GITS_IIDR_REV_MASK		(0xf << GITS_IIDR_REV_SHIFT)
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 06/59] irqchip/gic-v3-its: Macro-ize its_send_single_command
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (4 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 05/59] irqchip/gic-v3-its: Add probing for VLPI properties Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 07/59] irqchip/gic-v3-its: Implement irq_set_irqchip_state for pending state Marc Zyngier
                   ` (52 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Most ITS commands do operate on a collection object, and require
a SYNC command to be performed on that collection in order to
guarantee the execution of the first command.

With GICv4 ITS, another set of commands perform similar operations
on a VPE object, and a VSYNC operations must be executed to guarantee
their execution.

Given the similarities (post a command, perform a synchronization
operation on a sync object), it makes sense to reuse the same
mechanism for both class of commands.

Let's start with turning its_send_single_command into a huge macro
that performs the bulk of the work, and a set of helpers that
make this macro usable for the GICv3 ITS commands.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 84 ++++++++++++++++++++++------------------
 1 file changed, 47 insertions(+), 37 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index e7a7dc9ad585..0f345c0fa700 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -488,43 +488,53 @@ static void its_wait_for_range_completion(struct its_node *its,
 	}
 }
 
-static void its_send_single_command(struct its_node *its,
-				    its_cmd_builder_t builder,
-				    struct its_cmd_desc *desc)
-{
-	struct its_cmd_block *cmd, *sync_cmd, *next_cmd;
-	struct its_collection *sync_col;
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&its->lock, flags);
-
-	cmd = its_allocate_entry(its);
-	if (!cmd) {		/* We're soooooo screewed... */
-		pr_err_ratelimited("ITS can't allocate, dropping command\n");
-		raw_spin_unlock_irqrestore(&its->lock, flags);
-		return;
-	}
-	sync_col = builder(cmd, desc);
-	its_flush_cmd(its, cmd);
-
-	if (sync_col) {
-		sync_cmd = its_allocate_entry(its);
-		if (!sync_cmd) {
-			pr_err_ratelimited("ITS can't SYNC, skipping\n");
-			goto post;
-		}
-		its_encode_cmd(sync_cmd, GITS_CMD_SYNC);
-		its_encode_target(sync_cmd, sync_col->target_address);
-		its_fixup_cmd(sync_cmd);
-		its_flush_cmd(its, sync_cmd);
-	}
-
-post:
-	next_cmd = its_post_commands(its);
-	raw_spin_unlock_irqrestore(&its->lock, flags);
-
-	its_wait_for_range_completion(its, cmd, next_cmd);
-}
+/* Warning, macro hell follows */
+#define BUILD_SINGLE_CMD_FUNC(name, buildtype, synctype, buildfn)	\
+void name(struct its_node *its,						\
+	  buildtype builder,						\
+	  struct its_cmd_desc *desc)					\
+{									\
+	struct its_cmd_block *cmd, *sync_cmd, *next_cmd;		\
+	synctype *sync_obj;						\
+	unsigned long flags;						\
+									\
+	raw_spin_lock_irqsave(&its->lock, flags);			\
+									\
+	cmd = its_allocate_entry(its);					\
+	if (!cmd) {		/* We're soooooo screewed... */		\
+		raw_spin_unlock_irqrestore(&its->lock, flags);		\
+		return;							\
+	}								\
+	sync_obj = builder(cmd, desc);					\
+	its_flush_cmd(its, cmd);					\
+									\
+	if (sync_obj) {							\
+		sync_cmd = its_allocate_entry(its);			\
+		if (!sync_cmd)						\
+			goto post;					\
+									\
+		buildfn(sync_cmd, sync_obj);				\
+		its_flush_cmd(its, sync_cmd);				\
+	}								\
+									\
+post:									\
+	next_cmd = its_post_commands(its);				\
+	raw_spin_unlock_irqrestore(&its->lock, flags);			\
+									\
+	its_wait_for_range_completion(its, cmd, next_cmd);		\
+}
+
+static void its_build_sync_cmd(struct its_cmd_block *sync_cmd,
+			       struct its_collection *sync_col)
+{
+	its_encode_cmd(sync_cmd, GITS_CMD_SYNC);
+	its_encode_target(sync_cmd, sync_col->target_address);
+
+	its_fixup_cmd(sync_cmd);
+}
+
+static BUILD_SINGLE_CMD_FUNC(its_send_single_command, its_cmd_builder_t,
+			     struct its_collection, its_build_sync_cmd)
 
 static void its_send_inv(struct its_device *dev, u32 event_id)
 {
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 07/59] irqchip/gic-v3-its: Implement irq_set_irqchip_state for pending state
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (5 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 06/59] irqchip/gic-v3-its: Macro-ize its_send_single_command Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 08/59] irqchip/gic-v3-its: Split out property table allocation Marc Zyngier
                   ` (51 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Allow the pending state of an LPI to be set or cleared via
irq_set_irqchip_state.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 78 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 0f345c0fa700..3e4ac8c13e21 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -167,6 +167,11 @@ struct its_cmd_desc {
 		struct {
 			struct its_device *dev;
 			u32 event_id;
+		} its_clear_cmd;
+
+		struct {
+			struct its_device *dev;
+			u32 event_id;
 		} its_int_cmd;
 
 		struct {
@@ -380,6 +385,40 @@ static struct its_collection *its_build_inv_cmd(struct its_cmd_block *cmd,
 	return col;
 }
 
+static struct its_collection *its_build_int_cmd(struct its_cmd_block *cmd,
+						struct its_cmd_desc *desc)
+{
+	struct its_collection *col;
+
+	col = dev_event_to_col(desc->its_int_cmd.dev,
+			       desc->its_int_cmd.event_id);
+
+	its_encode_cmd(cmd, GITS_CMD_INT);
+	its_encode_devid(cmd, desc->its_int_cmd.dev->device_id);
+	its_encode_event_id(cmd, desc->its_int_cmd.event_id);
+
+	its_fixup_cmd(cmd);
+
+	return col;
+}
+
+static struct its_collection *its_build_clear_cmd(struct its_cmd_block *cmd,
+						  struct its_cmd_desc *desc)
+{
+	struct its_collection *col;
+
+	col = dev_event_to_col(desc->its_clear_cmd.dev,
+			       desc->its_clear_cmd.event_id);
+
+	its_encode_cmd(cmd, GITS_CMD_CLEAR);
+	its_encode_devid(cmd, desc->its_clear_cmd.dev->device_id);
+	its_encode_event_id(cmd, desc->its_clear_cmd.event_id);
+
+	its_fixup_cmd(cmd);
+
+	return col;
+}
+
 static struct its_collection *its_build_invall_cmd(struct its_cmd_block *cmd,
 						   struct its_cmd_desc *desc)
 {
@@ -536,6 +575,26 @@ static void its_build_sync_cmd(struct its_cmd_block *sync_cmd,
 static BUILD_SINGLE_CMD_FUNC(its_send_single_command, its_cmd_builder_t,
 			     struct its_collection, its_build_sync_cmd)
 
+static void its_send_int(struct its_device *dev, u32 event_id)
+{
+	struct its_cmd_desc desc;
+
+	desc.its_int_cmd.dev = dev;
+	desc.its_int_cmd.event_id = event_id;
+
+	its_send_single_command(dev->its, its_build_int_cmd, &desc);
+}
+
+static void its_send_clear(struct its_device *dev, u32 event_id)
+{
+	struct its_cmd_desc desc;
+
+	desc.its_clear_cmd.dev = dev;
+	desc.its_clear_cmd.event_id = event_id;
+
+	its_send_single_command(dev->its, its_build_clear_cmd, &desc);
+}
+
 static void its_send_inv(struct its_device *dev, u32 event_id)
 {
 	struct its_cmd_desc desc;
@@ -702,6 +761,24 @@ static void its_irq_compose_msi_msg(struct irq_data *d, struct msi_msg *msg)
 	iommu_dma_map_msi_msg(d->irq, msg);
 }
 
+static int its_irq_set_irqchip_state(struct irq_data *d,
+				     enum irqchip_irq_state which,
+				     bool state)
+{
+	struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+	u32 event = its_get_event_id(d);
+
+	if (which != IRQCHIP_STATE_PENDING)
+		return -EINVAL;
+
+	if (state)
+		its_send_int(its_dev, event);
+	else
+		its_send_clear(its_dev, event);
+
+	return 0;
+}
+
 static struct irq_chip its_irq_chip = {
 	.name			= "ITS",
 	.irq_mask		= its_mask_irq,
@@ -709,6 +786,7 @@ static struct irq_chip its_irq_chip = {
 	.irq_eoi		= irq_chip_eoi_parent,
 	.irq_set_affinity	= its_set_affinity,
 	.irq_compose_msi_msg	= its_irq_compose_msi_msg,
+	.irq_set_irqchip_state	= its_irq_set_irqchip_state,
 };
 
 /*
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 08/59] irqchip/gic-v3-its: Split out property table allocation
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (6 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 07/59] irqchip/gic-v3-its: Implement irq_set_irqchip_state for pending state Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 09/59] irqchip/gic-v3-its: Allow use of indirect VCPU tables Marc Zyngier
                   ` (50 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Move the LPI property table allocation into its own function, as
this is going to be required for those associated with VMs in
the future.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 3e4ac8c13e21..039626d21a73 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -899,13 +899,32 @@ static void its_lpi_free(struct event_lpi_map *map)
 	kfree(map->col_map);
 }
 
+static struct page *its_allocate_prop_table(gfp_t gfp_flags)
+{
+	struct page *prop_page;
+
+	prop_page = alloc_pages(gfp_flags, get_order(LPI_PROPBASE_SZ));
+	if (!prop_page)
+		return NULL;
+
+	/* Priority 0xa0, Group-1, disabled */
+	memset(page_address(prop_page),
+	       LPI_PROP_DEFAULT_PRIO | LPI_PROP_GROUP1,
+	       LPI_PROPBASE_SZ);
+
+	/* Make sure the GIC will observe the written configuration */
+	gic_flush_dcache_to_poc(page_address(prop_page), LPI_PROPBASE_SZ);
+
+	return prop_page;
+}
+
+
 static int __init its_alloc_lpi_tables(void)
 {
 	phys_addr_t paddr;
 
 	lpi_id_bits = min_t(u32, gic_rdists->id_bits, ITS_MAX_LPI_NRBITS);
-	gic_rdists->prop_page = alloc_pages(GFP_NOWAIT,
-					   get_order(LPI_PROPBASE_SZ));
+	gic_rdists->prop_page = its_allocate_prop_table(GFP_NOWAIT);
 	if (!gic_rdists->prop_page) {
 		pr_err("Failed to allocate PROPBASE\n");
 		return -ENOMEM;
@@ -914,14 +933,6 @@ static int __init its_alloc_lpi_tables(void)
 	paddr = page_to_phys(gic_rdists->prop_page);
 	pr_info("GIC: using LPI property table @%pa\n", &paddr);
 
-	/* Priority 0xa0, Group-1, disabled */
-	memset(page_address(gic_rdists->prop_page),
-	       LPI_PROP_DEFAULT_PRIO | LPI_PROP_GROUP1,
-	       LPI_PROPBASE_SZ);
-
-	/* Make sure the GIC will observe the written configuration */
-	gic_flush_dcache_to_poc(page_address(gic_rdists->prop_page), LPI_PROPBASE_SZ);
-
 	return its_lpi_init(lpi_id_bits);
 }
 
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 09/59] irqchip/gic-v3-its: Allow use of indirect VCPU tables
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (7 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 08/59] irqchip/gic-v3-its: Split out property table allocation Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 10/59] irqchip/gic-v3-its: Split out pending table allocation Marc Zyngier
                   ` (49 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

The VCPU tables can be quite sparse as well, and it makes sense
to use indirect tables as well if possible.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 039626d21a73..9a317934455c 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1071,10 +1071,13 @@ static int its_setup_baser(struct its_node *its, struct its_baser *baser,
 	return 0;
 }
 
-static bool its_parse_baser_device(struct its_node *its, struct its_baser *baser,
-				   u32 psz, u32 *order)
+static bool its_parse_indirect_baser(struct its_node *its,
+				     struct its_baser *baser,
+				     u32 psz, u32 *order)
 {
-	u64 esz = GITS_BASER_ENTRY_SIZE(its_read_baser(its, baser));
+	u64 tmp = its_read_baser(its, baser);
+	u64 type = GITS_BASER_TYPE(tmp);
+	u64 esz = GITS_BASER_ENTRY_SIZE(tmp);
 	u64 val = GITS_BASER_InnerShareable | GITS_BASER_RaWaWb;
 	u32 ids = its->device_ids;
 	u32 new_order = *order;
@@ -1113,8 +1116,9 @@ static bool its_parse_baser_device(struct its_node *its, struct its_baser *baser
 	if (new_order >= MAX_ORDER) {
 		new_order = MAX_ORDER - 1;
 		ids = ilog2(PAGE_ORDER_TO_SIZE(new_order) / (int)esz);
-		pr_warn("ITS@%pa: Device Table too large, reduce ids %u->%u\n",
-			&its->phys_base, its->device_ids, ids);
+		pr_warn("ITS@%pa: %s Table too large, reduce ids %u->%u\n",
+			&its->phys_base, its_base_type_string[type],
+			its->device_ids, ids);
 	}
 
 	*order = new_order;
@@ -1162,11 +1166,16 @@ static int its_alloc_tables(struct its_node *its)
 		u32 order = get_order(psz);
 		bool indirect = false;
 
-		if (type == GITS_BASER_TYPE_NONE)
+		switch (type) {
+		case GITS_BASER_TYPE_NONE:
 			continue;
 
-		if (type == GITS_BASER_TYPE_DEVICE)
-			indirect = its_parse_baser_device(its, baser, psz, &order);
+		case GITS_BASER_TYPE_DEVICE:
+		case GITS_BASER_TYPE_VCPU:
+			indirect = its_parse_indirect_baser(its, baser,
+							    psz, &order);
+			break;
+		}
 
 		err = its_setup_baser(its, baser, cache, shr, psz, order, indirect);
 		if (err < 0) {
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 10/59] irqchip/gic-v3-its: Split out pending table allocation
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (8 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 09/59] irqchip/gic-v3-its: Allow use of indirect VCPU tables Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 11/59] irqchip/gic-v3-its: Rework LPI freeing Marc Zyngier
                   ` (48 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm
  Cc: Christoffer Dall, Thomas Gleixner, Jason Cooper, Eric Auger,
	Shanker Donthineni, Mark Rutland, Shameerali Kolothum Thodi

Just as for the property table, let's move the pending table
allocation to a separate function.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 9a317934455c..ebdb1603b95d 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1202,6 +1202,24 @@ static int its_alloc_collections(struct its_node *its)
 	return 0;
 }
 
+static struct page *its_allocate_pending_table(gfp_t gfp_flags)
+{
+	struct page *pend_page;
+	/*
+	 * The pending pages have to be at least 64kB aligned,
+	 * hence the 'max(LPI_PENDBASE_SZ, SZ_64K)' below.
+	 */
+	pend_page = alloc_pages(gfp_flags | __GFP_ZERO,
+				get_order(max_t(u32, LPI_PENDBASE_SZ, SZ_64K)));
+	if (!pend_page)
+		return NULL;
+
+	/* Make sure the GIC will observe the zero-ed page */
+	gic_flush_dcache_to_poc(page_address(pend_page), LPI_PENDBASE_SZ);
+
+	return pend_page;
+}
+
 static void its_cpu_init_lpis(void)
 {
 	void __iomem *rbase = gic_data_rdist_rd_base();
@@ -1212,21 +1230,14 @@ static void its_cpu_init_lpis(void)
 	pend_page = gic_data_rdist()->pend_page;
 	if (!pend_page) {
 		phys_addr_t paddr;
-		/*
-		 * The pending pages have to be at least 64kB aligned,
-		 * hence the 'max(LPI_PENDBASE_SZ, SZ_64K)' below.
-		 */
-		pend_page = alloc_pages(GFP_NOWAIT | __GFP_ZERO,
-					get_order(max_t(u32, LPI_PENDBASE_SZ, SZ_64K)));
+
+		pend_page = its_allocate_pending_table(GFP_NOWAIT);
 		if (!pend_page) {
 			pr_err("Failed to allocate PENDBASE for CPU%d\n",
 			       smp_processor_id());
 			return;
 		}
 
-		/* Make sure the GIC will observe the zero-ed page */
-		gic_flush_dcache_to_poc(page_address(pend_page), LPI_PENDBASE_SZ);
-
 		paddr = page_to_phys(pend_page);
 		pr_info("CPU%d: using LPI pending table @%pa\n",
 			smp_processor_id(), &paddr);
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 11/59] irqchip/gic-v3-its: Rework LPI freeing
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (9 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 10/59] irqchip/gic-v3-its: Split out pending table allocation Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 12/59] irqchip/gic-v3-its: Generalize device table allocation Marc Zyngier
                   ` (47 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Rework LPI deallocation so that it can be reused by the v4 support
code.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index ebdb1603b95d..1298a9bca56a 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -875,16 +875,15 @@ static unsigned long *its_lpi_alloc_chunks(int nr_irqs, int *base, int *nr_ids)
 	return bitmap;
 }
 
-static void its_lpi_free(struct event_lpi_map *map)
+static void its_lpi_free_chunks(unsigned long *bitmap, int base, int nr_ids)
 {
-	int base = map->lpi_base;
-	int nr_ids = map->nr_lpis;
 	int lpi;
 
 	spin_lock(&lpi_lock);
 
 	for (lpi = base; lpi < (base + nr_ids); lpi += IRQS_PER_CHUNK) {
 		int chunk = its_lpi_to_chunk(lpi);
+
 		BUG_ON(chunk > lpi_chunks);
 		if (test_bit(chunk, lpi_bitmap)) {
 			clear_bit(chunk, lpi_bitmap);
@@ -895,8 +894,7 @@ static void its_lpi_free(struct event_lpi_map *map)
 
 	spin_unlock(&lpi_lock);
 
-	kfree(map->lpi_map);
-	kfree(map->col_map);
+	kfree(bitmap);
 }
 
 static struct page *its_allocate_prop_table(gfp_t gfp_flags)
@@ -1668,7 +1666,10 @@ static void its_irq_domain_free(struct irq_domain *domain, unsigned int virq,
 	/* If all interrupts have been freed, start mopping the floor */
 	if (bitmap_empty(its_dev->event_map.lpi_map,
 			 its_dev->event_map.nr_lpis)) {
-		its_lpi_free(&its_dev->event_map);
+		its_lpi_free_chunks(its_dev->event_map.lpi_map,
+				    its_dev->event_map.lpi_base,
+				    its_dev->event_map.nr_lpis);
+		kfree(its_dev->event_map.col_map);
 
 		/* Unmap device/itt */
 		its_send_mapd(its_dev, 0);
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 12/59] irqchip/gic-v3-its: Generalize device table allocation
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (10 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 11/59] irqchip/gic-v3-its: Rework LPI freeing Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 13/59] irqchip/gic-v3-its: Generalize LPI configuration Marc Zyngier
                   ` (46 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm
  Cc: Christoffer Dall, Thomas Gleixner, Jason Cooper, Eric Auger,
	Shanker Donthineni, Mark Rutland, Shameerali Kolothum Thodi

As we want to use 2-level tables for VCPUs, let's hack the device
table allocator in order to make it slightly more generic. It
will get reused in subsequent patches.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 1298a9bca56a..1c2d6bdf85cb 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1386,26 +1386,19 @@ static struct its_baser *its_get_baser(struct its_node *its, u32 type)
 	return NULL;
 }
 
-static bool its_alloc_device_table(struct its_node *its, u32 dev_id)
+static bool its_alloc_table_entry(struct its_baser *baser, u32 id)
 {
-	struct its_baser *baser;
 	struct page *page;
 	u32 esz, idx;
 	__le64 *table;
 
-	baser = its_get_baser(its, GITS_BASER_TYPE_DEVICE);
-
-	/* Don't allow device id that exceeds ITS hardware limit */
-	if (!baser)
-		return (ilog2(dev_id) < its->device_ids);
-
 	/* Don't allow device id that exceeds single, flat table limit */
 	esz = GITS_BASER_ENTRY_SIZE(baser->val);
 	if (!(baser->val & GITS_BASER_INDIRECT))
-		return (dev_id < (PAGE_ORDER_TO_SIZE(baser->order) / esz));
+		return (id < (PAGE_ORDER_TO_SIZE(baser->order) / esz));
 
 	/* Compute 1st level table index & check if that exceeds table limit */
-	idx = dev_id >> ilog2(baser->psz / esz);
+	idx = id >> ilog2(baser->psz / esz);
 	if (idx >= (PAGE_ORDER_TO_SIZE(baser->order) / GITS_LVL1_ENTRY_SIZE))
 		return false;
 
@@ -1434,6 +1427,19 @@ static bool its_alloc_device_table(struct its_node *its, u32 dev_id)
 	return true;
 }
 
+static bool its_alloc_device_table(struct its_node *its, u32 dev_id)
+{
+	struct its_baser *baser;
+
+	baser = its_get_baser(its, GITS_BASER_TYPE_DEVICE);
+
+	/* Don't allow device id that exceeds ITS hardware limit */
+	if (!baser)
+		return (ilog2(dev_id) < its->device_ids);
+
+	return its_alloc_table_entry(baser, dev_id);
+}
+
 static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
 					    int nvecs)
 {
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 13/59] irqchip/gic-v3-its: Generalize LPI configuration
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (11 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 12/59] irqchip/gic-v3-its: Generalize device table allocation Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 14/59] irqchip/gic-v4: Add management structure definitions Marc Zyngier
                   ` (45 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

We're are going to need to change a bit more than just the enable
bit in the LPI property table in the future. So let's change the
LPI configuration funtion to take a set of bits to be cleared,
and a set of bits to be set.

This way, we'll be able to use it when a guest updates an LPI
property (priority, for example).

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 1c2d6bdf85cb..7ef448a963c1 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -678,17 +678,18 @@ static inline u32 its_get_event_id(struct irq_data *d)
 	return d->hwirq - its_dev->event_map.lpi_base;
 }
 
-static void lpi_set_config(struct irq_data *d, bool enable)
+static void lpi_update_config(struct irq_data *d, u8 clr, u8 set)
 {
 	struct its_device *its_dev = irq_data_get_irq_chip_data(d);
 	irq_hw_number_t hwirq = d->hwirq;
-	u32 id = its_get_event_id(d);
-	u8 *cfg = page_address(gic_rdists->prop_page) + hwirq - 8192;
+	struct page *prop_page;
+	u8 *cfg;
 
-	if (enable)
-		*cfg |= LPI_PROP_ENABLED;
-	else
-		*cfg &= ~LPI_PROP_ENABLED;
+	prop_page = gic_rdists->prop_page;
+
+	cfg = page_address(prop_page) + hwirq - 8192;
+	*cfg &= ~clr;
+	*cfg |= set;
 
 	/*
 	 * Make the above write visible to the redistributors.
@@ -699,17 +700,17 @@ static void lpi_set_config(struct irq_data *d, bool enable)
 		gic_flush_dcache_to_poc(cfg, sizeof(*cfg));
 	else
 		dsb(ishst);
-	its_send_inv(its_dev, id);
+	its_send_inv(its_dev, its_get_event_id(d));
 }
 
 static void its_mask_irq(struct irq_data *d)
 {
-	lpi_set_config(d, false);
+	lpi_update_config(d, LPI_PROP_ENABLED, 0);
 }
 
 static void its_unmask_irq(struct irq_data *d)
 {
-	lpi_set_config(d, true);
+	lpi_update_config(d, 0, LPI_PROP_ENABLED);
 }
 
 static int its_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 14/59] irqchip/gic-v4: Add management structure definitions
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (12 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 13/59] irqchip/gic-v3-its: Generalize LPI configuration Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 15/59] irqchip/gic-v3-its: Add GICv4 ITS command definitions Marc Zyngier
                   ` (44 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Add a bunch of GICv4-specific data structures that will get used in
subsequent patches.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 include/linux/irqchip/arm-gic-v4.h | 92 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100644 include/linux/irqchip/arm-gic-v4.h

diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h
new file mode 100644
index 000000000000..5ba0fb6b094d
--- /dev/null
+++ b/include/linux/irqchip/arm-gic-v4.h
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2016,2017 ARM Limited, All Rights Reserved.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __LINUX_IRQCHIP_ARM_GIC_V4_H
+#define __LINUX_IRQCHIP_ARM_GIC_V4_H
+
+struct its_vpe;
+
+/* Embedded in kvm.arch */
+struct its_vm {
+	struct fwnode_handle	*fwnode;
+	struct irq_domain	*domain;
+	struct page		*vprop_page;
+	struct its_vpe		**vpes;
+	int			nr_vpes;
+	irq_hw_number_t		db_lpi_base;
+	unsigned long		*db_bitmap;
+	int			nr_db_lpis;
+};
+
+/* Embedded in kvm_vcpu.arch */
+struct its_vpe {
+	struct page 		*vpt_page;
+	struct its_vm		*its_vm;
+	/* Doorbell interrupt */
+	int			irq;
+	irq_hw_number_t		vpe_db_lpi;
+	/*
+	 * This collection ID is used to indirect the target
+	 * redistributor for this VPE. The ID itself isn't involved in
+	 * programming of the ITS.
+	 */
+	u16			col_idx;
+	/* Unique (system-wide) VPE identifier */
+	u16			vpe_id;
+	/* Implementation Defined Area Invalid */
+	bool			idai;
+	/* Pending VLPIs on schedule out? */
+	bool			pending_last;
+};
+
+/*
+ * struct its_vlpi_map: structure describing the mapping of a
+ * VLPI. Only to be interpreted in the context of a physical interrupt
+ * it complements.  To be used as the vcpu_info passed to
+ * irq_set_vcpu_affinity().
+ *
+ * @vm:		Pointer to the GICv4 notion of a VM
+ * @vintid:	Virtual LPI number
+ * @db_enabled:	Is the VPE doorbell to be generated?
+ * @vpe_idx:	Index (0-based) of the VPE in this VM. Not the vpe_id!
+ */
+struct its_vlpi_map {
+	struct its_vm		*vm;
+	u32			vintid;
+	bool			db_enabled;
+	u16			vpe_idx;
+};
+
+enum its_vcpu_info_cmd_type {
+	MAP_VLPI,
+	GET_VLPI,
+	PROP_UPDATE_VLPI,
+	PROP_UPDATE_AND_INV_VLPI,
+	SCHEDULE_VPE,
+	DESCHEDULE_VPE,
+	INVALL_VPE,
+};
+
+struct its_cmd_info {
+	enum its_vcpu_info_cmd_type	cmd_type;
+	union {
+		struct its_vlpi_map	*map;
+		u8			config;
+	};
+};
+
+#endif
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 15/59] irqchip/gic-v3-its: Add GICv4 ITS command definitions
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (13 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 14/59] irqchip/gic-v4: Add management structure definitions Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 16/59] irqchip/gic-v3-its: Add VLPI configuration hook Marc Zyngier
                   ` (43 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm
  Cc: Christoffer Dall, Thomas Gleixner, Jason Cooper, Eric Auger,
	Shanker Donthineni, Mark Rutland, Shameerali Kolothum Thodi

Add the new GICv4 ITS command definitions, most of them, being
defined in terms of their physical counterparts.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c   |  2 +-
 include/linux/irqchip/arm-gic-v3.h | 12 ++++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 7ef448a963c1..bc396ab24037 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013, 2014 ARM Limited, All Rights Reserved.
+ * Copyright (C) 2013-2017 ARM Limited, All Rights Reserved.
  * Author: Marc Zyngier <marc.zyngier@arm.com>
  *
  * This program is free software; you can redistribute it and/or modify
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index af8c55105fc2..7c6fd8f3e36c 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -348,6 +348,18 @@
 #define GITS_CMD_SYNC			0x05
 
 /*
+ * GICv4 ITS specific commands
+ */
+#define GITS_CMD_GICv4(x)		((x) | 0x20)
+#define GITS_CMD_VINVALL		GITS_CMD_GICv4(GITS_CMD_INVALL)
+#define GITS_CMD_VMAPP			GITS_CMD_GICv4(GITS_CMD_MAPC)
+#define GITS_CMD_VMAPTI			GITS_CMD_GICv4(GITS_CMD_MAPTI)
+#define GITS_CMD_VMOVI			GITS_CMD_GICv4(GITS_CMD_MOVI)
+#define GITS_CMD_VSYNC			GITS_CMD_GICv4(GITS_CMD_SYNC)
+/* VMOVP is the odd one, as it doesn't have a physical counterpart */
+#define GITS_CMD_VMOVP			GITS_CMD_GICv4(2)
+
+/*
  * ITS error numbers
  */
 #define E_ITS_MOVI_UNMAPPED_INTERRUPT		0x010107
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 16/59] irqchip/gic-v3-its: Add VLPI configuration hook
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (14 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 15/59] irqchip/gic-v3-its: Add GICv4 ITS command definitions Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 17/59] irqchip/gic-v3-its: Add VLPI map/unmap operations Marc Zyngier
                   ` (42 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Add the skeleton irq_set_vcpu_affinity method that will be used
to configure VLPIs.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index bc396ab24037..9ef4f161690a 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -36,6 +36,7 @@
 
 #include <linux/irqchip.h>
 #include <linux/irqchip/arm-gic-v3.h>
+#include <linux/irqchip/arm-gic-v4.h>
 
 #include <asm/cputype.h>
 #include <asm/exception.h>
@@ -780,6 +781,28 @@ static int its_irq_set_irqchip_state(struct irq_data *d,
 	return 0;
 }
 
+static int its_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
+{
+	struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+	struct its_cmd_info *info = vcpu_info;
+
+	/* Need a v4 ITS */
+	if (!its_dev->its->is_v4 || !info)
+		return -EINVAL;
+
+	switch (info->cmd_type) {
+	case MAP_VLPI:
+
+	case GET_VLPI:
+
+	case PROP_UPDATE_VLPI:
+	case PROP_UPDATE_AND_INV_VLPI:
+
+	default:
+		return -EINVAL;
+	}
+}
+
 static struct irq_chip its_irq_chip = {
 	.name			= "ITS",
 	.irq_mask		= its_mask_irq,
@@ -788,6 +811,7 @@ static struct irq_chip its_irq_chip = {
 	.irq_set_affinity	= its_set_affinity,
 	.irq_compose_msi_msg	= its_irq_compose_msi_msg,
 	.irq_set_irqchip_state	= its_irq_set_irqchip_state,
+	.irq_set_vcpu_affinity	= its_irq_set_vcpu_affinity,
 };
 
 /*
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 17/59] irqchip/gic-v3-its: Add VLPI map/unmap operations
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (15 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 16/59] irqchip/gic-v3-its: Add VLPI configuration hook Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 18/59] irqchip/gic-v3-its: Add VLPI configuration handling Marc Zyngier
                   ` (41 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

In order to let a VLPI being injected into a guest, the VLPI must
be mapped using the VMAPTI command. When moved to a different vcpu,
it must be moved with the VMOVI command.

These commands are issued via the irq_set_vcpu_affinity method,
making sure we unmap the corresponding host LPI first.

The reverse is also done when the VLPI is unmapped from the guest.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 250 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 247 insertions(+), 3 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 9ef4f161690a..ef31c3e58c01 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -115,11 +115,17 @@ struct event_lpi_map {
 	u16			*col_map;
 	irq_hw_number_t		lpi_base;
 	int			nr_lpis;
+	struct mutex		vlpi_lock;
+	struct its_vm		*vm;
+	struct its_vlpi_map	*vlpi_maps;
+	int			nr_vlpis;
 };
 
 /*
- * The ITS view of a device - belongs to an ITS, a collection, owns an
- * interrupt translation table, and a list of interrupts.
+ * The ITS view of a device - belongs to an ITS, owns an interrupt
+ * translation table, and a list of interrupts.  If it some of its
+ * LPIs are injected into a guest (GICv4), the event_map.vm field
+ * indicates which one.
  */
 struct its_device {
 	struct list_head	entry;
@@ -205,6 +211,21 @@ struct its_cmd_desc {
 		struct {
 			struct its_collection *col;
 		} its_invall_cmd;
+
+		struct {
+			struct its_vpe *vpe;
+			struct its_device *dev;
+			u32 virt_id;
+			u32 event_id;
+			bool db_enabled;
+		} its_vmapti_cmd;
+
+		struct {
+			struct its_vpe *vpe;
+			struct its_device *dev;
+			u32 event_id;
+			bool db_enabled;
+		} its_vmovi_cmd;
 	};
 };
 
@@ -221,6 +242,9 @@ struct its_cmd_block {
 typedef struct its_collection *(*its_cmd_builder_t)(struct its_cmd_block *,
 						    struct its_cmd_desc *);
 
+typedef struct its_vpe *(*its_cmd_vbuilder_t)(struct its_cmd_block *,
+					      struct its_cmd_desc *);
+
 static void its_mask_encode(u64 *raw_cmd, u64 val, int h, int l)
 {
 	u64 mask = GENMASK_ULL(h, l);
@@ -273,6 +297,26 @@ static void its_encode_collection(struct its_cmd_block *cmd, u16 col)
 	its_mask_encode(&cmd->raw_cmd[2], col, 15, 0);
 }
 
+static void its_encode_vpeid(struct its_cmd_block *cmd, u16 vpeid)
+{
+	its_mask_encode(&cmd->raw_cmd[1], vpeid, 47, 32);
+}
+
+static void its_encode_virt_id(struct its_cmd_block *cmd, u32 virt_id)
+{
+	its_mask_encode(&cmd->raw_cmd[2], virt_id, 31, 0);
+}
+
+static void its_encode_db_phys_id(struct its_cmd_block *cmd, u32 db_phys_id)
+{
+	its_mask_encode(&cmd->raw_cmd[2], db_phys_id, 63, 32);
+}
+
+static void its_encode_db_valid(struct its_cmd_block *cmd, bool db_valid)
+{
+	its_mask_encode(&cmd->raw_cmd[2], db_valid, 0, 0);
+}
+
 static inline void its_fixup_cmd(struct its_cmd_block *cmd)
 {
 	/* Let's fixup BE commands */
@@ -431,6 +475,50 @@ static struct its_collection *its_build_invall_cmd(struct its_cmd_block *cmd,
 	return NULL;
 }
 
+static struct its_vpe *its_build_vmapti_cmd(struct its_cmd_block *cmd,
+					    struct its_cmd_desc *desc)
+{
+	u32 db;
+
+	if (desc->its_vmapti_cmd.db_enabled)
+		db = desc->its_vmapti_cmd.vpe->vpe_db_lpi;
+	else
+		db = 1023;
+
+	its_encode_cmd(cmd, GITS_CMD_VMAPTI);
+	its_encode_devid(cmd, desc->its_vmapti_cmd.dev->device_id);
+	its_encode_vpeid(cmd, desc->its_vmapti_cmd.vpe->vpe_id);
+	its_encode_event_id(cmd, desc->its_vmapti_cmd.event_id);
+	its_encode_db_phys_id(cmd, db);
+	its_encode_virt_id(cmd, desc->its_vmapti_cmd.virt_id);
+
+	its_fixup_cmd(cmd);
+
+	return desc->its_vmapti_cmd.vpe;
+}
+
+static struct its_vpe *its_build_vmovi_cmd(struct its_cmd_block *cmd,
+					   struct its_cmd_desc *desc)
+{
+	u32 db;
+
+	if (desc->its_vmovi_cmd.db_enabled)
+		db = desc->its_vmovi_cmd.vpe->vpe_db_lpi;
+	else
+		db = 1023;
+
+	its_encode_cmd(cmd, GITS_CMD_VMOVI);
+	its_encode_devid(cmd, desc->its_vmovi_cmd.dev->device_id);
+	its_encode_vpeid(cmd, desc->its_vmovi_cmd.vpe->vpe_id);
+	its_encode_event_id(cmd, desc->its_vmovi_cmd.event_id);
+	its_encode_db_phys_id(cmd, db);
+	its_encode_db_valid(cmd, true);
+
+	its_fixup_cmd(cmd);
+
+	return desc->its_vmovi_cmd.vpe;
+}
+
 static u64 its_cmd_ptr_to_offset(struct its_node *its,
 				 struct its_cmd_block *ptr)
 {
@@ -576,6 +664,18 @@ static void its_build_sync_cmd(struct its_cmd_block *sync_cmd,
 static BUILD_SINGLE_CMD_FUNC(its_send_single_command, its_cmd_builder_t,
 			     struct its_collection, its_build_sync_cmd)
 
+static void its_build_vsync_cmd(struct its_cmd_block *sync_cmd,
+				struct its_vpe *sync_vpe)
+{
+	its_encode_cmd(sync_cmd, GITS_CMD_VSYNC);
+	its_encode_vpeid(sync_cmd, sync_vpe->vpe_id);
+
+	its_fixup_cmd(sync_cmd);
+}
+
+static BUILD_SINGLE_CMD_FUNC(its_send_single_vcommand, its_cmd_vbuilder_t,
+			     struct its_vpe, its_build_vsync_cmd)
+
 static void its_send_int(struct its_device *dev, u32 event_id)
 {
 	struct its_cmd_desc desc;
@@ -669,6 +769,33 @@ static void its_send_invall(struct its_node *its, struct its_collection *col)
 	its_send_single_command(its, its_build_invall_cmd, &desc);
 }
 
+static void its_send_vmapti(struct its_device *dev, u32 id)
+{
+	struct its_vlpi_map *map = &dev->event_map.vlpi_maps[id];
+	struct its_cmd_desc desc;
+
+	desc.its_vmapti_cmd.vpe = map->vm->vpes[map->vpe_idx];
+	desc.its_vmapti_cmd.dev = dev;
+	desc.its_vmapti_cmd.virt_id = map->vintid;
+	desc.its_vmapti_cmd.event_id = id;
+	desc.its_vmapti_cmd.db_enabled = map->db_enabled;
+
+	its_send_single_vcommand(dev->its, its_build_vmapti_cmd, &desc);
+}
+
+static void its_send_vmovi(struct its_device *dev, u32 id)
+{
+	struct its_vlpi_map *map = &dev->event_map.vlpi_maps[id];
+	struct its_cmd_desc desc;
+
+	desc.its_vmovi_cmd.vpe = map->vm->vpes[map->vpe_idx];
+	desc.its_vmovi_cmd.dev = dev;
+	desc.its_vmovi_cmd.event_id = id;
+	desc.its_vmovi_cmd.db_enabled = map->db_enabled;
+
+	its_send_single_vcommand(dev->its, its_build_vmovi_cmd, &desc);
+}
+
 /*
  * irqchip functions - assumes MSI, mostly.
  */
@@ -781,19 +908,135 @@ static int its_irq_set_irqchip_state(struct irq_data *d,
 	return 0;
 }
 
+static int its_vlpi_map(struct irq_data *d, struct its_cmd_info *info)
+{
+	struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+	u32 event = its_get_event_id(d);
+	int ret = 0;
+
+	if (!info->map)
+		return -EINVAL;
+
+	mutex_lock(&its_dev->event_map.vlpi_lock);
+
+	if (!its_dev->event_map.vm) {
+		struct its_vlpi_map *maps;
+
+		maps = kzalloc(sizeof(*maps) * its_dev->event_map.nr_lpis,
+			       GFP_KERNEL);
+		if (!maps) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		its_dev->event_map.vm = info->map->vm;
+		its_dev->event_map.vlpi_maps = maps;
+	} else if (its_dev->event_map.vm != info->map->vm) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Get our private copy of the mapping information */
+	its_dev->event_map.vlpi_maps[event] = *info->map;
+
+	if (irqd_is_forwarded_to_vcpu(d)) {
+		/* Already mapped, move it around */
+		its_send_vmovi(its_dev, event);
+	} else {
+		/* Drop the physical mapping */
+		its_send_discard(its_dev, event);
+
+		/* and install the virtual one */
+		its_send_vmapti(its_dev, event);
+		irqd_set_forwarded_to_vcpu(d);
+
+		/* Increment the number of VLPIs */
+		its_dev->event_map.nr_vlpis++;
+	}
+
+out:
+	mutex_unlock(&its_dev->event_map.vlpi_lock);
+	return ret;
+}
+
+static int its_vlpi_get(struct irq_data *d, struct its_cmd_info *info)
+{
+	struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+	u32 event = its_get_event_id(d);
+	int ret = 0;
+
+	mutex_lock(&its_dev->event_map.vlpi_lock);
+
+	if (!its_dev->event_map.vm ||
+	    !its_dev->event_map.vlpi_maps[event].vm) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Copy our mapping information to the incoming request */
+	*info->map = its_dev->event_map.vlpi_maps[event];
+
+out:
+	mutex_unlock(&its_dev->event_map.vlpi_lock);
+	return ret;
+}
+
+static int its_vlpi_unmap(struct irq_data *d)
+{
+	struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+	u32 event = its_get_event_id(d);
+	int ret = 0;
+
+	mutex_lock(&its_dev->event_map.vlpi_lock);
+
+	if (!its_dev->event_map.vm || !irqd_is_forwarded_to_vcpu(d)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Drop the virtual mapping */
+	its_send_discard(its_dev, event);
+
+	/* and restore the physical one */
+	irqd_clr_forwarded_to_vcpu(d);
+	its_send_mapti(its_dev, d->hwirq, event);
+	lpi_update_config(d, 0xff, (LPI_PROP_DEFAULT_PRIO |
+				    LPI_PROP_ENABLED |
+				    LPI_PROP_GROUP1));
+
+	/*
+	 * Drop the refcount and make the device available again if
+	 * this was the last VLPI.
+	 */
+	if (!--its_dev->event_map.nr_vlpis) {
+		its_dev->event_map.vm = NULL;
+		kfree(its_dev->event_map.vlpi_maps);
+	}
+
+out:
+	mutex_unlock(&its_dev->event_map.vlpi_lock);
+	return ret;
+}
+
 static int its_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
 {
 	struct its_device *its_dev = irq_data_get_irq_chip_data(d);
 	struct its_cmd_info *info = vcpu_info;
 
 	/* Need a v4 ITS */
-	if (!its_dev->its->is_v4 || !info)
+	if (!its_dev->its->is_v4)
 		return -EINVAL;
 
+	/* Unmap request? */
+	if (!info)
+		return its_vlpi_unmap(d);
+
 	switch (info->cmd_type) {
 	case MAP_VLPI:
+		return its_vlpi_map(d, info);
 
 	case GET_VLPI:
+		return its_vlpi_get(d, info);
 
 	case PROP_UPDATE_VLPI:
 	case PROP_UPDATE_AND_INV_VLPI:
@@ -1512,6 +1755,7 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
 	dev->event_map.col_map = col_map;
 	dev->event_map.lpi_base = lpi_base;
 	dev->event_map.nr_lpis = nr_lpis;
+	mutex_init(&dev->event_map.vlpi_lock);
 	dev->device_id = dev_id;
 	INIT_LIST_HEAD(&dev->entry);
 
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 18/59] irqchip/gic-v3-its: Add VLPI configuration handling
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (16 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 17/59] irqchip/gic-v3-its: Add VLPI map/unmap operations Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 19/59] irqchip/gic-v3-its: Add VPE domain infrastructure Marc Zyngier
                   ` (40 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

When a VLPI is reconfigured (enabled, disabled, change in priority),
the full configuration byte must be written, and the caches invalidated.

Also, when using the irq_mask/irq_unmask methods, it is necessary
to disable the doorbell for that particular interrupt (by mapping it
to 1023) on top of clearing the Enable bit.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 75 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 70 insertions(+), 5 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index ef31c3e58c01..b618c259be8b 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -806,18 +806,26 @@ static inline u32 its_get_event_id(struct irq_data *d)
 	return d->hwirq - its_dev->event_map.lpi_base;
 }
 
-static void lpi_update_config(struct irq_data *d, u8 clr, u8 set)
+static void lpi_write_config(struct irq_data *d, u8 clr, u8 set)
 {
-	struct its_device *its_dev = irq_data_get_irq_chip_data(d);
-	irq_hw_number_t hwirq = d->hwirq;
+	irq_hw_number_t hwirq;
 	struct page *prop_page;
 	u8 *cfg;
 
-	prop_page = gic_rdists->prop_page;
+	if (irqd_is_forwarded_to_vcpu(d)) {
+		struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+		u32 event = its_get_event_id(d);
+
+		prop_page = its_dev->event_map.vm->vprop_page;
+		hwirq = its_dev->event_map.vlpi_maps[event].vintid;
+	} else {
+		prop_page = gic_rdists->prop_page;
+		hwirq = d->hwirq;
+	}
 
 	cfg = page_address(prop_page) + hwirq - 8192;
 	*cfg &= ~clr;
-	*cfg |= set;
+	*cfg |= set | LPI_PROP_GROUP1;
 
 	/*
 	 * Make the above write visible to the redistributors.
@@ -828,16 +836,52 @@ static void lpi_update_config(struct irq_data *d, u8 clr, u8 set)
 		gic_flush_dcache_to_poc(cfg, sizeof(*cfg));
 	else
 		dsb(ishst);
+}
+
+static void lpi_update_config(struct irq_data *d, u8 clr, u8 set)
+{
+	struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+
+	lpi_write_config(d, clr, set);
 	its_send_inv(its_dev, its_get_event_id(d));
 }
 
+static void its_vlpi_set_doorbell(struct irq_data *d, bool enable)
+{
+	struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+	u32 event = its_get_event_id(d);
+
+	if (its_dev->event_map.vlpi_maps[event].db_enabled == enable)
+		return;
+
+	its_dev->event_map.vlpi_maps[event].db_enabled = enable;
+
+	/*
+	 * More fun with the architecture:
+	 *
+	 * Ideally, we'd issue a VMAPTI to set the doorbell to its LPI
+	 * value or to 1023, depending on the enable bit. But that
+	 * would be issueing a mapping for an /existing/ DevID+EventID
+	 * pair, which is UNPREDICTABLE. Instead, let's issue a VMOVI
+	 * to the /same/ vPE, using this opportunity to adjust the
+	 * doorbell. Mouahahahaha. We loves it, Precious.
+	 */
+	its_send_vmovi(its_dev, event);
+}
+
 static void its_mask_irq(struct irq_data *d)
 {
+	if (irqd_is_forwarded_to_vcpu(d))
+		its_vlpi_set_doorbell(d, false);
+
 	lpi_update_config(d, LPI_PROP_ENABLED, 0);
 }
 
 static void its_unmask_irq(struct irq_data *d)
 {
+	if (irqd_is_forwarded_to_vcpu(d))
+		its_vlpi_set_doorbell(d, true);
+
 	lpi_update_config(d, 0, LPI_PROP_ENABLED);
 }
 
@@ -850,6 +894,10 @@ static int its_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
 	struct its_collection *target_col;
 	u32 id = its_get_event_id(d);
 
+	/* A forwarded interrupt should use irq_set_vcpu_affinity */
+	if (irqd_is_forwarded_to_vcpu(d))
+		return -EINVAL;
+
        /* lpi cannot be routed to a redistributor that is on a foreign node */
 	if (its_dev->its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_23144) {
 		if (its_dev->its->numa_node >= 0) {
@@ -1018,6 +1066,22 @@ static int its_vlpi_unmap(struct irq_data *d)
 	return ret;
 }
 
+static int its_vlpi_prop_update(struct irq_data *d, struct its_cmd_info *info)
+{
+	struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+
+	if (!its_dev->event_map.vm || !irqd_is_forwarded_to_vcpu(d))
+		return -EINVAL;
+
+	if (info->cmd_type == PROP_UPDATE_AND_INV_VLPI)
+		lpi_update_config(d, 0xff, info->config);
+	else
+		lpi_write_config(d, 0xff, info->config);
+	its_vlpi_set_doorbell(d, !!(info->config & LPI_PROP_ENABLED));
+
+	return 0;
+}
+
 static int its_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
 {
 	struct its_device *its_dev = irq_data_get_irq_chip_data(d);
@@ -1040,6 +1104,7 @@ static int its_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
 
 	case PROP_UPDATE_VLPI:
 	case PROP_UPDATE_AND_INV_VLPI:
+		return its_vlpi_prop_update(d, info);
 
 	default:
 		return -EINVAL;
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 19/59] irqchip/gic-v3-its: Add VPE domain infrastructure
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (17 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 18/59] irqchip/gic-v3-its: Add VLPI configuration handling Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 20/59] irqchip/gic-v3-its: Add VPE irq domain allocation/teardown Marc Zyngier
                   ` (39 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Add the basic GICv4 VPE (vcpu in GICv4 parlance) infrastructure
(irqchip, irq domain) that is going to be populated in the following
patches.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index b618c259be8b..1fa345d53088 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -2026,6 +2026,13 @@ static const struct irq_domain_ops its_domain_ops = {
 	.deactivate		= its_irq_domain_deactivate,
 };
 
+static struct irq_chip its_vpe_irq_chip = {
+	.name			= "GICv4-vpe",
+};
+
+static const struct irq_domain_ops its_vpe_domain_ops = {
+};
+
 static int its_force_quiescent(void __iomem *base)
 {
 	u32 count = 1000000;	/* 1s */
@@ -2142,6 +2149,11 @@ static int its_init_domain(struct fwnode_handle *handle, struct its_node *its)
 	return 0;
 }
 
+static int its_init_vpe_domain(void)
+{
+	return 0;
+}
+
 static int __init its_compute_its_list_map(struct resource *res,
 					   void __iomem *its_base)
 {
@@ -2484,6 +2496,9 @@ int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,
 		    struct irq_domain *parent_domain)
 {
 	struct device_node *of_node;
+	struct its_node *its;
+	bool has_v4 = false;
+	int err;
 
 	its_parent = parent_domain;
 	of_node = to_of_node(handle);
@@ -2498,5 +2513,21 @@ int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,
 	}
 
 	gic_rdists = rdists;
-	return its_alloc_lpi_tables();
+	err = its_alloc_lpi_tables();
+	if (err)
+		return err;
+
+	its_lpi_init(rdists->id_bits);
+
+	list_for_each_entry(its, &its_nodes, entry)
+		has_v4 |= its->is_v4;
+
+	if (has_v4 & rdists->has_vlpis) {
+		if (its_init_vpe_domain()) {
+			rdists->has_vlpis = false;
+			pr_err("ITS: Disabling GICv4 support\n");
+		}
+	}
+
+	return 0;
 }
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 20/59] irqchip/gic-v3-its: Add VPE irq domain allocation/teardown
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (18 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 19/59] irqchip/gic-v3-its: Add VPE domain infrastructure Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:25 ` [PATCH v3 21/59] irqchip/gic-v3-its: Add VPE irq domain [de]activation Marc Zyngier
                   ` (38 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

When creating a VM, the low level GICv4 code is responsible for:
- allocating each VPE a unique VPEID
- allocating a doorbell interrupt for each VPE
- allocating the pending tables for each VPE
- allocating the property table for the VM

This of course has to be reversed when the VM is brought down.

All of this is wired into the irq domain alloc/free methods.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 169 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 169 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 1fa345d53088..0f9a487448b9 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -148,6 +148,7 @@ static struct irq_domain *its_parent;
 #define ITS_LIST_MAX		16
 
 static unsigned long its_list_map;
+static DEFINE_IDA(its_vpeid_ida);
 
 #define gic_data_rdist()		(raw_cpu_ptr(gic_rdists->rdist))
 #define gic_data_rdist_rd_base()	(gic_data_rdist()->rd_base)
@@ -1249,6 +1250,11 @@ static struct page *its_allocate_prop_table(gfp_t gfp_flags)
 	return prop_page;
 }
 
+static void its_free_prop_table(struct page *prop_page)
+{
+	free_pages((unsigned long)page_address(prop_page),
+		   get_order(LPI_PROPBASE_SZ));
+}
 
 static int __init its_alloc_lpi_tables(void)
 {
@@ -1551,6 +1557,12 @@ static struct page *its_allocate_pending_table(gfp_t gfp_flags)
 	return pend_page;
 }
 
+static void its_free_pending_table(struct page *pt)
+{
+	free_pages((unsigned long)page_address(pt),
+		   get_order(max_t(u32, LPI_PENDBASE_SZ, SZ_64K)));
+}
+
 static void its_cpu_init_lpis(void)
 {
 	void __iomem *rbase = gic_data_rdist_rd_base();
@@ -1773,6 +1785,34 @@ static bool its_alloc_device_table(struct its_node *its, u32 dev_id)
 	return its_alloc_table_entry(baser, dev_id);
 }
 
+static bool its_alloc_vpe_table(u32 vpe_id)
+{
+	struct its_node *its;
+
+	/*
+	 * Make sure the L2 tables are allocated on *all* v4 ITSs. We
+	 * could try and only do it on ITSs corresponding to devices
+	 * that have interrupts targeted at this VPE, but the
+	 * complexity becomes crazy (and you have tons of memory
+	 * anyway, right?).
+	 */
+	list_for_each_entry(its, &its_nodes, entry) {
+		struct its_baser *baser;
+
+		if (!its->is_v4)
+			continue;
+
+		baser = its_get_baser(its, GITS_BASER_TYPE_VCPU);
+		if (!baser)
+			return false;
+
+		if (!its_alloc_table_entry(baser, vpe_id))
+			return false;
+	}
+
+	return true;
+}
+
 static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
 					    int nvecs)
 {
@@ -2030,7 +2070,136 @@ static struct irq_chip its_vpe_irq_chip = {
 	.name			= "GICv4-vpe",
 };
 
+static int its_vpe_id_alloc(void)
+{
+	return ida_simple_get(&its_vpeid_ida, 0, 1 << 16, GFP_KERNEL);
+}
+
+static void its_vpe_id_free(u16 id)
+{
+	ida_simple_remove(&its_vpeid_ida, id);
+}
+
+static int its_vpe_init(struct its_vpe *vpe)
+{
+	struct page *vpt_page;
+	int vpe_id;
+
+	/* Allocate vpe_id */
+	vpe_id = its_vpe_id_alloc();
+	if (vpe_id < 0)
+		return vpe_id;
+
+	/* Allocate VPT */
+	vpt_page = its_allocate_pending_table(GFP_KERNEL);
+	if (!vpt_page) {
+		its_vpe_id_free(vpe_id);
+		return -ENOMEM;
+	}
+
+	if (!its_alloc_vpe_table(vpe_id)) {
+		its_vpe_id_free(vpe_id);
+		its_free_pending_table(vpe->vpt_page);
+		return -ENOMEM;
+	}
+
+	vpe->vpe_id = vpe_id;
+	vpe->vpt_page = vpt_page;
+
+	return 0;
+}
+
+static void its_vpe_teardown(struct its_vpe *vpe)
+{
+	its_vpe_id_free(vpe->vpe_id);
+	its_free_pending_table(vpe->vpt_page);
+}
+
+static void its_vpe_irq_domain_free(struct irq_domain *domain,
+				    unsigned int virq,
+				    unsigned int nr_irqs)
+{
+	struct its_vm *vm = domain->host_data;
+	int i;
+
+	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
+
+	for (i = 0; i < nr_irqs; i++) {
+		struct irq_data *data = irq_domain_get_irq_data(domain,
+								virq + i);
+		struct its_vpe *vpe = irq_data_get_irq_chip_data(data);
+
+		BUG_ON(vm != vpe->its_vm);
+
+		clear_bit(data->hwirq, vm->db_bitmap);
+		its_vpe_teardown(vpe);
+		irq_domain_reset_irq_data(data);
+	}
+
+	if (bitmap_empty(vm->db_bitmap, vm->nr_db_lpis)) {
+		its_lpi_free_chunks(vm->db_bitmap, vm->db_lpi_base, vm->nr_db_lpis);
+		its_free_prop_table(vm->vprop_page);
+	}
+}
+
+static int its_vpe_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				    unsigned int nr_irqs, void *args)
+{
+	struct its_vm *vm = args;
+	unsigned long *bitmap;
+	struct page *vprop_page;
+	int base, nr_ids, i, err = 0;
+
+	BUG_ON(!vm);
+
+	bitmap = its_lpi_alloc_chunks(nr_irqs, &base, &nr_ids);
+	if (!bitmap)
+		return -ENOMEM;
+
+	if (nr_ids < nr_irqs) {
+		its_lpi_free_chunks(bitmap, base, nr_ids);
+		return -ENOMEM;
+	}
+
+	vprop_page = its_allocate_prop_table(GFP_KERNEL);
+	if (!vprop_page) {
+		its_lpi_free_chunks(bitmap, base, nr_ids);
+		return -ENOMEM;
+	}
+
+	vm->db_bitmap = bitmap;
+	vm->db_lpi_base = base;
+	vm->nr_db_lpis = nr_ids;
+	vm->vprop_page = vprop_page;
+
+	for (i = 0; i < nr_irqs; i++) {
+		vm->vpes[i]->vpe_db_lpi = base + i;
+		err = its_vpe_init(vm->vpes[i]);
+		if (err)
+			break;
+		err = its_irq_gic_domain_alloc(domain, virq + i,
+					       vm->vpes[i]->vpe_db_lpi);
+		if (err)
+			break;
+		irq_domain_set_hwirq_and_chip(domain, virq + i, i,
+					      &its_vpe_irq_chip, vm->vpes[i]);
+		set_bit(i, bitmap);
+	}
+
+	if (err) {
+		if (i > 0)
+			its_vpe_irq_domain_free(domain, virq, i - 1);
+
+		its_lpi_free_chunks(bitmap, base, nr_ids);
+		its_free_prop_table(vprop_page);
+	}
+
+	return err;
+}
+
 static const struct irq_domain_ops its_vpe_domain_ops = {
+	.alloc			= its_vpe_irq_domain_alloc,
+	.free			= its_vpe_irq_domain_free,
 };
 
 static int its_force_quiescent(void __iomem *base)
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 21/59] irqchip/gic-v3-its: Add VPE irq domain [de]activation
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (19 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 20/59] irqchip/gic-v3-its: Add VPE irq domain allocation/teardown Marc Zyngier
@ 2017-07-31 17:25 ` Marc Zyngier
  2017-07-31 17:26 ` [PATCH v3 22/59] irqchip/gic-v3-its: Add VPENDBASER/VPROPBASER accessors Marc Zyngier
                   ` (37 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:25 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

On activation, a VPE is mapped using the VMAPP command, followed
by a VINVALL for a good measure. On deactivation, the VPE is
simply unmapped.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 102 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 0f9a487448b9..5ca1e571c1b4 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -215,6 +215,16 @@ struct its_cmd_desc {
 
 		struct {
 			struct its_vpe *vpe;
+		} its_vinvall_cmd;
+
+		struct {
+			struct its_vpe *vpe;
+			struct its_collection *col;
+			bool valid;
+		} its_vmapp_cmd;
+
+		struct {
+			struct its_vpe *vpe;
 			struct its_device *dev;
 			u32 virt_id;
 			u32 event_id;
@@ -318,6 +328,16 @@ static void its_encode_db_valid(struct its_cmd_block *cmd, bool db_valid)
 	its_mask_encode(&cmd->raw_cmd[2], db_valid, 0, 0);
 }
 
+static void its_encode_vpt_addr(struct its_cmd_block *cmd, u64 vpt_pa)
+{
+	its_mask_encode(&cmd->raw_cmd[3], vpt_pa >> 16, 50, 16);
+}
+
+static void its_encode_vpt_size(struct its_cmd_block *cmd, u8 vpt_size)
+{
+	its_mask_encode(&cmd->raw_cmd[3], vpt_size, 4, 0);
+}
+
 static inline void its_fixup_cmd(struct its_cmd_block *cmd)
 {
 	/* Let's fixup BE commands */
@@ -476,6 +496,36 @@ static struct its_collection *its_build_invall_cmd(struct its_cmd_block *cmd,
 	return NULL;
 }
 
+static struct its_vpe *its_build_vinvall_cmd(struct its_cmd_block *cmd,
+					     struct its_cmd_desc *desc)
+{
+	its_encode_cmd(cmd, GITS_CMD_VINVALL);
+	its_encode_vpeid(cmd, desc->its_vinvall_cmd.vpe->vpe_id);
+
+	its_fixup_cmd(cmd);
+
+	return desc->its_vinvall_cmd.vpe;
+}
+
+static struct its_vpe *its_build_vmapp_cmd(struct its_cmd_block *cmd,
+					   struct its_cmd_desc *desc)
+{
+	unsigned long vpt_addr;
+
+	vpt_addr = virt_to_phys(page_address(desc->its_vmapp_cmd.vpe->vpt_page));
+
+	its_encode_cmd(cmd, GITS_CMD_VMAPP);
+	its_encode_vpeid(cmd, desc->its_vmapp_cmd.vpe->vpe_id);
+	its_encode_valid(cmd, desc->its_vmapp_cmd.valid);
+	its_encode_target(cmd, desc->its_vmapp_cmd.col->target_address);
+	its_encode_vpt_addr(cmd, vpt_addr);
+	its_encode_vpt_size(cmd, LPI_NRBITS - 1);
+
+	its_fixup_cmd(cmd);
+
+	return desc->its_vmapp_cmd.vpe;
+}
+
 static struct its_vpe *its_build_vmapti_cmd(struct its_cmd_block *cmd,
 					    struct its_cmd_desc *desc)
 {
@@ -797,6 +847,37 @@ static void its_send_vmovi(struct its_device *dev, u32 id)
 	its_send_single_vcommand(dev->its, its_build_vmovi_cmd, &desc);
 }
 
+static void its_send_vmapp(struct its_vpe *vpe, bool valid)
+{
+	struct its_cmd_desc desc;
+	struct its_node *its;
+
+	desc.its_vmapp_cmd.vpe = vpe;
+	desc.its_vmapp_cmd.valid = valid;
+
+	list_for_each_entry(its, &its_nodes, entry) {
+		if (!its->is_v4)
+			continue;
+
+		desc.its_vmapp_cmd.col = &its->collections[vpe->col_idx];
+		its_send_single_vcommand(its, its_build_vmapp_cmd, &desc);
+	}
+}
+
+static void its_send_vinvall(struct its_vpe *vpe)
+{
+	struct its_cmd_desc desc;
+	struct its_node *its;
+
+	desc.its_vinvall_cmd.vpe = vpe;
+
+	list_for_each_entry(its, &its_nodes, entry) {
+		if (!its->is_v4)
+			continue;
+		its_send_single_vcommand(its, its_build_vinvall_cmd, &desc);
+	}
+}
+
 /*
  * irqchip functions - assumes MSI, mostly.
  */
@@ -2197,9 +2278,30 @@ static int its_vpe_irq_domain_alloc(struct irq_domain *domain, unsigned int virq
 	return err;
 }
 
+static void its_vpe_irq_domain_activate(struct irq_domain *domain,
+					struct irq_data *d)
+{
+	struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
+
+	/* Map the VPE to the first possible CPU */
+	vpe->col_idx = cpumask_first(cpu_online_mask);
+	its_send_vmapp(vpe, true);
+	its_send_vinvall(vpe);
+}
+
+static void its_vpe_irq_domain_deactivate(struct irq_domain *domain,
+					  struct irq_data *d)
+{
+	struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
+
+	its_send_vmapp(vpe, false);
+}
+
 static const struct irq_domain_ops its_vpe_domain_ops = {
 	.alloc			= its_vpe_irq_domain_alloc,
 	.free			= its_vpe_irq_domain_free,
+	.activate		= its_vpe_irq_domain_activate,
+	.deactivate		= its_vpe_irq_domain_deactivate,
 };
 
 static int its_force_quiescent(void __iomem *base)
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 22/59] irqchip/gic-v3-its: Add VPENDBASER/VPROPBASER accessors
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (20 preceding siblings ...)
  2017-07-31 17:25 ` [PATCH v3 21/59] irqchip/gic-v3-its: Add VPE irq domain [de]activation Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-07-31 17:26 ` [PATCH v3 23/59] irqchip/gic-v3-its: Add VPE scheduling Marc Zyngier
                   ` (36 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

V{PEND,PROP}BASER being 64bit registers, they need some ad-hoc
accessors on 32bit, specially given that VPENDBASER contains
a Valid bit, making the access a bit convoluted.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 arch/arm/include/asm/arch_gicv3.h   | 28 ++++++++++++++++++++++++++++
 arch/arm64/include/asm/arch_gicv3.h |  5 +++++
 include/linux/irqchip/arm-gic-v3.h  |  5 +++++
 3 files changed, 38 insertions(+)

diff --git a/arch/arm/include/asm/arch_gicv3.h b/arch/arm/include/asm/arch_gicv3.h
index 27475904e096..8d45e88feac9 100644
--- a/arch/arm/include/asm/arch_gicv3.h
+++ b/arch/arm/include/asm/arch_gicv3.h
@@ -291,5 +291,33 @@ static inline u64 __gic_readq_nonatomic(const volatile void __iomem *addr)
  */
 #define gits_write_cwriter(v, c)	__gic_writeq_nonatomic(v, c)
 
+/*
+ * GITS_VPROPBASER - hi and lo bits may be accessed independently.
+ */
+#define gits_write_vpropbaser(v, c)	__gic_writeq_nonatomic(v, c)
+
+/*
+ * GITS_VPENDBASER - the Valid bit must be cleared before changing
+ * anything else.
+ */
+static inline void gits_write_vpendbaser(u64 val, void * __iomem addr)
+{
+	u32 tmp;
+
+	tmp = readl_relaxed(addr + 4);
+	if (tmp & (GICR_VPENDBASER_Valid >> 32)) {
+		tmp &= ~(GICR_VPENDBASER_Valid >> 32);
+		writel_relaxed(tmp, addr + 4);
+	}
+
+	/*
+	 * Use the fact that __gic_writeq_nonatomic writes the second
+	 * half of the 64bit quantity after the first.
+	 */
+	__gic_writeq_nonatomic(val, addr);
+}
+
+#define gits_read_vpendbaser(c)		__gic_readq_nonatomic(c)
+
 #endif /* !__ASSEMBLY__ */
 #endif /* !__ASM_ARCH_GICV3_H */
diff --git a/arch/arm64/include/asm/arch_gicv3.h b/arch/arm64/include/asm/arch_gicv3.h
index 8cef47fa2218..0d2a53457c30 100644
--- a/arch/arm64/include/asm/arch_gicv3.h
+++ b/arch/arm64/include/asm/arch_gicv3.h
@@ -133,5 +133,10 @@ static inline void gic_write_bpr1(u32 val)
 #define gicr_write_pendbaser(v, c)	writeq_relaxed(v, c)
 #define gicr_read_pendbaser(c)		readq_relaxed(c)
 
+#define gits_write_vpropbaser(v, c)	writeq_relaxed(v, c)
+
+#define gits_write_vpendbaser(v, c)	writeq_relaxed(v, c)
+#define gits_read_vpendbaser(c)		readq_relaxed(c)
+
 #endif /* __ASSEMBLY__ */
 #endif /* __ASM_ARCH_GICV3_H */
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index 7c6fd8f3e36c..17ba0d732f12 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -212,6 +212,11 @@
 #define LPI_PROP_GROUP1			(1 << 1)
 #define LPI_PROP_ENABLED		(1 << 0)
 
+#define GICR_VPENDBASER_Dirty		(1ULL << 60)
+#define GICR_VPENDBASER_PendingLast	(1ULL << 61)
+#define GICR_VPENDBASER_IDAI		(1ULL << 62)
+#define GICR_VPENDBASER_Valid		(1ULL << 63)
+
 /*
  * ITS registers, offsets from ITS_base
  */
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 23/59] irqchip/gic-v3-its: Add VPE scheduling
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (21 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 22/59] irqchip/gic-v3-its: Add VPENDBASER/VPROPBASER accessors Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-07-31 17:26 ` [PATCH v3 24/59] irqchip/gic-v3-its: Add VPE invalidation hook Marc Zyngier
                   ` (35 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

When a VPE is scheduled to run, the corresponding redistributor must
be told so, by setting VPROPBASER to the VM's property table, and
VPENDBASER to the vcpu's pending table.

When scheduled out, we preserve the IDAI and PendingLast bits. The
latter is specially important, as it tells the hypervisor that
there are pending interrupts for this vcpu.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c   | 85 ++++++++++++++++++++++++++++++++++++++
 include/linux/irqchip/arm-gic-v3.h | 58 ++++++++++++++++++++++++++
 2 files changed, 143 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 5ca1e571c1b4..d94a51489f6c 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -152,6 +152,7 @@ static DEFINE_IDA(its_vpeid_ida);
 
 #define gic_data_rdist()		(raw_cpu_ptr(gic_rdists->rdist))
 #define gic_data_rdist_rd_base()	(gic_data_rdist()->rd_base)
+#define gic_data_rdist_vlpi_base()	(gic_data_rdist_rd_base() + SZ_128K)
 
 static struct its_collection *dev_event_to_col(struct its_device *its_dev,
 					       u32 event)
@@ -2147,8 +2148,92 @@ static const struct irq_domain_ops its_domain_ops = {
 	.deactivate		= its_irq_domain_deactivate,
 };
 
+static void its_vpe_schedule(struct its_vpe *vpe)
+{
+	void * __iomem vlpi_base = gic_data_rdist_vlpi_base();
+	u64 val;
+
+	/* Schedule the VPE */
+	val  = virt_to_phys(page_address(vpe->its_vm->vprop_page)) &
+		GENMASK_ULL(51, 12);
+	val |= (LPI_NRBITS - 1) & GICR_VPROPBASER_IDBITS_MASK;
+	val |= GICR_VPROPBASER_RaWb;
+	val |= GICR_VPROPBASER_InnerShareable;
+	gits_write_vpropbaser(val, vlpi_base + GICR_VPROPBASER);
+
+	val  = virt_to_phys(page_address(vpe->vpt_page)) &
+		GENMASK_ULL(51, 16);
+	val |= GICR_VPENDBASER_RaWaWb;
+	val |= GICR_VPENDBASER_NonShareable;
+	/*
+	 * There is no good way of finding out if the pending table is
+	 * empty as we can race against the doorbell interrupt very
+	 * easily. So in the end, vpe->pending_last is only an
+	 * indication that the vcpu has something pending, not one
+	 * that the pending table is empty. A good implementation
+	 * would be able to read its coarse map pretty quickly anyway,
+	 * making this a tolerable issue.
+	 */
+	val |= GICR_VPENDBASER_PendingLast;
+	val |= vpe->idai ? GICR_VPENDBASER_IDAI : 0;
+	val |= GICR_VPENDBASER_Valid;
+	gits_write_vpendbaser(val, vlpi_base + GICR_VPENDBASER);
+}
+
+static void its_vpe_deschedule(struct its_vpe *vpe)
+{
+	void * __iomem vlpi_base = gic_data_rdist_vlpi_base();
+	u32 count = 1000000;	/* 1s! */
+	bool clean;
+	u64 val;
+
+	/* We're being scheduled out */
+	val = gits_read_vpendbaser(vlpi_base + GICR_VPENDBASER);
+	val &= ~GICR_VPENDBASER_Valid;
+	gits_write_vpendbaser(val, vlpi_base + GICR_VPENDBASER);
+
+	do {
+		val = gits_read_vpendbaser(vlpi_base + GICR_VPENDBASER);
+		clean = !(val & GICR_VPENDBASER_Dirty);
+		if (!clean) {
+			count--;
+			cpu_relax();
+			udelay(1);
+		}
+	} while (!clean && count);
+
+	if (unlikely(!clean && !count)) {
+		pr_err_ratelimited("ITS virtual pending table not cleaning\n");
+		vpe->idai = false;
+		vpe->pending_last = true;
+	} else {
+		vpe->idai = !!(val & GICR_VPENDBASER_IDAI);
+		vpe->pending_last = !!(val & GICR_VPENDBASER_PendingLast);
+	}
+}
+
+static int its_vpe_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
+{
+	struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
+	struct its_cmd_info *info = vcpu_info;
+
+	switch (info->cmd_type) {
+	case SCHEDULE_VPE:
+		its_vpe_schedule(vpe);
+		return 0;
+
+	case DESCHEDULE_VPE:
+		its_vpe_deschedule(vpe);
+		return 0;
+
+	default:
+		return -EINVAL;
+	}
+}
+
 static struct irq_chip its_vpe_irq_chip = {
 	.name			= "GICv4-vpe",
+	.irq_set_vcpu_affinity	= its_vpe_set_vcpu_affinity,
 };
 
 static int its_vpe_id_alloc(void)
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index 17ba0d732f12..6bc142cfa616 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -212,6 +212,64 @@
 #define LPI_PROP_GROUP1			(1 << 1)
 #define LPI_PROP_ENABLED		(1 << 0)
 
+/*
+ * Re-Distributor registers, offsets from VLPI_base
+ */
+#define GICR_VPROPBASER			0x0070
+
+#define GICR_VPROPBASER_IDBITS_MASK	0x1f
+
+#define GICR_VPROPBASER_SHAREABILITY_SHIFT		(10)
+#define GICR_VPROPBASER_INNER_CACHEABILITY_SHIFT	(7)
+#define GICR_VPROPBASER_OUTER_CACHEABILITY_SHIFT	(56)
+
+#define GICR_VPROPBASER_SHAREABILITY_MASK				\
+	GIC_BASER_SHAREABILITY(GICR_VPROPBASER, SHAREABILITY_MASK)
+#define GICR_VPROPBASER_INNER_CACHEABILITY_MASK				\
+	GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, MASK)
+#define GICR_VPROPBASER_OUTER_CACHEABILITY_MASK				\
+	GIC_BASER_CACHEABILITY(GICR_VPROPBASER, OUTER, MASK)
+#define GICR_VPROPBASER_CACHEABILITY_MASK				\
+	GICR_VPROPBASER_INNER_CACHEABILITY_MASK
+
+#define GICR_VPROPBASER_InnerShareable					\
+	GIC_BASER_SHAREABILITY(GICR_VPROPBASER, InnerShareable)
+
+#define GICR_VPROPBASER_nCnB	GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, nCnB)
+#define GICR_VPROPBASER_nC 	GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, nC)
+#define GICR_VPROPBASER_RaWt	GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, RaWt)
+#define GICR_VPROPBASER_RaWb	GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, RaWt)
+#define GICR_VPROPBASER_WaWt	GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, WaWt)
+#define GICR_VPROPBASER_WaWb	GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, WaWb)
+#define GICR_VPROPBASER_RaWaWt	GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, RaWaWt)
+#define GICR_VPROPBASER_RaWaWb	GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, RaWaWb)
+
+#define GICR_VPENDBASER			0x0078
+
+#define GICR_VPENDBASER_SHAREABILITY_SHIFT		(10)
+#define GICR_VPENDBASER_INNER_CACHEABILITY_SHIFT	(7)
+#define GICR_VPENDBASER_OUTER_CACHEABILITY_SHIFT	(56)
+#define GICR_VPENDBASER_SHAREABILITY_MASK				\
+	GIC_BASER_SHAREABILITY(GICR_VPENDBASER, SHAREABILITY_MASK)
+#define GICR_VPENDBASER_INNER_CACHEABILITY_MASK				\
+	GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, MASK)
+#define GICR_VPENDBASER_OUTER_CACHEABILITY_MASK				\
+	GIC_BASER_CACHEABILITY(GICR_VPENDBASER, OUTER, MASK)
+#define GICR_VPENDBASER_CACHEABILITY_MASK				\
+	GICR_VPENDBASER_INNER_CACHEABILITY_MASK
+
+#define GICR_VPENDBASER_NonShareable					\
+	GIC_BASER_SHAREABILITY(GICR_VPENDBASER, NonShareable)
+
+#define GICR_VPENDBASER_nCnB	GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, nCnB)
+#define GICR_VPENDBASER_nC 	GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, nC)
+#define GICR_VPENDBASER_RaWt	GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, RaWt)
+#define GICR_VPENDBASER_RaWb	GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, RaWt)
+#define GICR_VPENDBASER_WaWt	GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, WaWt)
+#define GICR_VPENDBASER_WaWb	GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, WaWb)
+#define GICR_VPENDBASER_RaWaWt	GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, RaWaWt)
+#define GICR_VPENDBASER_RaWaWb	GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, RaWaWb)
+
 #define GICR_VPENDBASER_Dirty		(1ULL << 60)
 #define GICR_VPENDBASER_PendingLast	(1ULL << 61)
 #define GICR_VPENDBASER_IDAI		(1ULL << 62)
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 24/59] irqchip/gic-v3-its: Add VPE invalidation hook
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (22 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 23/59] irqchip/gic-v3-its: Add VPE scheduling Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-07-31 17:26 ` [PATCH v3 25/59] irqchip/gic-v3-its: Add VPE affinity changes Marc Zyngier
                   ` (34 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

When a guest issues a INVALL command targetting a collection, it must
be translated into a VINVALL for the VPE that has this collection.

This patch implements a hook that offers this functionallity to the
hypervisor.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index d94a51489f6c..16cdd1f60ebf 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -2226,6 +2226,10 @@ static int its_vpe_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
 		its_vpe_deschedule(vpe);
 		return 0;
 
+	case INVALL_VPE:
+		its_send_vinvall(vpe);
+		return 0;
+
 	default:
 		return -EINVAL;
 	}
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 25/59] irqchip/gic-v3-its: Add VPE affinity changes
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (23 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 24/59] irqchip/gic-v3-its: Add VPE invalidation hook Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-07-31 17:26 ` [PATCH v3 26/59] irqchip/gic-v3-its: Add VPE interrupt masking Marc Zyngier
                   ` (33 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

When we're about to run a vcpu, it is crucial that the redistributor
associated with the physical CPU is being told about the new residency.

This is abstracted by hijacking the irq_set_affinity method for the
doorbell interrupt associated with the VPE. It is expected that the
hypervisor will call this method before scheduling the VPE.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 96 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 16cdd1f60ebf..0a9aedaf6da2 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -148,6 +148,9 @@ static struct irq_domain *its_parent;
 #define ITS_LIST_MAX		16
 
 static unsigned long its_list_map;
+static u16 vmovp_seq_num;
+static DEFINE_RAW_SPINLOCK(vmovp_lock);
+
 static DEFINE_IDA(its_vpeid_ida);
 
 #define gic_data_rdist()		(raw_cpu_ptr(gic_rdists->rdist))
@@ -238,6 +241,13 @@ struct its_cmd_desc {
 			u32 event_id;
 			bool db_enabled;
 		} its_vmovi_cmd;
+
+		struct {
+			struct its_vpe *vpe;
+			struct its_collection *col;
+			u16 seq_num;
+			u16 its_list;
+		} its_vmovp_cmd;
 	};
 };
 
@@ -329,6 +339,16 @@ static void its_encode_db_valid(struct its_cmd_block *cmd, bool db_valid)
 	its_mask_encode(&cmd->raw_cmd[2], db_valid, 0, 0);
 }
 
+static void its_encode_seq_num(struct its_cmd_block *cmd, u16 seq_num)
+{
+	its_mask_encode(&cmd->raw_cmd[0], seq_num, 47, 32);
+}
+
+static void its_encode_its_list(struct its_cmd_block *cmd, u16 its_list)
+{
+	its_mask_encode(&cmd->raw_cmd[1], its_list, 15, 0);
+}
+
 static void its_encode_vpt_addr(struct its_cmd_block *cmd, u64 vpt_pa)
 {
 	its_mask_encode(&cmd->raw_cmd[3], vpt_pa >> 16, 50, 16);
@@ -571,6 +591,20 @@ static struct its_vpe *its_build_vmovi_cmd(struct its_cmd_block *cmd,
 	return desc->its_vmovi_cmd.vpe;
 }
 
+static struct its_vpe *its_build_vmovp_cmd(struct its_cmd_block *cmd,
+					   struct its_cmd_desc *desc)
+{
+	its_encode_cmd(cmd, GITS_CMD_VMOVP);
+	its_encode_seq_num(cmd, desc->its_vmovp_cmd.seq_num);
+	its_encode_its_list(cmd, desc->its_vmovp_cmd.its_list);
+	its_encode_vpeid(cmd, desc->its_vmovp_cmd.vpe->vpe_id);
+	its_encode_target(cmd, desc->its_vmovp_cmd.col->target_address);
+
+	its_fixup_cmd(cmd);
+
+	return desc->its_vmovp_cmd.vpe;
+}
+
 static u64 its_cmd_ptr_to_offset(struct its_node *its,
 				 struct its_cmd_block *ptr)
 {
@@ -865,6 +899,48 @@ static void its_send_vmapp(struct its_vpe *vpe, bool valid)
 	}
 }
 
+static void its_send_vmovp(struct its_vpe *vpe)
+{
+	struct its_cmd_desc desc;
+	struct its_node *its;
+	unsigned long flags;
+	int col_id = vpe->col_idx;
+
+	desc.its_vmovp_cmd.vpe = vpe;
+	desc.its_vmovp_cmd.its_list = (u16)its_list_map;
+
+	if (!its_list_map) {
+		its = list_first_entry(&its_nodes, struct its_node, entry);
+		desc.its_vmovp_cmd.seq_num = 0;
+		desc.its_vmovp_cmd.col = &its->collections[col_id];
+		its_send_single_vcommand(its, its_build_vmovp_cmd, &desc);
+		return;
+	}
+
+	/*
+	 * Yet another marvel of the architecture. If using the
+	 * its_list "feature", we need to make sure that all ITSs
+	 * receive all VMOVP commands in the same order. The only way
+	 * to guarantee this is to make vmovp a serialization point.
+	 *
+	 * Wall <-- Head.
+	 */
+	raw_spin_lock_irqsave(&vmovp_lock, flags);
+
+	desc.its_vmovp_cmd.seq_num = vmovp_seq_num++;
+
+	/* Emit VMOVPs */
+	list_for_each_entry(its, &its_nodes, entry) {
+		if (!its->is_v4)
+			continue;
+
+		desc.its_vmovp_cmd.col = &its->collections[col_id];
+		its_send_single_vcommand(its, its_build_vmovp_cmd, &desc);
+	}
+
+	raw_spin_unlock_irqrestore(&vmovp_lock, flags);
+}
+
 static void its_send_vinvall(struct its_vpe *vpe)
 {
 	struct its_cmd_desc desc;
@@ -2148,6 +2224,25 @@ static const struct irq_domain_ops its_domain_ops = {
 	.deactivate		= its_irq_domain_deactivate,
 };
 
+static int its_vpe_set_affinity(struct irq_data *d,
+				const struct cpumask *mask_val,
+				bool force)
+{
+	struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
+	int cpu = cpumask_first(mask_val);
+
+	/*
+	 * Changing affinity is mega expensive, so let's be as lazy as
+	 * we can and only do it if we really have to.
+	 */
+	if (vpe->col_idx != cpu) {
+		vpe->col_idx = cpu;
+		its_send_vmovp(vpe);
+	}
+
+	return IRQ_SET_MASK_OK_DONE;
+}
+
 static void its_vpe_schedule(struct its_vpe *vpe)
 {
 	void * __iomem vlpi_base = gic_data_rdist_vlpi_base();
@@ -2237,6 +2332,7 @@ static int its_vpe_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
 
 static struct irq_chip its_vpe_irq_chip = {
 	.name			= "GICv4-vpe",
+	.irq_set_affinity	= its_vpe_set_affinity,
 	.irq_set_vcpu_affinity	= its_vpe_set_vcpu_affinity,
 };
 
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 26/59] irqchip/gic-v3-its: Add VPE interrupt masking
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (24 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 25/59] irqchip/gic-v3-its: Add VPE affinity changes Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-07-31 17:26 ` [PATCH v3 27/59] irqchip/gic-v3-its: Support VPE doorbell invalidation even when !DirectLPI Marc Zyngier
                   ` (32 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

When masking/unmasking a doorbell interrupt, it is necessary
to issue an invalidation to the corresponding redistributor.
We use the DirectLPI feature by writting directly to the corresponding
redistributor.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 arch/arm/include/asm/arch_gicv3.h   |  5 +++++
 arch/arm64/include/asm/arch_gicv3.h |  1 +
 drivers/irqchip/irq-gic-v3-its.c    | 31 +++++++++++++++++++++++++++++++
 3 files changed, 37 insertions(+)

diff --git a/arch/arm/include/asm/arch_gicv3.h b/arch/arm/include/asm/arch_gicv3.h
index 8d45e88feac9..550fb0bcccf8 100644
--- a/arch/arm/include/asm/arch_gicv3.h
+++ b/arch/arm/include/asm/arch_gicv3.h
@@ -276,6 +276,11 @@ static inline u64 __gic_readq_nonatomic(const volatile void __iomem *addr)
 #define gicr_write_pendbaser(v, c)	__gic_writeq_nonatomic(v, c)
 
 /*
+ * GICR_xLPIR - only the lower bits are significant
+ */
+#define gic_write_lpir(v, c)		writel_relaxed(lower_32_bits(v), c)
+
+/*
  * GITS_TYPER is an ID register and doesn't need atomicity.
  */
 #define gits_read_typer(c)		__gic_readq_nonatomic(c)
diff --git a/arch/arm64/include/asm/arch_gicv3.h b/arch/arm64/include/asm/arch_gicv3.h
index 0d2a53457c30..c2de3ff374a0 100644
--- a/arch/arm64/include/asm/arch_gicv3.h
+++ b/arch/arm64/include/asm/arch_gicv3.h
@@ -116,6 +116,7 @@ static inline void gic_write_bpr1(u32 val)
 
 #define gic_read_typer(c)		readq_relaxed(c)
 #define gic_write_irouter(v, c)		writeq_relaxed(v, c)
+#define gic_write_lpir(v, c)		writeq_relaxed(v, c)
 
 #define gic_flush_dcache_to_poc(a,l)	__flush_dcache_area((a), (l))
 
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 0a9aedaf6da2..d871d105be9d 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -2330,8 +2330,39 @@ static int its_vpe_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
 	}
 }
 
+static void its_vpe_send_inv(struct irq_data *d)
+{
+	struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
+	void __iomem *rdbase;
+
+	rdbase = per_cpu_ptr(gic_rdists->rdist, vpe->col_idx)->rd_base;
+	gic_write_lpir(vpe->vpe_db_lpi, rdbase + GICR_INVLPIR);
+}
+
+static void its_vpe_mask_irq(struct irq_data *d)
+{
+	/*
+	 * We need to unmask the LPI, which is described by the parent
+	 * irq_data. Instead of calling into the parent (which won't
+	 * exactly do the right thing, let's simply use the
+	 * parent_data pointer. Yes, I'm naughty.
+	 */
+	lpi_write_config(d->parent_data, LPI_PROP_ENABLED, 0);
+	its_vpe_send_inv(d);
+}
+
+static void its_vpe_unmask_irq(struct irq_data *d)
+{
+	/* Same hack as above... */
+	lpi_write_config(d->parent_data, 0, LPI_PROP_ENABLED);
+	its_vpe_send_inv(d);
+}
+
 static struct irq_chip its_vpe_irq_chip = {
 	.name			= "GICv4-vpe",
+	.irq_mask		= its_vpe_mask_irq,
+	.irq_unmask		= its_vpe_unmask_irq,
+	.irq_eoi		= irq_chip_eoi_parent,
 	.irq_set_affinity	= its_vpe_set_affinity,
 	.irq_set_vcpu_affinity	= its_vpe_set_vcpu_affinity,
 };
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 27/59] irqchip/gic-v3-its: Support VPE doorbell invalidation even when !DirectLPI
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (25 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 26/59] irqchip/gic-v3-its: Add VPE interrupt masking Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-07-31 17:26 ` [PATCH v3 28/59] irqchip/gic-v3-its: Allow doorbell interrupts to be injected/cleared Marc Zyngier
                   ` (31 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

When we don't have the DirectLPI feature, we must work around the
architecture shortcomings to be able to perform the required
invalidation.

For this, we create a fake device whose sole purpose is to
provide a way to issue a map/inv/unmap sequence (and the corresponding
sync operations). That's 6 commands and a full serialization point
to be able to do this.

You just have to hope the hypervisor won't do that too often...

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 73 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 70 insertions(+), 3 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index d871d105be9d..210840e0ec92 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -136,6 +136,9 @@ struct its_device {
 	u32			device_id;
 };
 
+static struct its_device *vpe_proxy_dev;
+static DEFINE_RAW_SPINLOCK(vpe_proxy_dev_lock);
+
 static LIST_HEAD(its_nodes);
 static DEFINE_SPINLOCK(its_lock);
 static struct rdists *gic_rdists;
@@ -2077,6 +2080,14 @@ static int its_msi_prepare(struct irq_domain *domain, struct device *dev,
 	msi_info = msi_get_domain_info(domain);
 	its = msi_info->data;
 
+	if (its->is_v4 && !gic_rdists->has_direct_lpi &&
+	    dev_id == vpe_proxy_dev->device_id) {
+		/* Bad luck. Get yourself a better implementation */
+		WARN_ONCE(1, "DevId %x clashes with GICv4 VPE proxy device\n",
+			  dev_id);
+		return -EINVAL;
+	}
+
 	its_dev = its_find_device(its, dev_id);
 	if (its_dev) {
 		/*
@@ -2330,13 +2341,48 @@ static int its_vpe_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
 	}
 }
 
+static void its_vpe_send_cmd(struct its_vpe *vpe,
+			     void (*cmd)(struct its_device *, u32))
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&vpe_proxy_dev_lock, flags);
+
+	vpe_proxy_dev->event_map.col_map[0] = vpe->col_idx;
+	its_send_mapti(vpe_proxy_dev, vpe->vpe_db_lpi, 0);
+	cmd(vpe_proxy_dev, 0);
+	its_send_discard(vpe_proxy_dev, 0);
+
+	raw_spin_unlock_irqrestore(&vpe_proxy_dev_lock, flags);
+}
+
 static void its_vpe_send_inv(struct irq_data *d)
 {
 	struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
-	void __iomem *rdbase;
 
-	rdbase = per_cpu_ptr(gic_rdists->rdist, vpe->col_idx)->rd_base;
-	gic_write_lpir(vpe->vpe_db_lpi, rdbase + GICR_INVLPIR);
+	if (gic_rdists->has_direct_lpi) {
+		void __iomem *rdbase;
+
+		rdbase = per_cpu_ptr(gic_rdists->rdist, vpe->col_idx)->rd_base;
+		gic_write_lpir(vpe->vpe_db_lpi, rdbase + GICR_INVLPIR);
+	} else {
+		/*
+		 * This is insane.
+		 *
+		 * If a GICv4 doesn't implement Direct LPIs (which is
+		 * extremely likely), the only way to perform an
+		 * invalidate is to use a fake device to issue a
+		 * MAP/INV/UNMAP sequence. Since each of these
+		 * commands has a sync operation, this is really
+		 * fast. Not.
+		 *
+		 * We always use event 0, and thus serialize all VPE
+		 * invalidations in the system.
+		 *
+		 * Broken by design(tm).
+		 */
+		its_vpe_send_cmd(vpe, its_send_inv);
+	}
 }
 
 static void its_vpe_mask_irq(struct irq_data *d)
@@ -2638,6 +2684,27 @@ static int its_init_domain(struct fwnode_handle *handle, struct its_node *its)
 
 static int its_init_vpe_domain(void)
 {
+	struct its_node *its;
+	u32 devid;
+
+	if (gic_rdists->has_direct_lpi) {
+		pr_info("ITS: Using DirectLPI for VPE invalidation\n");
+		return 0;
+	}
+
+	/* Any ITS will do, even if not v4 */
+	its = list_first_entry(&its_nodes, struct its_node, entry);
+
+	/* Use the last possible DevID */
+	devid = GENMASK(its->device_ids - 1, 0);
+	vpe_proxy_dev = its_create_device(its, devid, 1);
+	if (!vpe_proxy_dev) {
+		pr_err("ITS: Can't allocate GICv4 proxy device\n");
+		return -ENODEV;
+	}
+
+	pr_info("ITS: Allocated DevID %x as GICv4 proxy device\n", devid);
+
 	return 0;
 }
 
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 28/59] irqchip/gic-v3-its: Allow doorbell interrupts to be injected/cleared
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (26 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 27/59] irqchip/gic-v3-its: Support VPE doorbell invalidation even when !DirectLPI Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-07-31 17:26 ` [PATCH v3 29/59] irqchip/gic-v3-its: Set implementation defined bit to enable VLPIs Marc Zyngier
                   ` (30 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

While the doorbell interrupts are usually driven by the HW itself,
having a way to trigger them independently has proved to be a
really useful debug feature. As it is actually very little code,
let's add it to the VPE irqchip operations.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 210840e0ec92..a177af0b1657 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -2404,12 +2404,41 @@ static void its_vpe_unmask_irq(struct irq_data *d)
 	its_vpe_send_inv(d);
 }
 
+/* This is really a debug feature */
+static int its_vpe_set_irqchip_state(struct irq_data *d,
+				     enum irqchip_irq_state which,
+				     bool state)
+{
+	struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
+
+	if (which != IRQCHIP_STATE_PENDING)
+		return -EINVAL;
+
+	if (gic_rdists->has_direct_lpi) {
+		void __iomem *rdbase;
+
+		rdbase = per_cpu_ptr(gic_rdists->rdist, vpe->col_idx)->rd_base;
+		if (state)
+			gic_write_lpir(vpe->vpe_db_lpi, rdbase + GICR_SETLPIR);
+		else
+			gic_write_lpir(vpe->vpe_db_lpi, rdbase + GICR_CLRLPIR);
+	} else {
+		if (state)
+			its_vpe_send_cmd(vpe, its_send_int);
+		else
+			its_vpe_send_cmd(vpe, its_send_clear);
+	}
+
+	return 0;
+}
+
 static struct irq_chip its_vpe_irq_chip = {
 	.name			= "GICv4-vpe",
 	.irq_mask		= its_vpe_mask_irq,
 	.irq_unmask		= its_vpe_unmask_irq,
 	.irq_eoi		= irq_chip_eoi_parent,
 	.irq_set_affinity	= its_vpe_set_affinity,
+	.irq_set_irqchip_state	= its_vpe_set_irqchip_state,
 	.irq_set_vcpu_affinity	= its_vpe_set_vcpu_affinity,
 };
 
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 29/59] irqchip/gic-v3-its: Set implementation defined bit to enable VLPIs
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (27 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 28/59] irqchip/gic-v3-its: Allow doorbell interrupts to be injected/cleared Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-07-31 17:26 ` [PATCH v3 30/59] irqchip/gic-v4: Add per-VM VPE domain creation Marc Zyngier
                   ` (29 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

A long time ago, GITS_CTLR[1] used to be called GITC_CTLR.EnableVLPI.
It has been subsequently deprecated and is now an "Implementation
Defined" bit that may ot may not be set for GICv4. Brilliant.

And the current crop of the FastModel requires that bit for VLPIs
to be enabled. Oh well... Let's set it and find out what breaks.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c   | 7 +++++--
 include/linux/irqchip/arm-gic-v3.h | 1 +
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index a177af0b1657..a5b1317d89eb 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -2610,7 +2610,7 @@ static int its_force_quiescent(void __iomem *base)
 		return 0;
 
 	/* Disable the generation of all interrupts to this ITS */
-	val &= ~GITS_CTLR_ENABLE;
+	val &= ~(GITS_CTLR_ENABLE | GITS_CTLR_ImDe);
 	writel_relaxed(val, base + GITS_CTLR);
 
 	/* Poll GITS_CTLR and wait until ITS becomes quiescent */
@@ -2879,7 +2879,10 @@ static int __init its_probe_one(struct resource *res,
 
 	gits_write_cwriter(0, its->base + GITS_CWRITER);
 	ctlr = readl_relaxed(its->base + GITS_CTLR);
-	writel_relaxed(ctlr | GITS_CTLR_ENABLE, its->base + GITS_CTLR);
+	ctlr |= GITS_CTLR_ENABLE;
+	if (its->is_v4)
+		ctlr |= GITS_CTLR_ImDe;
+	writel_relaxed(ctlr, its->base + GITS_CTLR);
 
 	err = its_init_domain(handle, its);
 	if (err)
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index 6bc142cfa616..1ea576c8126f 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -298,6 +298,7 @@
 #define GITS_TRANSLATER			0x10040
 
 #define GITS_CTLR_ENABLE		(1U << 0)
+#define GITS_CTLR_ImDe			(1U << 1)
 #define	GITS_CTLR_ITS_NUMBER_SHIFT	4
 #define	GITS_CTLR_ITS_NUMBER		(0xFU << GITS_CTLR_ITS_NUMBER_SHIFT)
 #define GITS_CTLR_QUIESCENT		(1U << 31)
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 30/59] irqchip/gic-v4: Add per-VM VPE domain creation
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (28 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 29/59] irqchip/gic-v3-its: Set implementation defined bit to enable VLPIs Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-07-31 17:26 ` [PATCH v3 31/59] irqchip/gic-v4: Add VPE command interface Marc Zyngier
                   ` (28 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

When creating a VM, it is very convenient to have an irq domain
containing all the doorbell interrupts associated with that VM
(each interrupt representing a VPE).

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v4.c       | 73 ++++++++++++++++++++++++++++++++++++++
 include/linux/irqchip/arm-gic-v4.h |  3 ++
 2 files changed, 76 insertions(+)
 create mode 100644 drivers/irqchip/irq-gic-v4.c

diff --git a/drivers/irqchip/irq-gic-v4.c b/drivers/irqchip/irq-gic-v4.c
new file mode 100644
index 000000000000..f7fe6181ec8d
--- /dev/null
+++ b/drivers/irqchip/irq-gic-v4.c
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2016,2017 ARM Limited, All Rights Reserved.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/msi.h>
+
+#include <linux/irqchip/arm-gic-v4.h>
+
+static struct irq_domain *gic_domain;
+static const struct irq_domain_ops *vpe_domain_ops;
+
+int its_alloc_vcpu_irqs(struct its_vm *vm)
+{
+	int vpe_base_irq, i;
+
+	vm->fwnode = irq_domain_alloc_named_id_fwnode("GICv4-vpe",
+						      task_pid_nr(current));
+	if (!vm->fwnode)
+		goto err;
+
+	vm->domain = irq_domain_create_hierarchy(gic_domain, 0, vm->nr_vpes,
+						 vm->fwnode, vpe_domain_ops,
+						 vm);
+	if (!vm->domain)
+		goto err;
+
+	for (i = 0; i < vm->nr_vpes; i++) {
+		vm->vpes[i]->its_vm = vm;
+		vm->vpes[i]->idai = true;
+	}
+
+	vpe_base_irq = __irq_domain_alloc_irqs(vm->domain, -1, vm->nr_vpes,
+					       NUMA_NO_NODE, vm,
+					       false, NULL);
+	if (vpe_base_irq <= 0)
+		goto err;
+
+	for (i = 0; i < vm->nr_vpes; i++)
+		vm->vpes[i]->irq = vpe_base_irq + i;
+
+	return 0;
+
+err:
+	if (vm->domain)
+		irq_domain_remove(vm->domain);
+	if (vm->fwnode)
+		irq_domain_free_fwnode(vm->fwnode);
+
+	return -ENOMEM;
+}
+
+void its_free_vcpu_irqs(struct its_vm *vm)
+{
+	irq_domain_free_irqs(vm->vpes[0]->irq, vm->nr_vpes);
+	irq_domain_remove(vm->domain);
+	irq_domain_free_fwnode(vm->fwnode);
+}
diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h
index 5ba0fb6b094d..b31fb8aeba03 100644
--- a/include/linux/irqchip/arm-gic-v4.h
+++ b/include/linux/irqchip/arm-gic-v4.h
@@ -89,4 +89,7 @@ struct its_cmd_info {
 	};
 };
 
+int its_alloc_vcpu_irqs(struct its_vm *vm);
+void its_free_vcpu_irqs(struct its_vm *vm);
+
 #endif
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 31/59] irqchip/gic-v4: Add VPE command interface
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (29 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 30/59] irqchip/gic-v4: Add per-VM VPE domain creation Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-07-31 17:26 ` [PATCH v3 32/59] irqchip/gic-v4: Add VLPI configuration interface Marc Zyngier
                   ` (27 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm
  Cc: Christoffer Dall, Thomas Gleixner, Jason Cooper, Eric Auger,
	Shanker Donthineni, Mark Rutland, Shameerali Kolothum Thodi

Add the required interfaces to schedule a VPE and perform a
VINVALL command.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v4.c       | 25 +++++++++++++++++++++++++
 include/linux/irqchip/arm-gic-v4.h |  2 ++
 2 files changed, 27 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v4.c b/drivers/irqchip/irq-gic-v4.c
index f7fe6181ec8d..86b46fb532ab 100644
--- a/drivers/irqchip/irq-gic-v4.c
+++ b/drivers/irqchip/irq-gic-v4.c
@@ -71,3 +71,28 @@ void its_free_vcpu_irqs(struct its_vm *vm)
 	irq_domain_remove(vm->domain);
 	irq_domain_free_fwnode(vm->fwnode);
 }
+
+static int its_send_vpe_cmd(struct its_vpe *vpe, struct its_cmd_info *info)
+{
+	return irq_set_vcpu_affinity(vpe->irq, info);
+}
+
+int its_schedule_vpe(struct its_vpe *vpe, bool on)
+{
+	struct its_cmd_info info;
+
+	WARN_ON(preemptible());
+
+	info.cmd_type = on ? SCHEDULE_VPE : DESCHEDULE_VPE;
+
+	return its_send_vpe_cmd(vpe, &info);
+}
+
+int its_invall_vpe(struct its_vpe *vpe)
+{
+	struct its_cmd_info info = {
+		.cmd_type = INVALL_VPE,
+	};
+
+	return its_send_vpe_cmd(vpe, &info);
+}
diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h
index b31fb8aeba03..faaafd12d8c7 100644
--- a/include/linux/irqchip/arm-gic-v4.h
+++ b/include/linux/irqchip/arm-gic-v4.h
@@ -91,5 +91,7 @@ struct its_cmd_info {
 
 int its_alloc_vcpu_irqs(struct its_vm *vm);
 void its_free_vcpu_irqs(struct its_vm *vm);
+int its_schedule_vpe(struct its_vpe *vpe, bool on);
+int its_invall_vpe(struct its_vpe *vpe);
 
 #endif
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 32/59] irqchip/gic-v4: Add VLPI configuration interface
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (30 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 31/59] irqchip/gic-v4: Add VPE command interface Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-07-31 17:26 ` [PATCH v3 33/59] irqchip/gic-v4: Add some basic documentation Marc Zyngier
                   ` (26 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Add the required interfaces to map, unmap and update a VLPI.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v4.c       | 42 ++++++++++++++++++++++++++++++++++++++
 include/linux/irqchip/arm-gic-v4.h |  4 ++++
 2 files changed, 46 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v4.c b/drivers/irqchip/irq-gic-v4.c
index 86b46fb532ab..6fe2e09172ed 100644
--- a/drivers/irqchip/irq-gic-v4.c
+++ b/drivers/irqchip/irq-gic-v4.c
@@ -96,3 +96,45 @@ int its_invall_vpe(struct its_vpe *vpe)
 
 	return its_send_vpe_cmd(vpe, &info);
 }
+
+int its_map_vlpi(int irq, struct its_vlpi_map *map)
+{
+	struct its_cmd_info info = {
+		.cmd_type = MAP_VLPI,
+		.map      = map,
+	};
+
+	/*
+	 * The host will never see that interrupt firing again, so it
+	 * is vital that we don't do any lazy masking.
+	 */
+	irq_set_status_flags(irq, IRQ_DISABLE_UNLAZY);
+
+	return irq_set_vcpu_affinity(irq, &info);
+}
+
+int its_get_vlpi(int irq, struct its_vlpi_map *map)
+{
+	struct its_cmd_info info = {
+		.cmd_type = GET_VLPI,
+		.map      = map,
+	};
+
+	return irq_set_vcpu_affinity(irq, &info);
+}
+
+int its_unmap_vlpi(int irq)
+{
+	irq_clear_status_flags(irq, IRQ_DISABLE_UNLAZY);
+	return irq_set_vcpu_affinity(irq, NULL);
+}
+
+int its_prop_update_vlpi(int irq, u8 config, bool inv)
+{
+	struct its_cmd_info info = {
+		.cmd_type = inv ? PROP_UPDATE_AND_INV_VLPI : PROP_UPDATE_VLPI,
+		.config   = config,
+	};
+
+	return irq_set_vcpu_affinity(irq, &info);
+}
diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h
index faaafd12d8c7..f495d4d1f7d7 100644
--- a/include/linux/irqchip/arm-gic-v4.h
+++ b/include/linux/irqchip/arm-gic-v4.h
@@ -93,5 +93,9 @@ int its_alloc_vcpu_irqs(struct its_vm *vm);
 void its_free_vcpu_irqs(struct its_vm *vm);
 int its_schedule_vpe(struct its_vpe *vpe, bool on);
 int its_invall_vpe(struct its_vpe *vpe);
+int its_map_vlpi(int irq, struct its_vlpi_map *map);
+int its_get_vlpi(int irq, struct its_vlpi_map *map);
+int its_unmap_vlpi(int irq);
+int its_prop_update_vlpi(int irq, u8 config, bool inv);
 
 #endif
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 33/59] irqchip/gic-v4: Add some basic documentation
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (31 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 32/59] irqchip/gic-v4: Add VLPI configuration interface Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-07-31 17:26 ` [PATCH v3 34/59] irqchip/gic-v4: Enable low-level GICv4 operations Marc Zyngier
                   ` (25 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Do a braindump of the way things are supposed to work.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v4.c | 71 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v4.c b/drivers/irqchip/irq-gic-v4.c
index 6fe2e09172ed..d10d73477d01 100644
--- a/drivers/irqchip/irq-gic-v4.c
+++ b/drivers/irqchip/irq-gic-v4.c
@@ -22,6 +22,77 @@
 
 #include <linux/irqchip/arm-gic-v4.h>
 
+/*
+ * WARNING: The blurb below assumes that you understand the
+ * intricacies of GICv3, GICv4, and how a guest's view of a GICv3 gets
+ * translated into GICv4 commands. So it effectively targets at most
+ * two individuals. You know who you are.
+ *
+ * The core GICv4 code is designed to *avoid* exposing too much of the
+ * core GIC code (that would in turn leak into the hypervisor code),
+ * and instead provide a hypervisor agnostic interface to the HW (of
+ * course, the astute reader will quickly realize that hypervisor
+ * agnostic actually means KVM-specific - what were you thinking?).
+ *
+ * In order to achieve a modicum of isolation, we try to hide most of
+ * the GICv4 "stuff" behind normal irqchip operations:
+ *
+ * - Any guest-visible VLPI is backed by a Linux interrupt (and a
+ *   physical LPI which gets unmapped when the guest maps the
+ *   VLPI). This allows the same DevID/EventID pair to be either
+ *   mapped to the LPI (host) or the VLPI (guest). Note that this is
+ *   exclusive, and you cannot have both.
+ *
+ * - Enabling/disabling a VLPI is done by issuing mask/unmask calls.
+ *
+ * - Guest INT/CLEAR commands are implemented through
+ *   irq_set_irqchip_state().
+ *
+ * - The *bizarre* stuff (mapping/unmapping an interrupt to a VLPI, or
+ *   issuing an INV after changing a priority) gets shoved into the
+ *   irq_set_vcpu_affinity() method. While this is quite horrible
+ *   (let's face it, this is the irqchip version of an ioctl), it
+ *   confines the crap to a single location. And map/unmap really is
+ *   about setting the affinity of a VLPI to a vcpu, so only INV is
+ *   majorly out of place. So there.
+ *
+ * A number of commands are simply not provided by this interface, as
+ * they do not make direct sense. For example, MAPD is purely local to
+ * the virtual ITS (because it references a virtual device, and the
+ * physical ITS is still very much in charge of the physical
+ * device). Same goes for things like MAPC (the physical ITS deals
+ * with the actual vPE affinity, and not the braindead concept of
+ * collection). SYNC is not provided either, as each and every command
+ * is followed by a VSYNC. This could be relaxed in the future, should
+ * this be seen as a bottleneck (yes, this means *never*).
+ *
+ * But handling VLPIs is only one side of the job of the GICv4
+ * code. The other (darker) side is to take care of the doorbell
+ * interrupts which are delivered when a VLPI targeting a non-running
+ * vcpu is being made pending.
+ *
+ * The choice made here is that each vcpu (VPE in old northern GICv4
+ * dialect) gets a single doorbell LPI, no matter how many interrupts
+ * are targeting it. This has a nice property, which is that the
+ * interrupt becomes a handle for the VPE, and that the hypervisor
+ * code can manipulate it through the normal interrupt API:
+ *
+ * - VMs (or rather the VM abstraction that matters to the GIC)
+ *   contain an irq domain where each interrupt maps to a VPE. In
+ *   turn, this domain sits on top of the normal LPI allocator, and a
+ *   specially crafted irq_chip implementation.
+ *
+ * - mask/unmask do what is expected on the doorbell interrupt.
+ *
+ * - irq_set_affinity is used to move a VPE from one redistributor to
+ *   another.
+ *
+ * - irq_set_vcpu_affinity once again gets hijacked for the purpose of
+ *   creating a new sub-API, namely scheduling/descheduling a VPE
+ *   (which involves programming GICR_V{PROP,PEND}BASER) and
+ *   performing INVALL operations.
+ */
+
 static struct irq_domain *gic_domain;
 static const struct irq_domain_ops *vpe_domain_ops;
 
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 34/59] irqchip/gic-v4: Enable low-level GICv4 operations
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (32 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 33/59] irqchip/gic-v4: Add some basic documentation Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-07-31 17:26 ` [PATCH v3 35/59] irqchip/gic-v3: Advertise GICv4 support to KVM Marc Zyngier
                   ` (24 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Get the show on the road...

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/Makefile           |  2 +-
 drivers/irqchip/irq-gic-v3-its.c   |  3 ++-
 drivers/irqchip/irq-gic-v4.c       | 13 +++++++++++++
 include/linux/irqchip/arm-gic-v4.h |  2 ++
 4 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index e88d856cc09c..7dd05ad6bcfb 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -28,7 +28,7 @@ obj-$(CONFIG_ARM_GIC_PM)		+= irq-gic-pm.o
 obj-$(CONFIG_ARCH_REALVIEW)		+= irq-gic-realview.o
 obj-$(CONFIG_ARM_GIC_V2M)		+= irq-gic-v2m.o
 obj-$(CONFIG_ARM_GIC_V3)		+= irq-gic-v3.o irq-gic-common.o
-obj-$(CONFIG_ARM_GIC_V3_ITS)		+= irq-gic-v3-its.o irq-gic-v3-its-pci-msi.o irq-gic-v3-its-platform-msi.o
+obj-$(CONFIG_ARM_GIC_V3_ITS)		+= irq-gic-v3-its.o irq-gic-v3-its-pci-msi.o irq-gic-v3-its-platform-msi.o irq-gic-v4.o
 obj-$(CONFIG_PARTITION_PERCPU)		+= irq-partition-percpu.o
 obj-$(CONFIG_HISILICON_IRQ_MBIGEN)	+= irq-mbigen.o
 obj-$(CONFIG_ARM_NVIC)			+= irq-nvic.o
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index a5b1317d89eb..9f32cd42238f 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -3109,7 +3109,8 @@ int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,
 		has_v4 |= its->is_v4;
 
 	if (has_v4 & rdists->has_vlpis) {
-		if (its_init_vpe_domain()) {
+		if (its_init_vpe_domain() ||
+		    its_init_v4(parent_domain, &its_vpe_domain_ops)) {
 			rdists->has_vlpis = false;
 			pr_err("ITS: Disabling GICv4 support\n");
 		}
diff --git a/drivers/irqchip/irq-gic-v4.c b/drivers/irqchip/irq-gic-v4.c
index d10d73477d01..400d9bbb0e56 100644
--- a/drivers/irqchip/irq-gic-v4.c
+++ b/drivers/irqchip/irq-gic-v4.c
@@ -209,3 +209,16 @@ int its_prop_update_vlpi(int irq, u8 config, bool inv)
 
 	return irq_set_vcpu_affinity(irq, &info);
 }
+
+int its_init_v4(struct irq_domain *domain, const struct irq_domain_ops *ops)
+{
+	if (domain) {
+		pr_info("ITS: Enabling GICv4 support\n");
+		gic_domain = domain;
+		vpe_domain_ops = ops;
+		return 0;
+	}
+
+	pr_err("ITS: No GICv4 VPE domain allocated\n");
+	return -ENODEV;
+}
diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h
index f495d4d1f7d7..3cf72af2c796 100644
--- a/include/linux/irqchip/arm-gic-v4.h
+++ b/include/linux/irqchip/arm-gic-v4.h
@@ -98,4 +98,6 @@ int its_get_vlpi(int irq, struct its_vlpi_map *map);
 int its_unmap_vlpi(int irq);
 int its_prop_update_vlpi(int irq, u8 config, bool inv);
 
+int its_init_v4(struct irq_domain *domain, const struct irq_domain_ops *ops);
+
 #endif
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 35/59] irqchip/gic-v3: Advertise GICv4 support to KVM
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (33 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 34/59] irqchip/gic-v4: Enable low-level GICv4 operations Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-07-31 17:26 ` [PATCH v3 36/59] KVM: arm: Select ARM_GIC_V3 and ARM_GIC_V3_ITS Marc Zyngier
                   ` (23 subsequent siblings)
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm
  Cc: Christoffer Dall, Thomas Gleixner, Jason Cooper, Eric Auger,
	Shanker Donthineni, Mark Rutland, Shameerali Kolothum Thodi

As KVM needs to know about the availability of GICv4 to enable
direct injection of interrupts, let's advertise the feature in
the gic_kvm_info structure.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3.c           | 2 ++
 include/linux/irqchip/arm-gic-common.h | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 17f0ad41864f..e2b8409dd76e 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -1159,6 +1159,7 @@ static void __init gic_of_setup_kvm_info(struct device_node *node)
 	if (!ret)
 		gic_v3_kvm_info.vcpu = r;
 
+	gic_v3_kvm_info.has_v4 = gic_data.rdists.has_vlpis;
 	gic_set_kvm_info(&gic_v3_kvm_info);
 }
 
@@ -1455,6 +1456,7 @@ static void __init gic_acpi_setup_kvm_info(void)
 		vcpu->end = vcpu->start + ACPI_GICV2_VCPU_MEM_SIZE - 1;
 	}
 
+	gic_v3_kvm_info.has_v4 = gic_data.rdists.has_vlpis;
 	gic_set_kvm_info(&gic_v3_kvm_info);
 }
 
diff --git a/include/linux/irqchip/arm-gic-common.h b/include/linux/irqchip/arm-gic-common.h
index c647b0547bcd..0a83b4379f34 100644
--- a/include/linux/irqchip/arm-gic-common.h
+++ b/include/linux/irqchip/arm-gic-common.h
@@ -27,6 +27,8 @@ struct gic_kvm_info {
 	unsigned int	maint_irq;
 	/* Virtual control interface */
 	struct resource vctrl;
+	/* vlpi support */
+	bool		has_v4;
 };
 
 const struct gic_kvm_info *gic_get_kvm_info(void);
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 36/59] KVM: arm: Select ARM_GIC_V3 and ARM_GIC_V3_ITS
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (34 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 35/59] irqchip/gic-v3: Advertise GICv4 support to KVM Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-26 19:49   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 37/59] KVM: arm/arm64: vgic: Move kvm_vgic_destroy call around Marc Zyngier
                   ` (22 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

The GICv4 support introduces a hard dependency between the KVM
core and the ITS infrastructure. arm64 already selects it at
the architecture level, but 32bit doesn't. In order to avoid
littering the kernel with #ifdefs, let's just select the whole
of the GICv3 suport code.

You know you want it.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 arch/arm/kvm/Kconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig
index 4e2b192a030a..52b50af04e3b 100644
--- a/arch/arm/kvm/Kconfig
+++ b/arch/arm/kvm/Kconfig
@@ -23,6 +23,8 @@ config KVM
 	select PREEMPT_NOTIFIERS
 	select ANON_INODES
 	select ARM_GIC
+	select ARM_GIC_V3
+	select ARM_GIC_V3_ITS
 	select HAVE_KVM_CPU_RELAX_INTERCEPT
 	select HAVE_KVM_ARCH_TLB_FLUSH_ALL
 	select KVM_MMIO
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 37/59] KVM: arm/arm64: vgic: Move kvm_vgic_destroy call around
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (35 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 36/59] KVM: arm: Select ARM_GIC_V3 and ARM_GIC_V3_ITS Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-26 19:49   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 38/59] KVM: arm/arm64: vITS: Add MSI translation helpers Marc Zyngier
                   ` (21 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

The way we call kvm_vgic_destroy is a bit bizarre. We call it
*after* having freed the vcpus, which sort of defeats the point
of cleaning up things before that point.

Let's move kvm_vgic_destroy towards the beginning of kvm_arch_destroy_vm,
which seems more sensible.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/arm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 7846a578db1a..ebab6c29e3be 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -177,6 +177,8 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 {
 	int i;
 
+	kvm_vgic_destroy(kvm);
+
 	free_percpu(kvm->arch.last_vcpu_ran);
 	kvm->arch.last_vcpu_ran = NULL;
 
@@ -186,8 +188,6 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 			kvm->vcpus[i] = NULL;
 		}
 	}
-
-	kvm_vgic_destroy(kvm);
 }
 
 int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 38/59] KVM: arm/arm64: vITS: Add MSI translation helpers
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (36 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 37/59] KVM: arm/arm64: vgic: Move kvm_vgic_destroy call around Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-26 19:49   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 39/59] KVM: arm/arm64: GICv4: Add property field and per-VM predicate Marc Zyngier
                   ` (20 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

The whole MSI injection process is fairly monolithic. An MSI write
gets turned into an injected LPI in one swift go. But this is actually
a more fine-grained process:

- First, a virtual ITS gets selected using the doorbell address
- Then the DevID/EventID pair gets translated into an LPI
- Finally the LPI is injected

Since the GICv4 code needs the first two steps in order to match
an IRQ routing entry to an LPI, let's expose them as helpers,
and refactor the existing code to use them

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/vgic/vgic-its.c | 93 +++++++++++++++++++++++++-------------------
 virt/kvm/arm/vgic/vgic.h     |  4 ++
 2 files changed, 57 insertions(+), 40 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index aa6b68db80b4..fb7be8673bff 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -504,15 +504,8 @@ static unsigned long vgic_mmio_read_its_idregs(struct kvm *kvm,
 	return 0;
 }
 
-/*
- * Find the target VCPU and the LPI number for a given devid/eventid pair
- * and make this IRQ pending, possibly injecting it.
- * Must be called with the its_lock mutex held.
- * Returns 0 on success, a positive error value for any ITS mapping
- * related errors and negative error values for generic errors.
- */
-static int vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its,
-				u32 devid, u32 eventid)
+int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
+			 u32 devid, u32 eventid, struct vgic_irq **irq)
 {
 	struct kvm_vcpu *vcpu;
 	struct its_ite *ite;
@@ -531,26 +524,60 @@ static int vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its,
 	if (!vcpu->arch.vgic_cpu.lpis_enabled)
 		return -EBUSY;
 
-	spin_lock(&ite->irq->irq_lock);
-	ite->irq->pending_latch = true;
-	vgic_queue_irq_unlock(kvm, ite->irq);
-
+	*irq = ite->irq;
 	return 0;
 }
 
-static struct vgic_io_device *vgic_get_its_iodev(struct kvm_io_device *dev)
+struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi)
 {
+	u64 address;
+	struct kvm_io_device *kvm_io_dev;
 	struct vgic_io_device *iodev;
 
-	if (dev->ops != &kvm_io_gic_ops)
-		return NULL;
+	if (!vgic_has_its(kvm))
+		return ERR_PTR(-ENODEV);
 
-	iodev = container_of(dev, struct vgic_io_device, dev);
+	if (!(msi->flags & KVM_MSI_VALID_DEVID))
+		return ERR_PTR(-EINVAL);
+
+	address = (u64)msi->address_hi << 32 | msi->address_lo;
+
+	kvm_io_dev = kvm_io_bus_get_dev(kvm, KVM_MMIO_BUS, address);
+	if (!kvm_io_dev)
+		return ERR_PTR(-EINVAL);
 
+	if (kvm_io_dev->ops != &kvm_io_gic_ops)
+		return ERR_PTR(-EINVAL);
+
+	iodev = container_of(kvm_io_dev, struct vgic_io_device, dev);
 	if (iodev->iodev_type != IODEV_ITS)
-		return NULL;
+		return ERR_PTR(-EINVAL);
 
-	return iodev;
+	return iodev->its;
+}
+
+/*
+ * Find the target VCPU and the LPI number for a given devid/eventid pair
+ * and make this IRQ pending, possibly injecting it.
+ * Must be called with the its_lock mutex held.
+ * Returns 0 on success, a positive error value for any ITS mapping
+ * related errors and negative error values for generic errors.
+ */
+static int vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its,
+				u32 devid, u32 eventid)
+{
+	struct vgic_irq *irq = NULL;
+	int err;
+
+	err = vgic_its_resolve_lpi(kvm, its, devid, eventid, &irq);
+	if (err)
+		return err;
+
+	spin_lock(&irq->irq_lock);
+	irq->pending_latch = true;
+	vgic_queue_irq_unlock(kvm, irq);
+
+	return 0;
 }
 
 /*
@@ -561,30 +588,16 @@ static struct vgic_io_device *vgic_get_its_iodev(struct kvm_io_device *dev)
  */
 int vgic_its_inject_msi(struct kvm *kvm, struct kvm_msi *msi)
 {
-	u64 address;
-	struct kvm_io_device *kvm_io_dev;
-	struct vgic_io_device *iodev;
+	struct vgic_its *its;
 	int ret;
 
-	if (!vgic_has_its(kvm))
-		return -ENODEV;
-
-	if (!(msi->flags & KVM_MSI_VALID_DEVID))
-		return -EINVAL;
-
-	address = (u64)msi->address_hi << 32 | msi->address_lo;
-
-	kvm_io_dev = kvm_io_bus_get_dev(kvm, KVM_MMIO_BUS, address);
-	if (!kvm_io_dev)
-		return -EINVAL;
+	its = vgic_msi_to_its(kvm, msi);
+	if (IS_ERR(its))
+		return PTR_ERR(its);
 
-	iodev = vgic_get_its_iodev(kvm_io_dev);
-	if (!iodev)
-		return -EINVAL;
-
-	mutex_lock(&iodev->its->its_lock);
-	ret = vgic_its_trigger_msi(kvm, iodev->its, msi->devid, msi->data);
-	mutex_unlock(&iodev->its->its_lock);
+	mutex_lock(&its->its_lock);
+	ret = vgic_its_trigger_msi(kvm, its, msi->devid, msi->data);
+	mutex_unlock(&its->its_lock);
 
 	if (ret < 0)
 		return ret;
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index da254ae29aec..3002b72d938b 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -225,4 +225,8 @@ int vgic_debug_destroy(struct kvm *kvm);
 bool lock_all_vcpus(struct kvm *kvm);
 void unlock_all_vcpus(struct kvm *kvm);
 
+int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
+			 u32 devid, u32 eventid, struct vgic_irq **irq);
+struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi);
+
 #endif
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 39/59] KVM: arm/arm64: GICv4: Add property field and per-VM predicate
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (37 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 38/59] KVM: arm/arm64: vITS: Add MSI translation helpers Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-26 19:49   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 40/59] KVM: arm/arm64: GICv4: Add init/teardown of the per-VM vPE irq domain Marc Zyngier
                   ` (19 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Add a new has_gicv4 field in the global VGIC state that indicates
whether the HW is GICv4 capable, as a per-VM predicate indicating
if there is a possibility for a VM to support direct injection
(the above being true and the VM having an ITS).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 include/kvm/arm_vgic.h           | 3 +++
 virt/kvm/arm/vgic/vgic-mmio-v3.c | 5 +++++
 virt/kvm/arm/vgic/vgic.h         | 2 ++
 3 files changed, 10 insertions(+)

diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index ee8587c8c715..84694b42373a 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -73,6 +73,9 @@ struct vgic_global {
 	/* Only needed for the legacy KVM_CREATE_IRQCHIP */
 	bool			can_emulate_gicv2;
 
+	/* Does have GICv4? */
+	bool			has_gicv4;
+
 	/* GIC system register CPU interface */
 	struct static_key_false gicv3_cpuif;
 
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index 714fa3933546..74109ca75cc0 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -54,6 +54,11 @@ bool vgic_has_its(struct kvm *kvm)
 	return dist->has_its;
 }
 
+bool vgic_is_v4_capable(struct kvm *kvm)
+{
+	return kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm);
+}
+
 static unsigned long vgic_mmio_read_v3_misc(struct kvm_vcpu *vcpu,
 					    gpa_t addr, unsigned int len)
 {
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 3002b72d938b..90f6436a11aa 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -229,4 +229,6 @@ int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
 			 u32 devid, u32 eventid, struct vgic_irq **irq);
 struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi);
 
+bool vgic_is_v4_capable(struct kvm *kvm);
+
 #endif
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 40/59] KVM: arm/arm64: GICv4: Add init/teardown of the per-VM vPE irq domain
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (38 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 39/59] KVM: arm/arm64: GICv4: Add property field and per-VM predicate Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-26 19:49   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass Marc Zyngier
                   ` (18 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm
  Cc: Christoffer Dall, Thomas Gleixner, Jason Cooper, Eric Auger,
	Shanker Donthineni, Mark Rutland, Shameerali Kolothum Thodi

In order to control the GICv4 view of virtual CPUs, we rely
on an irqdomain allocated for that purpose. Let's add a couple
of helpers to that effect.

At the same time, the vgic data structures gain new fields to
track all this... erm... wonderful stuff.

They way we hook into the vgic init is slightly convoluted. We
need the vgic to be initialized (in order to guarantee that
the number of vcpus is now fixed), and we must have a vITS
(otherwise this is all very pointless). So we end-up calling
the init from both sites...

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 arch/arm/kvm/Makefile         |  1 +
 arch/arm64/kvm/Makefile       |  1 +
 include/kvm/arm_vgic.h        |  8 +++++
 virt/kvm/arm/vgic/vgic-init.c |  9 ++++++
 virt/kvm/arm/vgic/vgic-its.c  |  8 +++++
 virt/kvm/arm/vgic/vgic-v4.c   | 74 +++++++++++++++++++++++++++++++++++++++++++
 virt/kvm/arm/vgic/vgic.h      |  2 ++
 7 files changed, 103 insertions(+)
 create mode 100644 virt/kvm/arm/vgic/vgic-v4.c

diff --git a/arch/arm/kvm/Makefile b/arch/arm/kvm/Makefile
index d9beee652d36..0a1dd2cdb928 100644
--- a/arch/arm/kvm/Makefile
+++ b/arch/arm/kvm/Makefile
@@ -31,6 +31,7 @@ obj-y += $(KVM)/arm/vgic/vgic-init.o
 obj-y += $(KVM)/arm/vgic/vgic-irqfd.o
 obj-y += $(KVM)/arm/vgic/vgic-v2.o
 obj-y += $(KVM)/arm/vgic/vgic-v3.o
+obj-y += $(KVM)/arm/vgic/vgic-v4.o
 obj-y += $(KVM)/arm/vgic/vgic-mmio.o
 obj-y += $(KVM)/arm/vgic/vgic-mmio-v2.o
 obj-y += $(KVM)/arm/vgic/vgic-mmio-v3.o
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index 5d9810086c25..c30fd388ef80 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -26,6 +26,7 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-init.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-irqfd.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-v2.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-v3.o
+kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-v4.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio-v2.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio-v3.o
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 84694b42373a..359eeffe9857 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -26,6 +26,8 @@
 #include <linux/list.h>
 #include <linux/jump_label.h>
 
+#include <linux/irqchip/arm-gic-v4.h>
+
 #define VGIC_V3_MAX_CPUS	255
 #define VGIC_V2_MAX_CPUS	8
 #define VGIC_NR_IRQS_LEGACY     256
@@ -236,6 +238,9 @@ struct vgic_dist {
 
 	/* used by vgic-debug */
 	struct vgic_state_iter *iter;
+
+	/* GICv4 ITS per-VM stuff */
+	struct its_vm		its_vm;
 };
 
 struct vgic_v2_cpu_if {
@@ -254,6 +259,9 @@ struct vgic_v3_cpu_if {
 	u32		vgic_ap0r[4];
 	u32		vgic_ap1r[4];
 	u64		vgic_lr[VGIC_V3_MAX_LRS];
+
+	/* GICv4 vPE info */
+	struct its_vpe	its_vpe;
 };
 
 struct vgic_cpu {
diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
index 5801261f3add..d1c6c775203d 100644
--- a/virt/kvm/arm/vgic/vgic-init.c
+++ b/virt/kvm/arm/vgic/vgic-init.c
@@ -285,6 +285,12 @@ int vgic_init(struct kvm *kvm)
 	if (ret)
 		goto out;
 
+	if (vgic_has_its(kvm) && vgic_is_v4_capable(kvm)) {
+		ret = vgic_v4_init(kvm);
+		if (ret)
+			goto out;
+	}
+
 	kvm_for_each_vcpu(i, vcpu, kvm)
 		kvm_vgic_vcpu_enable(vcpu);
 
@@ -320,6 +326,9 @@ static void kvm_vgic_dist_destroy(struct kvm *kvm)
 
 	kfree(dist->spis);
 	dist->nr_spis = 0;
+
+	if (vgic_is_v4_capable(kvm))
+		vgic_v4_teardown(kvm);
 }
 
 void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index fb7be8673bff..a2217f53bbe5 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -1603,6 +1603,14 @@ static int vgic_its_create(struct kvm_device *dev, u32 type)
 	if (!its)
 		return -ENOMEM;
 
+	if (vgic_initialized(dev->kvm)) {
+		int ret = vgic_v4_init(dev->kvm);
+		if (ret) {
+			kfree(its);
+			return ret;
+		}
+	}
+	
 	mutex_init(&its->its_lock);
 	mutex_init(&its->cmd_lock);
 
diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
new file mode 100644
index 000000000000..207e1fda0dcd
--- /dev/null
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2017 ARM Ltd.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/kvm_host.h>
+
+#include "vgic.h"
+
+int vgic_v4_init(struct kvm *kvm)
+{
+	struct vgic_dist *dist = &kvm->arch.vgic;
+	struct kvm_vcpu *vcpu;
+	int i, nr_vcpus, ret;
+
+	/*
+	 * We may be called each time a vITS is created, or when the
+	 * vgic is initialized. This relies on kvm->lock to be
+	 * held. In both cases, the number of vcpus should now be
+	 * fixed.
+	 */
+	if (dist->its_vm.vpes)
+		return 0;
+
+	nr_vcpus = atomic_read(&kvm->online_vcpus);
+
+	dist->its_vm.vpes = kzalloc(sizeof(*dist->its_vm.vpes) * nr_vcpus,
+				    GFP_KERNEL);
+	if (!dist->its_vm.vpes)
+		return -ENOMEM;
+
+	dist->its_vm.nr_vpes = nr_vcpus;
+
+	kvm_for_each_vcpu(i, vcpu, kvm)
+		dist->its_vm.vpes[i] = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;
+
+	ret = its_alloc_vcpu_irqs(&dist->its_vm);
+	if (ret < 0) {
+		kvm_err("VPE IRQ allocation failure\n");
+		kfree(dist->its_vm.vpes);
+		dist->its_vm.nr_vpes = 0;
+		dist->its_vm.vpes = NULL;
+		return ret;
+	}
+
+	return ret;
+}
+
+void vgic_v4_teardown(struct kvm *kvm)
+{
+	struct its_vm *its_vm = &kvm->arch.vgic.its_vm;
+
+	if (!its_vm->vpes)
+		return;
+
+	its_free_vcpu_irqs(its_vm);
+	kfree(its_vm->vpes);
+	its_vm->nr_vpes = 0;
+	its_vm->vpes = NULL;
+}
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 90f6436a11aa..1356f485d7cf 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -230,5 +230,7 @@ int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
 struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi);
 
 bool vgic_is_v4_capable(struct kvm *kvm);
+int vgic_v4_init(struct kvm *kvm);
+void vgic_v4_teardown(struct kvm *kvm);
 
 #endif
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (39 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 40/59] KVM: arm/arm64: GICv4: Add init/teardown of the per-VM vPE irq domain Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-26 19:48   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 42/59] KVM: arm/arm64: GICv4: Handle INT command applied to a VLPI Marc Zyngier
                   ` (17 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Let's use the irq bypass mechanism introduced for platform device
interrupts to intercept the virtual PCIe endpoint configuration
and establish our LPI->VLPI mapping.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 include/kvm/arm_vgic.h      |   8 ++++
 virt/kvm/arm/arm.c          |  27 ++++++++----
 virt/kvm/arm/vgic/vgic-v4.c | 103 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 130 insertions(+), 8 deletions(-)

diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 359eeffe9857..050f78d4fb42 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -367,4 +367,12 @@ int kvm_vgic_set_forwarding(struct kvm *kvm, unsigned int host_irq,
 void kvm_vgic_unset_forwarding(struct kvm *kvm, unsigned int host_irq,
 			       unsigned int vintid);
 
+struct kvm_kernel_irq_routing_entry;
+
+int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int irq,
+			       struct kvm_kernel_irq_routing_entry *irq_entry);
+
+int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int irq,
+				 struct kvm_kernel_irq_routing_entry *irq_entry);
+
 #endif /* __KVM_ARM_VGIC_H */
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index ebab6c29e3be..6803ea27c47d 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -1457,11 +1457,16 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
 	struct kvm_kernel_irqfd *irqfd =
 		container_of(cons, struct kvm_kernel_irqfd, consumer);
 
-	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
+	switch (prod->type) {
+	case IRQ_BYPASS_VFIO_PLATFORM:
+		return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
+					       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
+	case IRQ_BYPASS_VFIO_PCI_MSI:
+		return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq,
+						  &irqfd->irq_entry);
+	default:
 		return 0;
-
-	return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
-				       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
+	}
 }
 void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
 				      struct irq_bypass_producer *prod)
@@ -1469,11 +1474,17 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
 	struct kvm_kernel_irqfd *irqfd =
 		container_of(cons, struct kvm_kernel_irqfd, consumer);
 
-	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
-		return;
+	switch (prod->type) {
+	case IRQ_BYPASS_VFIO_PLATFORM:
+		kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
+					  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
+		break;
 
-	kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
-				  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
+	case IRQ_BYPASS_VFIO_PCI_MSI:
+		kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq,
+					     &irqfd->irq_entry);
+		break;
+	}
 }
 
 void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
index 207e1fda0dcd..338c86c5159f 100644
--- a/virt/kvm/arm/vgic/vgic-v4.c
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -72,3 +72,106 @@ void vgic_v4_teardown(struct kvm *kvm)
 	its_vm->nr_vpes = 0;
 	its_vm->vpes = NULL;
 }
+
+static struct vgic_its *vgic_get_its(struct kvm *kvm,
+				     struct kvm_kernel_irq_routing_entry *irq_entry)
+{
+	struct kvm_msi msi  = (struct kvm_msi) {
+		.address_lo	= irq_entry->msi.address_lo,
+		.address_hi	= irq_entry->msi.address_hi,
+		.data		= irq_entry->msi.data,
+		.flags		= irq_entry->msi.flags,
+		.devid		= irq_entry->msi.devid,
+	};
+
+	/*
+	 * Get a reference on the LPI. If NULL, this is not a valid
+	 * translation for any of our vITSs.
+	 */
+	return vgic_msi_to_its(kvm, &msi);
+}
+
+int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
+			       struct kvm_kernel_irq_routing_entry *irq_entry)
+{
+	struct vgic_its *its;
+	struct vgic_irq *irq;
+	struct its_vlpi_map map;
+	int ret;
+
+	if (!vgic_is_v4_capable(kvm))
+		return 0;
+
+	/*
+	 * Get the ITS, and escape early on error (not a valid
+	 * doorbell for any of our vITSs).
+	 */
+	its = vgic_get_its(kvm, irq_entry);
+	if (IS_ERR(its))
+		return 0;
+
+	mutex_lock(&its->its_lock);
+
+	/* Perform then actual DevID/EventID -> LPI translation. */
+	ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid,
+				   irq_entry->msi.data, &irq);
+	if (ret)
+		goto out;
+
+	/*
+	 * Emit the mapping request. If it fails, the ITS probably
+	 * isn't v4 compatible, so let's silently bail out. Holding
+	 * the ITS lock should ensure that nothing can modify the
+	 * target vcpu.
+	 */
+	map = (struct its_vlpi_map) {
+		.vm		= &kvm->arch.vgic.its_vm,
+		.vintid		= irq->intid,
+		.db_enabled	= true,
+		.vpe_idx	= irq->target_vcpu->vcpu_id,
+	};
+
+	if (its_map_vlpi(virq, &map))
+		goto out;
+
+	irq->hw		= true;
+	irq->host_irq	= virq;
+
+out:
+	mutex_unlock(&its->its_lock);
+	return 0;
+}
+
+int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int virq,
+				 struct kvm_kernel_irq_routing_entry *irq_entry)
+{
+	struct vgic_its *its;
+	struct vgic_irq *irq;
+	int ret;
+
+	if (!vgic_is_v4_capable(kvm))
+		return 0;
+
+	/*
+	 * Get the ITS, and escape early on error (not a valid
+	 * doorbell for any of our vITSs).
+	 */
+	its = vgic_get_its(kvm, irq_entry);
+	if (IS_ERR(its))
+		return 0;
+
+	mutex_lock(&its->its_lock);
+
+	ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid,
+				   irq_entry->msi.data, &irq);
+	if (ret)
+		goto out;
+
+	WARN_ON(!(irq->hw && irq->host_irq == virq));
+	irq->hw = false;
+	ret = its_unmap_vlpi(virq);
+
+out:
+	mutex_unlock(&its->its_lock);
+	return ret;
+}
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 42/59] KVM: arm/arm64: GICv4: Handle INT command applied to a VLPI
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (40 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-28 18:18   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 43/59] KVM: arm/arm64: GICv4: Unmap VLPI when freeing an LPI Marc Zyngier
                   ` (16 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

If the guest issues an INT command targetting a VLPI, let's
call into the irq_set_irqchip_state() helper to make it pending
on the physical side.

This works just as well if userspace decides to inject an interrupt
using the normal userspace API...

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/vgic/vgic-its.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index a2217f53bbe5..40aeadef33fe 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -573,6 +573,10 @@ static int vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its,
 	if (err)
 		return err;
 
+	if (irq->hw)
+		return irq_set_irqchip_state(irq->host_irq,
+					     IRQCHIP_STATE_PENDING, true);
+
 	spin_lock(&irq->irq_lock);
 	irq->pending_latch = true;
 	vgic_queue_irq_unlock(kvm, irq);
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 43/59] KVM: arm/arm64: GICv4: Unmap VLPI when freeing an LPI
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (41 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 42/59] KVM: arm/arm64: GICv4: Handle INT command applied to a VLPI Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-28 18:18   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 44/59] KVM: arm/arm64: GICv4: Handle MOVI applied to a VLPI Marc Zyngier
                   ` (15 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

When freeing an LPI (on a DISCARD command, for example), we need
to unmap the VLPI down to the physical ITS level.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/vgic/vgic-its.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 40aeadef33fe..79bac93d3e7d 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -623,8 +623,12 @@ static void its_free_ite(struct kvm *kvm, struct its_ite *ite)
 	list_del(&ite->ite_list);
 
 	/* This put matches the get in vgic_add_lpi. */
-	if (ite->irq)
+	if (ite->irq) {
+		if (ite->irq->hw)
+			its_unmap_vlpi(ite->irq->host_irq);
+
 		vgic_put_irq(kvm, ite->irq);
+	}
 
 	kfree(ite);
 }
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 44/59] KVM: arm/arm64: GICv4: Handle MOVI applied to a VLPI
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (42 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 43/59] KVM: arm/arm64: GICv4: Unmap VLPI when freeing an LPI Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-28 18:18   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 45/59] KVM: arm/arm64: GICv4: Handle CLEAR " Marc Zyngier
                   ` (14 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

When the guest issues a MOVI, we need to tell the physical ITS
that we're now targetting a new vcpu. This is done by extracting
the current mapping, updating the target, and reapplying the
mapping. The core ITS code should do the right thing.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/vgic/vgic-its.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 79bac93d3e7d..aaad577ce328 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -706,6 +706,19 @@ static int vgic_its_cmd_handle_movi(struct kvm *kvm, struct vgic_its *its,
 	ite->irq->target_vcpu = vcpu;
 	spin_unlock(&ite->irq->irq_lock);
 
+	if (ite->irq->hw) {
+		struct its_vlpi_map map;
+		int ret;
+
+		ret = its_get_vlpi(ite->irq->host_irq, &map);
+		if (ret)
+			return ret;
+
+		map.vpe_idx = vcpu->vcpu_id;
+
+		return its_map_vlpi(ite->irq->host_irq, &map);
+	}
+
 	return 0;
 }
 
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 45/59] KVM: arm/arm64: GICv4: Handle CLEAR applied to a VLPI
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (43 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 44/59] KVM: arm/arm64: GICv4: Handle MOVI applied to a VLPI Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-28 18:18   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 46/59] KVM: arm/arm64: GICv4: Handle MOVALL applied to a vPE Marc Zyngier
                   ` (13 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Handling CLEAR is pretty easy. Just ask the ITS driver to clear
the corresponding pending bit (which will turn into a CLEAR
command on the physical side).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/vgic/vgic-its.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index aaad577ce328..2c065c970ba0 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -1069,6 +1069,10 @@ static int vgic_its_cmd_handle_clear(struct kvm *kvm, struct vgic_its *its,
 
 	ite->irq->pending_latch = false;
 
+	if (ite->irq->hw)
+		return irq_set_irqchip_state(ite->irq->host_irq,
+					     IRQCHIP_STATE_PENDING, false);
+
 	return 0;
 }
 
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 46/59] KVM: arm/arm64: GICv4: Handle MOVALL applied to a vPE
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (44 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 45/59] KVM: arm/arm64: GICv4: Handle CLEAR " Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-28 18:18   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 47/59] KVM: arm/arm64: GICv4: Propagate property updates to VLPIs Marc Zyngier
                   ` (12 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

The current implementation of MOVALL doesn't allow us to call
into the core ITS code as we hold a number of spinlocks.

Let's try a method used in other parts of the code, were we copy
the intids of the candicate interrupts, and then do whatever
we need to do with them outside of the critical section.

This allows us to move the interrupts one by one, at the expense
of a bit of CPU time. Who cares? MOVALL is such a stupid command
anyway...

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/vgic/vgic-its.c | 27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 2c065c970ba0..65cc77fde609 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -1147,11 +1147,12 @@ static int vgic_its_cmd_handle_invall(struct kvm *kvm, struct vgic_its *its,
 static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
 				      u64 *its_cmd)
 {
-	struct vgic_dist *dist = &kvm->arch.vgic;
 	u32 target1_addr = its_cmd_get_target_addr(its_cmd);
 	u32 target2_addr = its_cmd_mask_field(its_cmd, 3, 16, 32);
 	struct kvm_vcpu *vcpu1, *vcpu2;
 	struct vgic_irq *irq;
+	u32 *intids;
+	int irq_count, i;
 
 	if (target1_addr >= atomic_read(&kvm->online_vcpus) ||
 	    target2_addr >= atomic_read(&kvm->online_vcpus))
@@ -1163,19 +1164,31 @@ static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
 	vcpu1 = kvm_get_vcpu(kvm, target1_addr);
 	vcpu2 = kvm_get_vcpu(kvm, target2_addr);
 
-	spin_lock(&dist->lpi_list_lock);
+	irq_count = vgic_copy_lpi_list(vcpu1, &intids);
+	if (irq_count < 0)
+		return irq_count;
 
-	list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) {
-		spin_lock(&irq->irq_lock);
+	for (i = 0; i < irq_count; i++) {
+		irq = vgic_get_irq(kvm, NULL, intids[i]);
+		if (!irq)
+			continue;
 
 		if (irq->target_vcpu == vcpu1)
 			irq->target_vcpu = vcpu2;
 
-		spin_unlock(&irq->irq_lock);
-	}
+		if (irq->hw) {
+			struct its_vlpi_map map;
 
-	spin_unlock(&dist->lpi_list_lock);
+			if (!its_get_vlpi(irq->host_irq, &map)) {
+				map.vpe_idx = vcpu2->vcpu_id;
+				its_map_vlpi(irq->host_irq, &map);
+			}
+		}
 
+		vgic_put_irq(kvm, irq);
+	}
+
+	kfree(intids);
 	return 0;
 }
 
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 47/59] KVM: arm/arm64: GICv4: Propagate property updates to VLPIs
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (45 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 46/59] KVM: arm/arm64: GICv4: Handle MOVALL applied to a vPE Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-28 18:18   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 48/59] KVM: arm/arm64: GICv4: Handle INVALL applied to a vPE Marc Zyngier
                   ` (11 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Upon updating a property, we propagate it all the way to the physical
ITS, and ask for an INV command to be executed there.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/vgic/vgic-its.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 65cc77fde609..9e46081e5f15 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -297,6 +297,9 @@ static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
 		spin_unlock(&irq->irq_lock);
 	}
 
+	if (irq->hw)
+		return its_prop_update_vlpi(irq->host_irq, prop, true);
+
 	return 0;
 }
 
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 48/59] KVM: arm/arm64: GICv4: Handle INVALL applied to a vPE
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (46 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 47/59] KVM: arm/arm64: GICv4: Propagate property updates to VLPIs Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-28 18:18   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 49/59] KVM: arm/arm64: GICv4: Propagate VLPI properties at map time Marc Zyngier
                   ` (10 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Since when updating the properties one LPI at a time, there is no
need to perform an INV each time we read one. Instead, we rely
on the final VINVALL that gets sent to the ITS to do the work.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/vgic/vgic-its.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 9e46081e5f15..b395df1bf47c 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -38,7 +38,7 @@ static int vgic_its_save_tables_v0(struct vgic_its *its);
 static int vgic_its_restore_tables_v0(struct vgic_its *its);
 static int vgic_its_commit_v0(struct vgic_its *its);
 static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
-			     struct kvm_vcpu *filter_vcpu);
+			     struct kvm_vcpu *filter_vcpu, bool needs_inv);
 
 /*
  * Creates a new (reference to a) struct vgic_irq for a given LPI.
@@ -106,7 +106,7 @@ static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid,
 	 * However we only have those structs for mapped IRQs, so we read in
 	 * the respective config data from memory here upon mapping the LPI.
 	 */
-	ret = update_lpi_config(kvm, irq, NULL);
+	ret = update_lpi_config(kvm, irq, NULL, false);
 	if (ret)
 		return ERR_PTR(ret);
 
@@ -274,7 +274,7 @@ static struct its_collection *find_collection(struct vgic_its *its, int coll_id)
  * VCPU. Unconditionally applies if filter_vcpu is NULL.
  */
 static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
-			     struct kvm_vcpu *filter_vcpu)
+			     struct kvm_vcpu *filter_vcpu, bool needs_inv)
 {
 	u64 propbase = GICR_PROPBASER_ADDRESS(kvm->arch.vgic.propbaser);
 	u8 prop;
@@ -298,7 +298,7 @@ static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
 	}
 
 	if (irq->hw)
-		return its_prop_update_vlpi(irq->host_irq, prop, true);
+		return its_prop_update_vlpi(irq->host_irq, prop, needs_inv);
 
 	return 0;
 }
@@ -1095,7 +1095,7 @@ static int vgic_its_cmd_handle_inv(struct kvm *kvm, struct vgic_its *its,
 	if (!ite)
 		return E_ITS_INV_UNMAPPED_INTERRUPT;
 
-	return update_lpi_config(kvm, ite->irq, NULL);
+	return update_lpi_config(kvm, ite->irq, NULL, true);
 }
 
 /*
@@ -1130,12 +1130,15 @@ static int vgic_its_cmd_handle_invall(struct kvm *kvm, struct vgic_its *its,
 		irq = vgic_get_irq(kvm, NULL, intids[i]);
 		if (!irq)
 			continue;
-		update_lpi_config(kvm, irq, vcpu);
+		update_lpi_config(kvm, irq, vcpu, false);
 		vgic_put_irq(kvm, irq);
 	}
 
 	kfree(intids);
 
+	if (vcpu->arch.vgic_cpu.vgic_v3.its_vpe.its_vm)
+		its_invall_vpe(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe);
+
 	return 0;
 }
 
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 49/59] KVM: arm/arm64: GICv4: Propagate VLPI properties at map time
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (47 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 48/59] KVM: arm/arm64: GICv4: Handle INVALL applied to a vPE Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-28 18:18   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 50/59] KVM: arm/arm64: GICv4: Use pending_last as a scheduling hint Marc Zyngier
                   ` (9 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm
  Cc: Christoffer Dall, Thomas Gleixner, Jason Cooper, Eric Auger,
	Shanker Donthineni, Mark Rutland, Shameerali Kolothum Thodi

When the VLPI gets mapped, it must inherit the configuration of
LPI configured at the vITS level. FOr that purpose, let's make
update_lpi_config globally available and call it just after
having performed the VLPI map operation.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/vgic/vgic-its.c | 6 ++----
 virt/kvm/arm/vgic/vgic-v4.c  | 2 ++
 virt/kvm/arm/vgic/vgic.h     | 2 ++
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index b395df1bf47c..d790d0c74b8b 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -37,8 +37,6 @@
 static int vgic_its_save_tables_v0(struct vgic_its *its);
 static int vgic_its_restore_tables_v0(struct vgic_its *its);
 static int vgic_its_commit_v0(struct vgic_its *its);
-static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
-			     struct kvm_vcpu *filter_vcpu, bool needs_inv);
 
 /*
  * Creates a new (reference to a) struct vgic_irq for a given LPI.
@@ -273,8 +271,8 @@ static struct its_collection *find_collection(struct vgic_its *its, int coll_id)
  * If filter_vcpu is not NULL, applies only if the IRQ is targeting this
  * VCPU. Unconditionally applies if filter_vcpu is NULL.
  */
-static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
-			     struct kvm_vcpu *filter_vcpu, bool needs_inv)
+int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
+		      struct kvm_vcpu *filter_vcpu, bool needs_inv)
 {
 	u64 propbase = GICR_PROPBASER_ADDRESS(kvm->arch.vgic.propbaser);
 	u8 prop;
diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
index 338c86c5159f..534d3051a078 100644
--- a/virt/kvm/arm/vgic/vgic-v4.c
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -137,6 +137,8 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
 	irq->hw		= true;
 	irq->host_irq	= virq;
 
+	/* Force the property update and invalidate */
+	update_lpi_config(kvm, irq, NULL, true);
 out:
 	mutex_unlock(&its->its_lock);
 	return 0;
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 1356f485d7cf..1210bf4681dc 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -228,6 +228,8 @@ void unlock_all_vcpus(struct kvm *kvm);
 int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
 			 u32 devid, u32 eventid, struct vgic_irq **irq);
 struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi);
+int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
+		      struct kvm_vcpu *filter_vcpu, bool needs_inv);
 
 bool vgic_is_v4_capable(struct kvm *kvm);
 int vgic_v4_init(struct kvm *kvm);
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 50/59] KVM: arm/arm64: GICv4: Use pending_last as a scheduling hint
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (48 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 49/59] KVM: arm/arm64: GICv4: Propagate VLPI properties at map time Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-28 18:18   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling Marc Zyngier
                   ` (8 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

When a vPE exits, the pending_last flag is set when there are
pending VLPIs stored in the pending table. Similarily, we set
this flag when a doorbell interrupt fires, as it indicates the
same condition.

Let's update kvm_vgic_vcpu_pending_irq() to account for that
flag as well, making a vcpu runnable when set.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/vgic/vgic.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index a96e566905d2..dfac894f6f03 100644
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -781,6 +781,9 @@ int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
 	if (!vcpu->kvm->arch.vgic.enabled)
 		return false;
 
+	if (vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last)
+		return true;
+
 	spin_lock(&vgic_cpu->ap_list_lock);
 
 	list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (49 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 50/59] KVM: arm/arm64: GICv4: Use pending_last as a scheduling hint Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-04  7:44   ` Marc Zyngier
                     ` (2 more replies)
  2017-07-31 17:26 ` [PATCH v3 52/59] KVM: arm/arm64: GICv4: Use the doorbell interrupt as an unblocking source Marc Zyngier
                   ` (7 subsequent siblings)
  58 siblings, 3 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

When a vPE is not running, a VLPI being made pending results in a
doorbell interrupt being delivered. Let's handle this interrupt
and update the pending_last flag that indicates that VLPIs are
pending. The corresponding vcpu is also kicked into action.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/vgic/vgic-v4.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
index 534d3051a078..6af3cde6d7d4 100644
--- a/virt/kvm/arm/vgic/vgic-v4.c
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -21,6 +21,19 @@
 
 #include "vgic.h"
 
+static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
+{
+	struct kvm_vcpu *vcpu = info;
+
+	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
+		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
+		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
+		kvm_vcpu_kick(vcpu);
+	}
+
+	return IRQ_HANDLED;
+}
+
 int vgic_v4_init(struct kvm *kvm)
 {
 	struct vgic_dist *dist = &kvm->arch.vgic;
@@ -57,16 +70,37 @@ int vgic_v4_init(struct kvm *kvm)
 		return ret;
 	}
 
+	kvm_for_each_vcpu(i, vcpu, kvm) {
+		int irq = dist->its_vm.vpes[i]->irq;
+
+		ret = request_irq(irq, vgic_v4_doorbell_handler,
+				  0, "vcpu", vcpu);
+		if (ret) {
+			kvm_err("failed to allocate vcpu IRQ%d\n", irq);
+			dist->its_vm.nr_vpes = i;
+			break;
+		}
+	}
+
+	if (ret)
+		vgic_v4_teardown(kvm);
+
 	return ret;
 }
 
 void vgic_v4_teardown(struct kvm *kvm)
 {
 	struct its_vm *its_vm = &kvm->arch.vgic.its_vm;
+	int i;
 
 	if (!its_vm->vpes)
 		return;
 
+	for (i = 0; i < its_vm->nr_vpes; i++) {
+		struct kvm_vcpu *vcpu = kvm_get_vcpu(kvm, i);
+		free_irq(its_vm->vpes[i]->irq, vcpu);
+	}
+
 	its_free_vcpu_irqs(its_vm);
 	kfree(its_vm->vpes);
 	its_vm->nr_vpes = 0;
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 52/59] KVM: arm/arm64: GICv4: Use the doorbell interrupt as an unblocking source
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (50 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-28 18:19   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 53/59] KVM: arm/arm64: GICv4: Hook vPE scheduling into vgic flush/sync Marc Zyngier
                   ` (6 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

The doorbell interrupt is only useful if the vcpu is blocked on WFI.
In all other cases, recieving a doorbell interrupt is just a waste
of cycles.

So let's only enable the doorbell if a vcpu is getting blocked,
and disable it when it is unblocked. This is very similar to
what we're doing for the background timer.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 include/kvm/arm_vgic.h      |  3 +++
 virt/kvm/arm/arm.c          |  2 ++
 virt/kvm/arm/vgic/vgic-v4.c | 32 +++++++++++++++++++++++++++++++-
 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 050f78d4fb42..7b1cc7ff5b42 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -375,4 +375,7 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int irq,
 int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int irq,
 				 struct kvm_kernel_irq_routing_entry *irq_entry);
 
+void kvm_vgic_v4_enable_doorbell(struct kvm_vcpu *vcpu);
+void kvm_vgic_v4_disable_doorbell(struct kvm_vcpu *vcpu);
+
 #endif /* __KVM_ARM_VGIC_H */
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 6803ea27c47d..5dbc8dc8fbf4 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -316,11 +316,13 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
 void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu)
 {
 	kvm_timer_schedule(vcpu);
+	kvm_vgic_v4_enable_doorbell(vcpu);
 }
 
 void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu)
 {
 	kvm_timer_unschedule(vcpu);
+	kvm_vgic_v4_disable_doorbell(vcpu);
 }
 
 int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
index 6af3cde6d7d4..50721c4e3da5 100644
--- a/virt/kvm/arm/vgic/vgic-v4.c
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -16,6 +16,7 @@
  */
 
 #include <linux/interrupt.h>
+#include <linux/irq.h>
 #include <linux/irqdomain.h>
 #include <linux/kvm_host.h>
 
@@ -73,6 +74,14 @@ int vgic_v4_init(struct kvm *kvm)
 	kvm_for_each_vcpu(i, vcpu, kvm) {
 		int irq = dist->its_vm.vpes[i]->irq;
 
+		/*
+		 * Don't automatically enable the doorbell, as we're
+		 * flipping it back and forth when the vcpu gets
+		 * blocked. Also disable the lazy disabling, as the
+		 * doorbell could kick us out of the guest too
+		 * early...
+		 */
+		irq_set_status_flags(irq, IRQ_NOAUTOEN | IRQ_DISABLE_UNLAZY);
 		ret = request_irq(irq, vgic_v4_doorbell_handler,
 				  0, "vcpu", vcpu);
 		if (ret) {
@@ -98,7 +107,10 @@ void vgic_v4_teardown(struct kvm *kvm)
 
 	for (i = 0; i < its_vm->nr_vpes; i++) {
 		struct kvm_vcpu *vcpu = kvm_get_vcpu(kvm, i);
-		free_irq(its_vm->vpes[i]->irq, vcpu);
+		int irq = its_vm->vpes[i]->irq;
+
+		irq_clear_status_flags(irq, IRQ_NOAUTOEN | IRQ_DISABLE_UNLAZY);
+		free_irq(irq, vcpu);
 	}
 
 	its_free_vcpu_irqs(its_vm);
@@ -211,3 +223,21 @@ int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int virq,
 	mutex_unlock(&its->its_lock);
 	return ret;
 }
+
+void kvm_vgic_v4_enable_doorbell(struct kvm_vcpu *vcpu)
+{
+	if (vgic_is_v4_capable(vcpu->kvm)) {
+		int irq = vcpu->arch.vgic_cpu.vgic_v3.its_vpe.irq;
+		if (irq)
+			enable_irq(irq);
+	}
+}
+
+void kvm_vgic_v4_disable_doorbell(struct kvm_vcpu *vcpu)
+{
+	if (vgic_is_v4_capable(vcpu->kvm)) {
+		int irq = vcpu->arch.vgic_cpu.vgic_v3.its_vpe.irq;
+		if (irq)
+			disable_irq(irq);
+	}
+}
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 53/59] KVM: arm/arm64: GICv4: Hook vPE scheduling into vgic flush/sync
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (51 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 52/59] KVM: arm/arm64: GICv4: Use the doorbell interrupt as an unblocking source Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-28 18:17   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 54/59] KVM: arm/arm64: GICv4: Enable virtual cpuif if VLPIs can be delivered Marc Zyngier
                   ` (5 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm
  Cc: Christoffer Dall, Thomas Gleixner, Jason Cooper, Eric Auger,
	Shanker Donthineni, Mark Rutland, Shameerali Kolothum Thodi

The redistributor needs to be told which vPE is about to be run,
and tells us whether there is any pending VLPI on exit.

Let's add the scheduling calls to the vgic flush/sync functions,
allowing the VLPIs to be delivered to the guest.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/vgic/vgic-v4.c | 24 ++++++++++++++++++++++++
 virt/kvm/arm/vgic/vgic.c    |  4 ++++
 virt/kvm/arm/vgic/vgic.h    |  1 +
 3 files changed, 29 insertions(+)

diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
index 50721c4e3da5..0a8deefbcf1c 100644
--- a/virt/kvm/arm/vgic/vgic-v4.c
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -119,6 +119,30 @@ void vgic_v4_teardown(struct kvm *kvm)
 	its_vm->vpes = NULL;
 }
 
+int vgic_v4_schedule(struct kvm_vcpu *vcpu, bool on)
+{
+	int irq = vcpu->arch.vgic_cpu.vgic_v3.its_vpe.irq;
+
+	if (!vgic_is_v4_capable(vcpu->kvm) || !irq)
+		return 0;
+
+	/*
+	 * Before making the VPE resident, make sure the redistributor
+	 * expects us here.
+	 */
+	if (on) {
+		int err;
+
+		err = irq_set_affinity(irq, cpumask_of(smp_processor_id()));
+		if (err) {
+			kvm_err("failed irq_set_affinity IRQ%d (%d)\n", irq, err);
+			return err;
+		}
+	}
+
+	return its_schedule_vpe(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe, on);
+}
+
 static struct vgic_its *vgic_get_its(struct kvm *kvm,
 				     struct kvm_kernel_irq_routing_entry *irq_entry)
 {
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index dfac894f6f03..9ab52108989d 100644
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -721,6 +721,8 @@ void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
 {
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 
+	WARN_ON(vgic_v4_schedule(vcpu, false));
+
 	/* An empty ap_list_head implies used_lrs == 0 */
 	if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head))
 		return;
@@ -733,6 +735,8 @@ void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
 /* Flush our emulation state into the GIC hardware before entering the guest. */
 void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
 {
+	WARN_ON(vgic_v4_schedule(vcpu, true));
+
 	/*
 	 * If there are no virtual interrupts active or pending for this
 	 * VCPU, then there is no work to do and we can bail out without
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 1210bf4681dc..693b654acf4d 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -234,5 +234,6 @@ int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
 bool vgic_is_v4_capable(struct kvm *kvm);
 int vgic_v4_init(struct kvm *kvm);
 void vgic_v4_teardown(struct kvm *kvm);
+int vgic_v4_schedule(struct kvm_vcpu *vcpu, bool on);
 
 #endif
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 54/59] KVM: arm/arm64: GICv4: Enable virtual cpuif if VLPIs can be delivered
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (52 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 53/59] KVM: arm/arm64: GICv4: Hook vPE scheduling into vgic flush/sync Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-28 18:20   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 55/59] KVM: arm/arm64: GICv4: Enable VLPI support Marc Zyngier
                   ` (4 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

In order for VLPIs to be delivered to the guest, we must make
sure that the cpuif is always enabled, irrespective of the
presence of virtual interrupt in the LRs.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/hyp/vgic-v3-sr.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/virt/kvm/arm/hyp/vgic-v3-sr.c b/virt/kvm/arm/hyp/vgic-v3-sr.c
index 91728faa13fd..f5c3d6d7019e 100644
--- a/virt/kvm/arm/hyp/vgic-v3-sr.c
+++ b/virt/kvm/arm/hyp/vgic-v3-sr.c
@@ -258,7 +258,8 @@ void __hyp_text __vgic_v3_save_state(struct kvm_vcpu *vcpu)
 			cpu_if->vgic_ap1r[0] = __vgic_v3_read_ap1rn(0);
 		}
 	} else {
-		if (static_branch_unlikely(&vgic_v3_cpuif_trap))
+		if (static_branch_unlikely(&vgic_v3_cpuif_trap) ||
+		    cpu_if->its_vpe.its_vm)
 			write_gicreg(0, ICH_HCR_EL2);
 
 		cpu_if->vgic_elrsr = 0xffff;
@@ -337,9 +338,11 @@ void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu)
 		/*
 		 * If we need to trap system registers, we must write
 		 * ICH_HCR_EL2 anyway, even if no interrupts are being
-		 * injected,
+		 * injected. Same thing if GICv4 is used, as VLPI
+		 * delivery is gated by ICH_HCR_EL2.En.
 		 */
-		if (static_branch_unlikely(&vgic_v3_cpuif_trap))
+		if (static_branch_unlikely(&vgic_v3_cpuif_trap) ||
+		    cpu_if->its_vpe.its_vm)
 			write_gicreg(cpu_if->vgic_hcr, ICH_HCR_EL2);
 	}
 
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 55/59] KVM: arm/arm64: GICv4: Enable VLPI support
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (53 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 54/59] KVM: arm/arm64: GICv4: Enable virtual cpuif if VLPIs can be delivered Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-28 18:25   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 56/59] KVM: arm/arm64: GICv4: Prevent heterogenous systems from using GICv4 Marc Zyngier
                   ` (3 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

All it takes is the has_v4 flag to be set in gic_kvm_info
as well as "kvm-arm.vgic_v4_enable=1" being passed on the
command line for GICv4 to be enabled in KVM.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 Documentation/admin-guide/kernel-parameters.txt |  4 ++++
 virt/kvm/arm/vgic/vgic-v3.c                     | 14 ++++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index d9c171ce4190..d2927d01d8b2 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1874,6 +1874,10 @@
 			[KVM,ARM] Trap guest accesses to GICv3 common
 			system registers
 
+	kvm-arm.vgic_v4_enable=
+			[KVM,ARM] Allow use of GICv4 for direct injection of
+			LPIs.
+
 	kvm-intel.ept=	[KVM,Intel] Disable extended page tables
 			(virtualized MMU) support on capable Intel chips.
 			Default is 1 (enabled)
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index 96ea597db0e7..405733678c2f 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -24,6 +24,7 @@
 static bool group0_trap;
 static bool group1_trap;
 static bool common_trap;
+static bool gicv4_enable;
 
 void vgic_v3_set_underflow(struct kvm_vcpu *vcpu)
 {
@@ -459,6 +460,12 @@ static int __init early_common_trap_cfg(char *buf)
 }
 early_param("kvm-arm.vgic_v3_common_trap", early_common_trap_cfg);
 
+static int __init early_gicv4_enable(char *buf)
+{
+	return strtobool(buf, &gicv4_enable);
+}
+early_param("kvm-arm.vgic_v4_enable", early_gicv4_enable);
+
 /**
  * vgic_v3_probe - probe for a GICv3 compatible interrupt controller in DT
  * @node:	pointer to the DT node
@@ -478,6 +485,13 @@ int vgic_v3_probe(const struct gic_kvm_info *info)
 	kvm_vgic_global_state.can_emulate_gicv2 = false;
 	kvm_vgic_global_state.ich_vtr_el2 = ich_vtr_el2;
 
+	/* GICv4 support? */
+	if (info->has_v4) {
+		kvm_vgic_global_state.has_gicv4 = gicv4_enable;
+		kvm_info("GICv4 support %sabled\n",
+			 gicv4_enable ? "en" : "dis");
+	}
+
 	if (!info->vcpu.start) {
 		kvm_info("GICv3: no GICV resource entry\n");
 		kvm_vgic_global_state.vcpu_base = 0;
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 56/59] KVM: arm/arm64: GICv4: Prevent heterogenous systems from using GICv4
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (54 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 55/59] KVM: arm/arm64: GICv4: Enable VLPI support Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-28 18:35   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 57/59] KVM: arm/arm64: GICv4: Theory of operations Marc Zyngier
                   ` (2 subsequent siblings)
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

The GICv4 architecture doesn't prevent CPUs implementing GICv4 to
cohabit with CPUs limited to GICv3 in the same system.

This is mad (the sheduler would have to be made aware of the v4
capability), and we're certainly not going to support this any
time soon. So let's check that all online CPUs are GICv4 capable,
and disable the functionnality if not.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 include/linux/irqchip/arm-gic-v3.h |  2 ++
 virt/kvm/arm/vgic/vgic-v3.c        | 22 +++++++++++++++++++++-
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index 1ea576c8126f..dfa4a51643d6 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -532,6 +532,8 @@
 #define ICH_VTR_SEIS_MASK		(1 << ICH_VTR_SEIS_SHIFT)
 #define ICH_VTR_A3V_SHIFT		21
 #define ICH_VTR_A3V_MASK		(1 << ICH_VTR_A3V_SHIFT)
+#define ICH_VTR_nV4_SHIFT		20
+#define ICH_VTR_nV4_MASK		(1 << ICH_VTR_nV4_SHIFT)
 
 #define ICC_IAR1_EL1_SPURIOUS		0x3ff
 
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index 405733678c2f..252268e83ade 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -466,6 +466,18 @@ static int __init early_gicv4_enable(char *buf)
 }
 early_param("kvm-arm.vgic_v4_enable", early_gicv4_enable);
 
+static void vgic_check_v4_cpuif(void *param)
+{
+	u32 ich_vtr_el2 = kvm_call_hyp(__vgic_v3_get_ich_vtr_el2);
+	bool *v4 = param, this_cpu_is_v4;
+
+	this_cpu_is_v4 = !(ich_vtr_el2 & ICH_VTR_nV4_MASK);
+	if (!this_cpu_is_v4)
+		kvm_info("CPU%d is not GICv4 capable\n", smp_processor_id());
+
+	*v4 &= this_cpu_is_v4;
+}
+
 /**
  * vgic_v3_probe - probe for a GICv3 compatible interrupt controller in DT
  * @node:	pointer to the DT node
@@ -485,8 +497,16 @@ int vgic_v3_probe(const struct gic_kvm_info *info)
 	kvm_vgic_global_state.can_emulate_gicv2 = false;
 	kvm_vgic_global_state.ich_vtr_el2 = ich_vtr_el2;
 
-	/* GICv4 support? */
+	/*
+	 * GICv4 support? We need to check on all CPUs in case of some
+	 * extremely creative form of big-little brain damage...
+	 */
 	if (info->has_v4) {
+		int cpu;
+
+		for_each_online_cpu(cpu)
+			smp_call_function_single(cpu, vgic_check_v4_cpuif,
+						 &gicv4_enable, 1);
 		kvm_vgic_global_state.has_gicv4 = gicv4_enable;
 		kvm_info("GICv4 support %sabled\n",
 			 gicv4_enable ? "en" : "dis");
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 57/59] KVM: arm/arm64: GICv4: Theory of operations
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (55 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 56/59] KVM: arm/arm64: GICv4: Prevent heterogenous systems from using GICv4 Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-08-28 18:18   ` Christoffer Dall
  2017-07-31 17:26 ` [PATCH v3 58/59] irqchip/gic-v3-its: Pass its_node pointer to each command bulder Marc Zyngier
  2017-07-31 17:26 ` [PATCH v3 59/59] irqchip/gic-v3-its: Workaround Huawei D05 redistributor addressing Marc Zyngier
  58 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

Yet another braindump so I can free some cells...

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/vgic/vgic-v4.c | 68 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
index 0a8deefbcf1c..0c002d2be620 100644
--- a/virt/kvm/arm/vgic/vgic-v4.c
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -22,6 +22,74 @@
 
 #include "vgic.h"
 
+/*
+ * How KVM uses GICv4 (insert rude comments here):
+ *
+ * The vgic-v4 layer acts as a bridge between several entities:
+ * - The GICv4 ITS representation offered by the ITS driver
+ * - VFIO, which is in charge of the PCI endpoint
+ * - The virtual ITS, which is the only thing the guest sees
+ *
+ * The configuration of VLPIs is triggered by a callback from VFIO,
+ * instructing KVM that a PCI device has been configured to deliver
+ * MSIs to a vITS.
+ *
+ * kvm_vgic_v4_set_forwarding() is thus called with the routing entry,
+ * and this is used to find the corresponding vITS data structures
+ * (ITS instance, device, event and irq) using a process that is
+ * extremely similar to the injection of an MSI.
+ *
+ * At this stage, we can link the guest's view of an LPI (uniquely
+ * identified by the routing entry) and the host irq, using the GICv4
+ * driver mapping operation. Should the mapping succeed, we've then
+ * successfully upgraded the guest's LPI to a VLPI. We can then start
+ * with updating GICv4's view of the property table and generating an
+ * INValidation in order to kickstart the delivery of this VLPI to the
+ * guest directly, without software intervention. Well, almost.
+ *
+ * When the PCI endpoint is deconfigured, this operation is reversed
+ * with VFIO calling kvm_vgic_v4_unset_forwarding().
+ *
+ * Once the VLPI has been mapped, it needs to follow any change the
+ * guest performs on its LPI through the vITS. For that, a number of
+ * command handlers have hooks to communicate these changes to the HW:
+ * - Any invalidation triggers a call to its_prop_update_vlpi()
+ * - The INT command results in a irq_set_irqchip_state(), which
+ *   generates an INT on the corresponding VLPI.
+ * - The CLEAR command results in a irq_set_irqchip_state(), which
+ *   generates an CLEAR on the corresponding VLPI.
+ * - DISCARD translates into an unmap, similar to a call to
+ *   kvm_vgic_v4_unset_forwarding().
+ * - MOVI is translated by an update of the existing mapping, changing
+ *   the target vcpu, resulting in a VMOVI being generated.
+ * - MOVALL is translated by a string of mapping updates (similar to
+ *   the handling of MOVI). MOVALL is horrible.
+ *
+ * Note that a DISCARD/MAPTI sequence emitted from the guest without
+ * reprogramming the PCI endpoint after MAPTI does not result in a
+ * VLPI being mapped, as there is no callback from VFIO (the guest
+ * will get the interrupt via the normal SW injection). Fixing this is
+ * not trivial, and requires some horrible messing with the VFIO
+ * internals. Not fun. Don't do that.
+ *
+ * Then there is the scheduling. Each time a vcpu is about to run on a
+ * physical CPU, KVM must tell the corresponding redistributor about
+ * it. And if we've migrated our vcpu from one CPU to another, we must
+ * tell the ITS (so that the messages reach the right redistributor).
+ * This is done in two steps: first issue a irq_set_affinity() on the
+ * irq corresponding to the vcpu, then call its_schedule_vpe(). You
+ * must be in a non-preemptible context. On exit, another call to
+ * its_schedule_vpe() tells the redistributor that we're done with the
+ * vcpu.
+ *
+ * Finally, the doorbell handling: Each vcpu is allocated an interrupt
+ * which will fire each time a VLPI is made pending whilst the vcpu is
+ * not running. Each time the vcpu gets blocked, the doorbell
+ * interrupt gets enabled. When the vcpu is unblocked (for whatever
+ * reason), the doorbell interrupt is disabled. This behaviour is
+ * pretty similar to that of the backgroud timer.
+ */
+
 static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
 {
 	struct kvm_vcpu *vcpu = info;
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 58/59] irqchip/gic-v3-its: Pass its_node pointer to each command bulder
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (56 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 57/59] KVM: arm/arm64: GICv4: Theory of operations Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  2017-07-31 17:26 ` [PATCH v3 59/59] irqchip/gic-v3-its: Workaround Huawei D05 redistributor addressing Marc Zyngier
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm
  Cc: Christoffer Dall, Thomas Gleixner, Jason Cooper, Eric Auger,
	Shanker Donthineni, Mark Rutland, Shameerali Kolothum Thodi

In order to be able to issue command variants depending on
how broken an ITS is, let's pass the its pointer to all
command building primitives.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 58 ++++++++++++++++++++++++++--------------
 1 file changed, 38 insertions(+), 20 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 9f32cd42238f..e22c8746ce89 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -264,10 +264,12 @@ struct its_cmd_block {
 #define ITS_CMD_QUEUE_SZ		SZ_64K
 #define ITS_CMD_QUEUE_NR_ENTRIES	(ITS_CMD_QUEUE_SZ / sizeof(struct its_cmd_block))
 
-typedef struct its_collection *(*its_cmd_builder_t)(struct its_cmd_block *,
+typedef struct its_collection *(*its_cmd_builder_t)(struct its_node *,
+						    struct its_cmd_block *,
 						    struct its_cmd_desc *);
 
-typedef struct its_vpe *(*its_cmd_vbuilder_t)(struct its_cmd_block *,
+typedef struct its_vpe *(*its_cmd_vbuilder_t)(struct its_node *,
+					      struct its_cmd_block *,
 					      struct its_cmd_desc *);
 
 static void its_mask_encode(u64 *raw_cmd, u64 val, int h, int l)
@@ -371,7 +373,8 @@ static inline void its_fixup_cmd(struct its_cmd_block *cmd)
 	cmd->raw_cmd[3] = cpu_to_le64(cmd->raw_cmd[3]);
 }
 
-static struct its_collection *its_build_mapd_cmd(struct its_cmd_block *cmd,
+static struct its_collection *its_build_mapd_cmd(struct its_node *its,
+						 struct its_cmd_block *cmd,
 						 struct its_cmd_desc *desc)
 {
 	unsigned long itt_addr;
@@ -391,7 +394,8 @@ static struct its_collection *its_build_mapd_cmd(struct its_cmd_block *cmd,
 	return NULL;
 }
 
-static struct its_collection *its_build_mapc_cmd(struct its_cmd_block *cmd,
+static struct its_collection *its_build_mapc_cmd(struct its_node *its,
+						 struct its_cmd_block *cmd,
 						 struct its_cmd_desc *desc)
 {
 	its_encode_cmd(cmd, GITS_CMD_MAPC);
@@ -404,7 +408,8 @@ static struct its_collection *its_build_mapc_cmd(struct its_cmd_block *cmd,
 	return desc->its_mapc_cmd.col;
 }
 
-static struct its_collection *its_build_mapti_cmd(struct its_cmd_block *cmd,
+static struct its_collection *its_build_mapti_cmd(struct its_node *its,
+						  struct its_cmd_block *cmd,
 						  struct its_cmd_desc *desc)
 {
 	struct its_collection *col;
@@ -423,7 +428,8 @@ static struct its_collection *its_build_mapti_cmd(struct its_cmd_block *cmd,
 	return col;
 }
 
-static struct its_collection *its_build_movi_cmd(struct its_cmd_block *cmd,
+static struct its_collection *its_build_movi_cmd(struct its_node *its,
+						 struct its_cmd_block *cmd,
 						 struct its_cmd_desc *desc)
 {
 	struct its_collection *col;
@@ -441,7 +447,8 @@ static struct its_collection *its_build_movi_cmd(struct its_cmd_block *cmd,
 	return col;
 }
 
-static struct its_collection *its_build_discard_cmd(struct its_cmd_block *cmd,
+static struct its_collection *its_build_discard_cmd(struct its_node *its,
+						    struct its_cmd_block *cmd,
 						    struct its_cmd_desc *desc)
 {
 	struct its_collection *col;
@@ -458,7 +465,8 @@ static struct its_collection *its_build_discard_cmd(struct its_cmd_block *cmd,
 	return col;
 }
 
-static struct its_collection *its_build_inv_cmd(struct its_cmd_block *cmd,
+static struct its_collection *its_build_inv_cmd(struct its_node *its,
+						struct its_cmd_block *cmd,
 						struct its_cmd_desc *desc)
 {
 	struct its_collection *col;
@@ -475,7 +483,8 @@ static struct its_collection *its_build_inv_cmd(struct its_cmd_block *cmd,
 	return col;
 }
 
-static struct its_collection *its_build_int_cmd(struct its_cmd_block *cmd,
+static struct its_collection *its_build_int_cmd(struct its_node *its,
+						struct its_cmd_block *cmd,
 						struct its_cmd_desc *desc)
 {
 	struct its_collection *col;
@@ -492,7 +501,8 @@ static struct its_collection *its_build_int_cmd(struct its_cmd_block *cmd,
 	return col;
 }
 
-static struct its_collection *its_build_clear_cmd(struct its_cmd_block *cmd,
+static struct its_collection *its_build_clear_cmd(struct its_node *its,
+						  struct its_cmd_block *cmd,
 						  struct its_cmd_desc *desc)
 {
 	struct its_collection *col;
@@ -509,7 +519,8 @@ static struct its_collection *its_build_clear_cmd(struct its_cmd_block *cmd,
 	return col;
 }
 
-static struct its_collection *its_build_invall_cmd(struct its_cmd_block *cmd,
+static struct its_collection *its_build_invall_cmd(struct its_node *its,
+						   struct its_cmd_block *cmd,
 						   struct its_cmd_desc *desc)
 {
 	its_encode_cmd(cmd, GITS_CMD_INVALL);
@@ -520,7 +531,8 @@ static struct its_collection *its_build_invall_cmd(struct its_cmd_block *cmd,
 	return NULL;
 }
 
-static struct its_vpe *its_build_vinvall_cmd(struct its_cmd_block *cmd,
+static struct its_vpe *its_build_vinvall_cmd(struct its_node *its,
+					     struct its_cmd_block *cmd,
 					     struct its_cmd_desc *desc)
 {
 	its_encode_cmd(cmd, GITS_CMD_VINVALL);
@@ -531,7 +543,8 @@ static struct its_vpe *its_build_vinvall_cmd(struct its_cmd_block *cmd,
 	return desc->its_vinvall_cmd.vpe;
 }
 
-static struct its_vpe *its_build_vmapp_cmd(struct its_cmd_block *cmd,
+static struct its_vpe *its_build_vmapp_cmd(struct its_node *its,
+					   struct its_cmd_block *cmd,
 					   struct its_cmd_desc *desc)
 {
 	unsigned long vpt_addr;
@@ -550,7 +563,8 @@ static struct its_vpe *its_build_vmapp_cmd(struct its_cmd_block *cmd,
 	return desc->its_vmapp_cmd.vpe;
 }
 
-static struct its_vpe *its_build_vmapti_cmd(struct its_cmd_block *cmd,
+static struct its_vpe *its_build_vmapti_cmd(struct its_node *its,
+					    struct its_cmd_block *cmd,
 					    struct its_cmd_desc *desc)
 {
 	u32 db;
@@ -572,7 +586,8 @@ static struct its_vpe *its_build_vmapti_cmd(struct its_cmd_block *cmd,
 	return desc->its_vmapti_cmd.vpe;
 }
 
-static struct its_vpe *its_build_vmovi_cmd(struct its_cmd_block *cmd,
+static struct its_vpe *its_build_vmovi_cmd(struct its_node *its,
+					   struct its_cmd_block *cmd,
 					   struct its_cmd_desc *desc)
 {
 	u32 db;
@@ -594,7 +609,8 @@ static struct its_vpe *its_build_vmovi_cmd(struct its_cmd_block *cmd,
 	return desc->its_vmovi_cmd.vpe;
 }
 
-static struct its_vpe *its_build_vmovp_cmd(struct its_cmd_block *cmd,
+static struct its_vpe *its_build_vmovp_cmd(struct its_node *its,
+					   struct its_cmd_block *cmd,
 					   struct its_cmd_desc *desc)
 {
 	its_encode_cmd(cmd, GITS_CMD_VMOVP);
@@ -722,7 +738,7 @@ void name(struct its_node *its,						\
 		raw_spin_unlock_irqrestore(&its->lock, flags);		\
 		return;							\
 	}								\
-	sync_obj = builder(cmd, desc);					\
+	sync_obj = builder(its, cmd, desc);				\
 	its_flush_cmd(its, cmd);					\
 									\
 	if (sync_obj) {							\
@@ -730,7 +746,7 @@ void name(struct its_node *its,						\
 		if (!sync_cmd)						\
 			goto post;					\
 									\
-		buildfn(sync_cmd, sync_obj);				\
+		buildfn(its, sync_cmd, sync_obj);			\
 		its_flush_cmd(its, sync_cmd);				\
 	}								\
 									\
@@ -741,7 +757,8 @@ post:									\
 	its_wait_for_range_completion(its, cmd, next_cmd);		\
 }
 
-static void its_build_sync_cmd(struct its_cmd_block *sync_cmd,
+static void its_build_sync_cmd(struct its_node *its,
+			       struct its_cmd_block *sync_cmd,
 			       struct its_collection *sync_col)
 {
 	its_encode_cmd(sync_cmd, GITS_CMD_SYNC);
@@ -753,7 +770,8 @@ static void its_build_sync_cmd(struct its_cmd_block *sync_cmd,
 static BUILD_SINGLE_CMD_FUNC(its_send_single_command, its_cmd_builder_t,
 			     struct its_collection, its_build_sync_cmd)
 
-static void its_build_vsync_cmd(struct its_cmd_block *sync_cmd,
+static void its_build_vsync_cmd(struct its_node *its,
+				struct its_cmd_block *sync_cmd,
 				struct its_vpe *sync_vpe)
 {
 	its_encode_cmd(sync_cmd, GITS_CMD_VSYNC);
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* [PATCH v3 59/59] irqchip/gic-v3-its: Workaround Huawei D05 redistributor addressing
  2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
                   ` (57 preceding siblings ...)
  2017-07-31 17:26 ` [PATCH v3 58/59] irqchip/gic-v3-its: Pass its_node pointer to each command bulder Marc Zyngier
@ 2017-07-31 17:26 ` Marc Zyngier
  58 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-07-31 17:26 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm; +Cc: Jason Cooper, Thomas Gleixner

The ITSes on the Huawei D05 are broken when it comes to addressing
the redistributors, and need to be explicitely told to address
the VLPI page instead of the redistributor base address.

So let's add yet another quirk, fixing up the target address
in the command stream.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index e22c8746ce89..32d8697bcb15 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -103,6 +103,7 @@ struct its_node {
 	u32			device_ids;
 	int			numa_node;
 	bool			is_v4;
+	int			vlpi_redist_offset;
 };
 
 #define ITS_ITT_ALIGN		SZ_256
@@ -548,13 +549,15 @@ static struct its_vpe *its_build_vmapp_cmd(struct its_node *its,
 					   struct its_cmd_desc *desc)
 {
 	unsigned long vpt_addr;
+	u64 target;
 
 	vpt_addr = virt_to_phys(page_address(desc->its_vmapp_cmd.vpe->vpt_page));
+	target = desc->its_vmapp_cmd.col->target_address + its->vlpi_redist_offset;
 
 	its_encode_cmd(cmd, GITS_CMD_VMAPP);
 	its_encode_vpeid(cmd, desc->its_vmapp_cmd.vpe->vpe_id);
 	its_encode_valid(cmd, desc->its_vmapp_cmd.valid);
-	its_encode_target(cmd, desc->its_vmapp_cmd.col->target_address);
+	its_encode_target(cmd, target);
 	its_encode_vpt_addr(cmd, vpt_addr);
 	its_encode_vpt_size(cmd, LPI_NRBITS - 1);
 
@@ -613,11 +616,14 @@ static struct its_vpe *its_build_vmovp_cmd(struct its_node *its,
 					   struct its_cmd_block *cmd,
 					   struct its_cmd_desc *desc)
 {
+	u64 target;
+
+	target = desc->its_vmapp_cmd.col->target_address + its->vlpi_redist_offset;
 	its_encode_cmd(cmd, GITS_CMD_VMOVP);
 	its_encode_seq_num(cmd, desc->its_vmovp_cmd.seq_num);
 	its_encode_its_list(cmd, desc->its_vmovp_cmd.its_list);
 	its_encode_vpeid(cmd, desc->its_vmovp_cmd.vpe->vpe_id);
-	its_encode_target(cmd, desc->its_vmovp_cmd.col->target_address);
+	its_encode_target(cmd, target);
 
 	its_fixup_cmd(cmd);
 
@@ -2668,6 +2674,17 @@ static void __maybe_unused its_enable_quirk_qdf2400_e0065(void *data)
 	its->ite_size = 16;
 }
 
+static void __maybe_unused its_enable_quirk_d05_vlpi_offset(void *data)
+{
+	struct its_node *its = data;
+
+	/*
+	 * D05 insists on using the wrong address for the VLPI
+	 * page. Trick it into doing the right thing...
+	 */
+	its->vlpi_redist_offset = SZ_128K;
+}
+
 static const struct gic_quirk its_quirks[] = {
 #ifdef CONFIG_CAVIUM_ERRATUM_22375
 	{
@@ -2694,6 +2711,12 @@ static const struct gic_quirk its_quirks[] = {
 	},
 #endif
 	{
+		.desc	= "ITS: D05 128kB VLPI offset",
+		.iidr	= 0x00000004,
+		.mask	= 0xffffffff,
+		.init	= its_enable_quirk_d05_vlpi_offset,
+	},
+	{
 	}
 };
 
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling
  2017-07-31 17:26 ` [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling Marc Zyngier
@ 2017-08-04  7:44   ` Marc Zyngier
  2017-08-28 18:18     ` Christoffer Dall
  2017-08-28 18:18   ` Christoffer Dall
  2017-09-06  9:06   ` Shannon Zhao
  2 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-08-04  7:44 UTC (permalink / raw)
  To: linux-kernel, linux-arm-kernel, kvmarm, kvm
  Cc: Christoffer Dall, Thomas Gleixner, Jason Cooper, Eric Auger,
	Shanker Donthineni, Mark Rutland, Shameerali Kolothum Thodi

On 31/07/17 18:26, Marc Zyngier wrote:
> When a vPE is not running, a VLPI being made pending results in a
> doorbell interrupt being delivered. Let's handle this interrupt
> and update the pending_last flag that indicates that VLPIs are
> pending. The corresponding vcpu is also kicked into action.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  virt/kvm/arm/vgic/vgic-v4.c | 34 ++++++++++++++++++++++++++++++++++
>  1 file changed, 34 insertions(+)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> index 534d3051a078..6af3cde6d7d4 100644
> --- a/virt/kvm/arm/vgic/vgic-v4.c
> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> @@ -21,6 +21,19 @@
>  
>  #include "vgic.h"
>  
> +static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
> +{
> +	struct kvm_vcpu *vcpu = info;
> +
> +	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
> +		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> +		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> +		kvm_vcpu_kick(vcpu);
> +	}

This code is so obviously broken that I completely overlooked it.

If we have take a doorbell interrupt, then it means nothing was
otherwise pending (because we'd have been kicked out of the blocking
state, and will have masked the doorbell). So checking for pending
interrupts is pointless.

Furthermore, calling kvm_vgic_vcpu_pending_irq() takes the ap_list
lock. If we take a doorbell interrupt while injecting a virtual
interrupt (from userspace, for example) on the same CPU, we end-up
in deadlock land. This would be solved by Christoffer's latest
crop of timer patches, but there is no point getting there the first
place.

The patchlet below solves it:

diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
index 15feb1151797..48e4d6ebeaa8 100644
--- a/virt/kvm/arm/vgic/vgic-v4.c
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -94,11 +94,9 @@ static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
 {
 	struct kvm_vcpu *vcpu = info;
 
-	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
-		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
-		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
-		kvm_vcpu_kick(vcpu);
-	}
+	vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
+	kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
+	kvm_vcpu_kick(vcpu);
 
 	return IRQ_HANDLED;
 }

and I've queued it for the next round.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass
  2017-07-31 17:26 ` [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass Marc Zyngier
@ 2017-08-26 19:48   ` Christoffer Dall
  2017-08-30  9:42     ` Marc Zyngier
  2017-08-30 10:28     ` Marc Zyngier
  0 siblings, 2 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-26 19:48 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On Mon, Jul 31, 2017 at 06:26:19PM +0100, Marc Zyngier wrote:
> Let's use the irq bypass mechanism introduced for platform device
> interrupts to intercept the virtual PCIe endpoint configuration
> and establish our LPI->VLPI mapping.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  include/kvm/arm_vgic.h      |   8 ++++
>  virt/kvm/arm/arm.c          |  27 ++++++++----
>  virt/kvm/arm/vgic/vgic-v4.c | 103 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 130 insertions(+), 8 deletions(-)
> 
> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> index 359eeffe9857..050f78d4fb42 100644
> --- a/include/kvm/arm_vgic.h
> +++ b/include/kvm/arm_vgic.h
> @@ -367,4 +367,12 @@ int kvm_vgic_set_forwarding(struct kvm *kvm, unsigned int host_irq,
>  void kvm_vgic_unset_forwarding(struct kvm *kvm, unsigned int host_irq,
>  			       unsigned int vintid);
>  
> +struct kvm_kernel_irq_routing_entry;
> +
> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int irq,
> +			       struct kvm_kernel_irq_routing_entry *irq_entry);
> +
> +int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int irq,
> +				 struct kvm_kernel_irq_routing_entry *irq_entry);
> +
>  #endif /* __KVM_ARM_VGIC_H */
> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
> index ebab6c29e3be..6803ea27c47d 100644
> --- a/virt/kvm/arm/arm.c
> +++ b/virt/kvm/arm/arm.c
> @@ -1457,11 +1457,16 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
>  	struct kvm_kernel_irqfd *irqfd =
>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
>  
> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
> +	switch (prod->type) {
> +	case IRQ_BYPASS_VFIO_PLATFORM:
> +		return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
> +					       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
> +	case IRQ_BYPASS_VFIO_PCI_MSI:
> +		return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq,
> +						  &irqfd->irq_entry);
> +	default:
>  		return 0;
> -
> -	return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
> -				       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
> +	}
>  }
>  void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
>  				      struct irq_bypass_producer *prod)
> @@ -1469,11 +1474,17 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
>  	struct kvm_kernel_irqfd *irqfd =
>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
>  
> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
> -		return;
> +	switch (prod->type) {
> +	case IRQ_BYPASS_VFIO_PLATFORM:
> +		kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
> +					  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
> +		break;
>  
> -	kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
> -				  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
> +	case IRQ_BYPASS_VFIO_PCI_MSI:
> +		kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq,
> +					     &irqfd->irq_entry);
> +		break;
> +	}
>  }
>  
>  void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> index 207e1fda0dcd..338c86c5159f 100644
> --- a/virt/kvm/arm/vgic/vgic-v4.c
> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> @@ -72,3 +72,106 @@ void vgic_v4_teardown(struct kvm *kvm)
>  	its_vm->nr_vpes = 0;
>  	its_vm->vpes = NULL;
>  }
> +
> +static struct vgic_its *vgic_get_its(struct kvm *kvm,
> +				     struct kvm_kernel_irq_routing_entry *irq_entry)
> +{
> +	struct kvm_msi msi  = (struct kvm_msi) {
> +		.address_lo	= irq_entry->msi.address_lo,
> +		.address_hi	= irq_entry->msi.address_hi,
> +		.data		= irq_entry->msi.data,
> +		.flags		= irq_entry->msi.flags,
> +		.devid		= irq_entry->msi.devid,
> +	};
> +
> +	/*
> +	 * Get a reference on the LPI. If NULL, this is not a valid
> +	 * translation for any of our vITSs.
> +	 */
> +	return vgic_msi_to_its(kvm, &msi);
> +}
> +
> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
> +			       struct kvm_kernel_irq_routing_entry *irq_entry)
> +{
> +	struct vgic_its *its;
> +	struct vgic_irq *irq;
> +	struct its_vlpi_map map;
> +	int ret;
> +
> +	if (!vgic_is_v4_capable(kvm))
> +		return 0;
> +
> +	/*
> +	 * Get the ITS, and escape early on error (not a valid
> +	 * doorbell for any of our vITSs).
> +	 */
> +	its = vgic_get_its(kvm, irq_entry);
> +	if (IS_ERR(its))
> +		return 0;
> +
> +	mutex_lock(&its->its_lock);
> +
> +	/* Perform then actual DevID/EventID -> LPI translation. */
> +	ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid,
> +				   irq_entry->msi.data, &irq);
> +	if (ret)
> +		goto out;
> +
> +	/*
> +	 * Emit the mapping request. If it fails, the ITS probably
> +	 * isn't v4 compatible, so let's silently bail out. Holding
> +	 * the ITS lock should ensure that nothing can modify the
> +	 * target vcpu.
> +	 */
> +	map = (struct its_vlpi_map) {
> +		.vm		= &kvm->arch.vgic.its_vm,
> +		.vintid		= irq->intid,
> +		.db_enabled	= true,
> +		.vpe_idx	= irq->target_vcpu->vcpu_id,
> +	};
> +
> +	if (its_map_vlpi(virq, &map))
> +		goto out;

This seems to be able to return things like -ENOMEM, whould we really
not report this back to the caller in any way?

> +
> +	irq->hw		= true;
> +	irq->host_irq	= virq;
> +
> +out:
> +	mutex_unlock(&its->its_lock);
> +	return 0;
> +}
> +
> +int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int virq,
> +				 struct kvm_kernel_irq_routing_entry *irq_entry)
> +{
> +	struct vgic_its *its;
> +	struct vgic_irq *irq;
> +	int ret;
> +
> +	if (!vgic_is_v4_capable(kvm))
> +		return 0;
> +
> +	/*
> +	 * Get the ITS, and escape early on error (not a valid
> +	 * doorbell for any of our vITSs).
> +	 */
> +	its = vgic_get_its(kvm, irq_entry);
> +	if (IS_ERR(its))
> +		return 0;
> +
> +	mutex_lock(&its->its_lock);
> +
> +	ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid,
> +				   irq_entry->msi.data, &irq);
> +	if (ret)
> +		goto out;
> +
> +	WARN_ON(!(irq->hw && irq->host_irq == virq));
> +	irq->hw = false;
> +	ret = its_unmap_vlpi(virq);
> +
> +out:
> +	mutex_unlock(&its->its_lock);
> +	return ret;
> +}
> -- 
> 2.11.0
> 
Otherwise looks good to me.

Thanks,
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 37/59] KVM: arm/arm64: vgic: Move kvm_vgic_destroy call around
  2017-07-31 17:26 ` [PATCH v3 37/59] KVM: arm/arm64: vgic: Move kvm_vgic_destroy call around Marc Zyngier
@ 2017-08-26 19:49   ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-26 19:49 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On Mon, Jul 31, 2017 at 06:26:15PM +0100, Marc Zyngier wrote:
> The way we call kvm_vgic_destroy is a bit bizarre. We call it
> *after* having freed the vcpus, which sort of defeats the point
> of cleaning up things before that point.
> 
> Let's move kvm_vgic_destroy towards the beginning of kvm_arch_destroy_vm,
> which seems more sensible.
> 

Acked-by: Christoffer Dall <cdall@linaro.org>

> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  virt/kvm/arm/arm.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
> index 7846a578db1a..ebab6c29e3be 100644
> --- a/virt/kvm/arm/arm.c
> +++ b/virt/kvm/arm/arm.c
> @@ -177,6 +177,8 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
>  {
>  	int i;
>  
> +	kvm_vgic_destroy(kvm);
> +
>  	free_percpu(kvm->arch.last_vcpu_ran);
>  	kvm->arch.last_vcpu_ran = NULL;
>  
> @@ -186,8 +188,6 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
>  			kvm->vcpus[i] = NULL;
>  		}
>  	}
> -
> -	kvm_vgic_destroy(kvm);
>  }
>  
>  int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
> -- 
> 2.11.0
> 

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 38/59] KVM: arm/arm64: vITS: Add MSI translation helpers
  2017-07-31 17:26 ` [PATCH v3 38/59] KVM: arm/arm64: vITS: Add MSI translation helpers Marc Zyngier
@ 2017-08-26 19:49   ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-26 19:49 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On Mon, Jul 31, 2017 at 06:26:16PM +0100, Marc Zyngier wrote:
> The whole MSI injection process is fairly monolithic. An MSI write
> gets turned into an injected LPI in one swift go. But this is actually
> a more fine-grained process:
> 
> - First, a virtual ITS gets selected using the doorbell address
> - Then the DevID/EventID pair gets translated into an LPI
> - Finally the LPI is injected
> 
> Since the GICv4 code needs the first two steps in order to match
> an IRQ routing entry to an LPI, let's expose them as helpers,
> and refactor the existing code to use them
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  virt/kvm/arm/vgic/vgic-its.c | 93 +++++++++++++++++++++++++-------------------
>  virt/kvm/arm/vgic/vgic.h     |  4 ++
>  2 files changed, 57 insertions(+), 40 deletions(-)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index aa6b68db80b4..fb7be8673bff 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -504,15 +504,8 @@ static unsigned long vgic_mmio_read_its_idregs(struct kvm *kvm,
>  	return 0;
>  }
>  
> -/*
> - * Find the target VCPU and the LPI number for a given devid/eventid pair
> - * and make this IRQ pending, possibly injecting it.
> - * Must be called with the its_lock mutex held.
> - * Returns 0 on success, a positive error value for any ITS mapping
> - * related errors and negative error values for generic errors.
> - */
> -static int vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its,
> -				u32 devid, u32 eventid)
> +int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
> +			 u32 devid, u32 eventid, struct vgic_irq **irq)
>  {
>  	struct kvm_vcpu *vcpu;
>  	struct its_ite *ite;
> @@ -531,26 +524,60 @@ static int vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its,
>  	if (!vcpu->arch.vgic_cpu.lpis_enabled)
>  		return -EBUSY;
>  
> -	spin_lock(&ite->irq->irq_lock);
> -	ite->irq->pending_latch = true;
> -	vgic_queue_irq_unlock(kvm, ite->irq);
> -
> +	*irq = ite->irq;
>  	return 0;
>  }
>  
> -static struct vgic_io_device *vgic_get_its_iodev(struct kvm_io_device *dev)
> +struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi)
>  {
> +	u64 address;
> +	struct kvm_io_device *kvm_io_dev;
>  	struct vgic_io_device *iodev;
>  
> -	if (dev->ops != &kvm_io_gic_ops)
> -		return NULL;
> +	if (!vgic_has_its(kvm))
> +		return ERR_PTR(-ENODEV);
>  
> -	iodev = container_of(dev, struct vgic_io_device, dev);
> +	if (!(msi->flags & KVM_MSI_VALID_DEVID))
> +		return ERR_PTR(-EINVAL);
> +
> +	address = (u64)msi->address_hi << 32 | msi->address_lo;
> +
> +	kvm_io_dev = kvm_io_bus_get_dev(kvm, KVM_MMIO_BUS, address);
> +	if (!kvm_io_dev)
> +		return ERR_PTR(-EINVAL);
>  
> +	if (kvm_io_dev->ops != &kvm_io_gic_ops)
> +		return ERR_PTR(-EINVAL);
> +
> +	iodev = container_of(kvm_io_dev, struct vgic_io_device, dev);
>  	if (iodev->iodev_type != IODEV_ITS)
> -		return NULL;
> +		return ERR_PTR(-EINVAL);
>  
> -	return iodev;
> +	return iodev->its;
> +}
> +
> +/*
> + * Find the target VCPU and the LPI number for a given devid/eventid pair
> + * and make this IRQ pending, possibly injecting it.
> + * Must be called with the its_lock mutex held.
> + * Returns 0 on success, a positive error value for any ITS mapping
> + * related errors and negative error values for generic errors.
> + */
> +static int vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its,
> +				u32 devid, u32 eventid)
> +{
> +	struct vgic_irq *irq = NULL;
> +	int err;
> +
> +	err = vgic_its_resolve_lpi(kvm, its, devid, eventid, &irq);
> +	if (err)
> +		return err;
> +
> +	spin_lock(&irq->irq_lock);
> +	irq->pending_latch = true;
> +	vgic_queue_irq_unlock(kvm, irq);
> +
> +	return 0;
>  }
>  
>  /*
> @@ -561,30 +588,16 @@ static struct vgic_io_device *vgic_get_its_iodev(struct kvm_io_device *dev)
>   */
>  int vgic_its_inject_msi(struct kvm *kvm, struct kvm_msi *msi)
>  {
> -	u64 address;
> -	struct kvm_io_device *kvm_io_dev;
> -	struct vgic_io_device *iodev;
> +	struct vgic_its *its;
>  	int ret;
>  
> -	if (!vgic_has_its(kvm))
> -		return -ENODEV;
> -
> -	if (!(msi->flags & KVM_MSI_VALID_DEVID))
> -		return -EINVAL;
> -
> -	address = (u64)msi->address_hi << 32 | msi->address_lo;
> -
> -	kvm_io_dev = kvm_io_bus_get_dev(kvm, KVM_MMIO_BUS, address);
> -	if (!kvm_io_dev)
> -		return -EINVAL;
> +	its = vgic_msi_to_its(kvm, msi);
> +	if (IS_ERR(its))
> +		return PTR_ERR(its);
>  
> -	iodev = vgic_get_its_iodev(kvm_io_dev);
> -	if (!iodev)
> -		return -EINVAL;
> -
> -	mutex_lock(&iodev->its->its_lock);
> -	ret = vgic_its_trigger_msi(kvm, iodev->its, msi->devid, msi->data);
> -	mutex_unlock(&iodev->its->its_lock);
> +	mutex_lock(&its->its_lock);
> +	ret = vgic_its_trigger_msi(kvm, its, msi->devid, msi->data);
> +	mutex_unlock(&its->its_lock);
>  
>  	if (ret < 0)
>  		return ret;
> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
> index da254ae29aec..3002b72d938b 100644
> --- a/virt/kvm/arm/vgic/vgic.h
> +++ b/virt/kvm/arm/vgic/vgic.h
> @@ -225,4 +225,8 @@ int vgic_debug_destroy(struct kvm *kvm);
>  bool lock_all_vcpus(struct kvm *kvm);
>  void unlock_all_vcpus(struct kvm *kvm);
>  
> +int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
> +			 u32 devid, u32 eventid, struct vgic_irq **irq);
> +struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi);
> +
>  #endif
> -- 
> 2.11.0
> 

Reviewed-by: Christoffer Dall <cdall@linaro.org>

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 39/59] KVM: arm/arm64: GICv4: Add property field and per-VM predicate
  2017-07-31 17:26 ` [PATCH v3 39/59] KVM: arm/arm64: GICv4: Add property field and per-VM predicate Marc Zyngier
@ 2017-08-26 19:49   ` Christoffer Dall
  2017-08-30  9:46     ` Marc Zyngier
  0 siblings, 1 reply; 118+ messages in thread
From: Christoffer Dall @ 2017-08-26 19:49 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On Mon, Jul 31, 2017 at 06:26:17PM +0100, Marc Zyngier wrote:
> Add a new has_gicv4 field in the global VGIC state that indicates
> whether the HW is GICv4 capable, as a per-VM predicate indicating
> if there is a possibility for a VM to support direct injection
> (the above being true and the VM having an ITS).
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  include/kvm/arm_vgic.h           | 3 +++
>  virt/kvm/arm/vgic/vgic-mmio-v3.c | 5 +++++
>  virt/kvm/arm/vgic/vgic.h         | 2 ++
>  3 files changed, 10 insertions(+)
> 
> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> index ee8587c8c715..84694b42373a 100644
> --- a/include/kvm/arm_vgic.h
> +++ b/include/kvm/arm_vgic.h
> @@ -73,6 +73,9 @@ struct vgic_global {
>  	/* Only needed for the legacy KVM_CREATE_IRQCHIP */
>  	bool			can_emulate_gicv2;
>  
> +	/* Does have GICv4? */

nit: questionable comment, how about

  /* Hardware has GICv4? */
or
  /* Do we have GICv4? */

> +	bool			has_gicv4;
> +
>  	/* GIC system register CPU interface */
>  	struct static_key_false gicv3_cpuif;
>  
> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> index 714fa3933546..74109ca75cc0 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> @@ -54,6 +54,11 @@ bool vgic_has_its(struct kvm *kvm)
>  	return dist->has_its;
>  }
>  
> +bool vgic_is_v4_capable(struct kvm *kvm)
> +{
> +	return kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm);
> +}
> +

uber nit: the naming here is a bit funny, because we won't be presenting
a GICv4 GIC to the guest, so I'd prefer something like
vgic_supports_direct_msis() or something like that, but this is
obviously not a deal breaker.

>  static unsigned long vgic_mmio_read_v3_misc(struct kvm_vcpu *vcpu,
>  					    gpa_t addr, unsigned int len)
>  {
> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
> index 3002b72d938b..90f6436a11aa 100644
> --- a/virt/kvm/arm/vgic/vgic.h
> +++ b/virt/kvm/arm/vgic/vgic.h
> @@ -229,4 +229,6 @@ int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
>  			 u32 devid, u32 eventid, struct vgic_irq **irq);
>  struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi);
>  
> +bool vgic_is_v4_capable(struct kvm *kvm);
> +
>  #endif
> -- 
> 2.11.0
> 

Thanks,
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 40/59] KVM: arm/arm64: GICv4: Add init/teardown of the per-VM vPE irq domain
  2017-07-31 17:26 ` [PATCH v3 40/59] KVM: arm/arm64: GICv4: Add init/teardown of the per-VM vPE irq domain Marc Zyngier
@ 2017-08-26 19:49   ` Christoffer Dall
  2017-08-30  9:50     ` Marc Zyngier
  0 siblings, 1 reply; 118+ messages in thread
From: Christoffer Dall @ 2017-08-26 19:49 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: Jason Cooper, kvm, linux-kernel, Thomas Gleixner, kvmarm,
	linux-arm-kernel

On Mon, Jul 31, 2017 at 06:26:18PM +0100, Marc Zyngier wrote:
> In order to control the GICv4 view of virtual CPUs, we rely
> on an irqdomain allocated for that purpose. Let's add a couple
> of helpers to that effect.
> 
> At the same time, the vgic data structures gain new fields to
> track all this... erm... wonderful stuff.
> 
> They way we hook into the vgic init is slightly convoluted. We

*The way ?

> need the vgic to be initialized (in order to guarantee that
> the number of vcpus is now fixed), and we must have a vITS
> (otherwise this is all very pointless). So we end-up calling
> the init from both sites...

Which sites (sides ?) are those?

> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  arch/arm/kvm/Makefile         |  1 +
>  arch/arm64/kvm/Makefile       |  1 +
>  include/kvm/arm_vgic.h        |  8 +++++
>  virt/kvm/arm/vgic/vgic-init.c |  9 ++++++
>  virt/kvm/arm/vgic/vgic-its.c  |  8 +++++
>  virt/kvm/arm/vgic/vgic-v4.c   | 74 +++++++++++++++++++++++++++++++++++++++++++
>  virt/kvm/arm/vgic/vgic.h      |  2 ++
>  7 files changed, 103 insertions(+)
>  create mode 100644 virt/kvm/arm/vgic/vgic-v4.c
> 
> diff --git a/arch/arm/kvm/Makefile b/arch/arm/kvm/Makefile
> index d9beee652d36..0a1dd2cdb928 100644
> --- a/arch/arm/kvm/Makefile
> +++ b/arch/arm/kvm/Makefile
> @@ -31,6 +31,7 @@ obj-y += $(KVM)/arm/vgic/vgic-init.o
>  obj-y += $(KVM)/arm/vgic/vgic-irqfd.o
>  obj-y += $(KVM)/arm/vgic/vgic-v2.o
>  obj-y += $(KVM)/arm/vgic/vgic-v3.o
> +obj-y += $(KVM)/arm/vgic/vgic-v4.o
>  obj-y += $(KVM)/arm/vgic/vgic-mmio.o
>  obj-y += $(KVM)/arm/vgic/vgic-mmio-v2.o
>  obj-y += $(KVM)/arm/vgic/vgic-mmio-v3.o
> diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
> index 5d9810086c25..c30fd388ef80 100644
> --- a/arch/arm64/kvm/Makefile
> +++ b/arch/arm64/kvm/Makefile
> @@ -26,6 +26,7 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-init.o
>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-irqfd.o
>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-v2.o
>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-v3.o
> +kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-v4.o
>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio.o
>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio-v2.o
>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio-v3.o
> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> index 84694b42373a..359eeffe9857 100644
> --- a/include/kvm/arm_vgic.h
> +++ b/include/kvm/arm_vgic.h
> @@ -26,6 +26,8 @@
>  #include <linux/list.h>
>  #include <linux/jump_label.h>
>  
> +#include <linux/irqchip/arm-gic-v4.h>
> +
>  #define VGIC_V3_MAX_CPUS	255
>  #define VGIC_V2_MAX_CPUS	8
>  #define VGIC_NR_IRQS_LEGACY     256
> @@ -236,6 +238,9 @@ struct vgic_dist {
>  
>  	/* used by vgic-debug */
>  	struct vgic_state_iter *iter;
> +
> +	/* GICv4 ITS per-VM stuff */

I think we can do a little better in this comment.  Is it possible to
succinctly explain the role of this field, e.g. ties together Linux IRQ
subsystem structures with the GIC, or what the role really is.

> +	struct its_vm		its_vm;
>  };
>  
>  struct vgic_v2_cpu_if {
> @@ -254,6 +259,9 @@ struct vgic_v3_cpu_if {
>  	u32		vgic_ap0r[4];
>  	u32		vgic_ap1r[4];
>  	u64		vgic_lr[VGIC_V3_MAX_LRS];
> +
> +	/* GICv4 vPE info */

same

> +	struct its_vpe	its_vpe;
>  };
>  
>  struct vgic_cpu {
> diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
> index 5801261f3add..d1c6c775203d 100644
> --- a/virt/kvm/arm/vgic/vgic-init.c
> +++ b/virt/kvm/arm/vgic/vgic-init.c
> @@ -285,6 +285,12 @@ int vgic_init(struct kvm *kvm)
>  	if (ret)
>  		goto out;
>  
> +	if (vgic_has_its(kvm) && vgic_is_v4_capable(kvm)) {
> +		ret = vgic_v4_init(kvm);
> +		if (ret)
> +			goto out;
> +	}
> +
>  	kvm_for_each_vcpu(i, vcpu, kvm)
>  		kvm_vgic_vcpu_enable(vcpu);
>  
> @@ -320,6 +326,9 @@ static void kvm_vgic_dist_destroy(struct kvm *kvm)
>  
>  	kfree(dist->spis);
>  	dist->nr_spis = 0;
> +
> +	if (vgic_is_v4_capable(kvm))
> +		vgic_v4_teardown(kvm);
>  }
>  
>  void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index fb7be8673bff..a2217f53bbe5 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -1603,6 +1603,14 @@ static int vgic_its_create(struct kvm_device *dev, u32 type)
>  	if (!its)
>  		return -ENOMEM;
>  
> +	if (vgic_initialized(dev->kvm)) {
> +		int ret = vgic_v4_init(dev->kvm);
> +		if (ret) {
> +			kfree(its);
> +			return ret;
> +		}
> +	}
> +	
>  	mutex_init(&its->its_lock);
>  	mutex_init(&its->cmd_lock);
>  
> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> new file mode 100644
> index 000000000000..207e1fda0dcd
> --- /dev/null
> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> @@ -0,0 +1,74 @@
> +/*
> + * Copyright (C) 2017 ARM Ltd.
> + * Author: Marc Zyngier <marc.zyngier@arm.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/interrupt.h>
> +#include <linux/irqdomain.h>
> +#include <linux/kvm_host.h>
> +
> +#include "vgic.h"
> +
> +int vgic_v4_init(struct kvm *kvm)
> +{
> +	struct vgic_dist *dist = &kvm->arch.vgic;
> +	struct kvm_vcpu *vcpu;
> +	int i, nr_vcpus, ret;
> +
> +	/*
> +	 * We may be called each time a vITS is created, or when the
> +	 * vgic is initialized. This relies on kvm->lock to be
> +	 * held. In both cases, the number of vcpus should now be
> +	 * fixed.
> +	 */

I don't really see the connection between this comment and the following
block.  Was this comment meant for the whole function?

> +	if (dist->its_vm.vpes)
> +		return 0;
> +
> +	nr_vcpus = atomic_read(&kvm->online_vcpus);
> +
> +	dist->its_vm.vpes = kzalloc(sizeof(*dist->its_vm.vpes) * nr_vcpus,
> +				    GFP_KERNEL);
> +	if (!dist->its_vm.vpes)
> +		return -ENOMEM;
> +
> +	dist->its_vm.nr_vpes = nr_vcpus;
> +
> +	kvm_for_each_vcpu(i, vcpu, kvm)
> +		dist->its_vm.vpes[i] = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;
> +
> +	ret = its_alloc_vcpu_irqs(&dist->its_vm);
> +	if (ret < 0) {
> +		kvm_err("VPE IRQ allocation failure\n");
> +		kfree(dist->its_vm.vpes);
> +		dist->its_vm.nr_vpes = 0;
> +		dist->its_vm.vpes = NULL;
> +		return ret;
> +	}
> +
> +	return ret;
> +}
> +
> +void vgic_v4_teardown(struct kvm *kvm)
> +{
> +	struct its_vm *its_vm = &kvm->arch.vgic.its_vm;
> +
> +	if (!its_vm->vpes)
> +		return;
> +
> +	its_free_vcpu_irqs(its_vm);
> +	kfree(its_vm->vpes);
> +	its_vm->nr_vpes = 0;
> +	its_vm->vpes = NULL;
> +}
> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
> index 90f6436a11aa..1356f485d7cf 100644
> --- a/virt/kvm/arm/vgic/vgic.h
> +++ b/virt/kvm/arm/vgic/vgic.h
> @@ -230,5 +230,7 @@ int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
>  struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi);
>  
>  bool vgic_is_v4_capable(struct kvm *kvm);
> +int vgic_v4_init(struct kvm *kvm);
> +void vgic_v4_teardown(struct kvm *kvm);
>  
>  #endif
> -- 
> 2.11.0
> 

Thanks,
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 36/59] KVM: arm: Select ARM_GIC_V3 and ARM_GIC_V3_ITS
  2017-07-31 17:26 ` [PATCH v3 36/59] KVM: arm: Select ARM_GIC_V3 and ARM_GIC_V3_ITS Marc Zyngier
@ 2017-08-26 19:49   ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-26 19:49 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On Mon, Jul 31, 2017 at 06:26:14PM +0100, Marc Zyngier wrote:
> The GICv4 support introduces a hard dependency between the KVM
> core and the ITS infrastructure. arm64 already selects it at
> the architecture level, but 32bit doesn't. In order to avoid
> littering the kernel with #ifdefs, let's just select the whole
> of the GICv3 suport code.
>
> You know you want it.

Acked-by: Christoffer Dall <cdall@linaro.org>

>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  arch/arm/kvm/Kconfig | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig
> index 4e2b192a030a..52b50af04e3b 100644
> --- a/arch/arm/kvm/Kconfig
> +++ b/arch/arm/kvm/Kconfig
> @@ -23,6 +23,8 @@ config KVM
>   select PREEMPT_NOTIFIERS
>   select ANON_INODES
>   select ARM_GIC
> + select ARM_GIC_V3
> + select ARM_GIC_V3_ITS
>   select HAVE_KVM_CPU_RELAX_INTERCEPT
>   select HAVE_KVM_ARCH_TLB_FLUSH_ALL
>   select KVM_MMIO
> --
> 2.11.0
>

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 53/59] KVM: arm/arm64: GICv4: Hook vPE scheduling into vgic flush/sync
  2017-07-31 17:26 ` [PATCH v3 53/59] KVM: arm/arm64: GICv4: Hook vPE scheduling into vgic flush/sync Marc Zyngier
@ 2017-08-28 18:17   ` Christoffer Dall
  2017-08-30  9:59     ` Marc Zyngier
  0 siblings, 1 reply; 118+ messages in thread
From: Christoffer Dall @ 2017-08-28 18:17 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On Mon, Jul 31, 2017 at 06:26:31PM +0100, Marc Zyngier wrote:
> The redistributor needs to be told which vPE is about to be run,
> and tells us whether there is any pending VLPI on exit.
> 
> Let's add the scheduling calls to the vgic flush/sync functions,
> allowing the VLPIs to be delivered to the guest.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  virt/kvm/arm/vgic/vgic-v4.c | 24 ++++++++++++++++++++++++
>  virt/kvm/arm/vgic/vgic.c    |  4 ++++
>  virt/kvm/arm/vgic/vgic.h    |  1 +
>  3 files changed, 29 insertions(+)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> index 50721c4e3da5..0a8deefbcf1c 100644
> --- a/virt/kvm/arm/vgic/vgic-v4.c
> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> @@ -119,6 +119,30 @@ void vgic_v4_teardown(struct kvm *kvm)
>  	its_vm->vpes = NULL;
>  }
>  
> +int vgic_v4_schedule(struct kvm_vcpu *vcpu, bool on)
> +{
> +	int irq = vcpu->arch.vgic_cpu.vgic_v3.its_vpe.irq;
> +
> +	if (!vgic_is_v4_capable(vcpu->kvm) || !irq)
> +		return 0;

why do we need to check the its_vpe.irq here?  This check is certainly
not untuitive, as I don't understand what happened on a v4 capable
system that somehow failed.  Is it because a specific VM is configured
to not use VLPIs, or?

> +
> +	/*
> +	 * Before making the VPE resident, make sure the redistributor
> +	 * expects us here.
> +	 */
> +	if (on) {
> +		int err;
> +
> +		err = irq_set_affinity(irq, cpumask_of(smp_processor_id()));

This is pretty unintuitive, and coming here without having read your
documentation may make people completely puzzled.  Could we provide a
pointer to the documentation that explains how the vpe irq hooks this
all together?

> +		if (err) {
> +			kvm_err("failed irq_set_affinity IRQ%d (%d)\n", irq, err);
> +			return err;
> +		}
> +	}
> +
> +	return its_schedule_vpe(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe, on);
> +}
> +

I'd prefer this function be split into two and follow the vgic notation
of having a flush and a sync function.

>  static struct vgic_its *vgic_get_its(struct kvm *kvm,
>  				     struct kvm_kernel_irq_routing_entry *irq_entry)
>  {
> diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
> index dfac894f6f03..9ab52108989d 100644
> --- a/virt/kvm/arm/vgic/vgic.c
> +++ b/virt/kvm/arm/vgic/vgic.c
> @@ -721,6 +721,8 @@ void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
>  {
>  	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
>  
> +	WARN_ON(vgic_v4_schedule(vcpu, false));
> +

This is in the critical path, so would it be worth considering a static
key to cater for non-GICv4 systems here?

>  	/* An empty ap_list_head implies used_lrs == 0 */
>  	if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head))
>  		return;
> @@ -733,6 +735,8 @@ void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
>  /* Flush our emulation state into the GIC hardware before entering the guest. */
>  void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
>  {
> +	WARN_ON(vgic_v4_schedule(vcpu, true));
> +
>  	/*
>  	 * If there are no virtual interrupts active or pending for this
>  	 * VCPU, then there is no work to do and we can bail out without
> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
> index 1210bf4681dc..693b654acf4d 100644
> --- a/virt/kvm/arm/vgic/vgic.h
> +++ b/virt/kvm/arm/vgic/vgic.h
> @@ -234,5 +234,6 @@ int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
>  bool vgic_is_v4_capable(struct kvm *kvm);
>  int vgic_v4_init(struct kvm *kvm);
>  void vgic_v4_teardown(struct kvm *kvm);
> +int vgic_v4_schedule(struct kvm_vcpu *vcpu, bool on);
>  
>  #endif
> -- 
> 2.11.0
> 
Functionally, this looks correct.

Thanks,
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 42/59] KVM: arm/arm64: GICv4: Handle INT command applied to a VLPI
  2017-07-31 17:26 ` [PATCH v3 42/59] KVM: arm/arm64: GICv4: Handle INT command applied to a VLPI Marc Zyngier
@ 2017-08-28 18:18   ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-28 18:18 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On Mon, Jul 31, 2017 at 06:26:20PM +0100, Marc Zyngier wrote:
> If the guest issues an INT command targetting a VLPI, let's
> call into the irq_set_irqchip_state() helper to make it pending
> on the physical side.
> 
> This works just as well if userspace decides to inject an interrupt
> using the normal userspace API...
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Acked-by: Christoffer Dall <cdall@linaro.org>

> ---
>  virt/kvm/arm/vgic/vgic-its.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index a2217f53bbe5..40aeadef33fe 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -573,6 +573,10 @@ static int vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its,
>  	if (err)
>  		return err;
>  
> +	if (irq->hw)
> +		return irq_set_irqchip_state(irq->host_irq,
> +					     IRQCHIP_STATE_PENDING, true);
> +
>  	spin_lock(&irq->irq_lock);
>  	irq->pending_latch = true;
>  	vgic_queue_irq_unlock(kvm, irq);
> -- 
> 2.11.0
> 

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 43/59] KVM: arm/arm64: GICv4: Unmap VLPI when freeing an LPI
  2017-07-31 17:26 ` [PATCH v3 43/59] KVM: arm/arm64: GICv4: Unmap VLPI when freeing an LPI Marc Zyngier
@ 2017-08-28 18:18   ` Christoffer Dall
  2017-08-30 11:03     ` Marc Zyngier
  0 siblings, 1 reply; 118+ messages in thread
From: Christoffer Dall @ 2017-08-28 18:18 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On Mon, Jul 31, 2017 at 06:26:21PM +0100, Marc Zyngier wrote:
> When freeing an LPI (on a DISCARD command, for example), we need
> to unmap the VLPI down to the physical ITS level.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  virt/kvm/arm/vgic/vgic-its.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 40aeadef33fe..79bac93d3e7d 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -623,8 +623,12 @@ static void its_free_ite(struct kvm *kvm, struct its_ite *ite)
>  	list_del(&ite->ite_list);
>  
>  	/* This put matches the get in vgic_add_lpi. */
> -	if (ite->irq)
> +	if (ite->irq) {
> +		if (ite->irq->hw)
> +			its_unmap_vlpi(ite->irq->host_irq);

nit: should we raise a warning on a bad return value?

Otherwise:

Acked-by: Christoffer Dall <cdall@linaro.org>

> +
>  		vgic_put_irq(kvm, ite->irq);
> +	}
>  
>  	kfree(ite);
>  }
> -- 
> 2.11.0
> 

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 57/59] KVM: arm/arm64: GICv4: Theory of operations
  2017-07-31 17:26 ` [PATCH v3 57/59] KVM: arm/arm64: GICv4: Theory of operations Marc Zyngier
@ 2017-08-28 18:18   ` Christoffer Dall
  2017-08-30 11:30     ` Marc Zyngier
  0 siblings, 1 reply; 118+ messages in thread
From: Christoffer Dall @ 2017-08-28 18:18 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On Mon, Jul 31, 2017 at 06:26:35PM +0100, Marc Zyngier wrote:
> Yet another braindump so I can free some cells...
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  virt/kvm/arm/vgic/vgic-v4.c | 68 +++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 68 insertions(+)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> index 0a8deefbcf1c..0c002d2be620 100644
> --- a/virt/kvm/arm/vgic/vgic-v4.c
> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> @@ -22,6 +22,74 @@
>  
>  #include "vgic.h"
>  
> +/*
> + * How KVM uses GICv4 (insert rude comments here):
> + *
> + * The vgic-v4 layer acts as a bridge between several entities:
> + * - The GICv4 ITS representation offered by the ITS driver
> + * - VFIO, which is in charge of the PCI endpoint
> + * - The virtual ITS, which is the only thing the guest sees
> + *
> + * The configuration of VLPIs is triggered by a callback from VFIO,
> + * instructing KVM that a PCI device has been configured to deliver
> + * MSIs to a vITS.
> + *
> + * kvm_vgic_v4_set_forwarding() is thus called with the routing entry,
> + * and this is used to find the corresponding vITS data structures
> + * (ITS instance, device, event and irq) using a process that is
> + * extremely similar to the injection of an MSI.
> + *
> + * At this stage, we can link the guest's view of an LPI (uniquely
> + * identified by the routing entry) and the host irq, using the GICv4
> + * driver mapping operation. Should the mapping succeed, we've then
> + * successfully upgraded the guest's LPI to a VLPI. We can then start
> + * with updating GICv4's view of the property table and generating an
> + * INValidation in order to kickstart the delivery of this VLPI to the
> + * guest directly, without software intervention. Well, almost.
> + *
> + * When the PCI endpoint is deconfigured, this operation is reversed
> + * with VFIO calling kvm_vgic_v4_unset_forwarding().
> + *
> + * Once the VLPI has been mapped, it needs to follow any change the
> + * guest performs on its LPI through the vITS. For that, a number of
> + * command handlers have hooks to communicate these changes to the HW:
> + * - Any invalidation triggers a call to its_prop_update_vlpi()
> + * - The INT command results in a irq_set_irqchip_state(), which
> + *   generates an INT on the corresponding VLPI.
> + * - The CLEAR command results in a irq_set_irqchip_state(), which
> + *   generates an CLEAR on the corresponding VLPI.
> + * - DISCARD translates into an unmap, similar to a call to
> + *   kvm_vgic_v4_unset_forwarding().

So is VFIO notified of this or does it still think the IRQ is
forwarded?  Or does it not care, and it's state maintained by the irq
subsystem?

> + * - MOVI is translated by an update of the existing mapping, changing
> + *   the target vcpu, resulting in a VMOVI being generated.
> + * - MOVALL is translated by a string of mapping updates (similar to
> + *   the handling of MOVI). MOVALL is horrible.
> + *
> + * Note that a DISCARD/MAPTI sequence emitted from the guest without
> + * reprogramming the PCI endpoint after MAPTI does not result in a
> + * VLPI being mapped, as there is no callback from VFIO (the guest
> + * will get the interrupt via the normal SW injection). Fixing this is
> + * not trivial, and requires some horrible messing with the VFIO
> + * internals. Not fun. Don't do that.

Is there not a quick way to check with VFIO or the irq subsystem if this
interrupt can be forwarded and attempt that when handling the MAPTI in
the vTIS, or does this break in horrible ways?

> + *
> + * Then there is the scheduling. Each time a vcpu is about to run on a
> + * physical CPU, KVM must tell the corresponding redistributor about
> + * it. And if we've migrated our vcpu from one CPU to another, we must
> + * tell the ITS (so that the messages reach the right redistributor).
> + * This is done in two steps: first issue a irq_set_affinity() on the
> + * irq corresponding to the vcpu, then call its_schedule_vpe(). You
> + * must be in a non-preemptible context. On exit, another call to
> + * its_schedule_vpe() tells the redistributor that we're done with the
> + * vcpu.
> + *
> + * Finally, the doorbell handling: Each vcpu is allocated an interrupt
> + * which will fire each time a VLPI is made pending whilst the vcpu is
> + * not running. Each time the vcpu gets blocked, the doorbell
> + * interrupt gets enabled. When the vcpu is unblocked (for whatever
> + * reason), the doorbell interrupt is disabled. This behaviour is
> + * pretty similar to that of the backgroud timer.

*background

However, I think you can probably drop the last sentence in interest of
clarity.

> + */
> +
>  static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
>  {
>  	struct kvm_vcpu *vcpu = info;
> -- 
> 2.11.0
> 

Thanks for an otherwise excellent (and of course entertaining) writeup!
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 44/59] KVM: arm/arm64: GICv4: Handle MOVI applied to a VLPI
  2017-07-31 17:26 ` [PATCH v3 44/59] KVM: arm/arm64: GICv4: Handle MOVI applied to a VLPI Marc Zyngier
@ 2017-08-28 18:18   ` Christoffer Dall
  2017-08-30 14:08     ` Marc Zyngier
  0 siblings, 1 reply; 118+ messages in thread
From: Christoffer Dall @ 2017-08-28 18:18 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On Mon, Jul 31, 2017 at 06:26:22PM +0100, Marc Zyngier wrote:
> When the guest issues a MOVI, we need to tell the physical ITS
> that we're now targetting a new vcpu. This is done by extracting
> the current mapping, updating the target, and reapplying the
> mapping. The core ITS code should do the right thing.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  virt/kvm/arm/vgic/vgic-its.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 79bac93d3e7d..aaad577ce328 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -706,6 +706,19 @@ static int vgic_its_cmd_handle_movi(struct kvm *kvm, struct vgic_its *its,
>  	ite->irq->target_vcpu = vcpu;
>  	spin_unlock(&ite->irq->irq_lock);
>  
> +	if (ite->irq->hw) {
> +		struct its_vlpi_map map;
> +		int ret;
> +
> +		ret = its_get_vlpi(ite->irq->host_irq, &map);
> +		if (ret)
> +			return ret;
> +
> +		map.vpe_idx = vcpu->vcpu_id;
> +
> +		return its_map_vlpi(ite->irq->host_irq, &map);

Since you're not holding the irq_lock across these two calls, would it
be possible that the forwarding was removed through some other call path
here, and could you end up passing an invalid host_irq to its_map_vlpi?

Thanks,
-Christoffer

> +	}
> +
>  	return 0;
>  }
>  
> -- 
> 2.11.0
> 

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 45/59] KVM: arm/arm64: GICv4: Handle CLEAR applied to a VLPI
  2017-07-31 17:26 ` [PATCH v3 45/59] KVM: arm/arm64: GICv4: Handle CLEAR " Marc Zyngier
@ 2017-08-28 18:18   ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-28 18:18 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On Mon, Jul 31, 2017 at 06:26:23PM +0100, Marc Zyngier wrote:
> Handling CLEAR is pretty easy. Just ask the ITS driver to clear
> the corresponding pending bit (which will turn into a CLEAR
> command on the physical side).
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Acked-by: Christoffer Dall <cdall@linaro.org>

> ---
>  virt/kvm/arm/vgic/vgic-its.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index aaad577ce328..2c065c970ba0 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -1069,6 +1069,10 @@ static int vgic_its_cmd_handle_clear(struct kvm *kvm, struct vgic_its *its,
>  
>  	ite->irq->pending_latch = false;
>  
> +	if (ite->irq->hw)
> +		return irq_set_irqchip_state(ite->irq->host_irq,
> +					     IRQCHIP_STATE_PENDING, false);
> +
>  	return 0;
>  }
>  
> -- 
> 2.11.0
> 

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 46/59] KVM: arm/arm64: GICv4: Handle MOVALL applied to a vPE
  2017-07-31 17:26 ` [PATCH v3 46/59] KVM: arm/arm64: GICv4: Handle MOVALL applied to a vPE Marc Zyngier
@ 2017-08-28 18:18   ` Christoffer Dall
  2017-08-30 14:46     ` Marc Zyngier
  0 siblings, 1 reply; 118+ messages in thread
From: Christoffer Dall @ 2017-08-28 18:18 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On Mon, Jul 31, 2017 at 06:26:24PM +0100, Marc Zyngier wrote:
> The current implementation of MOVALL doesn't allow us to call
> into the core ITS code as we hold a number of spinlocks.
> 
> Let's try a method used in other parts of the code, were we copy
> the intids of the candicate interrupts, and then do whatever
> we need to do with them outside of the critical section.
> 
> This allows us to move the interrupts one by one, at the expense
> of a bit of CPU time. Who cares? MOVALL is such a stupid command
> anyway...
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  virt/kvm/arm/vgic/vgic-its.c | 27 ++++++++++++++++++++-------
>  1 file changed, 20 insertions(+), 7 deletions(-)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 2c065c970ba0..65cc77fde609 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -1147,11 +1147,12 @@ static int vgic_its_cmd_handle_invall(struct kvm *kvm, struct vgic_its *its,
>  static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
>  				      u64 *its_cmd)
>  {
> -	struct vgic_dist *dist = &kvm->arch.vgic;
>  	u32 target1_addr = its_cmd_get_target_addr(its_cmd);
>  	u32 target2_addr = its_cmd_mask_field(its_cmd, 3, 16, 32);
>  	struct kvm_vcpu *vcpu1, *vcpu2;
>  	struct vgic_irq *irq;
> +	u32 *intids;
> +	int irq_count, i;
>  
>  	if (target1_addr >= atomic_read(&kvm->online_vcpus) ||
>  	    target2_addr >= atomic_read(&kvm->online_vcpus))
> @@ -1163,19 +1164,31 @@ static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
>  	vcpu1 = kvm_get_vcpu(kvm, target1_addr);
>  	vcpu2 = kvm_get_vcpu(kvm, target2_addr);
>  
> -	spin_lock(&dist->lpi_list_lock);
> +	irq_count = vgic_copy_lpi_list(vcpu1, &intids);
> +	if (irq_count < 0)
> +		return irq_count;
>  
> -	list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) {
> -		spin_lock(&irq->irq_lock);
> +	for (i = 0; i < irq_count; i++) {
> +		irq = vgic_get_irq(kvm, NULL, intids[i]);
> +		if (!irq)
> +			continue;

Getting irq == NULL means that we've removed this LPI since
vgic_copy_lpi_list, right?  Can this really happen while we hold the its
mutex?

Also, we don't check this in its_sync_lpi_pending_table which would
indicate that we either have a bug there or are being overly careful
here (or should change the continue to BUG).


>  
>  		if (irq->target_vcpu == vcpu1)
>  			irq->target_vcpu = vcpu2;
>  
> -		spin_unlock(&irq->irq_lock);

Is it safe to modify target_vcpu without holding the irq_lock?

> -	}
> +		if (irq->hw) {
> +			struct its_vlpi_map map;
>  
> -	spin_unlock(&dist->lpi_list_lock);
> +			if (!its_get_vlpi(irq->host_irq, &map)) {
> +				map.vpe_idx = vcpu2->vcpu_id;
> +				its_map_vlpi(irq->host_irq, &map);
> +			}
> +		}
>  
> +		vgic_put_irq(kvm, irq);
> +	}
> +
> +	kfree(intids);
>  	return 0;
>  }
>  
> -- 
> 2.11.0
> 

Thanks,
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 47/59] KVM: arm/arm64: GICv4: Propagate property updates to VLPIs
  2017-07-31 17:26 ` [PATCH v3 47/59] KVM: arm/arm64: GICv4: Propagate property updates to VLPIs Marc Zyngier
@ 2017-08-28 18:18   ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-28 18:18 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On Mon, Jul 31, 2017 at 06:26:25PM +0100, Marc Zyngier wrote:
> Upon updating a property, we propagate it all the way to the physical
> ITS, and ask for an INV command to be executed there.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Acked-by: Christoffer Dall <cdall@linaro.org>

> ---
>  virt/kvm/arm/vgic/vgic-its.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 65cc77fde609..9e46081e5f15 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -297,6 +297,9 @@ static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
>  		spin_unlock(&irq->irq_lock);
>  	}
>  
> +	if (irq->hw)
> +		return its_prop_update_vlpi(irq->host_irq, prop, true);
> +
>  	return 0;
>  }
>  
> -- 
> 2.11.0
> 

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 48/59] KVM: arm/arm64: GICv4: Handle INVALL applied to a vPE
  2017-07-31 17:26 ` [PATCH v3 48/59] KVM: arm/arm64: GICv4: Handle INVALL applied to a vPE Marc Zyngier
@ 2017-08-28 18:18   ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-28 18:18 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On Mon, Jul 31, 2017 at 06:26:26PM +0100, Marc Zyngier wrote:
> Since when updating the properties one LPI at a time, there is no
> need to perform an INV each time we read one. Instead, we rely
> on the final VINVALL that gets sent to the ITS to do the work.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Acked-by: Christoffer Dall <cdall@linaro.org>

> ---
>  virt/kvm/arm/vgic/vgic-its.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 9e46081e5f15..b395df1bf47c 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -38,7 +38,7 @@ static int vgic_its_save_tables_v0(struct vgic_its *its);
>  static int vgic_its_restore_tables_v0(struct vgic_its *its);
>  static int vgic_its_commit_v0(struct vgic_its *its);
>  static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
> -			     struct kvm_vcpu *filter_vcpu);
> +			     struct kvm_vcpu *filter_vcpu, bool needs_inv);
>  
>  /*
>   * Creates a new (reference to a) struct vgic_irq for a given LPI.
> @@ -106,7 +106,7 @@ static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid,
>  	 * However we only have those structs for mapped IRQs, so we read in
>  	 * the respective config data from memory here upon mapping the LPI.
>  	 */
> -	ret = update_lpi_config(kvm, irq, NULL);
> +	ret = update_lpi_config(kvm, irq, NULL, false);
>  	if (ret)
>  		return ERR_PTR(ret);
>  
> @@ -274,7 +274,7 @@ static struct its_collection *find_collection(struct vgic_its *its, int coll_id)
>   * VCPU. Unconditionally applies if filter_vcpu is NULL.
>   */
>  static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
> -			     struct kvm_vcpu *filter_vcpu)
> +			     struct kvm_vcpu *filter_vcpu, bool needs_inv)
>  {
>  	u64 propbase = GICR_PROPBASER_ADDRESS(kvm->arch.vgic.propbaser);
>  	u8 prop;
> @@ -298,7 +298,7 @@ static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
>  	}
>  
>  	if (irq->hw)
> -		return its_prop_update_vlpi(irq->host_irq, prop, true);
> +		return its_prop_update_vlpi(irq->host_irq, prop, needs_inv);
>  
>  	return 0;
>  }
> @@ -1095,7 +1095,7 @@ static int vgic_its_cmd_handle_inv(struct kvm *kvm, struct vgic_its *its,
>  	if (!ite)
>  		return E_ITS_INV_UNMAPPED_INTERRUPT;
>  
> -	return update_lpi_config(kvm, ite->irq, NULL);
> +	return update_lpi_config(kvm, ite->irq, NULL, true);
>  }
>  
>  /*
> @@ -1130,12 +1130,15 @@ static int vgic_its_cmd_handle_invall(struct kvm *kvm, struct vgic_its *its,
>  		irq = vgic_get_irq(kvm, NULL, intids[i]);
>  		if (!irq)
>  			continue;
> -		update_lpi_config(kvm, irq, vcpu);
> +		update_lpi_config(kvm, irq, vcpu, false);
>  		vgic_put_irq(kvm, irq);
>  	}
>  
>  	kfree(intids);
>  
> +	if (vcpu->arch.vgic_cpu.vgic_v3.its_vpe.its_vm)
> +		its_invall_vpe(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe);
> +
>  	return 0;
>  }
>  
> -- 
> 2.11.0
> 

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 49/59] KVM: arm/arm64: GICv4: Propagate VLPI properties at map time
  2017-07-31 17:26 ` [PATCH v3 49/59] KVM: arm/arm64: GICv4: Propagate VLPI properties at map time Marc Zyngier
@ 2017-08-28 18:18   ` Christoffer Dall
  2017-08-30 14:56     ` Marc Zyngier
  0 siblings, 1 reply; 118+ messages in thread
From: Christoffer Dall @ 2017-08-28 18:18 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On Mon, Jul 31, 2017 at 06:26:27PM +0100, Marc Zyngier wrote:
> When the VLPI gets mapped, it must inherit the configuration of
> LPI configured at the vITS level. FOr that purpose, let's make

*the LPI
*For that

> update_lpi_config globally available and call it just after
> having performed the VLPI map operation.
> 

I assume this means that the GIC compares the priorities of virtual
interrupts in the LRs with the priorities of the pending VLPIs and
figures out what to signal first?  I couldn't find anywhere in the spec
where this is explicitly stated.

> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  virt/kvm/arm/vgic/vgic-its.c | 6 ++----
>  virt/kvm/arm/vgic/vgic-v4.c  | 2 ++
>  virt/kvm/arm/vgic/vgic.h     | 2 ++
>  3 files changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index b395df1bf47c..d790d0c74b8b 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -37,8 +37,6 @@
>  static int vgic_its_save_tables_v0(struct vgic_its *its);
>  static int vgic_its_restore_tables_v0(struct vgic_its *its);
>  static int vgic_its_commit_v0(struct vgic_its *its);
> -static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
> -			     struct kvm_vcpu *filter_vcpu, bool needs_inv);
>  
>  /*
>   * Creates a new (reference to a) struct vgic_irq for a given LPI.
> @@ -273,8 +271,8 @@ static struct its_collection *find_collection(struct vgic_its *its, int coll_id)
>   * If filter_vcpu is not NULL, applies only if the IRQ is targeting this
>   * VCPU. Unconditionally applies if filter_vcpu is NULL.
>   */
> -static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
> -			     struct kvm_vcpu *filter_vcpu, bool needs_inv)
> +int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
> +		      struct kvm_vcpu *filter_vcpu, bool needs_inv)
>  {
>  	u64 propbase = GICR_PROPBASER_ADDRESS(kvm->arch.vgic.propbaser);
>  	u8 prop;
> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> index 338c86c5159f..534d3051a078 100644
> --- a/virt/kvm/arm/vgic/vgic-v4.c
> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> @@ -137,6 +137,8 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
>  	irq->hw		= true;
>  	irq->host_irq	= virq;
>  
> +	/* Force the property update and invalidate */
> +	update_lpi_config(kvm, irq, NULL, true);
>  out:
>  	mutex_unlock(&its->its_lock);
>  	return 0;
> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
> index 1356f485d7cf..1210bf4681dc 100644
> --- a/virt/kvm/arm/vgic/vgic.h
> +++ b/virt/kvm/arm/vgic/vgic.h
> @@ -228,6 +228,8 @@ void unlock_all_vcpus(struct kvm *kvm);
>  int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
>  			 u32 devid, u32 eventid, struct vgic_irq **irq);
>  struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi);
> +int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
> +		      struct kvm_vcpu *filter_vcpu, bool needs_inv);
>  
>  bool vgic_is_v4_capable(struct kvm *kvm);
>  int vgic_v4_init(struct kvm *kvm);
> -- 
> 2.11.0
> 

Acked-by: Christoffer Dall <cdall@linaro.org>

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 50/59] KVM: arm/arm64: GICv4: Use pending_last as a scheduling hint
  2017-07-31 17:26 ` [PATCH v3 50/59] KVM: arm/arm64: GICv4: Use pending_last as a scheduling hint Marc Zyngier
@ 2017-08-28 18:18   ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-28 18:18 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On Mon, Jul 31, 2017 at 06:26:28PM +0100, Marc Zyngier wrote:
> When a vPE exits, the pending_last flag is set when there are
> pending VLPIs stored in the pending table. Similarily, we set
> this flag when a doorbell interrupt fires, as it indicates the
> same condition.
> 
> Let's update kvm_vgic_vcpu_pending_irq() to account for that
> flag as well, making a vcpu runnable when set.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  virt/kvm/arm/vgic/vgic.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
> index a96e566905d2..dfac894f6f03 100644
> --- a/virt/kvm/arm/vgic/vgic.c
> +++ b/virt/kvm/arm/vgic/vgic.c
> @@ -781,6 +781,9 @@ int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
>  	if (!vcpu->kvm->arch.vgic.enabled)
>  		return false;
>  
> +	if (vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last)
> +		return true;
> +
>  	spin_lock(&vgic_cpu->ap_list_lock);
>  
>  	list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
> -- 
> 2.11.0
> 

Acked-by: Christoffer Dall <cdall@linaro.org>

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling
  2017-08-04  7:44   ` Marc Zyngier
@ 2017-08-28 18:18     ` Christoffer Dall
  2017-08-30 10:31       ` Andrew Jones
  2017-08-31 12:18       ` Marc Zyngier
  0 siblings, 2 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-28 18:18 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi, Andrew Jones

On Fri, Aug 04, 2017 at 08:44:04AM +0100, Marc Zyngier wrote:
> On 31/07/17 18:26, Marc Zyngier wrote:
> > When a vPE is not running, a VLPI being made pending results in a
> > doorbell interrupt being delivered. Let's handle this interrupt
> > and update the pending_last flag that indicates that VLPIs are
> > pending. The corresponding vcpu is also kicked into action.
> > 
> > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> > ---
> >  virt/kvm/arm/vgic/vgic-v4.c | 34 ++++++++++++++++++++++++++++++++++
> >  1 file changed, 34 insertions(+)
> > 
> > diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> > index 534d3051a078..6af3cde6d7d4 100644
> > --- a/virt/kvm/arm/vgic/vgic-v4.c
> > +++ b/virt/kvm/arm/vgic/vgic-v4.c
> > @@ -21,6 +21,19 @@
> >  
> >  #include "vgic.h"
> >  
> > +static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
> > +{
> > +	struct kvm_vcpu *vcpu = info;
> > +
> > +	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
> > +		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> > +		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> > +		kvm_vcpu_kick(vcpu);
> > +	}
> 
> This code is so obviously broken that I completely overlooked it.
> 
> If we have take a doorbell interrupt, then it means nothing was
> otherwise pending (because we'd have been kicked out of the blocking
> state, and will have masked the doorbell). So checking for pending
> interrupts is pointless.
> 
> Furthermore, calling kvm_vgic_vcpu_pending_irq() takes the ap_list
> lock. If we take a doorbell interrupt while injecting a virtual
> interrupt (from userspace, for example) on the same CPU, we end-up
> in deadlock land. This would be solved by Christoffer's latest
> crop of timer patches, but there is no point getting there the first
> place.
> 
> The patchlet below solves it:
> 
> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> index 15feb1151797..48e4d6ebeaa8 100644
> --- a/virt/kvm/arm/vgic/vgic-v4.c
> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> @@ -94,11 +94,9 @@ static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
>  {
>  	struct kvm_vcpu *vcpu = info;
>  
> -	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
> -		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> -		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> -		kvm_vcpu_kick(vcpu);
> -	}
> +	vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> +	kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> +	kvm_vcpu_kick(vcpu);

I don't think you need the request and kick, because if you're getting
this doorbell, doesn't that also mean that the VCPU is not running in
the guest and you simply need to make sure the VCPU thread gets
scheduled again, so you could call kvm_vcpu_wake_up() instead.

Unless the request is there to ensure proper memory barriers around
setting pending_last?

In that case, is the read barrier taken care of by prepare_to_swait in
kvm_vcpu_block()?

Drew?


Thanks,
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling
  2017-07-31 17:26 ` [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling Marc Zyngier
  2017-08-04  7:44   ` Marc Zyngier
@ 2017-08-28 18:18   ` Christoffer Dall
  2017-08-30 15:36     ` Marc Zyngier
  2017-09-06  9:06   ` Shannon Zhao
  2 siblings, 1 reply; 118+ messages in thread
From: Christoffer Dall @ 2017-08-28 18:18 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On Mon, Jul 31, 2017 at 06:26:29PM +0100, Marc Zyngier wrote:
> When a vPE is not running, a VLPI being made pending results in a
> doorbell interrupt being delivered. Let's handle this interrupt
> and update the pending_last flag that indicates that VLPIs are
> pending. The corresponding vcpu is also kicked into action.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  virt/kvm/arm/vgic/vgic-v4.c | 34 ++++++++++++++++++++++++++++++++++
>  1 file changed, 34 insertions(+)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> index 534d3051a078..6af3cde6d7d4 100644
> --- a/virt/kvm/arm/vgic/vgic-v4.c
> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> @@ -21,6 +21,19 @@
>  
>  #include "vgic.h"
>  
> +static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
> +{
> +	struct kvm_vcpu *vcpu = info;
> +
> +	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
> +		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> +		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> +		kvm_vcpu_kick(vcpu);
> +	}

Can this ever fire while vgic_v4_init() is running and before te rest of
the system has been properly initialized with some entertaining results
to follow?  (I'm not sure if spurious doorbell non-resident vPE
interrupts is a thing or not).

> +
> +	return IRQ_HANDLED;
> +}
> +
>  int vgic_v4_init(struct kvm *kvm)
>  {
>  	struct vgic_dist *dist = &kvm->arch.vgic;
> @@ -57,16 +70,37 @@ int vgic_v4_init(struct kvm *kvm)
>  		return ret;
>  	}
>  
> +	kvm_for_each_vcpu(i, vcpu, kvm) {
> +		int irq = dist->its_vm.vpes[i]->irq;
> +
> +		ret = request_irq(irq, vgic_v4_doorbell_handler,
> +				  0, "vcpu", vcpu);
> +		if (ret) {
> +			kvm_err("failed to allocate vcpu IRQ%d\n", irq);
> +			dist->its_vm.nr_vpes = i;

That's a neat trick for the error handling.  Might deserve a tiny
comment.

> +			break;
> +		}
> +	}
> +
> +	if (ret)
> +		vgic_v4_teardown(kvm);
> +
>  	return ret;
>  }
>  
>  void vgic_v4_teardown(struct kvm *kvm)
>  {
>  	struct its_vm *its_vm = &kvm->arch.vgic.its_vm;
> +	int i;
>  
>  	if (!its_vm->vpes)
>  		return;
>  
> +	for (i = 0; i < its_vm->nr_vpes; i++) {
> +		struct kvm_vcpu *vcpu = kvm_get_vcpu(kvm, i);
> +		free_irq(its_vm->vpes[i]->irq, vcpu);
> +	}
> +
>  	its_free_vcpu_irqs(its_vm);
>  	kfree(its_vm->vpes);
>  	its_vm->nr_vpes = 0;
> -- 
> 2.11.0
> 

Thanks,
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 52/59] KVM: arm/arm64: GICv4: Use the doorbell interrupt as an unblocking source
  2017-07-31 17:26 ` [PATCH v3 52/59] KVM: arm/arm64: GICv4: Use the doorbell interrupt as an unblocking source Marc Zyngier
@ 2017-08-28 18:19   ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-28 18:19 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On Mon, Jul 31, 2017 at 06:26:30PM +0100, Marc Zyngier wrote:
> The doorbell interrupt is only useful if the vcpu is blocked on WFI.
> In all other cases, recieving a doorbell interrupt is just a waste
> of cycles.
> 
> So let's only enable the doorbell if a vcpu is getting blocked,
> and disable it when it is unblocked. This is very similar to
> what we're doing for the background timer.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  include/kvm/arm_vgic.h      |  3 +++
>  virt/kvm/arm/arm.c          |  2 ++
>  virt/kvm/arm/vgic/vgic-v4.c | 32 +++++++++++++++++++++++++++++++-
>  3 files changed, 36 insertions(+), 1 deletion(-)
> 
> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> index 050f78d4fb42..7b1cc7ff5b42 100644
> --- a/include/kvm/arm_vgic.h
> +++ b/include/kvm/arm_vgic.h
> @@ -375,4 +375,7 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int irq,
>  int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int irq,
>  				 struct kvm_kernel_irq_routing_entry *irq_entry);
>  
> +void kvm_vgic_v4_enable_doorbell(struct kvm_vcpu *vcpu);
> +void kvm_vgic_v4_disable_doorbell(struct kvm_vcpu *vcpu);
> +
>  #endif /* __KVM_ARM_VGIC_H */
> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
> index 6803ea27c47d..5dbc8dc8fbf4 100644
> --- a/virt/kvm/arm/arm.c
> +++ b/virt/kvm/arm/arm.c
> @@ -316,11 +316,13 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
>  void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu)
>  {
>  	kvm_timer_schedule(vcpu);
> +	kvm_vgic_v4_enable_doorbell(vcpu);
>  }
>  
>  void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu)
>  {
>  	kvm_timer_unschedule(vcpu);
> +	kvm_vgic_v4_disable_doorbell(vcpu);
>  }
>  
>  int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> index 6af3cde6d7d4..50721c4e3da5 100644
> --- a/virt/kvm/arm/vgic/vgic-v4.c
> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> @@ -16,6 +16,7 @@
>   */
>  
>  #include <linux/interrupt.h>
> +#include <linux/irq.h>
>  #include <linux/irqdomain.h>
>  #include <linux/kvm_host.h>
>  
> @@ -73,6 +74,14 @@ int vgic_v4_init(struct kvm *kvm)
>  	kvm_for_each_vcpu(i, vcpu, kvm) {
>  		int irq = dist->its_vm.vpes[i]->irq;
>  
> +		/*
> +		 * Don't automatically enable the doorbell, as we're
> +		 * flipping it back and forth when the vcpu gets
> +		 * blocked. Also disable the lazy disabling, as the
> +		 * doorbell could kick us out of the guest too
> +		 * early...
> +		 */
> +		irq_set_status_flags(irq, IRQ_NOAUTOEN | IRQ_DISABLE_UNLAZY);
>  		ret = request_irq(irq, vgic_v4_doorbell_handler,
>  				  0, "vcpu", vcpu);
>  		if (ret) {
> @@ -98,7 +107,10 @@ void vgic_v4_teardown(struct kvm *kvm)
>  
>  	for (i = 0; i < its_vm->nr_vpes; i++) {
>  		struct kvm_vcpu *vcpu = kvm_get_vcpu(kvm, i);
> -		free_irq(its_vm->vpes[i]->irq, vcpu);
> +		int irq = its_vm->vpes[i]->irq;
> +
> +		irq_clear_status_flags(irq, IRQ_NOAUTOEN | IRQ_DISABLE_UNLAZY);
> +		free_irq(irq, vcpu);
>  	}
>  
>  	its_free_vcpu_irqs(its_vm);
> @@ -211,3 +223,21 @@ int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int virq,
>  	mutex_unlock(&its->its_lock);
>  	return ret;
>  }
> +
> +void kvm_vgic_v4_enable_doorbell(struct kvm_vcpu *vcpu)
> +{
> +	if (vgic_is_v4_capable(vcpu->kvm)) {
> +		int irq = vcpu->arch.vgic_cpu.vgic_v3.its_vpe.irq;
> +		if (irq)
> +			enable_irq(irq);
> +	}
> +}
> +
> +void kvm_vgic_v4_disable_doorbell(struct kvm_vcpu *vcpu)
> +{
> +	if (vgic_is_v4_capable(vcpu->kvm)) {
> +		int irq = vcpu->arch.vgic_cpu.vgic_v3.its_vpe.irq;
> +		if (irq)
> +			disable_irq(irq);
> +	}
> +}
> -- 
> 2.11.0
> 
Reviewed-by: Christoffer Dall <cdall@linaro.org>

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 54/59] KVM: arm/arm64: GICv4: Enable virtual cpuif if VLPIs can be delivered
  2017-07-31 17:26 ` [PATCH v3 54/59] KVM: arm/arm64: GICv4: Enable virtual cpuif if VLPIs can be delivered Marc Zyngier
@ 2017-08-28 18:20   ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-28 18:20 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On Mon, Jul 31, 2017 at 06:26:32PM +0100, Marc Zyngier wrote:
> In order for VLPIs to be delivered to the guest, we must make
> sure that the cpuif is always enabled, irrespective of the
> presence of virtual interrupt in the LRs.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  virt/kvm/arm/hyp/vgic-v3-sr.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/virt/kvm/arm/hyp/vgic-v3-sr.c b/virt/kvm/arm/hyp/vgic-v3-sr.c
> index 91728faa13fd..f5c3d6d7019e 100644
> --- a/virt/kvm/arm/hyp/vgic-v3-sr.c
> +++ b/virt/kvm/arm/hyp/vgic-v3-sr.c
> @@ -258,7 +258,8 @@ void __hyp_text __vgic_v3_save_state(struct kvm_vcpu *vcpu)
>  			cpu_if->vgic_ap1r[0] = __vgic_v3_read_ap1rn(0);
>  		}
>  	} else {
> -		if (static_branch_unlikely(&vgic_v3_cpuif_trap))
> +		if (static_branch_unlikely(&vgic_v3_cpuif_trap) ||
> +		    cpu_if->its_vpe.its_vm)
>  			write_gicreg(0, ICH_HCR_EL2);
>  
>  		cpu_if->vgic_elrsr = 0xffff;
> @@ -337,9 +338,11 @@ void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu)
>  		/*
>  		 * If we need to trap system registers, we must write
>  		 * ICH_HCR_EL2 anyway, even if no interrupts are being
> -		 * injected,
> +		 * injected. Same thing if GICv4 is used, as VLPI
> +		 * delivery is gated by ICH_HCR_EL2.En.
>  		 */
> -		if (static_branch_unlikely(&vgic_v3_cpuif_trap))
> +		if (static_branch_unlikely(&vgic_v3_cpuif_trap) ||
> +		    cpu_if->its_vpe.its_vm)
>  			write_gicreg(cpu_if->vgic_hcr, ICH_HCR_EL2);
>  	}
>  
> -- 
> 2.11.0
> 

Acked-by: Christoffer Dall <cdall@linaro.org>

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 55/59] KVM: arm/arm64: GICv4: Enable VLPI support
  2017-07-31 17:26 ` [PATCH v3 55/59] KVM: arm/arm64: GICv4: Enable VLPI support Marc Zyngier
@ 2017-08-28 18:25   ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-28 18:25 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On Mon, Jul 31, 2017 at 06:26:33PM +0100, Marc Zyngier wrote:
> All it takes is the has_v4 flag to be set in gic_kvm_info
> as well as "kvm-arm.vgic_v4_enable=1" being passed on the
> command line for GICv4 to be enabled in KVM.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

So I'm wondering if we should have a per-VM option to turn this on or
off, which may be useful for debugging and profiling.

On the other hand, I can't see x86 having this feature, so maybe it's
not worth it.

For this patch:

Acked-by: Christoffer Dall <cdall@linaro.org>

> ---
>  Documentation/admin-guide/kernel-parameters.txt |  4 ++++
>  virt/kvm/arm/vgic/vgic-v3.c                     | 14 ++++++++++++++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index d9c171ce4190..d2927d01d8b2 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -1874,6 +1874,10 @@
>  			[KVM,ARM] Trap guest accesses to GICv3 common
>  			system registers
>  
> +	kvm-arm.vgic_v4_enable=
> +			[KVM,ARM] Allow use of GICv4 for direct injection of
> +			LPIs.
> +
>  	kvm-intel.ept=	[KVM,Intel] Disable extended page tables
>  			(virtualized MMU) support on capable Intel chips.
>  			Default is 1 (enabled)
> diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
> index 96ea597db0e7..405733678c2f 100644
> --- a/virt/kvm/arm/vgic/vgic-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-v3.c
> @@ -24,6 +24,7 @@
>  static bool group0_trap;
>  static bool group1_trap;
>  static bool common_trap;
> +static bool gicv4_enable;
>  
>  void vgic_v3_set_underflow(struct kvm_vcpu *vcpu)
>  {
> @@ -459,6 +460,12 @@ static int __init early_common_trap_cfg(char *buf)
>  }
>  early_param("kvm-arm.vgic_v3_common_trap", early_common_trap_cfg);
>  
> +static int __init early_gicv4_enable(char *buf)
> +{
> +	return strtobool(buf, &gicv4_enable);
> +}
> +early_param("kvm-arm.vgic_v4_enable", early_gicv4_enable);
> +
>  /**
>   * vgic_v3_probe - probe for a GICv3 compatible interrupt controller in DT
>   * @node:	pointer to the DT node
> @@ -478,6 +485,13 @@ int vgic_v3_probe(const struct gic_kvm_info *info)
>  	kvm_vgic_global_state.can_emulate_gicv2 = false;
>  	kvm_vgic_global_state.ich_vtr_el2 = ich_vtr_el2;
>  
> +	/* GICv4 support? */
> +	if (info->has_v4) {
> +		kvm_vgic_global_state.has_gicv4 = gicv4_enable;
> +		kvm_info("GICv4 support %sabled\n",
> +			 gicv4_enable ? "en" : "dis");
> +	}
> +
>  	if (!info->vcpu.start) {
>  		kvm_info("GICv3: no GICV resource entry\n");
>  		kvm_vgic_global_state.vcpu_base = 0;
> -- 
> 2.11.0
> 

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 56/59] KVM: arm/arm64: GICv4: Prevent heterogenous systems from using GICv4
  2017-07-31 17:26 ` [PATCH v3 56/59] KVM: arm/arm64: GICv4: Prevent heterogenous systems from using GICv4 Marc Zyngier
@ 2017-08-28 18:35   ` Christoffer Dall
  2017-08-30 16:03     ` Marc Zyngier
  0 siblings, 1 reply; 118+ messages in thread
From: Christoffer Dall @ 2017-08-28 18:35 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On Mon, Jul 31, 2017 at 06:26:34PM +0100, Marc Zyngier wrote:
> The GICv4 architecture doesn't prevent CPUs implementing GICv4 to
> cohabit with CPUs limited to GICv3 in the same system.
> 
> This is mad (the sheduler would have to be made aware of the v4

*scheduler

> capability), and we're certainly not going to support this any
> time soon. So let's check that all online CPUs are GICv4 capable,
> and disable the functionnality if not.

*functionality

> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  include/linux/irqchip/arm-gic-v3.h |  2 ++
>  virt/kvm/arm/vgic/vgic-v3.c        | 22 +++++++++++++++++++++-
>  2 files changed, 23 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
> index 1ea576c8126f..dfa4a51643d6 100644
> --- a/include/linux/irqchip/arm-gic-v3.h
> +++ b/include/linux/irqchip/arm-gic-v3.h
> @@ -532,6 +532,8 @@
>  #define ICH_VTR_SEIS_MASK		(1 << ICH_VTR_SEIS_SHIFT)
>  #define ICH_VTR_A3V_SHIFT		21
>  #define ICH_VTR_A3V_MASK		(1 << ICH_VTR_A3V_SHIFT)
> +#define ICH_VTR_nV4_SHIFT		20
> +#define ICH_VTR_nV4_MASK		(1 << ICH_VTR_nV4_SHIFT)
>  
>  #define ICC_IAR1_EL1_SPURIOUS		0x3ff
>  
> diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
> index 405733678c2f..252268e83ade 100644
> --- a/virt/kvm/arm/vgic/vgic-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-v3.c
> @@ -466,6 +466,18 @@ static int __init early_gicv4_enable(char *buf)
>  }
>  early_param("kvm-arm.vgic_v4_enable", early_gicv4_enable);
>  
> +static void vgic_check_v4_cpuif(void *param)
> +{
> +	u32 ich_vtr_el2 = kvm_call_hyp(__vgic_v3_get_ich_vtr_el2);
> +	bool *v4 = param, this_cpu_is_v4;
> +
> +	this_cpu_is_v4 = !(ich_vtr_el2 & ICH_VTR_nV4_MASK);
> +	if (!this_cpu_is_v4)
> +		kvm_info("CPU%d is not GICv4 capable\n", smp_processor_id());
> +
> +	*v4 &= this_cpu_is_v4;

nit: You could make this function look slightly less scary by declaring
this_cpu_is_v4 on a separate line and not use a bitwise operator on a
boolean type.  Actually, having a function called 'check' with a side
effect is not the nicest thing either, so why not just return what this
particular CPU does and do the comparison in the calling loop.

#bikeshedding


Thanks,
-Christoffer



> +}
> +
>  /**
>   * vgic_v3_probe - probe for a GICv3 compatible interrupt controller in DT
>   * @node:	pointer to the DT node
> @@ -485,8 +497,16 @@ int vgic_v3_probe(const struct gic_kvm_info *info)
>  	kvm_vgic_global_state.can_emulate_gicv2 = false;
>  	kvm_vgic_global_state.ich_vtr_el2 = ich_vtr_el2;
>  
> -	/* GICv4 support? */
> +	/*
> +	 * GICv4 support? We need to check on all CPUs in case of some
> +	 * extremely creative form of big-little brain damage...
> +	 */
>  	if (info->has_v4) {
> +		int cpu;
> +
> +		for_each_online_cpu(cpu)
> +			smp_call_function_single(cpu, vgic_check_v4_cpuif,
> +						 &gicv4_enable, 1);
>  		kvm_vgic_global_state.has_gicv4 = gicv4_enable;
>  		kvm_info("GICv4 support %sabled\n",
>  			 gicv4_enable ? "en" : "dis");
> -- 
> 2.11.0
> 

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass
  2017-08-26 19:48   ` Christoffer Dall
@ 2017-08-30  9:42     ` Marc Zyngier
  2017-08-30 10:20       ` Auger Eric
  2017-08-30 10:28     ` Marc Zyngier
  1 sibling, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-08-30  9:42 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On 26/08/17 20:48, Christoffer Dall wrote:
> On Mon, Jul 31, 2017 at 06:26:19PM +0100, Marc Zyngier wrote:
>> Let's use the irq bypass mechanism introduced for platform device
>> interrupts to intercept the virtual PCIe endpoint configuration
>> and establish our LPI->VLPI mapping.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>>  include/kvm/arm_vgic.h      |   8 ++++
>>  virt/kvm/arm/arm.c          |  27 ++++++++----
>>  virt/kvm/arm/vgic/vgic-v4.c | 103 ++++++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 130 insertions(+), 8 deletions(-)
>>
>> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
>> index 359eeffe9857..050f78d4fb42 100644
>> --- a/include/kvm/arm_vgic.h
>> +++ b/include/kvm/arm_vgic.h
>> @@ -367,4 +367,12 @@ int kvm_vgic_set_forwarding(struct kvm *kvm, unsigned int host_irq,
>>  void kvm_vgic_unset_forwarding(struct kvm *kvm, unsigned int host_irq,
>>  			       unsigned int vintid);
>>  
>> +struct kvm_kernel_irq_routing_entry;
>> +
>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int irq,
>> +			       struct kvm_kernel_irq_routing_entry *irq_entry);
>> +
>> +int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int irq,
>> +				 struct kvm_kernel_irq_routing_entry *irq_entry);
>> +
>>  #endif /* __KVM_ARM_VGIC_H */
>> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
>> index ebab6c29e3be..6803ea27c47d 100644
>> --- a/virt/kvm/arm/arm.c
>> +++ b/virt/kvm/arm/arm.c
>> @@ -1457,11 +1457,16 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
>>  	struct kvm_kernel_irqfd *irqfd =
>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
>>  
>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
>> +	switch (prod->type) {
>> +	case IRQ_BYPASS_VFIO_PLATFORM:
>> +		return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
>> +					       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
>> +		return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq,
>> +						  &irqfd->irq_entry);
>> +	default:
>>  		return 0;
>> -
>> -	return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
>> -				       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>> +	}
>>  }
>>  void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
>>  				      struct irq_bypass_producer *prod)
>> @@ -1469,11 +1474,17 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
>>  	struct kvm_kernel_irqfd *irqfd =
>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
>>  
>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
>> -		return;
>> +	switch (prod->type) {
>> +	case IRQ_BYPASS_VFIO_PLATFORM:
>> +		kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
>> +					  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>> +		break;
>>  
>> -	kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
>> -				  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
>> +		kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq,
>> +					     &irqfd->irq_entry);
>> +		break;
>> +	}
>>  }
>>  
>>  void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>> index 207e1fda0dcd..338c86c5159f 100644
>> --- a/virt/kvm/arm/vgic/vgic-v4.c
>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>> @@ -72,3 +72,106 @@ void vgic_v4_teardown(struct kvm *kvm)
>>  	its_vm->nr_vpes = 0;
>>  	its_vm->vpes = NULL;
>>  }
>> +
>> +static struct vgic_its *vgic_get_its(struct kvm *kvm,
>> +				     struct kvm_kernel_irq_routing_entry *irq_entry)
>> +{
>> +	struct kvm_msi msi  = (struct kvm_msi) {
>> +		.address_lo	= irq_entry->msi.address_lo,
>> +		.address_hi	= irq_entry->msi.address_hi,
>> +		.data		= irq_entry->msi.data,
>> +		.flags		= irq_entry->msi.flags,
>> +		.devid		= irq_entry->msi.devid,
>> +	};
>> +
>> +	/*
>> +	 * Get a reference on the LPI. If NULL, this is not a valid
>> +	 * translation for any of our vITSs.
>> +	 */
>> +	return vgic_msi_to_its(kvm, &msi);
>> +}
>> +
>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
>> +			       struct kvm_kernel_irq_routing_entry *irq_entry)
>> +{
>> +	struct vgic_its *its;
>> +	struct vgic_irq *irq;
>> +	struct its_vlpi_map map;
>> +	int ret;
>> +
>> +	if (!vgic_is_v4_capable(kvm))
>> +		return 0;
>> +
>> +	/*
>> +	 * Get the ITS, and escape early on error (not a valid
>> +	 * doorbell for any of our vITSs).
>> +	 */
>> +	its = vgic_get_its(kvm, irq_entry);
>> +	if (IS_ERR(its))
>> +		return 0;
>> +
>> +	mutex_lock(&its->its_lock);
>> +
>> +	/* Perform then actual DevID/EventID -> LPI translation. */
>> +	ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid,
>> +				   irq_entry->msi.data, &irq);
>> +	if (ret)
>> +		goto out;
>> +
>> +	/*
>> +	 * Emit the mapping request. If it fails, the ITS probably
>> +	 * isn't v4 compatible, so let's silently bail out. Holding
>> +	 * the ITS lock should ensure that nothing can modify the
>> +	 * target vcpu.
>> +	 */
>> +	map = (struct its_vlpi_map) {
>> +		.vm		= &kvm->arch.vgic.its_vm,
>> +		.vintid		= irq->intid,
>> +		.db_enabled	= true,
>> +		.vpe_idx	= irq->target_vcpu->vcpu_id,
>> +	};
>> +
>> +	if (its_map_vlpi(virq, &map))
>> +		goto out;
> 
> This seems to be able to return things like -ENOMEM, whould we really
> not report this back to the caller in any way?


That's a good question.

If we return -ENOMEM, we'll probably end-up returning an error to
userspace (as a result of the VFIO ioctl), which will in turn probably
terminate the guest (I'm guessing, I haven't actually looked at what
userspace does).

If we don't return the error, then we have a chance to keep the guest
running by sticking to software injection.

I'm not sure what is preferable...

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 39/59] KVM: arm/arm64: GICv4: Add property field and per-VM predicate
  2017-08-26 19:49   ` Christoffer Dall
@ 2017-08-30  9:46     ` Marc Zyngier
  0 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-08-30  9:46 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On 26/08/17 20:49, Christoffer Dall wrote:
> On Mon, Jul 31, 2017 at 06:26:17PM +0100, Marc Zyngier wrote:
>> Add a new has_gicv4 field in the global VGIC state that indicates
>> whether the HW is GICv4 capable, as a per-VM predicate indicating
>> if there is a possibility for a VM to support direct injection
>> (the above being true and the VM having an ITS).
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>>  include/kvm/arm_vgic.h           | 3 +++
>>  virt/kvm/arm/vgic/vgic-mmio-v3.c | 5 +++++
>>  virt/kvm/arm/vgic/vgic.h         | 2 ++
>>  3 files changed, 10 insertions(+)
>>
>> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
>> index ee8587c8c715..84694b42373a 100644
>> --- a/include/kvm/arm_vgic.h
>> +++ b/include/kvm/arm_vgic.h
>> @@ -73,6 +73,9 @@ struct vgic_global {
>>  	/* Only needed for the legacy KVM_CREATE_IRQCHIP */
>>  	bool			can_emulate_gicv2;
>>  
>> +	/* Does have GICv4? */
> 
> nit: questionable comment, how about
> 
>   /* Hardware has GICv4? */
> or
>   /* Do we have GICv4? */

Yup, reads much better.

>> +	bool			has_gicv4;
>> +
>>  	/* GIC system register CPU interface */
>>  	struct static_key_false gicv3_cpuif;
>>  
>> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> index 714fa3933546..74109ca75cc0 100644
>> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> @@ -54,6 +54,11 @@ bool vgic_has_its(struct kvm *kvm)
>>  	return dist->has_its;
>>  }
>>  
>> +bool vgic_is_v4_capable(struct kvm *kvm)
>> +{
>> +	return kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm);
>> +}
>> +
> 
> uber nit: the naming here is a bit funny, because we won't be presenting
> a GICv4 GIC to the guest, so I'd prefer something like
> vgic_supports_direct_msis() or something like that, but this is
> obviously not a deal breaker.

I like it. It has the advantage of not tying the predicate to a
particular direct injection method, should we one day have a GICv6 (no,
please...).

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 40/59] KVM: arm/arm64: GICv4: Add init/teardown of the per-VM vPE irq domain
  2017-08-26 19:49   ` Christoffer Dall
@ 2017-08-30  9:50     ` Marc Zyngier
  0 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-08-30  9:50 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Thomas Gleixner,
	Jason Cooper, Eric Auger, Shanker Donthineni, Mark Rutland,
	Shameerali Kolothum Thodi

On 26/08/17 20:49, Christoffer Dall wrote:
> On Mon, Jul 31, 2017 at 06:26:18PM +0100, Marc Zyngier wrote:
>> In order to control the GICv4 view of virtual CPUs, we rely
>> on an irqdomain allocated for that purpose. Let's add a couple
>> of helpers to that effect.
>>
>> At the same time, the vgic data structures gain new fields to
>> track all this... erm... wonderful stuff.
>>
>> They way we hook into the vgic init is slightly convoluted. We
> 
> *The way ?
> 
>> need the vgic to be initialized (in order to guarantee that
>> the number of vcpus is now fixed), and we must have a vITS
>> (otherwise this is all very pointless). So we end-up calling
>> the init from both sites...
> 
> Which sites (sides ?) are those?

That's vgic_init() and  vgic_its_create().

> 
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>>  arch/arm/kvm/Makefile         |  1 +
>>  arch/arm64/kvm/Makefile       |  1 +
>>  include/kvm/arm_vgic.h        |  8 +++++
>>  virt/kvm/arm/vgic/vgic-init.c |  9 ++++++
>>  virt/kvm/arm/vgic/vgic-its.c  |  8 +++++
>>  virt/kvm/arm/vgic/vgic-v4.c   | 74 +++++++++++++++++++++++++++++++++++++++++++
>>  virt/kvm/arm/vgic/vgic.h      |  2 ++
>>  7 files changed, 103 insertions(+)
>>  create mode 100644 virt/kvm/arm/vgic/vgic-v4.c
>>
>> diff --git a/arch/arm/kvm/Makefile b/arch/arm/kvm/Makefile
>> index d9beee652d36..0a1dd2cdb928 100644
>> --- a/arch/arm/kvm/Makefile
>> +++ b/arch/arm/kvm/Makefile
>> @@ -31,6 +31,7 @@ obj-y += $(KVM)/arm/vgic/vgic-init.o
>>  obj-y += $(KVM)/arm/vgic/vgic-irqfd.o
>>  obj-y += $(KVM)/arm/vgic/vgic-v2.o
>>  obj-y += $(KVM)/arm/vgic/vgic-v3.o
>> +obj-y += $(KVM)/arm/vgic/vgic-v4.o
>>  obj-y += $(KVM)/arm/vgic/vgic-mmio.o
>>  obj-y += $(KVM)/arm/vgic/vgic-mmio-v2.o
>>  obj-y += $(KVM)/arm/vgic/vgic-mmio-v3.o
>> diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
>> index 5d9810086c25..c30fd388ef80 100644
>> --- a/arch/arm64/kvm/Makefile
>> +++ b/arch/arm64/kvm/Makefile
>> @@ -26,6 +26,7 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-init.o
>>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-irqfd.o
>>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-v2.o
>>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-v3.o
>> +kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-v4.o
>>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio.o
>>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio-v2.o
>>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio-v3.o
>> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
>> index 84694b42373a..359eeffe9857 100644
>> --- a/include/kvm/arm_vgic.h
>> +++ b/include/kvm/arm_vgic.h
>> @@ -26,6 +26,8 @@
>>  #include <linux/list.h>
>>  #include <linux/jump_label.h>
>>  
>> +#include <linux/irqchip/arm-gic-v4.h>
>> +
>>  #define VGIC_V3_MAX_CPUS	255
>>  #define VGIC_V2_MAX_CPUS	8
>>  #define VGIC_NR_IRQS_LEGACY     256
>> @@ -236,6 +238,9 @@ struct vgic_dist {
>>  
>>  	/* used by vgic-debug */
>>  	struct vgic_state_iter *iter;
>> +
>> +	/* GICv4 ITS per-VM stuff */
> 
> I think we can do a little better in this comment.  Is it possible to
> succinctly explain the role of this field, e.g. ties together Linux IRQ
> subsystem structures with the GIC, or what the role really is.

Absolutely. I'll fix that (and the vPE field as well).

>> +	struct its_vm		its_vm;
>>  };
>>  
>>  struct vgic_v2_cpu_if {
>> @@ -254,6 +259,9 @@ struct vgic_v3_cpu_if {
>>  	u32		vgic_ap0r[4];
>>  	u32		vgic_ap1r[4];
>>  	u64		vgic_lr[VGIC_V3_MAX_LRS];
>> +
>> +	/* GICv4 vPE info */
> 
> same
> 
>> +	struct its_vpe	its_vpe;
>>  };
>>  
>>  struct vgic_cpu {
>> diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
>> index 5801261f3add..d1c6c775203d 100644
>> --- a/virt/kvm/arm/vgic/vgic-init.c
>> +++ b/virt/kvm/arm/vgic/vgic-init.c
>> @@ -285,6 +285,12 @@ int vgic_init(struct kvm *kvm)
>>  	if (ret)
>>  		goto out;
>>  
>> +	if (vgic_has_its(kvm) && vgic_is_v4_capable(kvm)) {
>> +		ret = vgic_v4_init(kvm);
>> +		if (ret)
>> +			goto out;
>> +	}
>> +
>>  	kvm_for_each_vcpu(i, vcpu, kvm)
>>  		kvm_vgic_vcpu_enable(vcpu);
>>  
>> @@ -320,6 +326,9 @@ static void kvm_vgic_dist_destroy(struct kvm *kvm)
>>  
>>  	kfree(dist->spis);
>>  	dist->nr_spis = 0;
>> +
>> +	if (vgic_is_v4_capable(kvm))
>> +		vgic_v4_teardown(kvm);
>>  }
>>  
>>  void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
>> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
>> index fb7be8673bff..a2217f53bbe5 100644
>> --- a/virt/kvm/arm/vgic/vgic-its.c
>> +++ b/virt/kvm/arm/vgic/vgic-its.c
>> @@ -1603,6 +1603,14 @@ static int vgic_its_create(struct kvm_device *dev, u32 type)
>>  	if (!its)
>>  		return -ENOMEM;
>>  
>> +	if (vgic_initialized(dev->kvm)) {
>> +		int ret = vgic_v4_init(dev->kvm);
>> +		if (ret) {
>> +			kfree(its);
>> +			return ret;
>> +		}
>> +	}
>> +	
>>  	mutex_init(&its->its_lock);
>>  	mutex_init(&its->cmd_lock);
>>  
>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>> new file mode 100644
>> index 000000000000..207e1fda0dcd
>> --- /dev/null
>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>> @@ -0,0 +1,74 @@
>> +/*
>> + * Copyright (C) 2017 ARM Ltd.
>> + * Author: Marc Zyngier <marc.zyngier@arm.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
>> + */
>> +
>> +#include <linux/interrupt.h>
>> +#include <linux/irqdomain.h>
>> +#include <linux/kvm_host.h>
>> +
>> +#include "vgic.h"
>> +
>> +int vgic_v4_init(struct kvm *kvm)
>> +{
>> +	struct vgic_dist *dist = &kvm->arch.vgic;
>> +	struct kvm_vcpu *vcpu;
>> +	int i, nr_vcpus, ret;
>> +
>> +	/*
>> +	 * We may be called each time a vITS is created, or when the
>> +	 * vgic is initialized. This relies on kvm->lock to be
>> +	 * held. In both cases, the number of vcpus should now be
>> +	 * fixed.
>> +	 */
> 
> I don't really see the connection between this comment and the following
> block.  Was this comment meant for the whole function?

Indeed. I'll move the comment up, and add some proper kerneldoc as well.

> 
>> +	if (dist->its_vm.vpes)
>> +		return 0;
>> +
>> +	nr_vcpus = atomic_read(&kvm->online_vcpus);
>> +
>> +	dist->its_vm.vpes = kzalloc(sizeof(*dist->its_vm.vpes) * nr_vcpus,
>> +				    GFP_KERNEL);
>> +	if (!dist->its_vm.vpes)
>> +		return -ENOMEM;
>> +
>> +	dist->its_vm.nr_vpes = nr_vcpus;
>> +
>> +	kvm_for_each_vcpu(i, vcpu, kvm)
>> +		dist->its_vm.vpes[i] = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;
>> +
>> +	ret = its_alloc_vcpu_irqs(&dist->its_vm);
>> +	if (ret < 0) {
>> +		kvm_err("VPE IRQ allocation failure\n");
>> +		kfree(dist->its_vm.vpes);
>> +		dist->its_vm.nr_vpes = 0;
>> +		dist->its_vm.vpes = NULL;
>> +		return ret;
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +void vgic_v4_teardown(struct kvm *kvm)
>> +{
>> +	struct its_vm *its_vm = &kvm->arch.vgic.its_vm;
>> +
>> +	if (!its_vm->vpes)
>> +		return;
>> +
>> +	its_free_vcpu_irqs(its_vm);
>> +	kfree(its_vm->vpes);
>> +	its_vm->nr_vpes = 0;
>> +	its_vm->vpes = NULL;
>> +}
>> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
>> index 90f6436a11aa..1356f485d7cf 100644
>> --- a/virt/kvm/arm/vgic/vgic.h
>> +++ b/virt/kvm/arm/vgic/vgic.h
>> @@ -230,5 +230,7 @@ int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
>>  struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi);
>>  
>>  bool vgic_is_v4_capable(struct kvm *kvm);
>> +int vgic_v4_init(struct kvm *kvm);
>> +void vgic_v4_teardown(struct kvm *kvm);
>>  
>>  #endif
>> -- 
>> 2.11.0
>>
> 
> Thanks,
> -Christoffer
> 

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 53/59] KVM: arm/arm64: GICv4: Hook vPE scheduling into vgic flush/sync
  2017-08-28 18:17   ` Christoffer Dall
@ 2017-08-30  9:59     ` Marc Zyngier
  2017-08-30 11:56       ` Christoffer Dall
  0 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-08-30  9:59 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On 28/08/17 19:17, Christoffer Dall wrote:
> On Mon, Jul 31, 2017 at 06:26:31PM +0100, Marc Zyngier wrote:
>> The redistributor needs to be told which vPE is about to be run,
>> and tells us whether there is any pending VLPI on exit.
>>
>> Let's add the scheduling calls to the vgic flush/sync functions,
>> allowing the VLPIs to be delivered to the guest.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>>  virt/kvm/arm/vgic/vgic-v4.c | 24 ++++++++++++++++++++++++
>>  virt/kvm/arm/vgic/vgic.c    |  4 ++++
>>  virt/kvm/arm/vgic/vgic.h    |  1 +
>>  3 files changed, 29 insertions(+)
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>> index 50721c4e3da5..0a8deefbcf1c 100644
>> --- a/virt/kvm/arm/vgic/vgic-v4.c
>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>> @@ -119,6 +119,30 @@ void vgic_v4_teardown(struct kvm *kvm)
>>  	its_vm->vpes = NULL;
>>  }
>>  
>> +int vgic_v4_schedule(struct kvm_vcpu *vcpu, bool on)
>> +{
>> +	int irq = vcpu->arch.vgic_cpu.vgic_v3.its_vpe.irq;
>> +
>> +	if (!vgic_is_v4_capable(vcpu->kvm) || !irq)
>> +		return 0;
> 
> why do we need to check the its_vpe.irq here?  This check is certainly
> not untuitive, as I don't understand what happened on a v4 capable
> system that somehow failed.  Is it because a specific VM is configured
> to not use VLPIs, or?

Hmm. I think that's a debug leftover from my early attempt at making
things work with QEMU, which initializes things in the opposite order
as kvmtool. It should be removed (or replaced by a fat WARN_ON).

>> +
>> +	/*
>> +	 * Before making the VPE resident, make sure the redistributor
>> +	 * expects us here.
>> +	 */
>> +	if (on) {
>> +		int err;
>> +
>> +		err = irq_set_affinity(irq, cpumask_of(smp_processor_id()));
> 
> This is pretty unintuitive, and coming here without having read your
> documentation may make people completely puzzled.  Could we provide a
> pointer to the documentation that explains how the vpe irq hooks this
> all together?

Sure, will do.

> 
>> +		if (err) {
>> +			kvm_err("failed irq_set_affinity IRQ%d (%d)\n", irq, err);
>> +			return err;
>> +		}
>> +	}
>> +
>> +	return its_schedule_vpe(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe, on);
>> +}
>> +
> 
> I'd prefer this function be split into two and follow the vgic notation
> of having a flush and a sync function.

Yes, makes sense.

>>  static struct vgic_its *vgic_get_its(struct kvm *kvm,
>>  				     struct kvm_kernel_irq_routing_entry *irq_entry)
>>  {
>> diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
>> index dfac894f6f03..9ab52108989d 100644
>> --- a/virt/kvm/arm/vgic/vgic.c
>> +++ b/virt/kvm/arm/vgic/vgic.c
>> @@ -721,6 +721,8 @@ void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
>>  {
>>  	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
>>  
>> +	WARN_ON(vgic_v4_schedule(vcpu, false));
>> +
> 
> This is in the critical path, so would it be worth considering a static
> key to cater for non-GICv4 systems here?

Hey, for once I wasn't trying to optimize early! ;-) This would be
useful indeed, as I expect GICv4 systems to be the absolute minority for
the foreseeable future.

> 
>>  	/* An empty ap_list_head implies used_lrs == 0 */
>>  	if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head))
>>  		return;
>> @@ -733,6 +735,8 @@ void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
>>  /* Flush our emulation state into the GIC hardware before entering the guest. */
>>  void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
>>  {
>> +	WARN_ON(vgic_v4_schedule(vcpu, true));
>> +
>>  	/*
>>  	 * If there are no virtual interrupts active or pending for this
>>  	 * VCPU, then there is no work to do and we can bail out without
>> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
>> index 1210bf4681dc..693b654acf4d 100644
>> --- a/virt/kvm/arm/vgic/vgic.h
>> +++ b/virt/kvm/arm/vgic/vgic.h
>> @@ -234,5 +234,6 @@ int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
>>  bool vgic_is_v4_capable(struct kvm *kvm);
>>  int vgic_v4_init(struct kvm *kvm);
>>  void vgic_v4_teardown(struct kvm *kvm);
>> +int vgic_v4_schedule(struct kvm_vcpu *vcpu, bool on);
>>  
>>  #endif
>> -- 
>> 2.11.0
>>
> Functionally, this looks correct.
> 
> Thanks,
> -Christoffer
> 

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass
  2017-08-30  9:42     ` Marc Zyngier
@ 2017-08-30 10:20       ` Auger Eric
  2017-08-30 10:42         ` Marc Zyngier
  0 siblings, 1 reply; 118+ messages in thread
From: Auger Eric @ 2017-08-30 10:20 UTC (permalink / raw)
  To: Marc Zyngier, Christoffer Dall
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

Hi Marc,

On 30/08/2017 11:42, Marc Zyngier wrote:
> On 26/08/17 20:48, Christoffer Dall wrote:
>> On Mon, Jul 31, 2017 at 06:26:19PM +0100, Marc Zyngier wrote:
>>> Let's use the irq bypass mechanism introduced for platform device
>>> interrupts to intercept the virtual PCIe endpoint configuration
>>> and establish our LPI->VLPI mapping.
>>>
>>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>>> ---
>>>  include/kvm/arm_vgic.h      |   8 ++++
>>>  virt/kvm/arm/arm.c          |  27 ++++++++----
>>>  virt/kvm/arm/vgic/vgic-v4.c | 103 ++++++++++++++++++++++++++++++++++++++++++++
>>>  3 files changed, 130 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
>>> index 359eeffe9857..050f78d4fb42 100644
>>> --- a/include/kvm/arm_vgic.h
>>> +++ b/include/kvm/arm_vgic.h
>>> @@ -367,4 +367,12 @@ int kvm_vgic_set_forwarding(struct kvm *kvm, unsigned int host_irq,
>>>  void kvm_vgic_unset_forwarding(struct kvm *kvm, unsigned int host_irq,
>>>  			       unsigned int vintid);
>>>  
>>> +struct kvm_kernel_irq_routing_entry;
>>> +
>>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int irq,
>>> +			       struct kvm_kernel_irq_routing_entry *irq_entry);
>>> +
>>> +int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int irq,
>>> +				 struct kvm_kernel_irq_routing_entry *irq_entry);
>>> +
>>>  #endif /* __KVM_ARM_VGIC_H */
>>> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
>>> index ebab6c29e3be..6803ea27c47d 100644
>>> --- a/virt/kvm/arm/arm.c
>>> +++ b/virt/kvm/arm/arm.c
>>> @@ -1457,11 +1457,16 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
>>>  	struct kvm_kernel_irqfd *irqfd =
>>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
>>>  
>>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
>>> +	switch (prod->type) {
>>> +	case IRQ_BYPASS_VFIO_PLATFORM:
>>> +		return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
>>> +					       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
>>> +		return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq,
>>> +						  &irqfd->irq_entry);
>>> +	default:
>>>  		return 0;
>>> -
>>> -	return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
>>> -				       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>> +	}
>>>  }
>>>  void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
>>>  				      struct irq_bypass_producer *prod)
>>> @@ -1469,11 +1474,17 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
>>>  	struct kvm_kernel_irqfd *irqfd =
>>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
>>>  
>>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
>>> -		return;
>>> +	switch (prod->type) {
>>> +	case IRQ_BYPASS_VFIO_PLATFORM:
>>> +		kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
>>> +					  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>> +		break;
>>>  
>>> -	kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
>>> -				  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
>>> +		kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq,
>>> +					     &irqfd->irq_entry);
>>> +		break;
>>> +	}
>>>  }
>>>  
>>>  void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
>>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>>> index 207e1fda0dcd..338c86c5159f 100644
>>> --- a/virt/kvm/arm/vgic/vgic-v4.c
>>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>>> @@ -72,3 +72,106 @@ void vgic_v4_teardown(struct kvm *kvm)
>>>  	its_vm->nr_vpes = 0;
>>>  	its_vm->vpes = NULL;
>>>  }
>>> +
>>> +static struct vgic_its *vgic_get_its(struct kvm *kvm,
>>> +				     struct kvm_kernel_irq_routing_entry *irq_entry)
>>> +{
>>> +	struct kvm_msi msi  = (struct kvm_msi) {
>>> +		.address_lo	= irq_entry->msi.address_lo,
>>> +		.address_hi	= irq_entry->msi.address_hi,
>>> +		.data		= irq_entry->msi.data,
>>> +		.flags		= irq_entry->msi.flags,
>>> +		.devid		= irq_entry->msi.devid,
>>> +	};
>>> +
>>> +	/*
>>> +	 * Get a reference on the LPI. If NULL, this is not a valid
>>> +	 * translation for any of our vITSs.
>>> +	 */
>>> +	return vgic_msi_to_its(kvm, &msi);
>>> +}
>>> +
>>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
>>> +			       struct kvm_kernel_irq_routing_entry *irq_entry)
>>> +{
>>> +	struct vgic_its *its;
>>> +	struct vgic_irq *irq;
>>> +	struct its_vlpi_map map;
>>> +	int ret;
>>> +
>>> +	if (!vgic_is_v4_capable(kvm))
>>> +		return 0;
>>> +
>>> +	/*
>>> +	 * Get the ITS, and escape early on error (not a valid
>>> +	 * doorbell for any of our vITSs).
>>> +	 */
>>> +	its = vgic_get_its(kvm, irq_entry);
>>> +	if (IS_ERR(its))
>>> +		return 0;
>>> +
>>> +	mutex_lock(&its->its_lock);
>>> +
>>> +	/* Perform then actual DevID/EventID -> LPI translation. */
>>> +	ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid,
>>> +				   irq_entry->msi.data, &irq);
>>> +	if (ret)
>>> +		goto out;
>>> +
>>> +	/*
>>> +	 * Emit the mapping request. If it fails, the ITS probably
>>> +	 * isn't v4 compatible, so let's silently bail out. Holding
>>> +	 * the ITS lock should ensure that nothing can modify the
>>> +	 * target vcpu.
>>> +	 */
>>> +	map = (struct its_vlpi_map) {
>>> +		.vm		= &kvm->arch.vgic.its_vm,
>>> +		.vintid		= irq->intid,
>>> +		.db_enabled	= true,
>>> +		.vpe_idx	= irq->target_vcpu->vcpu_id,
>>> +	};
>>> +
>>> +	if (its_map_vlpi(virq, &map))
>>> +		goto out;
>>
>> This seems to be able to return things like -ENOMEM, whould we really
>> not report this back to the caller in any way?
> 
> 
> That's a good question.
> 
> If we return -ENOMEM, we'll probably end-up returning an error to
> userspace (as a result of the VFIO ioctl), which will in turn probably
> terminate the guest (I'm guessing, I haven't actually looked at what
> userspace does).
> 
> If we don't return the error, then we have a chance to keep the guest
> running by sticking to software injection.
I have not read the whole stuff yet but userspace is not aware of this
negotiation. Everything happens under the hood in kernel, see
virt/lib/irqbypass.c __connect(): if add_producer() fails
prod->del_consumer() is called and we should return to the not optimized
injection.

Thanks

Eric
> 
> I'm not sure what is preferable...
> 
> Thanks,
> 
> 	M.
> 

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass
  2017-08-26 19:48   ` Christoffer Dall
  2017-08-30  9:42     ` Marc Zyngier
@ 2017-08-30 10:28     ` Marc Zyngier
  2017-08-30 11:46       ` Christoffer Dall
  1 sibling, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-08-30 10:28 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On 26/08/17 20:48, Christoffer Dall wrote:
> On Mon, Jul 31, 2017 at 06:26:19PM +0100, Marc Zyngier wrote:
>> Let's use the irq bypass mechanism introduced for platform device
>> interrupts to intercept the virtual PCIe endpoint configuration
>> and establish our LPI->VLPI mapping.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>>  include/kvm/arm_vgic.h      |   8 ++++
>>  virt/kvm/arm/arm.c          |  27 ++++++++----
>>  virt/kvm/arm/vgic/vgic-v4.c | 103 ++++++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 130 insertions(+), 8 deletions(-)
>>
>> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
>> index 359eeffe9857..050f78d4fb42 100644
>> --- a/include/kvm/arm_vgic.h
>> +++ b/include/kvm/arm_vgic.h
>> @@ -367,4 +367,12 @@ int kvm_vgic_set_forwarding(struct kvm *kvm, unsigned int host_irq,
>>  void kvm_vgic_unset_forwarding(struct kvm *kvm, unsigned int host_irq,
>>  			       unsigned int vintid);
>>  
>> +struct kvm_kernel_irq_routing_entry;
>> +
>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int irq,
>> +			       struct kvm_kernel_irq_routing_entry *irq_entry);
>> +
>> +int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int irq,
>> +				 struct kvm_kernel_irq_routing_entry *irq_entry);
>> +
>>  #endif /* __KVM_ARM_VGIC_H */
>> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
>> index ebab6c29e3be..6803ea27c47d 100644
>> --- a/virt/kvm/arm/arm.c
>> +++ b/virt/kvm/arm/arm.c
>> @@ -1457,11 +1457,16 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
>>  	struct kvm_kernel_irqfd *irqfd =
>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
>>  
>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
>> +	switch (prod->type) {
>> +	case IRQ_BYPASS_VFIO_PLATFORM:
>> +		return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
>> +					       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
>> +		return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq,
>> +						  &irqfd->irq_entry);
>> +	default:
>>  		return 0;
>> -
>> -	return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
>> -				       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>> +	}
>>  }
>>  void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
>>  				      struct irq_bypass_producer *prod)
>> @@ -1469,11 +1474,17 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
>>  	struct kvm_kernel_irqfd *irqfd =
>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
>>  
>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
>> -		return;
>> +	switch (prod->type) {
>> +	case IRQ_BYPASS_VFIO_PLATFORM:
>> +		kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
>> +					  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>> +		break;
>>  
>> -	kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
>> -				  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
>> +		kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq,
>> +					     &irqfd->irq_entry);
>> +		break;
>> +	}
>>  }
>>  
>>  void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>> index 207e1fda0dcd..338c86c5159f 100644
>> --- a/virt/kvm/arm/vgic/vgic-v4.c
>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>> @@ -72,3 +72,106 @@ void vgic_v4_teardown(struct kvm *kvm)
>>  	its_vm->nr_vpes = 0;
>>  	its_vm->vpes = NULL;
>>  }
>> +
>> +static struct vgic_its *vgic_get_its(struct kvm *kvm,
>> +				     struct kvm_kernel_irq_routing_entry *irq_entry)
>> +{
>> +	struct kvm_msi msi  = (struct kvm_msi) {
>> +		.address_lo	= irq_entry->msi.address_lo,
>> +		.address_hi	= irq_entry->msi.address_hi,
>> +		.data		= irq_entry->msi.data,
>> +		.flags		= irq_entry->msi.flags,
>> +		.devid		= irq_entry->msi.devid,
>> +	};
>> +
>> +	/*
>> +	 * Get a reference on the LPI. If NULL, this is not a valid
>> +	 * translation for any of our vITSs.
>> +	 */
>> +	return vgic_msi_to_its(kvm, &msi);
>> +}
>> +
>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
>> +			       struct kvm_kernel_irq_routing_entry *irq_entry)
>> +{
>> +	struct vgic_its *its;
>> +	struct vgic_irq *irq;
>> +	struct its_vlpi_map map;
>> +	int ret;
>> +
>> +	if (!vgic_is_v4_capable(kvm))
>> +		return 0;
>> +
>> +	/*
>> +	 * Get the ITS, and escape early on error (not a valid
>> +	 * doorbell for any of our vITSs).
>> +	 */
>> +	its = vgic_get_its(kvm, irq_entry);
>> +	if (IS_ERR(its))
>> +		return 0;
>> +
>> +	mutex_lock(&its->its_lock);
>> +
>> +	/* Perform then actual DevID/EventID -> LPI translation. */
>> +	ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid,
>> +				   irq_entry->msi.data, &irq);
>> +	if (ret)
>> +		goto out;
>> +
>> +	/*
>> +	 * Emit the mapping request. If it fails, the ITS probably
>> +	 * isn't v4 compatible, so let's silently bail out. Holding
>> +	 * the ITS lock should ensure that nothing can modify the
>> +	 * target vcpu.
>> +	 */
>> +	map = (struct its_vlpi_map) {
>> +		.vm		= &kvm->arch.vgic.its_vm,
>> +		.vintid		= irq->intid,
>> +		.db_enabled	= true,
>> +		.vpe_idx	= irq->target_vcpu->vcpu_id,

This is just wrong. We cannot assume that the vcpu_id has anything to do
with the vpe_idx. It happens to be the same thing now, but the two things
should be clearly disconnected.

I suggest the following (untested):

diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
index cf5d6e2de6b8..0146e004401a 100644
--- a/virt/kvm/arm/vgic/vgic-v4.c
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -251,13 +251,27 @@ static void dump_routing(int virq, struct kvm_kernel_irq_routing_entry *irq_entr
 
 }
 
+static int vgic_v4_vcpu_to_index(struct its_vm *its_vm, struct kvm_vcpu *vcpu)
+{
+	int i;
+
+	for (i = 0; i < its_vm->nr_vpes; i++) {
+		struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;
+
+		if (its_vm->vpes[i] == vpe)
+			return i;
+	}
+
+	return -ENODEV;
+}
+
 int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
 			       struct kvm_kernel_irq_routing_entry *irq_entry)
 {
 	struct vgic_its *its;
 	struct vgic_irq *irq;
 	struct its_vlpi_map map;
-	int ret;
+	int ret, idx;
 
 	dump_routing(virq, irq_entry, true);
 
@@ -280,6 +294,11 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
 	if (ret)
 		goto out;
 
+	idx = vgic_v4_vcpu_to_index(&kvm->arch.vgic.its_vm,
+				    irq->target_vcpu);
+	if (idx < 0)
+		goto out;
+
 	/*
 	 * Emit the mapping request. If it fails, the ITS probably
 	 * isn't v4 compatible, so let's silently bail out. Holding
@@ -290,7 +309,7 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
 		.vm		= &kvm->arch.vgic.its_vm,
 		.vintid		= irq->intid,
 		.db_enabled	= true,
-		.vpe_idx	= irq->target_vcpu->vcpu_id,
+		.vpe_idx	= idx,
 	};
 
 	if (its_map_vlpi(virq, &map))

Another option would be to just pass the pointer to the vpe instead,
and let the irq code to figure out the index, which can easily be
derived the doorbells (vpe->vpe_db_lpi - vpe->its_vm->db_lpi_base).

I'll work something out for the next version.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling
  2017-08-28 18:18     ` Christoffer Dall
@ 2017-08-30 10:31       ` Andrew Jones
  2017-08-30 11:55         ` Christoffer Dall
  2017-08-31 12:18       ` Marc Zyngier
  1 sibling, 1 reply; 118+ messages in thread
From: Andrew Jones @ 2017-08-30 10:31 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: Jason Cooper, kvm, Marc Zyngier, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On Mon, Aug 28, 2017 at 08:18:50PM +0200, Christoffer Dall wrote:
> On Fri, Aug 04, 2017 at 08:44:04AM +0100, Marc Zyngier wrote:
> > On 31/07/17 18:26, Marc Zyngier wrote:
> > > When a vPE is not running, a VLPI being made pending results in a
> > > doorbell interrupt being delivered. Let's handle this interrupt
> > > and update the pending_last flag that indicates that VLPIs are
> > > pending. The corresponding vcpu is also kicked into action.
> > > 
> > > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> > > ---
> > >  virt/kvm/arm/vgic/vgic-v4.c | 34 ++++++++++++++++++++++++++++++++++
> > >  1 file changed, 34 insertions(+)
> > > 
> > > diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> > > index 534d3051a078..6af3cde6d7d4 100644
> > > --- a/virt/kvm/arm/vgic/vgic-v4.c
> > > +++ b/virt/kvm/arm/vgic/vgic-v4.c
> > > @@ -21,6 +21,19 @@
> > >  
> > >  #include "vgic.h"
> > >  
> > > +static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
> > > +{
> > > +	struct kvm_vcpu *vcpu = info;
> > > +
> > > +	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
> > > +		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> > > +		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> > > +		kvm_vcpu_kick(vcpu);
> > > +	}
> > 
> > This code is so obviously broken that I completely overlooked it.
> > 
> > If we have take a doorbell interrupt, then it means nothing was
> > otherwise pending (because we'd have been kicked out of the blocking
> > state, and will have masked the doorbell). So checking for pending
> > interrupts is pointless.
> > 
> > Furthermore, calling kvm_vgic_vcpu_pending_irq() takes the ap_list
> > lock. If we take a doorbell interrupt while injecting a virtual
> > interrupt (from userspace, for example) on the same CPU, we end-up
> > in deadlock land. This would be solved by Christoffer's latest
> > crop of timer patches, but there is no point getting there the first
> > place.
> > 
> > The patchlet below solves it:
> > 
> > diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> > index 15feb1151797..48e4d6ebeaa8 100644
> > --- a/virt/kvm/arm/vgic/vgic-v4.c
> > +++ b/virt/kvm/arm/vgic/vgic-v4.c
> > @@ -94,11 +94,9 @@ static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
> >  {
> >  	struct kvm_vcpu *vcpu = info;
> >  
> > -	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
> > -		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> > -		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> > -		kvm_vcpu_kick(vcpu);
> > -	}
> > +	vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> > +	kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> > +	kvm_vcpu_kick(vcpu);
> 
> I don't think you need the request and kick, because if you're getting
> this doorbell, doesn't that also mean that the VCPU is not running in
> the guest and you simply need to make sure the VCPU thread gets
> scheduled again, so you could call kvm_vcpu_wake_up() instead.

While we do that in kvm_timer_inject_irq_work(), which is scheduled from
the same function that vgic_v4_doorbell_handler() would be enabled from
(kvm_vcpu_block->kvm_arch_vcpu_blocking), just a wake up isn't sufficient
in this case.

> 
> Unless the request is there to ensure proper memory barriers around
> setting pending_last?

Right, unlike pending timers, we need the barriers in this handler.
Pending timers are safe because their pending test compares state set by
the VCPU thread itself to state acquired by the VCPU thread reading a host
sysreg itself. IOW, handlers making "set vcpu timer pending requests"
don't need to do anything but wake up the VCPU. Handlers that set some
sort of irq pending state, like vgic_v4_doorbell_handler(), do need to
worry about the visibility of that state though.

> 
> In that case, is the read barrier taken care of by prepare_to_swait in
> kvm_vcpu_block()?

Thanks for the bug report :-)

There's a barrier, but it's not properly paired. Currently we have

 VCPU                                        handler
 ----                                        -------
 for (;;) {
   WRITE_ONCE(task->state, INTERRUPTIBLE);   pending=true;
   smp_mb();                                 smp_wmb(); // kvm_make_request()
   if (pending) {                            WRITE_ONCE(vcpu->state, NORMAL);
     ... stop waiting ...
   }
   schedule();
 }

Proper barrier use with swait/swake should instead look like this

 VCPU                                        handler
 ----                                        -------
 for (;;) {
   WRITE_ONCE(task->state, INTERRUPTIBLE);
   smp_mb();
   if (READ_ONCE(task->state) == NORMAL) {   pending=true;
     smp_rmb();                              smp_wmb();
     if (pending)                            WRITE_ONCE(vcpu->state, NORMAL);
       ... stop waiting ...
     else
       continue;
   }
   schedule();
 }

But checking task state adds complexity and would only cover a small
window anyway (the window between prepare_to_swait() and
kvm_vcpu_check_block()). We need to cover a larger window, for this
particular case it's from kvm_arch_vcpu_blocking() to
kvm_vcpu_check_block(). Better use of VCPU requests is the answer:

 VCPU                                        handler
 ----                                        -------
 kvm_arch_vcpu_blocking();
 for (;;) {
   prepare_to_swait(); 
   if (test_bit(IRQ_PENDING)) {              pending=true;
     smp_rmb();                              smp_wmb();
     if (pending)                            set_bit(IRQ_PENDING);
       ... stop waiting ...
     else
       continue;
   }
   schedule();
 }

The handler side is covered by kvm_make_request() and the vcpu kick, so
this patch looks good. However we need a patch to kvm_arch_vcpu_runnable()
to fix the VCPU side.

 int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
 {
-       return ((!!v->arch.irq_lines || kvm_vgic_vcpu_pending_irq(v))
-               && !v->arch.power_off && !v->arch.pause);
+       if (v->arch.power_off || v->arch.pause)
+               return false;
+
+       if (kvm_test_request(KVM_REQ_IRQ_PENDING, vcpu)) {
+               smp_rmb();
+               return true;
+       }
 }

We can keep the kvm_vgic_vcpu_pending_irq() check, after the IRQ_PENDING
check, if there are cases where IRQ_PENDING wouldn't be set, but
kvm_vgic_vcpu_pending_irq() would return true. Either way we also get a
bit of an optimization with this fix.

I'll think/test some more, and then send a patch.

Thanks,
drew

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass
  2017-08-30 10:20       ` Auger Eric
@ 2017-08-30 10:42         ` Marc Zyngier
  2017-08-30 12:54           ` Auger Eric
  0 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-08-30 10:42 UTC (permalink / raw)
  To: Auger Eric, Christoffer Dall
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

Hi Eric,

On 30/08/17 11:20, Auger Eric wrote:
> Hi Marc,
> 
> On 30/08/2017 11:42, Marc Zyngier wrote:
>> On 26/08/17 20:48, Christoffer Dall wrote:
>>> On Mon, Jul 31, 2017 at 06:26:19PM +0100, Marc Zyngier wrote:
>>>> Let's use the irq bypass mechanism introduced for platform device
>>>> interrupts to intercept the virtual PCIe endpoint configuration
>>>> and establish our LPI->VLPI mapping.
>>>>
>>>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>>>> ---
>>>>  include/kvm/arm_vgic.h      |   8 ++++
>>>>  virt/kvm/arm/arm.c          |  27 ++++++++----
>>>>  virt/kvm/arm/vgic/vgic-v4.c | 103 ++++++++++++++++++++++++++++++++++++++++++++
>>>>  3 files changed, 130 insertions(+), 8 deletions(-)
>>>>
>>>> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
>>>> index 359eeffe9857..050f78d4fb42 100644
>>>> --- a/include/kvm/arm_vgic.h
>>>> +++ b/include/kvm/arm_vgic.h
>>>> @@ -367,4 +367,12 @@ int kvm_vgic_set_forwarding(struct kvm *kvm, unsigned int host_irq,
>>>>  void kvm_vgic_unset_forwarding(struct kvm *kvm, unsigned int host_irq,
>>>>  			       unsigned int vintid);
>>>>  
>>>> +struct kvm_kernel_irq_routing_entry;
>>>> +
>>>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int irq,
>>>> +			       struct kvm_kernel_irq_routing_entry *irq_entry);
>>>> +
>>>> +int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int irq,
>>>> +				 struct kvm_kernel_irq_routing_entry *irq_entry);
>>>> +
>>>>  #endif /* __KVM_ARM_VGIC_H */
>>>> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
>>>> index ebab6c29e3be..6803ea27c47d 100644
>>>> --- a/virt/kvm/arm/arm.c
>>>> +++ b/virt/kvm/arm/arm.c
>>>> @@ -1457,11 +1457,16 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
>>>>  	struct kvm_kernel_irqfd *irqfd =
>>>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
>>>>  
>>>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
>>>> +	switch (prod->type) {
>>>> +	case IRQ_BYPASS_VFIO_PLATFORM:
>>>> +		return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
>>>> +					       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
>>>> +		return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq,
>>>> +						  &irqfd->irq_entry);
>>>> +	default:
>>>>  		return 0;
>>>> -
>>>> -	return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
>>>> -				       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>>> +	}
>>>>  }
>>>>  void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
>>>>  				      struct irq_bypass_producer *prod)
>>>> @@ -1469,11 +1474,17 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
>>>>  	struct kvm_kernel_irqfd *irqfd =
>>>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
>>>>  
>>>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
>>>> -		return;
>>>> +	switch (prod->type) {
>>>> +	case IRQ_BYPASS_VFIO_PLATFORM:
>>>> +		kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
>>>> +					  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>>> +		break;
>>>>  
>>>> -	kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
>>>> -				  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
>>>> +		kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq,
>>>> +					     &irqfd->irq_entry);
>>>> +		break;
>>>> +	}
>>>>  }
>>>>  
>>>>  void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
>>>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>>>> index 207e1fda0dcd..338c86c5159f 100644
>>>> --- a/virt/kvm/arm/vgic/vgic-v4.c
>>>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>>>> @@ -72,3 +72,106 @@ void vgic_v4_teardown(struct kvm *kvm)
>>>>  	its_vm->nr_vpes = 0;
>>>>  	its_vm->vpes = NULL;
>>>>  }
>>>> +
>>>> +static struct vgic_its *vgic_get_its(struct kvm *kvm,
>>>> +				     struct kvm_kernel_irq_routing_entry *irq_entry)
>>>> +{
>>>> +	struct kvm_msi msi  = (struct kvm_msi) {
>>>> +		.address_lo	= irq_entry->msi.address_lo,
>>>> +		.address_hi	= irq_entry->msi.address_hi,
>>>> +		.data		= irq_entry->msi.data,
>>>> +		.flags		= irq_entry->msi.flags,
>>>> +		.devid		= irq_entry->msi.devid,
>>>> +	};
>>>> +
>>>> +	/*
>>>> +	 * Get a reference on the LPI. If NULL, this is not a valid
>>>> +	 * translation for any of our vITSs.
>>>> +	 */
>>>> +	return vgic_msi_to_its(kvm, &msi);
>>>> +}
>>>> +
>>>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
>>>> +			       struct kvm_kernel_irq_routing_entry *irq_entry)
>>>> +{
>>>> +	struct vgic_its *its;
>>>> +	struct vgic_irq *irq;
>>>> +	struct its_vlpi_map map;
>>>> +	int ret;
>>>> +
>>>> +	if (!vgic_is_v4_capable(kvm))
>>>> +		return 0;
>>>> +
>>>> +	/*
>>>> +	 * Get the ITS, and escape early on error (not a valid
>>>> +	 * doorbell for any of our vITSs).
>>>> +	 */
>>>> +	its = vgic_get_its(kvm, irq_entry);
>>>> +	if (IS_ERR(its))
>>>> +		return 0;
>>>> +
>>>> +	mutex_lock(&its->its_lock);
>>>> +
>>>> +	/* Perform then actual DevID/EventID -> LPI translation. */
>>>> +	ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid,
>>>> +				   irq_entry->msi.data, &irq);
>>>> +	if (ret)
>>>> +		goto out;
>>>> +
>>>> +	/*
>>>> +	 * Emit the mapping request. If it fails, the ITS probably
>>>> +	 * isn't v4 compatible, so let's silently bail out. Holding
>>>> +	 * the ITS lock should ensure that nothing can modify the
>>>> +	 * target vcpu.
>>>> +	 */
>>>> +	map = (struct its_vlpi_map) {
>>>> +		.vm		= &kvm->arch.vgic.its_vm,
>>>> +		.vintid		= irq->intid,
>>>> +		.db_enabled	= true,
>>>> +		.vpe_idx	= irq->target_vcpu->vcpu_id,
>>>> +	};
>>>> +
>>>> +	if (its_map_vlpi(virq, &map))
>>>> +		goto out;
>>>
>>> This seems to be able to return things like -ENOMEM, whould we really
>>> not report this back to the caller in any way?
>>
>>
>> That's a good question.
>>
>> If we return -ENOMEM, we'll probably end-up returning an error to
>> userspace (as a result of the VFIO ioctl), which will in turn probably
>> terminate the guest (I'm guessing, I haven't actually looked at what
>> userspace does).
>>
>> If we don't return the error, then we have a chance to keep the guest
>> running by sticking to software injection.
> I have not read the whole stuff yet but userspace is not aware of this
> negotiation. Everything happens under the hood in kernel, see
> virt/lib/irqbypass.c __connect(): if add_producer() fails
> prod->del_consumer() is called and we should return to the not optimized
> injection.

Ah, fair enough. I guess del_consumer() does nothing on PCI?

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 43/59] KVM: arm/arm64: GICv4: Unmap VLPI when freeing an LPI
  2017-08-28 18:18   ` Christoffer Dall
@ 2017-08-30 11:03     ` Marc Zyngier
  0 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-08-30 11:03 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On 28/08/17 19:18, Christoffer Dall wrote:
> On Mon, Jul 31, 2017 at 06:26:21PM +0100, Marc Zyngier wrote:
>> When freeing an LPI (on a DISCARD command, for example), we need
>> to unmap the VLPI down to the physical ITS level.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>>  virt/kvm/arm/vgic/vgic-its.c | 6 +++++-
>>  1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
>> index 40aeadef33fe..79bac93d3e7d 100644
>> --- a/virt/kvm/arm/vgic/vgic-its.c
>> +++ b/virt/kvm/arm/vgic/vgic-its.c
>> @@ -623,8 +623,12 @@ static void its_free_ite(struct kvm *kvm, struct its_ite *ite)
>>  	list_del(&ite->ite_list);
>>  
>>  	/* This put matches the get in vgic_add_lpi. */
>> -	if (ite->irq)
>> +	if (ite->irq) {
>> +		if (ite->irq->hw)
>> +			its_unmap_vlpi(ite->irq->host_irq);
> 
> nit: should we raise a warning on a bad return value?

I guess we could. Getting an error here is am indication that something
has gone wrong...

> Otherwise:
> 
> Acked-by: Christoffer Dall <cdall@linaro.org>
Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 57/59] KVM: arm/arm64: GICv4: Theory of operations
  2017-08-28 18:18   ` Christoffer Dall
@ 2017-08-30 11:30     ` Marc Zyngier
  2017-08-30 11:58       ` Christoffer Dall
  0 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-08-30 11:30 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On 28/08/17 19:18, Christoffer Dall wrote:
> On Mon, Jul 31, 2017 at 06:26:35PM +0100, Marc Zyngier wrote:
>> Yet another braindump so I can free some cells...
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>>  virt/kvm/arm/vgic/vgic-v4.c | 68 +++++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 68 insertions(+)
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>> index 0a8deefbcf1c..0c002d2be620 100644
>> --- a/virt/kvm/arm/vgic/vgic-v4.c
>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>> @@ -22,6 +22,74 @@
>>  
>>  #include "vgic.h"
>>  
>> +/*
>> + * How KVM uses GICv4 (insert rude comments here):
>> + *
>> + * The vgic-v4 layer acts as a bridge between several entities:
>> + * - The GICv4 ITS representation offered by the ITS driver
>> + * - VFIO, which is in charge of the PCI endpoint
>> + * - The virtual ITS, which is the only thing the guest sees
>> + *
>> + * The configuration of VLPIs is triggered by a callback from VFIO,
>> + * instructing KVM that a PCI device has been configured to deliver
>> + * MSIs to a vITS.
>> + *
>> + * kvm_vgic_v4_set_forwarding() is thus called with the routing entry,
>> + * and this is used to find the corresponding vITS data structures
>> + * (ITS instance, device, event and irq) using a process that is
>> + * extremely similar to the injection of an MSI.
>> + *
>> + * At this stage, we can link the guest's view of an LPI (uniquely
>> + * identified by the routing entry) and the host irq, using the GICv4
>> + * driver mapping operation. Should the mapping succeed, we've then
>> + * successfully upgraded the guest's LPI to a VLPI. We can then start
>> + * with updating GICv4's view of the property table and generating an
>> + * INValidation in order to kickstart the delivery of this VLPI to the
>> + * guest directly, without software intervention. Well, almost.
>> + *
>> + * When the PCI endpoint is deconfigured, this operation is reversed
>> + * with VFIO calling kvm_vgic_v4_unset_forwarding().
>> + *
>> + * Once the VLPI has been mapped, it needs to follow any change the
>> + * guest performs on its LPI through the vITS. For that, a number of
>> + * command handlers have hooks to communicate these changes to the HW:
>> + * - Any invalidation triggers a call to its_prop_update_vlpi()
>> + * - The INT command results in a irq_set_irqchip_state(), which
>> + *   generates an INT on the corresponding VLPI.
>> + * - The CLEAR command results in a irq_set_irqchip_state(), which
>> + *   generates an CLEAR on the corresponding VLPI.
>> + * - DISCARD translates into an unmap, similar to a call to
>> + *   kvm_vgic_v4_unset_forwarding().
> 
> So is VFIO notified of this or does it still think the IRQ is
> forwarded?  Or does it not care, and it's state maintained by the irq
> subsystem?

VFIO shouldn't care. The whole forward/bypass looks pretty stateless,
and VFIO will happily inject the interrupt if it gets remapped, as its
own interrupt handlers are still live.

>> + * - MOVI is translated by an update of the existing mapping, changing
>> + *   the target vcpu, resulting in a VMOVI being generated.
>> + * - MOVALL is translated by a string of mapping updates (similar to
>> + *   the handling of MOVI). MOVALL is horrible.
>> + *
>> + * Note that a DISCARD/MAPTI sequence emitted from the guest without
>> + * reprogramming the PCI endpoint after MAPTI does not result in a
>> + * VLPI being mapped, as there is no callback from VFIO (the guest
>> + * will get the interrupt via the normal SW injection). Fixing this is
>> + * not trivial, and requires some horrible messing with the VFIO
>> + * internals. Not fun. Don't do that.
> 
> Is there not a quick way to check with VFIO or the irq subsystem if this
> interrupt can be forwarded and attempt that when handling the MAPTI in
> the vTIS, or does this break in horrible ways?

The problem we have here is that we need to map a purely virtual
interrupt to a Linux IRQ. VFIO does that job by using the offset of the
guest write into the MSI-X table and finding which MSI descriptor is
associated with this entry, giving us the corresponding interrupt.

We could keep track of the previous mappings we've been given, use that
as a hint for the new mapping, and be able to revert it should the guest
update the MSI on the endpoint. It feels pretty involved for something
that is pretty theoretical right now, but I'm happy to try it...

>> + *
>> + * Then there is the scheduling. Each time a vcpu is about to run on a
>> + * physical CPU, KVM must tell the corresponding redistributor about
>> + * it. And if we've migrated our vcpu from one CPU to another, we must
>> + * tell the ITS (so that the messages reach the right redistributor).
>> + * This is done in two steps: first issue a irq_set_affinity() on the
>> + * irq corresponding to the vcpu, then call its_schedule_vpe(). You
>> + * must be in a non-preemptible context. On exit, another call to
>> + * its_schedule_vpe() tells the redistributor that we're done with the
>> + * vcpu.
>> + *
>> + * Finally, the doorbell handling: Each vcpu is allocated an interrupt
>> + * which will fire each time a VLPI is made pending whilst the vcpu is
>> + * not running. Each time the vcpu gets blocked, the doorbell
>> + * interrupt gets enabled. When the vcpu is unblocked (for whatever
>> + * reason), the doorbell interrupt is disabled. This behaviour is
>> + * pretty similar to that of the backgroud timer.
> 
> *background
> 
> However, I think you can probably drop the last sentence in interest of
> clarity.

Fair enough.

> 
>> + */
>> +
>>  static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
>>  {
>>  	struct kvm_vcpu *vcpu = info;
>> -- 
>> 2.11.0
>>
> 
> Thanks for an otherwise excellent (and of course entertaining) writeup!
> -Christoffer
> 

Thanks!

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass
  2017-08-30 10:28     ` Marc Zyngier
@ 2017-08-30 11:46       ` Christoffer Dall
  2017-08-30 12:53         ` Marc Zyngier
  0 siblings, 1 reply; 118+ messages in thread
From: Christoffer Dall @ 2017-08-30 11:46 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On Wed, Aug 30, 2017 at 11:28:08AM +0100, Marc Zyngier wrote:
> On 26/08/17 20:48, Christoffer Dall wrote:
> > On Mon, Jul 31, 2017 at 06:26:19PM +0100, Marc Zyngier wrote:
> >> Let's use the irq bypass mechanism introduced for platform device
> >> interrupts to intercept the virtual PCIe endpoint configuration
> >> and establish our LPI->VLPI mapping.
> >>
> >> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> >> ---
> >>  include/kvm/arm_vgic.h      |   8 ++++
> >>  virt/kvm/arm/arm.c          |  27 ++++++++----
> >>  virt/kvm/arm/vgic/vgic-v4.c | 103 ++++++++++++++++++++++++++++++++++++++++++++
> >>  3 files changed, 130 insertions(+), 8 deletions(-)
> >>
> >> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> >> index 359eeffe9857..050f78d4fb42 100644
> >> --- a/include/kvm/arm_vgic.h
> >> +++ b/include/kvm/arm_vgic.h
> >> @@ -367,4 +367,12 @@ int kvm_vgic_set_forwarding(struct kvm *kvm, unsigned int host_irq,
> >>  void kvm_vgic_unset_forwarding(struct kvm *kvm, unsigned int host_irq,
> >>  			       unsigned int vintid);
> >>  
> >> +struct kvm_kernel_irq_routing_entry;
> >> +
> >> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int irq,
> >> +			       struct kvm_kernel_irq_routing_entry *irq_entry);
> >> +
> >> +int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int irq,
> >> +				 struct kvm_kernel_irq_routing_entry *irq_entry);
> >> +
> >>  #endif /* __KVM_ARM_VGIC_H */
> >> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
> >> index ebab6c29e3be..6803ea27c47d 100644
> >> --- a/virt/kvm/arm/arm.c
> >> +++ b/virt/kvm/arm/arm.c
> >> @@ -1457,11 +1457,16 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
> >>  	struct kvm_kernel_irqfd *irqfd =
> >>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
> >>  
> >> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
> >> +	switch (prod->type) {
> >> +	case IRQ_BYPASS_VFIO_PLATFORM:
> >> +		return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
> >> +					       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
> >> +	case IRQ_BYPASS_VFIO_PCI_MSI:
> >> +		return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq,
> >> +						  &irqfd->irq_entry);
> >> +	default:
> >>  		return 0;
> >> -
> >> -	return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
> >> -				       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
> >> +	}
> >>  }
> >>  void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
> >>  				      struct irq_bypass_producer *prod)
> >> @@ -1469,11 +1474,17 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
> >>  	struct kvm_kernel_irqfd *irqfd =
> >>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
> >>  
> >> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
> >> -		return;
> >> +	switch (prod->type) {
> >> +	case IRQ_BYPASS_VFIO_PLATFORM:
> >> +		kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
> >> +					  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
> >> +		break;
> >>  
> >> -	kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
> >> -				  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
> >> +	case IRQ_BYPASS_VFIO_PCI_MSI:
> >> +		kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq,
> >> +					     &irqfd->irq_entry);
> >> +		break;
> >> +	}
> >>  }
> >>  
> >>  void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
> >> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> >> index 207e1fda0dcd..338c86c5159f 100644
> >> --- a/virt/kvm/arm/vgic/vgic-v4.c
> >> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> >> @@ -72,3 +72,106 @@ void vgic_v4_teardown(struct kvm *kvm)
> >>  	its_vm->nr_vpes = 0;
> >>  	its_vm->vpes = NULL;
> >>  }
> >> +
> >> +static struct vgic_its *vgic_get_its(struct kvm *kvm,
> >> +				     struct kvm_kernel_irq_routing_entry *irq_entry)
> >> +{
> >> +	struct kvm_msi msi  = (struct kvm_msi) {
> >> +		.address_lo	= irq_entry->msi.address_lo,
> >> +		.address_hi	= irq_entry->msi.address_hi,
> >> +		.data		= irq_entry->msi.data,
> >> +		.flags		= irq_entry->msi.flags,
> >> +		.devid		= irq_entry->msi.devid,
> >> +	};
> >> +
> >> +	/*
> >> +	 * Get a reference on the LPI. If NULL, this is not a valid
> >> +	 * translation for any of our vITSs.
> >> +	 */
> >> +	return vgic_msi_to_its(kvm, &msi);
> >> +}
> >> +
> >> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
> >> +			       struct kvm_kernel_irq_routing_entry *irq_entry)
> >> +{
> >> +	struct vgic_its *its;
> >> +	struct vgic_irq *irq;
> >> +	struct its_vlpi_map map;
> >> +	int ret;
> >> +
> >> +	if (!vgic_is_v4_capable(kvm))
> >> +		return 0;
> >> +
> >> +	/*
> >> +	 * Get the ITS, and escape early on error (not a valid
> >> +	 * doorbell for any of our vITSs).
> >> +	 */
> >> +	its = vgic_get_its(kvm, irq_entry);
> >> +	if (IS_ERR(its))
> >> +		return 0;
> >> +
> >> +	mutex_lock(&its->its_lock);
> >> +
> >> +	/* Perform then actual DevID/EventID -> LPI translation. */
> >> +	ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid,
> >> +				   irq_entry->msi.data, &irq);
> >> +	if (ret)
> >> +		goto out;
> >> +
> >> +	/*
> >> +	 * Emit the mapping request. If it fails, the ITS probably
> >> +	 * isn't v4 compatible, so let's silently bail out. Holding
> >> +	 * the ITS lock should ensure that nothing can modify the
> >> +	 * target vcpu.
> >> +	 */
> >> +	map = (struct its_vlpi_map) {
> >> +		.vm		= &kvm->arch.vgic.its_vm,
> >> +		.vintid		= irq->intid,
> >> +		.db_enabled	= true,
> >> +		.vpe_idx	= irq->target_vcpu->vcpu_id,
> 
> This is just wrong. We cannot assume that the vcpu_id has anything to do
> with the vpe_idx. It happens to be the same thing now, but the two things
> should be clearly disconnected.
> 
> I suggest the following (untested):
> 
> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> index cf5d6e2de6b8..0146e004401a 100644
> --- a/virt/kvm/arm/vgic/vgic-v4.c
> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> @@ -251,13 +251,27 @@ static void dump_routing(int virq, struct kvm_kernel_irq_routing_entry *irq_entr
>  
>  }
>  
> +static int vgic_v4_vcpu_to_index(struct its_vm *its_vm, struct kvm_vcpu *vcpu)
> +{
> +	int i;
> +
> +	for (i = 0; i < its_vm->nr_vpes; i++) {
> +		struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;
> +
> +		if (its_vm->vpes[i] == vpe)
> +			return i;
> +	}
> +
> +	return -ENODEV;
> +}
> +

Stupid question: Can we change the struct its_vlpi_map to contain a
vpe pointer or in stead of or in addition to the index?

Alternatively, can you look it up using
vcpu->arch.vgic_cpu.vgic_v3.its_vpe.irq() and another 'ioctl' in
irq_set_vcpu_affinity() somehow instead of looping around and testing?

>  int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
>  			       struct kvm_kernel_irq_routing_entry *irq_entry)
>  {
>  	struct vgic_its *its;
>  	struct vgic_irq *irq;
>  	struct its_vlpi_map map;
> -	int ret;
> +	int ret, idx;
>  
>  	dump_routing(virq, irq_entry, true);
>  
> @@ -280,6 +294,11 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
>  	if (ret)
>  		goto out;
>  
> +	idx = vgic_v4_vcpu_to_index(&kvm->arch.vgic.its_vm,
> +				    irq->target_vcpu);
> +	if (idx < 0)
> +		goto out;
> +
>  	/*
>  	 * Emit the mapping request. If it fails, the ITS probably
>  	 * isn't v4 compatible, so let's silently bail out. Holding
> @@ -290,7 +309,7 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
>  		.vm		= &kvm->arch.vgic.its_vm,
>  		.vintid		= irq->intid,
>  		.db_enabled	= true,
> -		.vpe_idx	= irq->target_vcpu->vcpu_id,
> +		.vpe_idx	= idx,
>  	};
>  
>  	if (its_map_vlpi(virq, &map))
> 
> Another option would be to just pass the pointer to the vpe instead,
> and let the irq code to figure out the index, which can easily be
> derived the doorbells (vpe->vpe_db_lpi - vpe->its_vm->db_lpi_base).
> 
> I'll work something out for the next version.

Ah, yeah, so I guess that is an option.

It should be pretty quick to loop over even hundreds of vcpus, but that
kind of thing just always seems wrong, somehow.

Thanks,
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling
  2017-08-30 10:31       ` Andrew Jones
@ 2017-08-30 11:55         ` Christoffer Dall
  2017-08-30 12:28           ` Andrew Jones
  0 siblings, 1 reply; 118+ messages in thread
From: Christoffer Dall @ 2017-08-30 11:55 UTC (permalink / raw)
  To: Andrew Jones
  Cc: Marc Zyngier, linux-kernel, linux-arm-kernel, kvmarm, kvm,
	Christoffer Dall, Thomas Gleixner, Jason Cooper, Eric Auger,
	Shanker Donthineni, Mark Rutland, Shameerali Kolothum Thodi

On Wed, Aug 30, 2017 at 12:31:41PM +0200, Andrew Jones wrote:
> On Mon, Aug 28, 2017 at 08:18:50PM +0200, Christoffer Dall wrote:
> > On Fri, Aug 04, 2017 at 08:44:04AM +0100, Marc Zyngier wrote:
> > > On 31/07/17 18:26, Marc Zyngier wrote:
> > > > When a vPE is not running, a VLPI being made pending results in a
> > > > doorbell interrupt being delivered. Let's handle this interrupt
> > > > and update the pending_last flag that indicates that VLPIs are
> > > > pending. The corresponding vcpu is also kicked into action.
> > > > 
> > > > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> > > > ---
> > > >  virt/kvm/arm/vgic/vgic-v4.c | 34 ++++++++++++++++++++++++++++++++++
> > > >  1 file changed, 34 insertions(+)
> > > > 
> > > > diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> > > > index 534d3051a078..6af3cde6d7d4 100644
> > > > --- a/virt/kvm/arm/vgic/vgic-v4.c
> > > > +++ b/virt/kvm/arm/vgic/vgic-v4.c
> > > > @@ -21,6 +21,19 @@
> > > >  
> > > >  #include "vgic.h"
> > > >  
> > > > +static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
> > > > +{
> > > > +	struct kvm_vcpu *vcpu = info;
> > > > +
> > > > +	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
> > > > +		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> > > > +		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> > > > +		kvm_vcpu_kick(vcpu);
> > > > +	}
> > > 
> > > This code is so obviously broken that I completely overlooked it.
> > > 
> > > If we have take a doorbell interrupt, then it means nothing was
> > > otherwise pending (because we'd have been kicked out of the blocking
> > > state, and will have masked the doorbell). So checking for pending
> > > interrupts is pointless.
> > > 
> > > Furthermore, calling kvm_vgic_vcpu_pending_irq() takes the ap_list
> > > lock. If we take a doorbell interrupt while injecting a virtual
> > > interrupt (from userspace, for example) on the same CPU, we end-up
> > > in deadlock land. This would be solved by Christoffer's latest
> > > crop of timer patches, but there is no point getting there the first
> > > place.
> > > 
> > > The patchlet below solves it:
> > > 
> > > diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> > > index 15feb1151797..48e4d6ebeaa8 100644
> > > --- a/virt/kvm/arm/vgic/vgic-v4.c
> > > +++ b/virt/kvm/arm/vgic/vgic-v4.c
> > > @@ -94,11 +94,9 @@ static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
> > >  {
> > >  	struct kvm_vcpu *vcpu = info;
> > >  
> > > -	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
> > > -		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> > > -		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> > > -		kvm_vcpu_kick(vcpu);
> > > -	}
> > > +	vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> > > +	kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> > > +	kvm_vcpu_kick(vcpu);
> > 
> > I don't think you need the request and kick, because if you're getting
> > this doorbell, doesn't that also mean that the VCPU is not running in
> > the guest and you simply need to make sure the VCPU thread gets
> > scheduled again, so you could call kvm_vcpu_wake_up() instead.
> 
> While we do that in kvm_timer_inject_irq_work(), which is scheduled from
> the same function that vgic_v4_doorbell_handler() would be enabled from
> (kvm_vcpu_block->kvm_arch_vcpu_blocking), just a wake up isn't sufficient
> in this case.
> 
> > 
> > Unless the request is there to ensure proper memory barriers around
> > setting pending_last?
> 
> Right, unlike pending timers, we need the barriers in this handler.
> Pending timers are safe because their pending test compares state set by
> the VCPU thread itself to state acquired by the VCPU thread reading a host
> sysreg itself. IOW, handlers making "set vcpu timer pending requests"
> don't need to do anything but wake up the VCPU. Handlers that set some
> sort of irq pending state, like vgic_v4_doorbell_handler(), do need to
> worry about the visibility of that state though.
> 
> > 
> > In that case, is the read barrier taken care of by prepare_to_swait in
> > kvm_vcpu_block()?
> 
> Thanks for the bug report :-)
> 
> There's a barrier, but it's not properly paired. Currently we have
> 
>  VCPU                                        handler
>  ----                                        -------
>  for (;;) {
>    WRITE_ONCE(task->state, INTERRUPTIBLE);   pending=true;
>    smp_mb();                                 smp_wmb(); // kvm_make_request()
>    if (pending) {                            WRITE_ONCE(vcpu->state, NORMAL);
>      ... stop waiting ...
>    }
>    schedule();
>  }
> 
> Proper barrier use with swait/swake should instead look like this
> 
>  VCPU                                        handler
>  ----                                        -------
>  for (;;) {
>    WRITE_ONCE(task->state, INTERRUPTIBLE);
>    smp_mb();
>    if (READ_ONCE(task->state) == NORMAL) {   pending=true;
>      smp_rmb();                              smp_wmb();
>      if (pending)                            WRITE_ONCE(vcpu->state, NORMAL);
>        ... stop waiting ...
>      else
>        continue;
>    }
>    schedule();
>  }
> 
> But checking task state adds complexity and would only cover a small
> window anyway (the window between prepare_to_swait() and
> kvm_vcpu_check_block()). We need to cover a larger window, for this
> particular case it's from kvm_arch_vcpu_blocking() to
> kvm_vcpu_check_block(). Better use of VCPU requests is the answer:
> 
>  VCPU                                        handler
>  ----                                        -------
>  kvm_arch_vcpu_blocking();
>  for (;;) {
>    prepare_to_swait(); 
>    if (test_bit(IRQ_PENDING)) {              pending=true;
>      smp_rmb();                              smp_wmb();
>      if (pending)                            set_bit(IRQ_PENDING);
>        ... stop waiting ...
>      else
>        continue;
>    }
>    schedule();
>  }
> 
> The handler side is covered by kvm_make_request() and the vcpu kick, so
> this patch looks good. However we need a patch to kvm_arch_vcpu_runnable()
> to fix the VCPU side.
> 
>  int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
>  {
> -       return ((!!v->arch.irq_lines || kvm_vgic_vcpu_pending_irq(v))
> -               && !v->arch.power_off && !v->arch.pause);
> +       if (v->arch.power_off || v->arch.pause)
> +               return false;

Why don't we need to ensure reads of these flags are observable when
waking up, if the thread waking us up had se the variables prior to
issuing the wake up call?

> +
> +       if (kvm_test_request(KVM_REQ_IRQ_PENDING, vcpu)) {
> +               smp_rmb();

This looks wrong.  What does this barrier ensure exactly?  Some kind of
read following whoever called this function?

> +               return true;
> +       }
>  }
> 
> We can keep the kvm_vgic_vcpu_pending_irq() check, after the IRQ_PENDING
> check, if there are cases where IRQ_PENDING wouldn't be set, but
> kvm_vgic_vcpu_pending_irq() would return true. Either way we also get a
> bit of an optimization with this fix.
> 
> I'll think/test some more, and then send a patch.
> 

I'll review it more thoroughly then.

Thanks,
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 53/59] KVM: arm/arm64: GICv4: Hook vPE scheduling into vgic flush/sync
  2017-08-30  9:59     ` Marc Zyngier
@ 2017-08-30 11:56       ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-30 11:56 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On Wed, Aug 30, 2017 at 10:59:46AM +0100, Marc Zyngier wrote:
> On 28/08/17 19:17, Christoffer Dall wrote:
> > On Mon, Jul 31, 2017 at 06:26:31PM +0100, Marc Zyngier wrote:
> >> The redistributor needs to be told which vPE is about to be run,
> >> and tells us whether there is any pending VLPI on exit.
> >>
> >> Let's add the scheduling calls to the vgic flush/sync functions,
> >> allowing the VLPIs to be delivered to the guest.
> >>
> >> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> >> ---
> >>  virt/kvm/arm/vgic/vgic-v4.c | 24 ++++++++++++++++++++++++
> >>  virt/kvm/arm/vgic/vgic.c    |  4 ++++
> >>  virt/kvm/arm/vgic/vgic.h    |  1 +
> >>  3 files changed, 29 insertions(+)
> >>
> >> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> >> index 50721c4e3da5..0a8deefbcf1c 100644
> >> --- a/virt/kvm/arm/vgic/vgic-v4.c
> >> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> >> @@ -119,6 +119,30 @@ void vgic_v4_teardown(struct kvm *kvm)
> >>  	its_vm->vpes = NULL;
> >>  }
> >>  
> >> +int vgic_v4_schedule(struct kvm_vcpu *vcpu, bool on)
> >> +{
> >> +	int irq = vcpu->arch.vgic_cpu.vgic_v3.its_vpe.irq;
> >> +
> >> +	if (!vgic_is_v4_capable(vcpu->kvm) || !irq)
> >> +		return 0;
> > 
> > why do we need to check the its_vpe.irq here?  This check is certainly
> > not untuitive, as I don't understand what happened on a v4 capable
> > system that somehow failed.  Is it because a specific VM is configured
> > to not use VLPIs, or?
> 
> Hmm. I think that's a debug leftover from my early attempt at making
> things work with QEMU, which initializes things in the opposite order
> as kvmtool. It should be removed (or replaced by a fat WARN_ON).
> 
> >> +
> >> +	/*
> >> +	 * Before making the VPE resident, make sure the redistributor
> >> +	 * expects us here.
> >> +	 */
> >> +	if (on) {
> >> +		int err;
> >> +
> >> +		err = irq_set_affinity(irq, cpumask_of(smp_processor_id()));
> > 
> > This is pretty unintuitive, and coming here without having read your
> > documentation may make people completely puzzled.  Could we provide a
> > pointer to the documentation that explains how the vpe irq hooks this
> > all together?
> 
> Sure, will do.
> 
> > 
> >> +		if (err) {
> >> +			kvm_err("failed irq_set_affinity IRQ%d (%d)\n", irq, err);
> >> +			return err;
> >> +		}
> >> +	}
> >> +
> >> +	return its_schedule_vpe(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe, on);
> >> +}
> >> +
> > 
> > I'd prefer this function be split into two and follow the vgic notation
> > of having a flush and a sync function.
> 
> Yes, makes sense.
> 
> >>  static struct vgic_its *vgic_get_its(struct kvm *kvm,
> >>  				     struct kvm_kernel_irq_routing_entry *irq_entry)
> >>  {
> >> diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
> >> index dfac894f6f03..9ab52108989d 100644
> >> --- a/virt/kvm/arm/vgic/vgic.c
> >> +++ b/virt/kvm/arm/vgic/vgic.c
> >> @@ -721,6 +721,8 @@ void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
> >>  {
> >>  	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
> >>  
> >> +	WARN_ON(vgic_v4_schedule(vcpu, false));
> >> +
> > 
> > This is in the critical path, so would it be worth considering a static
> > key to cater for non-GICv4 systems here?
> 
> Hey, for once I wasn't trying to optimize early! ;-) This would be
> useful indeed, as I expect GICv4 systems to be the absolute minority for
> the foreseeable future.
> 

Right.  For the record, I don't mind getting this functional first, and
adding the static key later, as you prefer.

Thanks,
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 57/59] KVM: arm/arm64: GICv4: Theory of operations
  2017-08-30 11:30     ` Marc Zyngier
@ 2017-08-30 11:58       ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-30 11:58 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On Wed, Aug 30, 2017 at 12:30:02PM +0100, Marc Zyngier wrote:
> On 28/08/17 19:18, Christoffer Dall wrote:
> > On Mon, Jul 31, 2017 at 06:26:35PM +0100, Marc Zyngier wrote:
> >> Yet another braindump so I can free some cells...
> >>
> >> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> >> ---
> >>  virt/kvm/arm/vgic/vgic-v4.c | 68 +++++++++++++++++++++++++++++++++++++++++++++
> >>  1 file changed, 68 insertions(+)
> >>
> >> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> >> index 0a8deefbcf1c..0c002d2be620 100644
> >> --- a/virt/kvm/arm/vgic/vgic-v4.c
> >> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> >> @@ -22,6 +22,74 @@
> >>  
> >>  #include "vgic.h"
> >>  
> >> +/*
> >> + * How KVM uses GICv4 (insert rude comments here):
> >> + *
> >> + * The vgic-v4 layer acts as a bridge between several entities:
> >> + * - The GICv4 ITS representation offered by the ITS driver
> >> + * - VFIO, which is in charge of the PCI endpoint
> >> + * - The virtual ITS, which is the only thing the guest sees
> >> + *
> >> + * The configuration of VLPIs is triggered by a callback from VFIO,
> >> + * instructing KVM that a PCI device has been configured to deliver
> >> + * MSIs to a vITS.
> >> + *
> >> + * kvm_vgic_v4_set_forwarding() is thus called with the routing entry,
> >> + * and this is used to find the corresponding vITS data structures
> >> + * (ITS instance, device, event and irq) using a process that is
> >> + * extremely similar to the injection of an MSI.
> >> + *
> >> + * At this stage, we can link the guest's view of an LPI (uniquely
> >> + * identified by the routing entry) and the host irq, using the GICv4
> >> + * driver mapping operation. Should the mapping succeed, we've then
> >> + * successfully upgraded the guest's LPI to a VLPI. We can then start
> >> + * with updating GICv4's view of the property table and generating an
> >> + * INValidation in order to kickstart the delivery of this VLPI to the
> >> + * guest directly, without software intervention. Well, almost.
> >> + *
> >> + * When the PCI endpoint is deconfigured, this operation is reversed
> >> + * with VFIO calling kvm_vgic_v4_unset_forwarding().
> >> + *
> >> + * Once the VLPI has been mapped, it needs to follow any change the
> >> + * guest performs on its LPI through the vITS. For that, a number of
> >> + * command handlers have hooks to communicate these changes to the HW:
> >> + * - Any invalidation triggers a call to its_prop_update_vlpi()
> >> + * - The INT command results in a irq_set_irqchip_state(), which
> >> + *   generates an INT on the corresponding VLPI.
> >> + * - The CLEAR command results in a irq_set_irqchip_state(), which
> >> + *   generates an CLEAR on the corresponding VLPI.
> >> + * - DISCARD translates into an unmap, similar to a call to
> >> + *   kvm_vgic_v4_unset_forwarding().
> > 
> > So is VFIO notified of this or does it still think the IRQ is
> > forwarded?  Or does it not care, and it's state maintained by the irq
> > subsystem?
> 
> VFIO shouldn't care. The whole forward/bypass looks pretty stateless,
> and VFIO will happily inject the interrupt if it gets remapped, as its
> own interrupt handlers are still live.
> 
> >> + * - MOVI is translated by an update of the existing mapping, changing
> >> + *   the target vcpu, resulting in a VMOVI being generated.
> >> + * - MOVALL is translated by a string of mapping updates (similar to
> >> + *   the handling of MOVI). MOVALL is horrible.
> >> + *
> >> + * Note that a DISCARD/MAPTI sequence emitted from the guest without
> >> + * reprogramming the PCI endpoint after MAPTI does not result in a
> >> + * VLPI being mapped, as there is no callback from VFIO (the guest
> >> + * will get the interrupt via the normal SW injection). Fixing this is
> >> + * not trivial, and requires some horrible messing with the VFIO
> >> + * internals. Not fun. Don't do that.
> > 
> > Is there not a quick way to check with VFIO or the irq subsystem if this
> > interrupt can be forwarded and attempt that when handling the MAPTI in
> > the vTIS, or does this break in horrible ways?
> 
> The problem we have here is that we need to map a purely virtual
> interrupt to a Linux IRQ. VFIO does that job by using the offset of the
> guest write into the MSI-X table and finding which MSI descriptor is
> associated with this entry, giving us the corresponding interrupt.
> 
> We could keep track of the previous mappings we've been given, use that
> as a hint for the new mapping, and be able to revert it should the guest
> update the MSI on the endpoint. It feels pretty involved for something
> that is pretty theoretical right now, but I'm happy to try it...
> 

I understand the problem now, and I think we should leave it alone until
someone comes along and shows us a performance problem with some guest
and driver that does this.


Thanks,
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling
  2017-08-30 11:55         ` Christoffer Dall
@ 2017-08-30 12:28           ` Andrew Jones
  0 siblings, 0 replies; 118+ messages in thread
From: Andrew Jones @ 2017-08-30 12:28 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: Marc Zyngier, linux-kernel, linux-arm-kernel, kvmarm, kvm,
	Christoffer Dall, Thomas Gleixner, Jason Cooper, Eric Auger,
	Shanker Donthineni, Mark Rutland, Shameerali Kolothum Thodi

On Wed, Aug 30, 2017 at 01:55:10PM +0200, Christoffer Dall wrote:
> On Wed, Aug 30, 2017 at 12:31:41PM +0200, Andrew Jones wrote:
> > On Mon, Aug 28, 2017 at 08:18:50PM +0200, Christoffer Dall wrote:
> > > On Fri, Aug 04, 2017 at 08:44:04AM +0100, Marc Zyngier wrote:
> > > > On 31/07/17 18:26, Marc Zyngier wrote:
> > > > > When a vPE is not running, a VLPI being made pending results in a
> > > > > doorbell interrupt being delivered. Let's handle this interrupt
> > > > > and update the pending_last flag that indicates that VLPIs are
> > > > > pending. The corresponding vcpu is also kicked into action.
> > > > > 
> > > > > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> > > > > ---
> > > > >  virt/kvm/arm/vgic/vgic-v4.c | 34 ++++++++++++++++++++++++++++++++++
> > > > >  1 file changed, 34 insertions(+)
> > > > > 
> > > > > diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> > > > > index 534d3051a078..6af3cde6d7d4 100644
> > > > > --- a/virt/kvm/arm/vgic/vgic-v4.c
> > > > > +++ b/virt/kvm/arm/vgic/vgic-v4.c
> > > > > @@ -21,6 +21,19 @@
> > > > >  
> > > > >  #include "vgic.h"
> > > > >  
> > > > > +static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
> > > > > +{
> > > > > +	struct kvm_vcpu *vcpu = info;
> > > > > +
> > > > > +	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
> > > > > +		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> > > > > +		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> > > > > +		kvm_vcpu_kick(vcpu);
> > > > > +	}
> > > > 
> > > > This code is so obviously broken that I completely overlooked it.
> > > > 
> > > > If we have take a doorbell interrupt, then it means nothing was
> > > > otherwise pending (because we'd have been kicked out of the blocking
> > > > state, and will have masked the doorbell). So checking for pending
> > > > interrupts is pointless.
> > > > 
> > > > Furthermore, calling kvm_vgic_vcpu_pending_irq() takes the ap_list
> > > > lock. If we take a doorbell interrupt while injecting a virtual
> > > > interrupt (from userspace, for example) on the same CPU, we end-up
> > > > in deadlock land. This would be solved by Christoffer's latest
> > > > crop of timer patches, but there is no point getting there the first
> > > > place.
> > > > 
> > > > The patchlet below solves it:
> > > > 
> > > > diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> > > > index 15feb1151797..48e4d6ebeaa8 100644
> > > > --- a/virt/kvm/arm/vgic/vgic-v4.c
> > > > +++ b/virt/kvm/arm/vgic/vgic-v4.c
> > > > @@ -94,11 +94,9 @@ static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
> > > >  {
> > > >  	struct kvm_vcpu *vcpu = info;
> > > >  
> > > > -	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
> > > > -		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> > > > -		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> > > > -		kvm_vcpu_kick(vcpu);
> > > > -	}
> > > > +	vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> > > > +	kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> > > > +	kvm_vcpu_kick(vcpu);
> > > 
> > > I don't think you need the request and kick, because if you're getting
> > > this doorbell, doesn't that also mean that the VCPU is not running in
> > > the guest and you simply need to make sure the VCPU thread gets
> > > scheduled again, so you could call kvm_vcpu_wake_up() instead.
> > 
> > While we do that in kvm_timer_inject_irq_work(), which is scheduled from
> > the same function that vgic_v4_doorbell_handler() would be enabled from
> > (kvm_vcpu_block->kvm_arch_vcpu_blocking), just a wake up isn't sufficient
> > in this case.
> > 
> > > 
> > > Unless the request is there to ensure proper memory barriers around
> > > setting pending_last?
> > 
> > Right, unlike pending timers, we need the barriers in this handler.
> > Pending timers are safe because their pending test compares state set by
> > the VCPU thread itself to state acquired by the VCPU thread reading a host
> > sysreg itself. IOW, handlers making "set vcpu timer pending requests"
> > don't need to do anything but wake up the VCPU. Handlers that set some
> > sort of irq pending state, like vgic_v4_doorbell_handler(), do need to
> > worry about the visibility of that state though.
> > 
> > > 
> > > In that case, is the read barrier taken care of by prepare_to_swait in
> > > kvm_vcpu_block()?
> > 
> > Thanks for the bug report :-)
> > 
> > There's a barrier, but it's not properly paired. Currently we have
> > 
> >  VCPU                                        handler
> >  ----                                        -------
> >  for (;;) {
> >    WRITE_ONCE(task->state, INTERRUPTIBLE);   pending=true;
> >    smp_mb();                                 smp_wmb(); // kvm_make_request()
> >    if (pending) {                            WRITE_ONCE(vcpu->state, NORMAL);
> >      ... stop waiting ...
> >    }
> >    schedule();
> >  }
> > 
> > Proper barrier use with swait/swake should instead look like this
> > 
> >  VCPU                                        handler
> >  ----                                        -------
> >  for (;;) {
> >    WRITE_ONCE(task->state, INTERRUPTIBLE);
> >    smp_mb();
> >    if (READ_ONCE(task->state) == NORMAL) {   pending=true;
> >      smp_rmb();                              smp_wmb();
> >      if (pending)                            WRITE_ONCE(vcpu->state, NORMAL);
> >        ... stop waiting ...
> >      else
> >        continue;
> >    }
> >    schedule();
> >  }
> > 
> > But checking task state adds complexity and would only cover a small
> > window anyway (the window between prepare_to_swait() and
> > kvm_vcpu_check_block()). We need to cover a larger window, for this
> > particular case it's from kvm_arch_vcpu_blocking() to
> > kvm_vcpu_check_block(). Better use of VCPU requests is the answer:
> > 
> >  VCPU                                        handler
> >  ----                                        -------
> >  kvm_arch_vcpu_blocking();
> >  for (;;) {
> >    prepare_to_swait(); 
> >    if (test_bit(IRQ_PENDING)) {              pending=true;
> >      smp_rmb();                              smp_wmb();
> >      if (pending)                            set_bit(IRQ_PENDING);
> >        ... stop waiting ...
> >      else
> >        continue;
> >    }
> >    schedule();
> >  }
> > 
> > The handler side is covered by kvm_make_request() and the vcpu kick, so
> > this patch looks good. However we need a patch to kvm_arch_vcpu_runnable()
> > to fix the VCPU side.
> > 
> >  int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
> >  {
> > -       return ((!!v->arch.irq_lines || kvm_vgic_vcpu_pending_irq(v))
> > -               && !v->arch.power_off && !v->arch.pause);
> > +       if (v->arch.power_off || v->arch.pause)
> > +               return false;
> 
> Why don't we need to ensure reads of these flags are observable when
> waking up, if the thread waking us up had se the variables prior to
> issuing the wake up call?

They're "special". I analyzed the cases for them and I *think* they're
all safe. I can do another round, or perhaps better would be to replace
them in some way with VCPU requests to make the analysis consistent.

> 
> > +
> > +       if (kvm_test_request(KVM_REQ_IRQ_PENDING, vcpu)) {
> > +               smp_rmb();
> 
> This looks wrong.  What does this barrier ensure exactly?  Some kind of
> read following whoever called this function?

Yes, it's similar to how kvm_check_request() is written. Actually, I
should probably just copy that more completely, i.e.

 if (kvm_test_request(KVM_REQ_IRQ_PENDING, vcpu)) {
    /*
     * Ensure the rest of the request is visible to the caller.
     * Pairs with the smp_wmb in kvm_make_request.
     */
     smp_mb__after_atomic();
     return true;
 }

> 
> > +               return true;
> > +       }
> >  }
> > 
> > We can keep the kvm_vgic_vcpu_pending_irq() check, after the IRQ_PENDING
> > check, if there are cases where IRQ_PENDING wouldn't be set, but
> > kvm_vgic_vcpu_pending_irq() would return true. Either way we also get a
> > bit of an optimization with this fix.
> > 
> > I'll think/test some more, and then send a patch.
> > 
> 
> I'll review it more thoroughly then.

Thanks,
drew

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass
  2017-08-30 11:46       ` Christoffer Dall
@ 2017-08-30 12:53         ` Marc Zyngier
  2017-08-30 19:59           ` Christoffer Dall
  0 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-08-30 12:53 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On 30/08/17 12:46, Christoffer Dall wrote:
> On Wed, Aug 30, 2017 at 11:28:08AM +0100, Marc Zyngier wrote:
>> On 26/08/17 20:48, Christoffer Dall wrote:
>>> On Mon, Jul 31, 2017 at 06:26:19PM +0100, Marc Zyngier wrote:
>>>> Let's use the irq bypass mechanism introduced for platform device
>>>> interrupts to intercept the virtual PCIe endpoint configuration
>>>> and establish our LPI->VLPI mapping.
>>>>
>>>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>>>> ---
>>>>  include/kvm/arm_vgic.h      |   8 ++++
>>>>  virt/kvm/arm/arm.c          |  27 ++++++++----
>>>>  virt/kvm/arm/vgic/vgic-v4.c | 103 ++++++++++++++++++++++++++++++++++++++++++++
>>>>  3 files changed, 130 insertions(+), 8 deletions(-)
>>>>
>>>> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
>>>> index 359eeffe9857..050f78d4fb42 100644
>>>> --- a/include/kvm/arm_vgic.h
>>>> +++ b/include/kvm/arm_vgic.h
>>>> @@ -367,4 +367,12 @@ int kvm_vgic_set_forwarding(struct kvm *kvm, unsigned int host_irq,
>>>>  void kvm_vgic_unset_forwarding(struct kvm *kvm, unsigned int host_irq,
>>>>  			       unsigned int vintid);
>>>>  
>>>> +struct kvm_kernel_irq_routing_entry;
>>>> +
>>>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int irq,
>>>> +			       struct kvm_kernel_irq_routing_entry *irq_entry);
>>>> +
>>>> +int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int irq,
>>>> +				 struct kvm_kernel_irq_routing_entry *irq_entry);
>>>> +
>>>>  #endif /* __KVM_ARM_VGIC_H */
>>>> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
>>>> index ebab6c29e3be..6803ea27c47d 100644
>>>> --- a/virt/kvm/arm/arm.c
>>>> +++ b/virt/kvm/arm/arm.c
>>>> @@ -1457,11 +1457,16 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
>>>>  	struct kvm_kernel_irqfd *irqfd =
>>>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
>>>>  
>>>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
>>>> +	switch (prod->type) {
>>>> +	case IRQ_BYPASS_VFIO_PLATFORM:
>>>> +		return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
>>>> +					       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
>>>> +		return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq,
>>>> +						  &irqfd->irq_entry);
>>>> +	default:
>>>>  		return 0;
>>>> -
>>>> -	return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
>>>> -				       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>>> +	}
>>>>  }
>>>>  void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
>>>>  				      struct irq_bypass_producer *prod)
>>>> @@ -1469,11 +1474,17 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
>>>>  	struct kvm_kernel_irqfd *irqfd =
>>>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
>>>>  
>>>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
>>>> -		return;
>>>> +	switch (prod->type) {
>>>> +	case IRQ_BYPASS_VFIO_PLATFORM:
>>>> +		kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
>>>> +					  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>>> +		break;
>>>>  
>>>> -	kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
>>>> -				  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
>>>> +		kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq,
>>>> +					     &irqfd->irq_entry);
>>>> +		break;
>>>> +	}
>>>>  }
>>>>  
>>>>  void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
>>>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>>>> index 207e1fda0dcd..338c86c5159f 100644
>>>> --- a/virt/kvm/arm/vgic/vgic-v4.c
>>>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>>>> @@ -72,3 +72,106 @@ void vgic_v4_teardown(struct kvm *kvm)
>>>>  	its_vm->nr_vpes = 0;
>>>>  	its_vm->vpes = NULL;
>>>>  }
>>>> +
>>>> +static struct vgic_its *vgic_get_its(struct kvm *kvm,
>>>> +				     struct kvm_kernel_irq_routing_entry *irq_entry)
>>>> +{
>>>> +	struct kvm_msi msi  = (struct kvm_msi) {
>>>> +		.address_lo	= irq_entry->msi.address_lo,
>>>> +		.address_hi	= irq_entry->msi.address_hi,
>>>> +		.data		= irq_entry->msi.data,
>>>> +		.flags		= irq_entry->msi.flags,
>>>> +		.devid		= irq_entry->msi.devid,
>>>> +	};
>>>> +
>>>> +	/*
>>>> +	 * Get a reference on the LPI. If NULL, this is not a valid
>>>> +	 * translation for any of our vITSs.
>>>> +	 */
>>>> +	return vgic_msi_to_its(kvm, &msi);
>>>> +}
>>>> +
>>>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
>>>> +			       struct kvm_kernel_irq_routing_entry *irq_entry)
>>>> +{
>>>> +	struct vgic_its *its;
>>>> +	struct vgic_irq *irq;
>>>> +	struct its_vlpi_map map;
>>>> +	int ret;
>>>> +
>>>> +	if (!vgic_is_v4_capable(kvm))
>>>> +		return 0;
>>>> +
>>>> +	/*
>>>> +	 * Get the ITS, and escape early on error (not a valid
>>>> +	 * doorbell for any of our vITSs).
>>>> +	 */
>>>> +	its = vgic_get_its(kvm, irq_entry);
>>>> +	if (IS_ERR(its))
>>>> +		return 0;
>>>> +
>>>> +	mutex_lock(&its->its_lock);
>>>> +
>>>> +	/* Perform then actual DevID/EventID -> LPI translation. */
>>>> +	ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid,
>>>> +				   irq_entry->msi.data, &irq);
>>>> +	if (ret)
>>>> +		goto out;
>>>> +
>>>> +	/*
>>>> +	 * Emit the mapping request. If it fails, the ITS probably
>>>> +	 * isn't v4 compatible, so let's silently bail out. Holding
>>>> +	 * the ITS lock should ensure that nothing can modify the
>>>> +	 * target vcpu.
>>>> +	 */
>>>> +	map = (struct its_vlpi_map) {
>>>> +		.vm		= &kvm->arch.vgic.its_vm,
>>>> +		.vintid		= irq->intid,
>>>> +		.db_enabled	= true,
>>>> +		.vpe_idx	= irq->target_vcpu->vcpu_id,
>>
>> This is just wrong. We cannot assume that the vcpu_id has anything to do
>> with the vpe_idx. It happens to be the same thing now, but the two things
>> should be clearly disconnected.
>>
>> I suggest the following (untested):
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>> index cf5d6e2de6b8..0146e004401a 100644
>> --- a/virt/kvm/arm/vgic/vgic-v4.c
>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>> @@ -251,13 +251,27 @@ static void dump_routing(int virq, struct kvm_kernel_irq_routing_entry *irq_entr
>>  
>>  }
>>  
>> +static int vgic_v4_vcpu_to_index(struct its_vm *its_vm, struct kvm_vcpu *vcpu)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < its_vm->nr_vpes; i++) {
>> +		struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;
>> +
>> +		if (its_vm->vpes[i] == vpe)
>> +			return i;
>> +	}
>> +
>> +	return -ENODEV;
>> +}
>> +
> 
> Stupid question: Can we change the struct its_vlpi_map to contain a
> vpe pointer or in stead of or in addition to the index?

This is obviously the right solution, because the *index* of the VPE 
doesn't really matter for a map/unmap (it only matters for doorbell 
operations, and that's a very different code path).

I came up with the following (untested, again), which is much more
appealing:

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index b47097a3e4b4..0607541fcafc 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -900,7 +900,7 @@ static void its_send_vmapti(struct its_device *dev, u32 id)
 	struct its_vlpi_map *map = &dev->event_map.vlpi_maps[id];
 	struct its_cmd_desc desc;
 
-	desc.its_vmapti_cmd.vpe = map->vm->vpes[map->vpe_idx];
+	desc.its_vmapti_cmd.vpe = map->vpe;
 	desc.its_vmapti_cmd.dev = dev;
 	desc.its_vmapti_cmd.virt_id = map->vintid;
 	desc.its_vmapti_cmd.event_id = id;
@@ -914,7 +914,7 @@ static void its_send_vmovi(struct its_device *dev, u32 id)
 	struct its_vlpi_map *map = &dev->event_map.vlpi_maps[id];
 	struct its_cmd_desc desc;
 
-	desc.its_vmovi_cmd.vpe = map->vm->vpes[map->vpe_idx];
+	desc.its_vmovi_cmd.vpe = map->vpe;
 	desc.its_vmovi_cmd.dev = dev;
 	desc.its_vmovi_cmd.event_id = id;
 	desc.its_vmovi_cmd.db_enabled = map->db_enabled;
diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h
index 52661b838821..58a4d89aa82c 100644
--- a/include/linux/irqchip/arm-gic-v4.h
+++ b/include/linux/irqchip/arm-gic-v4.h
@@ -62,15 +62,15 @@ struct its_vpe {
  * irq_set_vcpu_affinity().
  *
  * @vm:		Pointer to the GICv4 notion of a VM
+ * @vpe:	Pointer to the GICv4 notion of a virtual CPU (VPE)
  * @vintid:	Virtual LPI number
  * @db_enabled:	Is the VPE doorbell to be generated?
- * @vpe_idx:	Index (0-based) of the VPE in this VM. Not the vpe_id!
  */
 struct its_vlpi_map {
 	struct its_vm		*vm;
+	struct its_vpe		*vpe;
 	u32			vintid;
 	bool			db_enabled;
-	u16			vpe_idx;
 };
 
 enum its_vcpu_info_cmd_type {
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index d790d0c74b8b..6ba3d73e0f70 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -715,7 +715,7 @@ static int vgic_its_cmd_handle_movi(struct kvm *kvm, struct vgic_its *its,
 		if (ret)
 			return ret;
 
-		map.vpe_idx = vcpu->vcpu_id;
+		map.vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;
 
 		return its_map_vlpi(ite->irq->host_irq, &map);
 	}
@@ -1184,7 +1184,7 @@ static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
 			struct its_vlpi_map map;
 
 			if (!its_get_vlpi(irq->host_irq, &map)) {
-				map.vpe_idx = vcpu2->vcpu_id;
+				map.vpe = &vcpu2->arch.vgic_cpu.vgic_v3.its_vpe;
 				its_map_vlpi(irq->host_irq, &map);
 			}
 		}
diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
index cf5d6e2de6b8..6ece88322013 100644
--- a/virt/kvm/arm/vgic/vgic-v4.c
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -288,9 +288,9 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
 	 */
 	map = (struct its_vlpi_map) {
 		.vm		= &kvm->arch.vgic.its_vm,
+		.vpe		= &irq->target_vcpu->arch.vgic_cpu.vgic_v3.its_vpe,
 		.vintid		= irq->intid,
 		.db_enabled	= true,
-		.vpe_idx	= irq->target_vcpu->vcpu_id,
 	};
 
 	if (its_map_vlpi(virq, &map))

Maybe I'll introduce a vcpu_to_vpe() helper, but it already looks much 
better to me...

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass
  2017-08-30 10:42         ` Marc Zyngier
@ 2017-08-30 12:54           ` Auger Eric
  0 siblings, 0 replies; 118+ messages in thread
From: Auger Eric @ 2017-08-30 12:54 UTC (permalink / raw)
  To: Marc Zyngier, Christoffer Dall
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

Hi Marc,

On 30/08/2017 12:42, Marc Zyngier wrote:
> Hi Eric,
> 
> On 30/08/17 11:20, Auger Eric wrote:
>> Hi Marc,
>>
>> On 30/08/2017 11:42, Marc Zyngier wrote:
>>> On 26/08/17 20:48, Christoffer Dall wrote:
>>>> On Mon, Jul 31, 2017 at 06:26:19PM +0100, Marc Zyngier wrote:
>>>>> Let's use the irq bypass mechanism introduced for platform device
>>>>> interrupts to intercept the virtual PCIe endpoint configuration
>>>>> and establish our LPI->VLPI mapping.
>>>>>
>>>>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>>>>> ---
>>>>>  include/kvm/arm_vgic.h      |   8 ++++
>>>>>  virt/kvm/arm/arm.c          |  27 ++++++++----
>>>>>  virt/kvm/arm/vgic/vgic-v4.c | 103 ++++++++++++++++++++++++++++++++++++++++++++
>>>>>  3 files changed, 130 insertions(+), 8 deletions(-)
>>>>>
>>>>> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
>>>>> index 359eeffe9857..050f78d4fb42 100644
>>>>> --- a/include/kvm/arm_vgic.h
>>>>> +++ b/include/kvm/arm_vgic.h
>>>>> @@ -367,4 +367,12 @@ int kvm_vgic_set_forwarding(struct kvm *kvm, unsigned int host_irq,
>>>>>  void kvm_vgic_unset_forwarding(struct kvm *kvm, unsigned int host_irq,
>>>>>  			       unsigned int vintid);
>>>>>  
>>>>> +struct kvm_kernel_irq_routing_entry;
>>>>> +
>>>>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int irq,
>>>>> +			       struct kvm_kernel_irq_routing_entry *irq_entry);
>>>>> +
>>>>> +int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int irq,
>>>>> +				 struct kvm_kernel_irq_routing_entry *irq_entry);
>>>>> +
>>>>>  #endif /* __KVM_ARM_VGIC_H */
>>>>> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
>>>>> index ebab6c29e3be..6803ea27c47d 100644
>>>>> --- a/virt/kvm/arm/arm.c
>>>>> +++ b/virt/kvm/arm/arm.c
>>>>> @@ -1457,11 +1457,16 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
>>>>>  	struct kvm_kernel_irqfd *irqfd =
>>>>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
>>>>>  
>>>>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
>>>>> +	switch (prod->type) {
>>>>> +	case IRQ_BYPASS_VFIO_PLATFORM:
>>>>> +		return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
>>>>> +					       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>>>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
>>>>> +		return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq,
>>>>> +						  &irqfd->irq_entry);
>>>>> +	default:
>>>>>  		return 0;
>>>>> -
>>>>> -	return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
>>>>> -				       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>>>> +	}
>>>>>  }
>>>>>  void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
>>>>>  				      struct irq_bypass_producer *prod)
>>>>> @@ -1469,11 +1474,17 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
>>>>>  	struct kvm_kernel_irqfd *irqfd =
>>>>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
>>>>>  
>>>>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
>>>>> -		return;
>>>>> +	switch (prod->type) {
>>>>> +	case IRQ_BYPASS_VFIO_PLATFORM:
>>>>> +		kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
>>>>> +					  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>>>> +		break;
>>>>>  
>>>>> -	kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
>>>>> -				  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>>>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
>>>>> +		kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq,
>>>>> +					     &irqfd->irq_entry);
>>>>> +		break;
>>>>> +	}
>>>>>  }
>>>>>  
>>>>>  void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
>>>>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>>>>> index 207e1fda0dcd..338c86c5159f 100644
>>>>> --- a/virt/kvm/arm/vgic/vgic-v4.c
>>>>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>>>>> @@ -72,3 +72,106 @@ void vgic_v4_teardown(struct kvm *kvm)
>>>>>  	its_vm->nr_vpes = 0;
>>>>>  	its_vm->vpes = NULL;
>>>>>  }
>>>>> +
>>>>> +static struct vgic_its *vgic_get_its(struct kvm *kvm,
>>>>> +				     struct kvm_kernel_irq_routing_entry *irq_entry)
>>>>> +{
>>>>> +	struct kvm_msi msi  = (struct kvm_msi) {
>>>>> +		.address_lo	= irq_entry->msi.address_lo,
>>>>> +		.address_hi	= irq_entry->msi.address_hi,
>>>>> +		.data		= irq_entry->msi.data,
>>>>> +		.flags		= irq_entry->msi.flags,
>>>>> +		.devid		= irq_entry->msi.devid,
>>>>> +	};
>>>>> +
>>>>> +	/*
>>>>> +	 * Get a reference on the LPI. If NULL, this is not a valid
>>>>> +	 * translation for any of our vITSs.
>>>>> +	 */
>>>>> +	return vgic_msi_to_its(kvm, &msi);
>>>>> +}
>>>>> +
>>>>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
>>>>> +			       struct kvm_kernel_irq_routing_entry *irq_entry)
>>>>> +{
>>>>> +	struct vgic_its *its;
>>>>> +	struct vgic_irq *irq;
>>>>> +	struct its_vlpi_map map;
>>>>> +	int ret;
>>>>> +
>>>>> +	if (!vgic_is_v4_capable(kvm))
>>>>> +		return 0;
>>>>> +
>>>>> +	/*
>>>>> +	 * Get the ITS, and escape early on error (not a valid
>>>>> +	 * doorbell for any of our vITSs).
>>>>> +	 */
>>>>> +	its = vgic_get_its(kvm, irq_entry);
>>>>> +	if (IS_ERR(its))
>>>>> +		return 0;
>>>>> +
>>>>> +	mutex_lock(&its->its_lock);
>>>>> +
>>>>> +	/* Perform then actual DevID/EventID -> LPI translation. */
>>>>> +	ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid,
>>>>> +				   irq_entry->msi.data, &irq);
>>>>> +	if (ret)
>>>>> +		goto out;
>>>>> +
>>>>> +	/*
>>>>> +	 * Emit the mapping request. If it fails, the ITS probably
>>>>> +	 * isn't v4 compatible, so let's silently bail out. Holding
>>>>> +	 * the ITS lock should ensure that nothing can modify the
>>>>> +	 * target vcpu.
>>>>> +	 */
>>>>> +	map = (struct its_vlpi_map) {
>>>>> +		.vm		= &kvm->arch.vgic.its_vm,
>>>>> +		.vintid		= irq->intid,
>>>>> +		.db_enabled	= true,
>>>>> +		.vpe_idx	= irq->target_vcpu->vcpu_id,
>>>>> +	};
>>>>> +
>>>>> +	if (its_map_vlpi(virq, &map))
>>>>> +		goto out;
>>>>
>>>> This seems to be able to return things like -ENOMEM, whould we really
>>>> not report this back to the caller in any way?
>>>
>>>
>>> That's a good question.
>>>
>>> If we return -ENOMEM, we'll probably end-up returning an error to
>>> userspace (as a result of the VFIO ioctl), which will in turn probably
>>> terminate the guest (I'm guessing, I haven't actually looked at what
>>> userspace does).
>>>
>>> If we don't return the error, then we have a chance to keep the guest
>>> running by sticking to software injection.
>> I have not read the whole stuff yet but userspace is not aware of this
>> negotiation. Everything happens under the hood in kernel, see
>> virt/lib/irqbypass.c __connect(): if add_producer() fails
>> prod->del_consumer() is called and we should return to the not optimized
>> injection.
> 
> Ah, fair enough. I guess del_consumer() does nothing on PCI?

Correct. For vfio-platform, it is switching back to automasked handler
but if you haven't implemented anything specific on vfio side in this
series, it is not even implemented.

Thanks

Eric
> 
> Thanks,
> 
> 	M.
> 

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 44/59] KVM: arm/arm64: GICv4: Handle MOVI applied to a VLPI
  2017-08-28 18:18   ` Christoffer Dall
@ 2017-08-30 14:08     ` Marc Zyngier
  2017-08-30 20:04       ` Christoffer Dall
  0 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-08-30 14:08 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On 28/08/17 19:18, Christoffer Dall wrote:
> On Mon, Jul 31, 2017 at 06:26:22PM +0100, Marc Zyngier wrote:
>> When the guest issues a MOVI, we need to tell the physical ITS
>> that we're now targetting a new vcpu. This is done by extracting
>> the current mapping, updating the target, and reapplying the
>> mapping. The core ITS code should do the right thing.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>>  virt/kvm/arm/vgic/vgic-its.c | 13 +++++++++++++
>>  1 file changed, 13 insertions(+)
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
>> index 79bac93d3e7d..aaad577ce328 100644
>> --- a/virt/kvm/arm/vgic/vgic-its.c
>> +++ b/virt/kvm/arm/vgic/vgic-its.c
>> @@ -706,6 +706,19 @@ static int vgic_its_cmd_handle_movi(struct kvm *kvm, struct vgic_its *its,
>>  	ite->irq->target_vcpu = vcpu;
>>  	spin_unlock(&ite->irq->irq_lock);
>>  
>> +	if (ite->irq->hw) {
>> +		struct its_vlpi_map map;
>> +		int ret;
>> +
>> +		ret = its_get_vlpi(ite->irq->host_irq, &map);
>> +		if (ret)
>> +			return ret;
>> +
>> +		map.vpe_idx = vcpu->vcpu_id;
>> +
>> +		return its_map_vlpi(ite->irq->host_irq, &map);
> 
> Since you're not holding the irq_lock across these two calls, would it
> be possible that the forwarding was removed through some other call path
> here, and could you end up passing an invalid host_irq to its_map_vlpi?
I believe we should be OK here, as we hold the ITS mutex during any
command processing, and both the forward/unforward paths take that same
mutex.

On a slightly different note, it looks like the MOVI code could benefit
from using vgic_its_resolve_lpi(), which has been introduce earlier in
this series.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 46/59] KVM: arm/arm64: GICv4: Handle MOVALL applied to a vPE
  2017-08-28 18:18   ` Christoffer Dall
@ 2017-08-30 14:46     ` Marc Zyngier
  2017-08-30 20:10       ` Christoffer Dall
  0 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-08-30 14:46 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On 28/08/17 19:18, Christoffer Dall wrote:
> On Mon, Jul 31, 2017 at 06:26:24PM +0100, Marc Zyngier wrote:
>> The current implementation of MOVALL doesn't allow us to call
>> into the core ITS code as we hold a number of spinlocks.
>>
>> Let's try a method used in other parts of the code, were we copy
>> the intids of the candicate interrupts, and then do whatever
>> we need to do with them outside of the critical section.
>>
>> This allows us to move the interrupts one by one, at the expense
>> of a bit of CPU time. Who cares? MOVALL is such a stupid command
>> anyway...
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>>  virt/kvm/arm/vgic/vgic-its.c | 27 ++++++++++++++++++++-------
>>  1 file changed, 20 insertions(+), 7 deletions(-)
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
>> index 2c065c970ba0..65cc77fde609 100644
>> --- a/virt/kvm/arm/vgic/vgic-its.c
>> +++ b/virt/kvm/arm/vgic/vgic-its.c
>> @@ -1147,11 +1147,12 @@ static int vgic_its_cmd_handle_invall(struct kvm *kvm, struct vgic_its *its,
>>  static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
>>  				      u64 *its_cmd)
>>  {
>> -	struct vgic_dist *dist = &kvm->arch.vgic;
>>  	u32 target1_addr = its_cmd_get_target_addr(its_cmd);
>>  	u32 target2_addr = its_cmd_mask_field(its_cmd, 3, 16, 32);
>>  	struct kvm_vcpu *vcpu1, *vcpu2;
>>  	struct vgic_irq *irq;
>> +	u32 *intids;
>> +	int irq_count, i;
>>  
>>  	if (target1_addr >= atomic_read(&kvm->online_vcpus) ||
>>  	    target2_addr >= atomic_read(&kvm->online_vcpus))
>> @@ -1163,19 +1164,31 @@ static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
>>  	vcpu1 = kvm_get_vcpu(kvm, target1_addr);
>>  	vcpu2 = kvm_get_vcpu(kvm, target2_addr);
>>  
>> -	spin_lock(&dist->lpi_list_lock);
>> +	irq_count = vgic_copy_lpi_list(vcpu1, &intids);
>> +	if (irq_count < 0)
>> +		return irq_count;
>>  
>> -	list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) {
>> -		spin_lock(&irq->irq_lock);
>> +	for (i = 0; i < irq_count; i++) {
>> +		irq = vgic_get_irq(kvm, NULL, intids[i]);
>> +		if (!irq)
>> +			continue;
> 
> Getting irq == NULL means that we've removed this LPI since
> vgic_copy_lpi_list, right?  Can this really happen while we hold the its
> mutex?

A disappearing LPI can only be the result of a DISCARD, which cannot
happen, as we indeed hold the ITS lock.

> Also, we don't check this in its_sync_lpi_pending_table which would
> indicate that we either have a bug there or are being overly careful
> here (or should change the continue to BUG).

Let's aim for consistency. I'll drop this test.

> 
> 
>>  
>>  		if (irq->target_vcpu == vcpu1)
>>  			irq->target_vcpu = vcpu2;
>>  
>> -		spin_unlock(&irq->irq_lock);
> 
> Is it safe to modify target_vcpu without holding the irq_lock?

Unintentional regression. I'll fix that. But I wonder if there is an
actual point in testing testing the target_vcpu here. Since we hold the
ITS lock, we're damn sure that the affinity can't be changed, right?

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 49/59] KVM: arm/arm64: GICv4: Propagate VLPI properties at map time
  2017-08-28 18:18   ` Christoffer Dall
@ 2017-08-30 14:56     ` Marc Zyngier
  2017-08-30 20:12       ` Christoffer Dall
  0 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-08-30 14:56 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On 28/08/17 19:18, Christoffer Dall wrote:
> On Mon, Jul 31, 2017 at 06:26:27PM +0100, Marc Zyngier wrote:
>> When the VLPI gets mapped, it must inherit the configuration of
>> LPI configured at the vITS level. FOr that purpose, let's make
> 
> *the LPI
> *For that

Will fix, thanks.

> 
>> update_lpi_config globally available and call it just after
>> having performed the VLPI map operation.
>>
> 
> I assume this means that the GIC compares the priorities of virtual
> interrupts in the LRs with the priorities of the pending VLPIs and
> figures out what to signal first?  I couldn't find anywhere in the spec
> where this is explicitly stated.

There is this mention in IHI0069D, 5.4 (Virtual LPI support):

"The Redistributor associated with the PE on which the vPE is scheduled
determines the highest priority pending vLPI, and forwards this to the
virtual CPU interface of the vPE. This vLPI and the interrupts in the
List register are then prioritized together to determine the highest
priority pending virtual interrupt for the vPE."

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling
  2017-08-28 18:18   ` Christoffer Dall
@ 2017-08-30 15:36     ` Marc Zyngier
  2017-08-30 20:58       ` Christoffer Dall
  0 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-08-30 15:36 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On 28/08/17 19:18, Christoffer Dall wrote:
> On Mon, Jul 31, 2017 at 06:26:29PM +0100, Marc Zyngier wrote:
>> When a vPE is not running, a VLPI being made pending results in a
>> doorbell interrupt being delivered. Let's handle this interrupt
>> and update the pending_last flag that indicates that VLPIs are
>> pending. The corresponding vcpu is also kicked into action.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>>  virt/kvm/arm/vgic/vgic-v4.c | 34 ++++++++++++++++++++++++++++++++++
>>  1 file changed, 34 insertions(+)
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>> index 534d3051a078..6af3cde6d7d4 100644
>> --- a/virt/kvm/arm/vgic/vgic-v4.c
>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>> @@ -21,6 +21,19 @@
>>  
>>  #include "vgic.h"
>>  
>> +static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
>> +{
>> +	struct kvm_vcpu *vcpu = info;
>> +
>> +	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
>> +		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
>> +		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
>> +		kvm_vcpu_kick(vcpu);
>> +	}
> 
> Can this ever fire while vgic_v4_init() is running and before te rest of
> the system has been properly initialized with some entertaining results
> to follow?  (I'm not sure if spurious doorbell non-resident vPE
> interrupts is a thing or not).

It could if you only had this patch. The following patch makes sure that
the interrupt does not get enabled at request time, meaning it will only
get enabled when the vcpu will eventually block.

And yes, spurious doorbells are a real thing. And they suck.

> 
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>>  int vgic_v4_init(struct kvm *kvm)
>>  {
>>  	struct vgic_dist *dist = &kvm->arch.vgic;
>> @@ -57,16 +70,37 @@ int vgic_v4_init(struct kvm *kvm)
>>  		return ret;
>>  	}
>>  
>> +	kvm_for_each_vcpu(i, vcpu, kvm) {
>> +		int irq = dist->its_vm.vpes[i]->irq;
>> +
>> +		ret = request_irq(irq, vgic_v4_doorbell_handler,
>> +				  0, "vcpu", vcpu);
>> +		if (ret) {
>> +			kvm_err("failed to allocate vcpu IRQ%d\n", irq);
>> +			dist->its_vm.nr_vpes = i;
> 
> That's a neat trick for the error handling.  Might deserve a tiny
> comment.

Ah, yes, will do.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 56/59] KVM: arm/arm64: GICv4: Prevent heterogenous systems from using GICv4
  2017-08-28 18:35   ` Christoffer Dall
@ 2017-08-30 16:03     ` Marc Zyngier
  2017-08-30 21:00       ` Christoffer Dall
  0 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-08-30 16:03 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On 28/08/17 19:35, Christoffer Dall wrote:
> On Mon, Jul 31, 2017 at 06:26:34PM +0100, Marc Zyngier wrote:
>> The GICv4 architecture doesn't prevent CPUs implementing GICv4 to
>> cohabit with CPUs limited to GICv3 in the same system.
>>
>> This is mad (the sheduler would have to be made aware of the v4
> 
> *scheduler
> 
>> capability), and we're certainly not going to support this any
>> time soon. So let's check that all online CPUs are GICv4 capable,
>> and disable the functionnality if not.
> 
> *functionality
> 
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>>  include/linux/irqchip/arm-gic-v3.h |  2 ++
>>  virt/kvm/arm/vgic/vgic-v3.c        | 22 +++++++++++++++++++++-
>>  2 files changed, 23 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
>> index 1ea576c8126f..dfa4a51643d6 100644
>> --- a/include/linux/irqchip/arm-gic-v3.h
>> +++ b/include/linux/irqchip/arm-gic-v3.h
>> @@ -532,6 +532,8 @@
>>  #define ICH_VTR_SEIS_MASK		(1 << ICH_VTR_SEIS_SHIFT)
>>  #define ICH_VTR_A3V_SHIFT		21
>>  #define ICH_VTR_A3V_MASK		(1 << ICH_VTR_A3V_SHIFT)
>> +#define ICH_VTR_nV4_SHIFT		20
>> +#define ICH_VTR_nV4_MASK		(1 << ICH_VTR_nV4_SHIFT)
>>  
>>  #define ICC_IAR1_EL1_SPURIOUS		0x3ff
>>  
>> diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
>> index 405733678c2f..252268e83ade 100644
>> --- a/virt/kvm/arm/vgic/vgic-v3.c
>> +++ b/virt/kvm/arm/vgic/vgic-v3.c
>> @@ -466,6 +466,18 @@ static int __init early_gicv4_enable(char *buf)
>>  }
>>  early_param("kvm-arm.vgic_v4_enable", early_gicv4_enable);
>>  
>> +static void vgic_check_v4_cpuif(void *param)
>> +{
>> +	u32 ich_vtr_el2 = kvm_call_hyp(__vgic_v3_get_ich_vtr_el2);
>> +	bool *v4 = param, this_cpu_is_v4;
>> +
>> +	this_cpu_is_v4 = !(ich_vtr_el2 & ICH_VTR_nV4_MASK);
>> +	if (!this_cpu_is_v4)
>> +		kvm_info("CPU%d is not GICv4 capable\n", smp_processor_id());
>> +
>> +	*v4 &= this_cpu_is_v4;
> 
> nit: You could make this function look slightly less scary by declaring
> this_cpu_is_v4 on a separate line and not use a bitwise operator on a
> boolean type.  Actually, having a function called 'check' with a side
> effect is not the nicest thing either, so why not just return what this
> particular CPU does and do the comparison in the calling loop.

Fair enough.

> #bikeshedding

How about this on top:

diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index 01eaf4ee2f63..e471750dc0a1 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -469,18 +469,16 @@ early_param("kvm-arm.vgic_v4_enable", early_gicv4_enable);
 static void vgic_check_v4_cpuif(void *param)
 {
 	u32 ich_vtr_el2 = kvm_call_hyp(__vgic_v3_get_ich_vtr_el2);
-	bool *v4 = param, this_cpu_is_v4;
+	bool *v4 = param;
 
-	this_cpu_is_v4 = !(ich_vtr_el2 & ICH_VTR_nV4_MASK);
-	if (!this_cpu_is_v4)
+	*v4 = !(ich_vtr_el2 & ICH_VTR_nV4_MASK);
+	if (!*v4)
 		kvm_info("CPU%d is not GICv4 capable\n", smp_processor_id());
-
-	*v4 &= this_cpu_is_v4;
 }
 
 /**
  * vgic_v3_probe - probe for a GICv3 compatible interrupt controller in DT
- * @node:	pointer to the DT node
+ * @info:	pointer to the firmware-agnostic GIC information
  *
  * Returns 0 if a GICv3 has been found, returns an error code otherwise
  */
@@ -504,9 +502,14 @@ int vgic_v3_probe(const struct gic_kvm_info *info)
 	if (info->has_v4) {
 		int cpu;
 
-		for_each_online_cpu(cpu)
+		for_each_online_cpu(cpu) {
+			bool enable;
+
 			smp_call_function_single(cpu, vgic_check_v4_cpuif,
-						 &gicv4_enable, 1);
+						 &enable, 1);
+			gicv4_enable = gicv4_enable && enable;
+		}
+
 		kvm_vgic_global_state.has_gicv4 = gicv4_enable;
 		kvm_info("GICv4 support %sabled\n",
 			 gicv4_enable ? "en" : "dis");

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply related	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass
  2017-08-30 12:53         ` Marc Zyngier
@ 2017-08-30 19:59           ` Christoffer Dall
  2017-08-31 10:24             ` Marc Zyngier
  0 siblings, 1 reply; 118+ messages in thread
From: Christoffer Dall @ 2017-08-30 19:59 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On Wed, Aug 30, 2017 at 01:53:30PM +0100, Marc Zyngier wrote:
> On 30/08/17 12:46, Christoffer Dall wrote:
> > On Wed, Aug 30, 2017 at 11:28:08AM +0100, Marc Zyngier wrote:
> >> On 26/08/17 20:48, Christoffer Dall wrote:
> >>> On Mon, Jul 31, 2017 at 06:26:19PM +0100, Marc Zyngier wrote:
> >>>> Let's use the irq bypass mechanism introduced for platform device
> >>>> interrupts to intercept the virtual PCIe endpoint configuration
> >>>> and establish our LPI->VLPI mapping.
> >>>>
> >>>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> >>>> ---
> >>>>  include/kvm/arm_vgic.h      |   8 ++++
> >>>>  virt/kvm/arm/arm.c          |  27 ++++++++----
> >>>>  virt/kvm/arm/vgic/vgic-v4.c | 103 ++++++++++++++++++++++++++++++++++++++++++++
> >>>>  3 files changed, 130 insertions(+), 8 deletions(-)
> >>>>
> >>>> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> >>>> index 359eeffe9857..050f78d4fb42 100644
> >>>> --- a/include/kvm/arm_vgic.h
> >>>> +++ b/include/kvm/arm_vgic.h
> >>>> @@ -367,4 +367,12 @@ int kvm_vgic_set_forwarding(struct kvm *kvm, unsigned int host_irq,
> >>>>  void kvm_vgic_unset_forwarding(struct kvm *kvm, unsigned int host_irq,
> >>>>  			       unsigned int vintid);
> >>>>  
> >>>> +struct kvm_kernel_irq_routing_entry;
> >>>> +
> >>>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int irq,
> >>>> +			       struct kvm_kernel_irq_routing_entry *irq_entry);
> >>>> +
> >>>> +int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int irq,
> >>>> +				 struct kvm_kernel_irq_routing_entry *irq_entry);
> >>>> +
> >>>>  #endif /* __KVM_ARM_VGIC_H */
> >>>> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
> >>>> index ebab6c29e3be..6803ea27c47d 100644
> >>>> --- a/virt/kvm/arm/arm.c
> >>>> +++ b/virt/kvm/arm/arm.c
> >>>> @@ -1457,11 +1457,16 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
> >>>>  	struct kvm_kernel_irqfd *irqfd =
> >>>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
> >>>>  
> >>>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
> >>>> +	switch (prod->type) {
> >>>> +	case IRQ_BYPASS_VFIO_PLATFORM:
> >>>> +		return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
> >>>> +					       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
> >>>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
> >>>> +		return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq,
> >>>> +						  &irqfd->irq_entry);
> >>>> +	default:
> >>>>  		return 0;
> >>>> -
> >>>> -	return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
> >>>> -				       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
> >>>> +	}
> >>>>  }
> >>>>  void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
> >>>>  				      struct irq_bypass_producer *prod)
> >>>> @@ -1469,11 +1474,17 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
> >>>>  	struct kvm_kernel_irqfd *irqfd =
> >>>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
> >>>>  
> >>>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
> >>>> -		return;
> >>>> +	switch (prod->type) {
> >>>> +	case IRQ_BYPASS_VFIO_PLATFORM:
> >>>> +		kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
> >>>> +					  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
> >>>> +		break;
> >>>>  
> >>>> -	kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
> >>>> -				  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
> >>>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
> >>>> +		kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq,
> >>>> +					     &irqfd->irq_entry);
> >>>> +		break;
> >>>> +	}
> >>>>  }
> >>>>  
> >>>>  void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
> >>>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> >>>> index 207e1fda0dcd..338c86c5159f 100644
> >>>> --- a/virt/kvm/arm/vgic/vgic-v4.c
> >>>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> >>>> @@ -72,3 +72,106 @@ void vgic_v4_teardown(struct kvm *kvm)
> >>>>  	its_vm->nr_vpes = 0;
> >>>>  	its_vm->vpes = NULL;
> >>>>  }
> >>>> +
> >>>> +static struct vgic_its *vgic_get_its(struct kvm *kvm,
> >>>> +				     struct kvm_kernel_irq_routing_entry *irq_entry)
> >>>> +{
> >>>> +	struct kvm_msi msi  = (struct kvm_msi) {
> >>>> +		.address_lo	= irq_entry->msi.address_lo,
> >>>> +		.address_hi	= irq_entry->msi.address_hi,
> >>>> +		.data		= irq_entry->msi.data,
> >>>> +		.flags		= irq_entry->msi.flags,
> >>>> +		.devid		= irq_entry->msi.devid,
> >>>> +	};
> >>>> +
> >>>> +	/*
> >>>> +	 * Get a reference on the LPI. If NULL, this is not a valid
> >>>> +	 * translation for any of our vITSs.
> >>>> +	 */
> >>>> +	return vgic_msi_to_its(kvm, &msi);
> >>>> +}
> >>>> +
> >>>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
> >>>> +			       struct kvm_kernel_irq_routing_entry *irq_entry)
> >>>> +{
> >>>> +	struct vgic_its *its;
> >>>> +	struct vgic_irq *irq;
> >>>> +	struct its_vlpi_map map;
> >>>> +	int ret;
> >>>> +
> >>>> +	if (!vgic_is_v4_capable(kvm))
> >>>> +		return 0;
> >>>> +
> >>>> +	/*
> >>>> +	 * Get the ITS, and escape early on error (not a valid
> >>>> +	 * doorbell for any of our vITSs).
> >>>> +	 */
> >>>> +	its = vgic_get_its(kvm, irq_entry);
> >>>> +	if (IS_ERR(its))
> >>>> +		return 0;
> >>>> +
> >>>> +	mutex_lock(&its->its_lock);
> >>>> +
> >>>> +	/* Perform then actual DevID/EventID -> LPI translation. */
> >>>> +	ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid,
> >>>> +				   irq_entry->msi.data, &irq);
> >>>> +	if (ret)
> >>>> +		goto out;
> >>>> +
> >>>> +	/*
> >>>> +	 * Emit the mapping request. If it fails, the ITS probably
> >>>> +	 * isn't v4 compatible, so let's silently bail out. Holding
> >>>> +	 * the ITS lock should ensure that nothing can modify the
> >>>> +	 * target vcpu.
> >>>> +	 */
> >>>> +	map = (struct its_vlpi_map) {
> >>>> +		.vm		= &kvm->arch.vgic.its_vm,
> >>>> +		.vintid		= irq->intid,
> >>>> +		.db_enabled	= true,
> >>>> +		.vpe_idx	= irq->target_vcpu->vcpu_id,
> >>
> >> This is just wrong. We cannot assume that the vcpu_id has anything to do
> >> with the vpe_idx. It happens to be the same thing now, but the two things
> >> should be clearly disconnected.
> >>
> >> I suggest the following (untested):
> >>
> >> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> >> index cf5d6e2de6b8..0146e004401a 100644
> >> --- a/virt/kvm/arm/vgic/vgic-v4.c
> >> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> >> @@ -251,13 +251,27 @@ static void dump_routing(int virq, struct kvm_kernel_irq_routing_entry *irq_entr
> >>  
> >>  }
> >>  
> >> +static int vgic_v4_vcpu_to_index(struct its_vm *its_vm, struct kvm_vcpu *vcpu)
> >> +{
> >> +	int i;
> >> +
> >> +	for (i = 0; i < its_vm->nr_vpes; i++) {
> >> +		struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;
> >> +
> >> +		if (its_vm->vpes[i] == vpe)
> >> +			return i;
> >> +	}
> >> +
> >> +	return -ENODEV;
> >> +}
> >> +
> > 
> > Stupid question: Can we change the struct its_vlpi_map to contain a
> > vpe pointer or in stead of or in addition to the index?
> 
> This is obviously the right solution, because the *index* of the VPE 
> doesn't really matter for a map/unmap (it only matters for doorbell 
> operations, and that's a very different code path).
> 
> I came up with the following (untested, again), which is much more
> appealing:
> 
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index b47097a3e4b4..0607541fcafc 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -900,7 +900,7 @@ static void its_send_vmapti(struct its_device *dev, u32 id)
>  	struct its_vlpi_map *map = &dev->event_map.vlpi_maps[id];
>  	struct its_cmd_desc desc;
>  
> -	desc.its_vmapti_cmd.vpe = map->vm->vpes[map->vpe_idx];
> +	desc.its_vmapti_cmd.vpe = map->vpe;
>  	desc.its_vmapti_cmd.dev = dev;
>  	desc.its_vmapti_cmd.virt_id = map->vintid;
>  	desc.its_vmapti_cmd.event_id = id;
> @@ -914,7 +914,7 @@ static void its_send_vmovi(struct its_device *dev, u32 id)
>  	struct its_vlpi_map *map = &dev->event_map.vlpi_maps[id];
>  	struct its_cmd_desc desc;
>  
> -	desc.its_vmovi_cmd.vpe = map->vm->vpes[map->vpe_idx];
> +	desc.its_vmovi_cmd.vpe = map->vpe;
>  	desc.its_vmovi_cmd.dev = dev;
>  	desc.its_vmovi_cmd.event_id = id;
>  	desc.its_vmovi_cmd.db_enabled = map->db_enabled;
> diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h
> index 52661b838821..58a4d89aa82c 100644
> --- a/include/linux/irqchip/arm-gic-v4.h
> +++ b/include/linux/irqchip/arm-gic-v4.h
> @@ -62,15 +62,15 @@ struct its_vpe {
>   * irq_set_vcpu_affinity().
>   *
>   * @vm:		Pointer to the GICv4 notion of a VM
> + * @vpe:	Pointer to the GICv4 notion of a virtual CPU (VPE)
>   * @vintid:	Virtual LPI number
>   * @db_enabled:	Is the VPE doorbell to be generated?
> - * @vpe_idx:	Index (0-based) of the VPE in this VM. Not the vpe_id!
>   */
>  struct its_vlpi_map {
>  	struct its_vm		*vm;
> +	struct its_vpe		*vpe;
>  	u32			vintid;
>  	bool			db_enabled;
> -	u16			vpe_idx;
>  };
>  
>  enum its_vcpu_info_cmd_type {
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index d790d0c74b8b..6ba3d73e0f70 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -715,7 +715,7 @@ static int vgic_its_cmd_handle_movi(struct kvm *kvm, struct vgic_its *its,
>  		if (ret)
>  			return ret;
>  
> -		map.vpe_idx = vcpu->vcpu_id;
> +		map.vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;
>  
>  		return its_map_vlpi(ite->irq->host_irq, &map);
>  	}
> @@ -1184,7 +1184,7 @@ static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
>  			struct its_vlpi_map map;
>  
>  			if (!its_get_vlpi(irq->host_irq, &map)) {
> -				map.vpe_idx = vcpu2->vcpu_id;
> +				map.vpe = &vcpu2->arch.vgic_cpu.vgic_v3.its_vpe;
>  				its_map_vlpi(irq->host_irq, &map);
>  			}
>  		}
> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> index cf5d6e2de6b8..6ece88322013 100644
> --- a/virt/kvm/arm/vgic/vgic-v4.c
> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> @@ -288,9 +288,9 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
>  	 */
>  	map = (struct its_vlpi_map) {
>  		.vm		= &kvm->arch.vgic.its_vm,
> +		.vpe		= &irq->target_vcpu->arch.vgic_cpu.vgic_v3.its_vpe,
>  		.vintid		= irq->intid,
>  		.db_enabled	= true,
> -		.vpe_idx	= irq->target_vcpu->vcpu_id,
>  	};
>  
>  	if (its_map_vlpi(virq, &map))
> 
> Maybe I'll introduce a vcpu_to_vpe() helper, but it already looks much 
> better to me...
> 
Yes, indeed.  Looks good to me as well.

The only thing that makes me slightly nervous is the use of target_vcpu,
but I think we rely on it never being NULL for LPIs elsewhere in the
code, so we should be fine.

Thanks,
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 44/59] KVM: arm/arm64: GICv4: Handle MOVI applied to a VLPI
  2017-08-30 14:08     ` Marc Zyngier
@ 2017-08-30 20:04       ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-30 20:04 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On Wed, Aug 30, 2017 at 03:08:01PM +0100, Marc Zyngier wrote:
> On 28/08/17 19:18, Christoffer Dall wrote:
> > On Mon, Jul 31, 2017 at 06:26:22PM +0100, Marc Zyngier wrote:
> >> When the guest issues a MOVI, we need to tell the physical ITS
> >> that we're now targetting a new vcpu. This is done by extracting
> >> the current mapping, updating the target, and reapplying the
> >> mapping. The core ITS code should do the right thing.
> >>
> >> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> >> ---
> >>  virt/kvm/arm/vgic/vgic-its.c | 13 +++++++++++++
> >>  1 file changed, 13 insertions(+)
> >>
> >> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> >> index 79bac93d3e7d..aaad577ce328 100644
> >> --- a/virt/kvm/arm/vgic/vgic-its.c
> >> +++ b/virt/kvm/arm/vgic/vgic-its.c
> >> @@ -706,6 +706,19 @@ static int vgic_its_cmd_handle_movi(struct kvm *kvm, struct vgic_its *its,
> >>  	ite->irq->target_vcpu = vcpu;
> >>  	spin_unlock(&ite->irq->irq_lock);
> >>  
> >> +	if (ite->irq->hw) {
> >> +		struct its_vlpi_map map;
> >> +		int ret;
> >> +
> >> +		ret = its_get_vlpi(ite->irq->host_irq, &map);
> >> +		if (ret)
> >> +			return ret;
> >> +
> >> +		map.vpe_idx = vcpu->vcpu_id;
> >> +
> >> +		return its_map_vlpi(ite->irq->host_irq, &map);
> > 
> > Since you're not holding the irq_lock across these two calls, would it
> > be possible that the forwarding was removed through some other call path
> > here, and could you end up passing an invalid host_irq to its_map_vlpi?
> I believe we should be OK here, as we hold the ITS mutex during any
> command processing, and both the forward/unforward paths take that same
> mutex.

ok, yes, as long as the only other modifirs are the forward/unforward
paths and they hold the mutex, we should be fine.

> 
> On a slightly different note, it looks like the MOVI code could benefit
> from using vgic_its_resolve_lpi(), which has been introduce earlier in
> this series.

Only problem is you'd need to get a handle to the ite as well to change
the collection pointer.  I suppose you could add another pointer
pointer.

-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 46/59] KVM: arm/arm64: GICv4: Handle MOVALL applied to a vPE
  2017-08-30 14:46     ` Marc Zyngier
@ 2017-08-30 20:10       ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-30 20:10 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On Wed, Aug 30, 2017 at 03:46:12PM +0100, Marc Zyngier wrote:
> On 28/08/17 19:18, Christoffer Dall wrote:
> > On Mon, Jul 31, 2017 at 06:26:24PM +0100, Marc Zyngier wrote:
> >> The current implementation of MOVALL doesn't allow us to call
> >> into the core ITS code as we hold a number of spinlocks.
> >>
> >> Let's try a method used in other parts of the code, were we copy
> >> the intids of the candicate interrupts, and then do whatever
> >> we need to do with them outside of the critical section.
> >>
> >> This allows us to move the interrupts one by one, at the expense
> >> of a bit of CPU time. Who cares? MOVALL is such a stupid command
> >> anyway...
> >>
> >> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> >> ---
> >>  virt/kvm/arm/vgic/vgic-its.c | 27 ++++++++++++++++++++-------
> >>  1 file changed, 20 insertions(+), 7 deletions(-)
> >>
> >> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> >> index 2c065c970ba0..65cc77fde609 100644
> >> --- a/virt/kvm/arm/vgic/vgic-its.c
> >> +++ b/virt/kvm/arm/vgic/vgic-its.c
> >> @@ -1147,11 +1147,12 @@ static int vgic_its_cmd_handle_invall(struct kvm *kvm, struct vgic_its *its,
> >>  static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
> >>  				      u64 *its_cmd)
> >>  {
> >> -	struct vgic_dist *dist = &kvm->arch.vgic;
> >>  	u32 target1_addr = its_cmd_get_target_addr(its_cmd);
> >>  	u32 target2_addr = its_cmd_mask_field(its_cmd, 3, 16, 32);
> >>  	struct kvm_vcpu *vcpu1, *vcpu2;
> >>  	struct vgic_irq *irq;
> >> +	u32 *intids;
> >> +	int irq_count, i;
> >>  
> >>  	if (target1_addr >= atomic_read(&kvm->online_vcpus) ||
> >>  	    target2_addr >= atomic_read(&kvm->online_vcpus))
> >> @@ -1163,19 +1164,31 @@ static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
> >>  	vcpu1 = kvm_get_vcpu(kvm, target1_addr);
> >>  	vcpu2 = kvm_get_vcpu(kvm, target2_addr);
> >>  
> >> -	spin_lock(&dist->lpi_list_lock);
> >> +	irq_count = vgic_copy_lpi_list(vcpu1, &intids);
> >> +	if (irq_count < 0)
> >> +		return irq_count;
> >>  
> >> -	list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) {
> >> -		spin_lock(&irq->irq_lock);
> >> +	for (i = 0; i < irq_count; i++) {
> >> +		irq = vgic_get_irq(kvm, NULL, intids[i]);
> >> +		if (!irq)
> >> +			continue;
> > 
> > Getting irq == NULL means that we've removed this LPI since
> > vgic_copy_lpi_list, right?  Can this really happen while we hold the its
> > mutex?
> 
> A disappearing LPI can only be the result of a DISCARD, which cannot
> happen, as we indeed hold the ITS lock.
> 
> > Also, we don't check this in its_sync_lpi_pending_table which would
> > indicate that we either have a bug there or are being overly careful
> > here (or should change the continue to BUG).
> 
> Let's aim for consistency. I'll drop this test.
> 
> > 
> > 
> >>  
> >>  		if (irq->target_vcpu == vcpu1)
> >>  			irq->target_vcpu = vcpu2;
> >>  
> >> -		spin_unlock(&irq->irq_lock);
> > 
> > Is it safe to modify target_vcpu without holding the irq_lock?
> 
> Unintentional regression. I'll fix that. But I wonder if there is an
> actual point in testing testing the target_vcpu here. Since we hold the
> ITS lock, we're damn sure that the affinity can't be changed, right?
> 

Ah, yes, because you filtered the list on the source VCPU already you
should be able to let go of this check.

Thanks,
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 49/59] KVM: arm/arm64: GICv4: Propagate VLPI properties at map time
  2017-08-30 14:56     ` Marc Zyngier
@ 2017-08-30 20:12       ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-30 20:12 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On Wed, Aug 30, 2017 at 03:56:57PM +0100, Marc Zyngier wrote:
> On 28/08/17 19:18, Christoffer Dall wrote:
> > On Mon, Jul 31, 2017 at 06:26:27PM +0100, Marc Zyngier wrote:
> >> When the VLPI gets mapped, it must inherit the configuration of
> >> LPI configured at the vITS level. FOr that purpose, let's make
> > 
> > *the LPI
> > *For that
> 
> Will fix, thanks.
> 
> > 
> >> update_lpi_config globally available and call it just after
> >> having performed the VLPI map operation.
> >>
> > 
> > I assume this means that the GIC compares the priorities of virtual
> > interrupts in the LRs with the priorities of the pending VLPIs and
> > figures out what to signal first?  I couldn't find anywhere in the spec
> > where this is explicitly stated.
> 
> There is this mention in IHI0069D, 5.4 (Virtual LPI support):
> 
> "The Redistributor associated with the PE on which the vPE is scheduled
> determines the highest priority pending vLPI, and forwards this to the
> virtual CPU interface of the vPE. This vLPI and the interrupts in the
> List register are then prioritized together to determine the highest
> priority pending virtual interrupt for the vPE."
> 

Wow, I didn't find that staring at the manual for a considerable amount
of time.  Thanks for the pointer.

Thanks,
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling
  2017-08-30 15:36     ` Marc Zyngier
@ 2017-08-30 20:58       ` Christoffer Dall
  2017-08-31  8:19         ` Marc Zyngier
  0 siblings, 1 reply; 118+ messages in thread
From: Christoffer Dall @ 2017-08-30 20:58 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On Wed, Aug 30, 2017 at 04:36:06PM +0100, Marc Zyngier wrote:
> On 28/08/17 19:18, Christoffer Dall wrote:
> > On Mon, Jul 31, 2017 at 06:26:29PM +0100, Marc Zyngier wrote:
> >> When a vPE is not running, a VLPI being made pending results in a
> >> doorbell interrupt being delivered. Let's handle this interrupt
> >> and update the pending_last flag that indicates that VLPIs are
> >> pending. The corresponding vcpu is also kicked into action.
> >>
> >> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> >> ---
> >>  virt/kvm/arm/vgic/vgic-v4.c | 34 ++++++++++++++++++++++++++++++++++
> >>  1 file changed, 34 insertions(+)
> >>
> >> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> >> index 534d3051a078..6af3cde6d7d4 100644
> >> --- a/virt/kvm/arm/vgic/vgic-v4.c
> >> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> >> @@ -21,6 +21,19 @@
> >>  
> >>  #include "vgic.h"
> >>  
> >> +static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
> >> +{
> >> +	struct kvm_vcpu *vcpu = info;
> >> +
> >> +	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
> >> +		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> >> +		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> >> +		kvm_vcpu_kick(vcpu);
> >> +	}
> > 
> > Can this ever fire while vgic_v4_init() is running and before te rest of
> > the system has been properly initialized with some entertaining results
> > to follow?  (I'm not sure if spurious doorbell non-resident vPE
> > interrupts is a thing or not).
> 
> It could if you only had this patch. The following patch makes sure that
> the interrupt does not get enabled at request time, meaning it will only
> get enabled when the vcpu will eventually block.
> 
> And yes, spurious doorbells are a real thing. And they suck.
> 

Ah, my abilities to forward read on a patch series are quite poor.

Thanks,
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 56/59] KVM: arm/arm64: GICv4: Prevent heterogenous systems from using GICv4
  2017-08-30 16:03     ` Marc Zyngier
@ 2017-08-30 21:00       ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-30 21:00 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On Wed, Aug 30, 2017 at 05:03:51PM +0100, Marc Zyngier wrote:
> On 28/08/17 19:35, Christoffer Dall wrote:
> > On Mon, Jul 31, 2017 at 06:26:34PM +0100, Marc Zyngier wrote:
> >> The GICv4 architecture doesn't prevent CPUs implementing GICv4 to
> >> cohabit with CPUs limited to GICv3 in the same system.
> >>
> >> This is mad (the sheduler would have to be made aware of the v4
> > 
> > *scheduler
> > 
> >> capability), and we're certainly not going to support this any
> >> time soon. So let's check that all online CPUs are GICv4 capable,
> >> and disable the functionnality if not.
> > 
> > *functionality
> > 
> >>
> >> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> >> ---
> >>  include/linux/irqchip/arm-gic-v3.h |  2 ++
> >>  virt/kvm/arm/vgic/vgic-v3.c        | 22 +++++++++++++++++++++-
> >>  2 files changed, 23 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
> >> index 1ea576c8126f..dfa4a51643d6 100644
> >> --- a/include/linux/irqchip/arm-gic-v3.h
> >> +++ b/include/linux/irqchip/arm-gic-v3.h
> >> @@ -532,6 +532,8 @@
> >>  #define ICH_VTR_SEIS_MASK		(1 << ICH_VTR_SEIS_SHIFT)
> >>  #define ICH_VTR_A3V_SHIFT		21
> >>  #define ICH_VTR_A3V_MASK		(1 << ICH_VTR_A3V_SHIFT)
> >> +#define ICH_VTR_nV4_SHIFT		20
> >> +#define ICH_VTR_nV4_MASK		(1 << ICH_VTR_nV4_SHIFT)
> >>  
> >>  #define ICC_IAR1_EL1_SPURIOUS		0x3ff
> >>  
> >> diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
> >> index 405733678c2f..252268e83ade 100644
> >> --- a/virt/kvm/arm/vgic/vgic-v3.c
> >> +++ b/virt/kvm/arm/vgic/vgic-v3.c
> >> @@ -466,6 +466,18 @@ static int __init early_gicv4_enable(char *buf)
> >>  }
> >>  early_param("kvm-arm.vgic_v4_enable", early_gicv4_enable);
> >>  
> >> +static void vgic_check_v4_cpuif(void *param)
> >> +{
> >> +	u32 ich_vtr_el2 = kvm_call_hyp(__vgic_v3_get_ich_vtr_el2);
> >> +	bool *v4 = param, this_cpu_is_v4;
> >> +
> >> +	this_cpu_is_v4 = !(ich_vtr_el2 & ICH_VTR_nV4_MASK);
> >> +	if (!this_cpu_is_v4)
> >> +		kvm_info("CPU%d is not GICv4 capable\n", smp_processor_id());
> >> +
> >> +	*v4 &= this_cpu_is_v4;
> > 
> > nit: You could make this function look slightly less scary by declaring
> > this_cpu_is_v4 on a separate line and not use a bitwise operator on a
> > boolean type.  Actually, having a function called 'check' with a side
> > effect is not the nicest thing either, so why not just return what this
> > particular CPU does and do the comparison in the calling loop.
> 
> Fair enough.
> 
> > #bikeshedding
> 
> How about this on top:
> 
> diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
> index 01eaf4ee2f63..e471750dc0a1 100644
> --- a/virt/kvm/arm/vgic/vgic-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-v3.c
> @@ -469,18 +469,16 @@ early_param("kvm-arm.vgic_v4_enable", early_gicv4_enable);
>  static void vgic_check_v4_cpuif(void *param)
>  {
>  	u32 ich_vtr_el2 = kvm_call_hyp(__vgic_v3_get_ich_vtr_el2);
> -	bool *v4 = param, this_cpu_is_v4;
> +	bool *v4 = param;
>  
> -	this_cpu_is_v4 = !(ich_vtr_el2 & ICH_VTR_nV4_MASK);
> -	if (!this_cpu_is_v4)
> +	*v4 = !(ich_vtr_el2 & ICH_VTR_nV4_MASK);
> +	if (!*v4)
>  		kvm_info("CPU%d is not GICv4 capable\n", smp_processor_id());
> -
> -	*v4 &= this_cpu_is_v4;
>  }
>  
>  /**
>   * vgic_v3_probe - probe for a GICv3 compatible interrupt controller in DT
> - * @node:	pointer to the DT node
> + * @info:	pointer to the firmware-agnostic GIC information
>   *
>   * Returns 0 if a GICv3 has been found, returns an error code otherwise
>   */
> @@ -504,9 +502,14 @@ int vgic_v3_probe(const struct gic_kvm_info *info)
>  	if (info->has_v4) {
>  		int cpu;
>  
> -		for_each_online_cpu(cpu)
> +		for_each_online_cpu(cpu) {
> +			bool enable;
> +
>  			smp_call_function_single(cpu, vgic_check_v4_cpuif,
> -						 &gicv4_enable, 1);
> +						 &enable, 1);
> +			gicv4_enable = gicv4_enable && enable;
> +		}
> +
>  		kvm_vgic_global_state.has_gicv4 = gicv4_enable;
>  		kvm_info("GICv4 support %sabled\n",
>  			 gicv4_enable ? "en" : "dis");
> 

Looks good to me, thanks!
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling
  2017-08-30 20:58       ` Christoffer Dall
@ 2017-08-31  8:19         ` Marc Zyngier
  0 siblings, 0 replies; 118+ messages in thread
From: Marc Zyngier @ 2017-08-31  8:19 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On 30/08/17 21:58, Christoffer Dall wrote:
> On Wed, Aug 30, 2017 at 04:36:06PM +0100, Marc Zyngier wrote:
>> On 28/08/17 19:18, Christoffer Dall wrote:
>>> On Mon, Jul 31, 2017 at 06:26:29PM +0100, Marc Zyngier wrote:
>>>> When a vPE is not running, a VLPI being made pending results in a
>>>> doorbell interrupt being delivered. Let's handle this interrupt
>>>> and update the pending_last flag that indicates that VLPIs are
>>>> pending. The corresponding vcpu is also kicked into action.
>>>>
>>>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>>>> ---
>>>>  virt/kvm/arm/vgic/vgic-v4.c | 34 ++++++++++++++++++++++++++++++++++
>>>>  1 file changed, 34 insertions(+)
>>>>
>>>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>>>> index 534d3051a078..6af3cde6d7d4 100644
>>>> --- a/virt/kvm/arm/vgic/vgic-v4.c
>>>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>>>> @@ -21,6 +21,19 @@
>>>>  
>>>>  #include "vgic.h"
>>>>  
>>>> +static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
>>>> +{
>>>> +	struct kvm_vcpu *vcpu = info;
>>>> +
>>>> +	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
>>>> +		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
>>>> +		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
>>>> +		kvm_vcpu_kick(vcpu);
>>>> +	}
>>>
>>> Can this ever fire while vgic_v4_init() is running and before te rest of
>>> the system has been properly initialized with some entertaining results
>>> to follow?  (I'm not sure if spurious doorbell non-resident vPE
>>> interrupts is a thing or not).
>>
>> It could if you only had this patch. The following patch makes sure that
>> the interrupt does not get enabled at request time, meaning it will only
>> get enabled when the vcpu will eventually block.
>>
>> And yes, spurious doorbells are a real thing. And they suck.
>>
> 
> Ah, my abilities to forward read on a patch series are quite poor.
Not quite. It indicates that the patch split is a bit wrong, and that

	irq_set_status_flags(irq, IRQ_NOAUTOEN | IRQ_DISABLE_UNLAZY);

should really be in this patch and not the following one.

I'll fix that as I rebase the whole thing.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass
  2017-08-30 19:59           ` Christoffer Dall
@ 2017-08-31 10:24             ` Marc Zyngier
  2017-08-31 12:36               ` Christoffer Dall
  0 siblings, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-08-31 10:24 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: Jason Cooper, kvm, linux-kernel, linux-arm-kernel,
	Thomas Gleixner, kvmarm

On 30/08/17 20:59, Christoffer Dall wrote:
> On Wed, Aug 30, 2017 at 01:53:30PM +0100, Marc Zyngier wrote:
>> On 30/08/17 12:46, Christoffer Dall wrote:
>>> On Wed, Aug 30, 2017 at 11:28:08AM +0100, Marc Zyngier wrote:
>>>> On 26/08/17 20:48, Christoffer Dall wrote:
>>>>> On Mon, Jul 31, 2017 at 06:26:19PM +0100, Marc Zyngier wrote:
>>>>>> Let's use the irq bypass mechanism introduced for platform device
>>>>>> interrupts to intercept the virtual PCIe endpoint configuration
>>>>>> and establish our LPI->VLPI mapping.
>>>>>>
>>>>>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>>>>>> ---
>>>>>>  include/kvm/arm_vgic.h      |   8 ++++
>>>>>>  virt/kvm/arm/arm.c          |  27 ++++++++----
>>>>>>  virt/kvm/arm/vgic/vgic-v4.c | 103 ++++++++++++++++++++++++++++++++++++++++++++
>>>>>>  3 files changed, 130 insertions(+), 8 deletions(-)
>>>>>>
>>>>>> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
>>>>>> index 359eeffe9857..050f78d4fb42 100644
>>>>>> --- a/include/kvm/arm_vgic.h
>>>>>> +++ b/include/kvm/arm_vgic.h
>>>>>> @@ -367,4 +367,12 @@ int kvm_vgic_set_forwarding(struct kvm *kvm, unsigned int host_irq,
>>>>>>  void kvm_vgic_unset_forwarding(struct kvm *kvm, unsigned int host_irq,
>>>>>>  			       unsigned int vintid);
>>>>>>  
>>>>>> +struct kvm_kernel_irq_routing_entry;
>>>>>> +
>>>>>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int irq,
>>>>>> +			       struct kvm_kernel_irq_routing_entry *irq_entry);
>>>>>> +
>>>>>> +int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int irq,
>>>>>> +				 struct kvm_kernel_irq_routing_entry *irq_entry);
>>>>>> +
>>>>>>  #endif /* __KVM_ARM_VGIC_H */
>>>>>> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
>>>>>> index ebab6c29e3be..6803ea27c47d 100644
>>>>>> --- a/virt/kvm/arm/arm.c
>>>>>> +++ b/virt/kvm/arm/arm.c
>>>>>> @@ -1457,11 +1457,16 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
>>>>>>  	struct kvm_kernel_irqfd *irqfd =
>>>>>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
>>>>>>  
>>>>>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
>>>>>> +	switch (prod->type) {
>>>>>> +	case IRQ_BYPASS_VFIO_PLATFORM:
>>>>>> +		return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
>>>>>> +					       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>>>>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
>>>>>> +		return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq,
>>>>>> +						  &irqfd->irq_entry);
>>>>>> +	default:
>>>>>>  		return 0;
>>>>>> -
>>>>>> -	return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
>>>>>> -				       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>>>>> +	}
>>>>>>  }
>>>>>>  void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
>>>>>>  				      struct irq_bypass_producer *prod)
>>>>>> @@ -1469,11 +1474,17 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
>>>>>>  	struct kvm_kernel_irqfd *irqfd =
>>>>>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
>>>>>>  
>>>>>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
>>>>>> -		return;
>>>>>> +	switch (prod->type) {
>>>>>> +	case IRQ_BYPASS_VFIO_PLATFORM:
>>>>>> +		kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
>>>>>> +					  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>>>>> +		break;
>>>>>>  
>>>>>> -	kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
>>>>>> -				  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
>>>>>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
>>>>>> +		kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq,
>>>>>> +					     &irqfd->irq_entry);
>>>>>> +		break;
>>>>>> +	}
>>>>>>  }
>>>>>>  
>>>>>>  void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
>>>>>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>>>>>> index 207e1fda0dcd..338c86c5159f 100644
>>>>>> --- a/virt/kvm/arm/vgic/vgic-v4.c
>>>>>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>>>>>> @@ -72,3 +72,106 @@ void vgic_v4_teardown(struct kvm *kvm)
>>>>>>  	its_vm->nr_vpes = 0;
>>>>>>  	its_vm->vpes = NULL;
>>>>>>  }
>>>>>> +
>>>>>> +static struct vgic_its *vgic_get_its(struct kvm *kvm,
>>>>>> +				     struct kvm_kernel_irq_routing_entry *irq_entry)
>>>>>> +{
>>>>>> +	struct kvm_msi msi  = (struct kvm_msi) {
>>>>>> +		.address_lo	= irq_entry->msi.address_lo,
>>>>>> +		.address_hi	= irq_entry->msi.address_hi,
>>>>>> +		.data		= irq_entry->msi.data,
>>>>>> +		.flags		= irq_entry->msi.flags,
>>>>>> +		.devid		= irq_entry->msi.devid,
>>>>>> +	};
>>>>>> +
>>>>>> +	/*
>>>>>> +	 * Get a reference on the LPI. If NULL, this is not a valid
>>>>>> +	 * translation for any of our vITSs.
>>>>>> +	 */
>>>>>> +	return vgic_msi_to_its(kvm, &msi);
>>>>>> +}
>>>>>> +
>>>>>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
>>>>>> +			       struct kvm_kernel_irq_routing_entry *irq_entry)
>>>>>> +{
>>>>>> +	struct vgic_its *its;
>>>>>> +	struct vgic_irq *irq;
>>>>>> +	struct its_vlpi_map map;
>>>>>> +	int ret;
>>>>>> +
>>>>>> +	if (!vgic_is_v4_capable(kvm))
>>>>>> +		return 0;
>>>>>> +
>>>>>> +	/*
>>>>>> +	 * Get the ITS, and escape early on error (not a valid
>>>>>> +	 * doorbell for any of our vITSs).
>>>>>> +	 */
>>>>>> +	its = vgic_get_its(kvm, irq_entry);
>>>>>> +	if (IS_ERR(its))
>>>>>> +		return 0;
>>>>>> +
>>>>>> +	mutex_lock(&its->its_lock);
>>>>>> +
>>>>>> +	/* Perform then actual DevID/EventID -> LPI translation. */
>>>>>> +	ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid,
>>>>>> +				   irq_entry->msi.data, &irq);
>>>>>> +	if (ret)
>>>>>> +		goto out;
>>>>>> +
>>>>>> +	/*
>>>>>> +	 * Emit the mapping request. If it fails, the ITS probably
>>>>>> +	 * isn't v4 compatible, so let's silently bail out. Holding
>>>>>> +	 * the ITS lock should ensure that nothing can modify the
>>>>>> +	 * target vcpu.
>>>>>> +	 */
>>>>>> +	map = (struct its_vlpi_map) {
>>>>>> +		.vm		= &kvm->arch.vgic.its_vm,
>>>>>> +		.vintid		= irq->intid,
>>>>>> +		.db_enabled	= true,
>>>>>> +		.vpe_idx	= irq->target_vcpu->vcpu_id,
>>>>
>>>> This is just wrong. We cannot assume that the vcpu_id has anything to do
>>>> with the vpe_idx. It happens to be the same thing now, but the two things
>>>> should be clearly disconnected.
>>>>
>>>> I suggest the following (untested):
>>>>
>>>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>>>> index cf5d6e2de6b8..0146e004401a 100644
>>>> --- a/virt/kvm/arm/vgic/vgic-v4.c
>>>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>>>> @@ -251,13 +251,27 @@ static void dump_routing(int virq, struct kvm_kernel_irq_routing_entry *irq_entr
>>>>  
>>>>  }
>>>>  
>>>> +static int vgic_v4_vcpu_to_index(struct its_vm *its_vm, struct kvm_vcpu *vcpu)
>>>> +{
>>>> +	int i;
>>>> +
>>>> +	for (i = 0; i < its_vm->nr_vpes; i++) {
>>>> +		struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;
>>>> +
>>>> +		if (its_vm->vpes[i] == vpe)
>>>> +			return i;
>>>> +	}
>>>> +
>>>> +	return -ENODEV;
>>>> +}
>>>> +
>>>
>>> Stupid question: Can we change the struct its_vlpi_map to contain a
>>> vpe pointer or in stead of or in addition to the index?
>>
>> This is obviously the right solution, because the *index* of the VPE 
>> doesn't really matter for a map/unmap (it only matters for doorbell 
>> operations, and that's a very different code path).
>>
>> I came up with the following (untested, again), which is much more
>> appealing:
>>
>> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
>> index b47097a3e4b4..0607541fcafc 100644
>> --- a/drivers/irqchip/irq-gic-v3-its.c
>> +++ b/drivers/irqchip/irq-gic-v3-its.c
>> @@ -900,7 +900,7 @@ static void its_send_vmapti(struct its_device *dev, u32 id)
>>  	struct its_vlpi_map *map = &dev->event_map.vlpi_maps[id];
>>  	struct its_cmd_desc desc;
>>  
>> -	desc.its_vmapti_cmd.vpe = map->vm->vpes[map->vpe_idx];
>> +	desc.its_vmapti_cmd.vpe = map->vpe;
>>  	desc.its_vmapti_cmd.dev = dev;
>>  	desc.its_vmapti_cmd.virt_id = map->vintid;
>>  	desc.its_vmapti_cmd.event_id = id;
>> @@ -914,7 +914,7 @@ static void its_send_vmovi(struct its_device *dev, u32 id)
>>  	struct its_vlpi_map *map = &dev->event_map.vlpi_maps[id];
>>  	struct its_cmd_desc desc;
>>  
>> -	desc.its_vmovi_cmd.vpe = map->vm->vpes[map->vpe_idx];
>> +	desc.its_vmovi_cmd.vpe = map->vpe;
>>  	desc.its_vmovi_cmd.dev = dev;
>>  	desc.its_vmovi_cmd.event_id = id;
>>  	desc.its_vmovi_cmd.db_enabled = map->db_enabled;
>> diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h
>> index 52661b838821..58a4d89aa82c 100644
>> --- a/include/linux/irqchip/arm-gic-v4.h
>> +++ b/include/linux/irqchip/arm-gic-v4.h
>> @@ -62,15 +62,15 @@ struct its_vpe {
>>   * irq_set_vcpu_affinity().
>>   *
>>   * @vm:		Pointer to the GICv4 notion of a VM
>> + * @vpe:	Pointer to the GICv4 notion of a virtual CPU (VPE)
>>   * @vintid:	Virtual LPI number
>>   * @db_enabled:	Is the VPE doorbell to be generated?
>> - * @vpe_idx:	Index (0-based) of the VPE in this VM. Not the vpe_id!
>>   */
>>  struct its_vlpi_map {
>>  	struct its_vm		*vm;
>> +	struct its_vpe		*vpe;
>>  	u32			vintid;
>>  	bool			db_enabled;
>> -	u16			vpe_idx;
>>  };
>>  
>>  enum its_vcpu_info_cmd_type {
>> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
>> index d790d0c74b8b..6ba3d73e0f70 100644
>> --- a/virt/kvm/arm/vgic/vgic-its.c
>> +++ b/virt/kvm/arm/vgic/vgic-its.c
>> @@ -715,7 +715,7 @@ static int vgic_its_cmd_handle_movi(struct kvm *kvm, struct vgic_its *its,
>>  		if (ret)
>>  			return ret;
>>  
>> -		map.vpe_idx = vcpu->vcpu_id;
>> +		map.vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;
>>  
>>  		return its_map_vlpi(ite->irq->host_irq, &map);
>>  	}
>> @@ -1184,7 +1184,7 @@ static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
>>  			struct its_vlpi_map map;
>>  
>>  			if (!its_get_vlpi(irq->host_irq, &map)) {
>> -				map.vpe_idx = vcpu2->vcpu_id;
>> +				map.vpe = &vcpu2->arch.vgic_cpu.vgic_v3.its_vpe;
>>  				its_map_vlpi(irq->host_irq, &map);
>>  			}
>>  		}
>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>> index cf5d6e2de6b8..6ece88322013 100644
>> --- a/virt/kvm/arm/vgic/vgic-v4.c
>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>> @@ -288,9 +288,9 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
>>  	 */
>>  	map = (struct its_vlpi_map) {
>>  		.vm		= &kvm->arch.vgic.its_vm,
>> +		.vpe		= &irq->target_vcpu->arch.vgic_cpu.vgic_v3.its_vpe,
>>  		.vintid		= irq->intid,
>>  		.db_enabled	= true,
>> -		.vpe_idx	= irq->target_vcpu->vcpu_id,
>>  	};
>>  
>>  	if (its_map_vlpi(virq, &map))
>>
>> Maybe I'll introduce a vcpu_to_vpe() helper, but it already looks much 
>> better to me...
>>
> Yes, indeed.  Looks good to me as well.
> 
> The only thing that makes me slightly nervous is the use of target_vcpu,
> but I think we rely on it never being NULL for LPIs elsewhere in the
> code, so we should be fine.
Hmmm. Maybe not. When mapping an LPI, you can assign it to a collection
that is not yet mapped to a redistributor, hence no target_vcpu.

But in this case, vgic_its_resolve_lpi() fails, and we just don't enter
this code path. Annoyingly, this also shows that I do not handle MAPC at
all in this code, which is pretty embarrassing (I rely on MAPC being
done before MAPI/MAPTI).

I'll address that in the next version.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling
  2017-08-28 18:18     ` Christoffer Dall
  2017-08-30 10:31       ` Andrew Jones
@ 2017-08-31 12:18       ` Marc Zyngier
  2017-08-31 12:41         ` Christoffer Dall
  1 sibling, 1 reply; 118+ messages in thread
From: Marc Zyngier @ 2017-08-31 12:18 UTC (permalink / raw)
  To: Christoffer Dall
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi, Andrew Jones

On 28/08/17 19:18, Christoffer Dall wrote:
> On Fri, Aug 04, 2017 at 08:44:04AM +0100, Marc Zyngier wrote:
>> On 31/07/17 18:26, Marc Zyngier wrote:
>>> When a vPE is not running, a VLPI being made pending results in a
>>> doorbell interrupt being delivered. Let's handle this interrupt
>>> and update the pending_last flag that indicates that VLPIs are
>>> pending. The corresponding vcpu is also kicked into action.
>>>
>>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>>> ---
>>>  virt/kvm/arm/vgic/vgic-v4.c | 34 ++++++++++++++++++++++++++++++++++
>>>  1 file changed, 34 insertions(+)
>>>
>>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>>> index 534d3051a078..6af3cde6d7d4 100644
>>> --- a/virt/kvm/arm/vgic/vgic-v4.c
>>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>>> @@ -21,6 +21,19 @@
>>>  
>>>  #include "vgic.h"
>>>  
>>> +static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
>>> +{
>>> +	struct kvm_vcpu *vcpu = info;
>>> +
>>> +	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
>>> +		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
>>> +		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
>>> +		kvm_vcpu_kick(vcpu);
>>> +	}
>>
>> This code is so obviously broken that I completely overlooked it.
>>
>> If we have take a doorbell interrupt, then it means nothing was
>> otherwise pending (because we'd have been kicked out of the blocking
>> state, and will have masked the doorbell). So checking for pending
>> interrupts is pointless.
>>
>> Furthermore, calling kvm_vgic_vcpu_pending_irq() takes the ap_list
>> lock. If we take a doorbell interrupt while injecting a virtual
>> interrupt (from userspace, for example) on the same CPU, we end-up
>> in deadlock land. This would be solved by Christoffer's latest
>> crop of timer patches, but there is no point getting there the first
>> place.
>>
>> The patchlet below solves it:
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>> index 15feb1151797..48e4d6ebeaa8 100644
>> --- a/virt/kvm/arm/vgic/vgic-v4.c
>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>> @@ -94,11 +94,9 @@ static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
>>  {
>>  	struct kvm_vcpu *vcpu = info;
>>  
>> -	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
>> -		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
>> -		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
>> -		kvm_vcpu_kick(vcpu);
>> -	}
>> +	vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
>> +	kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
>> +	kvm_vcpu_kick(vcpu);
> 
> I don't think you need the request and kick, because if you're getting
> this doorbell, doesn't that also mean that the VCPU is not running in
> the guest and you simply need to make sure the VCPU thread gets
> scheduled again, so you could call kvm_vcpu_wake_up() instead.
> 
> Unless the request is there to ensure proper memory barriers around
> setting pending_last?

We definitely need some form of barrier here (the write needs to be
observed on the CPU we're waking up on), and I wanted to model this in a
similar way to our injection path (where we do have the make_request +
kick pattern).

After all, we really have an interrupt pending that deserves attention.
Is there any reason why we'd want to model it differently from the rest
of the injection path?

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass
  2017-08-31 10:24             ` Marc Zyngier
@ 2017-08-31 12:36               ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-31 12:36 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi

On Thu, Aug 31, 2017 at 11:24:37AM +0100, Marc Zyngier wrote:
> On 30/08/17 20:59, Christoffer Dall wrote:
> > On Wed, Aug 30, 2017 at 01:53:30PM +0100, Marc Zyngier wrote:
> >> On 30/08/17 12:46, Christoffer Dall wrote:
> >>> On Wed, Aug 30, 2017 at 11:28:08AM +0100, Marc Zyngier wrote:
> >>>> On 26/08/17 20:48, Christoffer Dall wrote:
> >>>>> On Mon, Jul 31, 2017 at 06:26:19PM +0100, Marc Zyngier wrote:
> >>>>>> Let's use the irq bypass mechanism introduced for platform device
> >>>>>> interrupts to intercept the virtual PCIe endpoint configuration
> >>>>>> and establish our LPI->VLPI mapping.
> >>>>>>
> >>>>>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> >>>>>> ---
> >>>>>>  include/kvm/arm_vgic.h      |   8 ++++
> >>>>>>  virt/kvm/arm/arm.c          |  27 ++++++++----
> >>>>>>  virt/kvm/arm/vgic/vgic-v4.c | 103 ++++++++++++++++++++++++++++++++++++++++++++
> >>>>>>  3 files changed, 130 insertions(+), 8 deletions(-)
> >>>>>>
> >>>>>> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> >>>>>> index 359eeffe9857..050f78d4fb42 100644
> >>>>>> --- a/include/kvm/arm_vgic.h
> >>>>>> +++ b/include/kvm/arm_vgic.h
> >>>>>> @@ -367,4 +367,12 @@ int kvm_vgic_set_forwarding(struct kvm *kvm, unsigned int host_irq,
> >>>>>>  void kvm_vgic_unset_forwarding(struct kvm *kvm, unsigned int host_irq,
> >>>>>>  			       unsigned int vintid);
> >>>>>>  
> >>>>>> +struct kvm_kernel_irq_routing_entry;
> >>>>>> +
> >>>>>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int irq,
> >>>>>> +			       struct kvm_kernel_irq_routing_entry *irq_entry);
> >>>>>> +
> >>>>>> +int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int irq,
> >>>>>> +				 struct kvm_kernel_irq_routing_entry *irq_entry);
> >>>>>> +
> >>>>>>  #endif /* __KVM_ARM_VGIC_H */
> >>>>>> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
> >>>>>> index ebab6c29e3be..6803ea27c47d 100644
> >>>>>> --- a/virt/kvm/arm/arm.c
> >>>>>> +++ b/virt/kvm/arm/arm.c
> >>>>>> @@ -1457,11 +1457,16 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
> >>>>>>  	struct kvm_kernel_irqfd *irqfd =
> >>>>>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
> >>>>>>  
> >>>>>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
> >>>>>> +	switch (prod->type) {
> >>>>>> +	case IRQ_BYPASS_VFIO_PLATFORM:
> >>>>>> +		return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
> >>>>>> +					       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
> >>>>>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
> >>>>>> +		return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq,
> >>>>>> +						  &irqfd->irq_entry);
> >>>>>> +	default:
> >>>>>>  		return 0;
> >>>>>> -
> >>>>>> -	return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
> >>>>>> -				       irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
> >>>>>> +	}
> >>>>>>  }
> >>>>>>  void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
> >>>>>>  				      struct irq_bypass_producer *prod)
> >>>>>> @@ -1469,11 +1474,17 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
> >>>>>>  	struct kvm_kernel_irqfd *irqfd =
> >>>>>>  		container_of(cons, struct kvm_kernel_irqfd, consumer);
> >>>>>>  
> >>>>>> -	if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
> >>>>>> -		return;
> >>>>>> +	switch (prod->type) {
> >>>>>> +	case IRQ_BYPASS_VFIO_PLATFORM:
> >>>>>> +		kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
> >>>>>> +					  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
> >>>>>> +		break;
> >>>>>>  
> >>>>>> -	kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
> >>>>>> -				  irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
> >>>>>> +	case IRQ_BYPASS_VFIO_PCI_MSI:
> >>>>>> +		kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq,
> >>>>>> +					     &irqfd->irq_entry);
> >>>>>> +		break;
> >>>>>> +	}
> >>>>>>  }
> >>>>>>  
> >>>>>>  void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
> >>>>>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> >>>>>> index 207e1fda0dcd..338c86c5159f 100644
> >>>>>> --- a/virt/kvm/arm/vgic/vgic-v4.c
> >>>>>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> >>>>>> @@ -72,3 +72,106 @@ void vgic_v4_teardown(struct kvm *kvm)
> >>>>>>  	its_vm->nr_vpes = 0;
> >>>>>>  	its_vm->vpes = NULL;
> >>>>>>  }
> >>>>>> +
> >>>>>> +static struct vgic_its *vgic_get_its(struct kvm *kvm,
> >>>>>> +				     struct kvm_kernel_irq_routing_entry *irq_entry)
> >>>>>> +{
> >>>>>> +	struct kvm_msi msi  = (struct kvm_msi) {
> >>>>>> +		.address_lo	= irq_entry->msi.address_lo,
> >>>>>> +		.address_hi	= irq_entry->msi.address_hi,
> >>>>>> +		.data		= irq_entry->msi.data,
> >>>>>> +		.flags		= irq_entry->msi.flags,
> >>>>>> +		.devid		= irq_entry->msi.devid,
> >>>>>> +	};
> >>>>>> +
> >>>>>> +	/*
> >>>>>> +	 * Get a reference on the LPI. If NULL, this is not a valid
> >>>>>> +	 * translation for any of our vITSs.
> >>>>>> +	 */
> >>>>>> +	return vgic_msi_to_its(kvm, &msi);
> >>>>>> +}
> >>>>>> +
> >>>>>> +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
> >>>>>> +			       struct kvm_kernel_irq_routing_entry *irq_entry)
> >>>>>> +{
> >>>>>> +	struct vgic_its *its;
> >>>>>> +	struct vgic_irq *irq;
> >>>>>> +	struct its_vlpi_map map;
> >>>>>> +	int ret;
> >>>>>> +
> >>>>>> +	if (!vgic_is_v4_capable(kvm))
> >>>>>> +		return 0;
> >>>>>> +
> >>>>>> +	/*
> >>>>>> +	 * Get the ITS, and escape early on error (not a valid
> >>>>>> +	 * doorbell for any of our vITSs).
> >>>>>> +	 */
> >>>>>> +	its = vgic_get_its(kvm, irq_entry);
> >>>>>> +	if (IS_ERR(its))
> >>>>>> +		return 0;
> >>>>>> +
> >>>>>> +	mutex_lock(&its->its_lock);
> >>>>>> +
> >>>>>> +	/* Perform then actual DevID/EventID -> LPI translation. */
> >>>>>> +	ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid,
> >>>>>> +				   irq_entry->msi.data, &irq);
> >>>>>> +	if (ret)
> >>>>>> +		goto out;
> >>>>>> +
> >>>>>> +	/*
> >>>>>> +	 * Emit the mapping request. If it fails, the ITS probably
> >>>>>> +	 * isn't v4 compatible, so let's silently bail out. Holding
> >>>>>> +	 * the ITS lock should ensure that nothing can modify the
> >>>>>> +	 * target vcpu.
> >>>>>> +	 */
> >>>>>> +	map = (struct its_vlpi_map) {
> >>>>>> +		.vm		= &kvm->arch.vgic.its_vm,
> >>>>>> +		.vintid		= irq->intid,
> >>>>>> +		.db_enabled	= true,
> >>>>>> +		.vpe_idx	= irq->target_vcpu->vcpu_id,
> >>>>
> >>>> This is just wrong. We cannot assume that the vcpu_id has anything to do
> >>>> with the vpe_idx. It happens to be the same thing now, but the two things
> >>>> should be clearly disconnected.
> >>>>
> >>>> I suggest the following (untested):
> >>>>
> >>>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> >>>> index cf5d6e2de6b8..0146e004401a 100644
> >>>> --- a/virt/kvm/arm/vgic/vgic-v4.c
> >>>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> >>>> @@ -251,13 +251,27 @@ static void dump_routing(int virq, struct kvm_kernel_irq_routing_entry *irq_entr
> >>>>  
> >>>>  }
> >>>>  
> >>>> +static int vgic_v4_vcpu_to_index(struct its_vm *its_vm, struct kvm_vcpu *vcpu)
> >>>> +{
> >>>> +	int i;
> >>>> +
> >>>> +	for (i = 0; i < its_vm->nr_vpes; i++) {
> >>>> +		struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;
> >>>> +
> >>>> +		if (its_vm->vpes[i] == vpe)
> >>>> +			return i;
> >>>> +	}
> >>>> +
> >>>> +	return -ENODEV;
> >>>> +}
> >>>> +
> >>>
> >>> Stupid question: Can we change the struct its_vlpi_map to contain a
> >>> vpe pointer or in stead of or in addition to the index?
> >>
> >> This is obviously the right solution, because the *index* of the VPE 
> >> doesn't really matter for a map/unmap (it only matters for doorbell 
> >> operations, and that's a very different code path).
> >>
> >> I came up with the following (untested, again), which is much more
> >> appealing:
> >>
> >> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> >> index b47097a3e4b4..0607541fcafc 100644
> >> --- a/drivers/irqchip/irq-gic-v3-its.c
> >> +++ b/drivers/irqchip/irq-gic-v3-its.c
> >> @@ -900,7 +900,7 @@ static void its_send_vmapti(struct its_device *dev, u32 id)
> >>  	struct its_vlpi_map *map = &dev->event_map.vlpi_maps[id];
> >>  	struct its_cmd_desc desc;
> >>  
> >> -	desc.its_vmapti_cmd.vpe = map->vm->vpes[map->vpe_idx];
> >> +	desc.its_vmapti_cmd.vpe = map->vpe;
> >>  	desc.its_vmapti_cmd.dev = dev;
> >>  	desc.its_vmapti_cmd.virt_id = map->vintid;
> >>  	desc.its_vmapti_cmd.event_id = id;
> >> @@ -914,7 +914,7 @@ static void its_send_vmovi(struct its_device *dev, u32 id)
> >>  	struct its_vlpi_map *map = &dev->event_map.vlpi_maps[id];
> >>  	struct its_cmd_desc desc;
> >>  
> >> -	desc.its_vmovi_cmd.vpe = map->vm->vpes[map->vpe_idx];
> >> +	desc.its_vmovi_cmd.vpe = map->vpe;
> >>  	desc.its_vmovi_cmd.dev = dev;
> >>  	desc.its_vmovi_cmd.event_id = id;
> >>  	desc.its_vmovi_cmd.db_enabled = map->db_enabled;
> >> diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h
> >> index 52661b838821..58a4d89aa82c 100644
> >> --- a/include/linux/irqchip/arm-gic-v4.h
> >> +++ b/include/linux/irqchip/arm-gic-v4.h
> >> @@ -62,15 +62,15 @@ struct its_vpe {
> >>   * irq_set_vcpu_affinity().
> >>   *
> >>   * @vm:		Pointer to the GICv4 notion of a VM
> >> + * @vpe:	Pointer to the GICv4 notion of a virtual CPU (VPE)
> >>   * @vintid:	Virtual LPI number
> >>   * @db_enabled:	Is the VPE doorbell to be generated?
> >> - * @vpe_idx:	Index (0-based) of the VPE in this VM. Not the vpe_id!
> >>   */
> >>  struct its_vlpi_map {
> >>  	struct its_vm		*vm;
> >> +	struct its_vpe		*vpe;
> >>  	u32			vintid;
> >>  	bool			db_enabled;
> >> -	u16			vpe_idx;
> >>  };
> >>  
> >>  enum its_vcpu_info_cmd_type {
> >> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> >> index d790d0c74b8b..6ba3d73e0f70 100644
> >> --- a/virt/kvm/arm/vgic/vgic-its.c
> >> +++ b/virt/kvm/arm/vgic/vgic-its.c
> >> @@ -715,7 +715,7 @@ static int vgic_its_cmd_handle_movi(struct kvm *kvm, struct vgic_its *its,
> >>  		if (ret)
> >>  			return ret;
> >>  
> >> -		map.vpe_idx = vcpu->vcpu_id;
> >> +		map.vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;
> >>  
> >>  		return its_map_vlpi(ite->irq->host_irq, &map);
> >>  	}
> >> @@ -1184,7 +1184,7 @@ static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
> >>  			struct its_vlpi_map map;
> >>  
> >>  			if (!its_get_vlpi(irq->host_irq, &map)) {
> >> -				map.vpe_idx = vcpu2->vcpu_id;
> >> +				map.vpe = &vcpu2->arch.vgic_cpu.vgic_v3.its_vpe;
> >>  				its_map_vlpi(irq->host_irq, &map);
> >>  			}
> >>  		}
> >> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> >> index cf5d6e2de6b8..6ece88322013 100644
> >> --- a/virt/kvm/arm/vgic/vgic-v4.c
> >> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> >> @@ -288,9 +288,9 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
> >>  	 */
> >>  	map = (struct its_vlpi_map) {
> >>  		.vm		= &kvm->arch.vgic.its_vm,
> >> +		.vpe		= &irq->target_vcpu->arch.vgic_cpu.vgic_v3.its_vpe,
> >>  		.vintid		= irq->intid,
> >>  		.db_enabled	= true,
> >> -		.vpe_idx	= irq->target_vcpu->vcpu_id,
> >>  	};
> >>  
> >>  	if (its_map_vlpi(virq, &map))
> >>
> >> Maybe I'll introduce a vcpu_to_vpe() helper, but it already looks much 
> >> better to me...
> >>
> > Yes, indeed.  Looks good to me as well.
> > 
> > The only thing that makes me slightly nervous is the use of target_vcpu,
> > but I think we rely on it never being NULL for LPIs elsewhere in the
> > code, so we should be fine.
> Hmmm. Maybe not. When mapping an LPI, you can assign it to a collection
> that is not yet mapped to a redistributor, hence no target_vcpu.

Oh right, the local vcpu varible in ...handle_mapi is initialized to
NULL, bummer I missed that.

> 
> But in this case, vgic_its_resolve_lpi() fails, and we just don't enter
> this code path. Annoyingly, this also shows that I do not handle MAPC at
> all in this code, which is pretty embarrassing (I rely on MAPC being
> done before MAPI/MAPTI).
> 
> I'll address that in the next version.
> 

Looking forward to it ;)

-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling
  2017-08-31 12:18       ` Marc Zyngier
@ 2017-08-31 12:41         ` Christoffer Dall
  0 siblings, 0 replies; 118+ messages in thread
From: Christoffer Dall @ 2017-08-31 12:41 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: linux-kernel, linux-arm-kernel, kvmarm, kvm, Christoffer Dall,
	Thomas Gleixner, Jason Cooper, Eric Auger, Shanker Donthineni,
	Mark Rutland, Shameerali Kolothum Thodi, Andrew Jones

On Thu, Aug 31, 2017 at 01:18:20PM +0100, Marc Zyngier wrote:
> On 28/08/17 19:18, Christoffer Dall wrote:
> > On Fri, Aug 04, 2017 at 08:44:04AM +0100, Marc Zyngier wrote:
> >> On 31/07/17 18:26, Marc Zyngier wrote:
> >>> When a vPE is not running, a VLPI being made pending results in a
> >>> doorbell interrupt being delivered. Let's handle this interrupt
> >>> and update the pending_last flag that indicates that VLPIs are
> >>> pending. The corresponding vcpu is also kicked into action.
> >>>
> >>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> >>> ---
> >>>  virt/kvm/arm/vgic/vgic-v4.c | 34 ++++++++++++++++++++++++++++++++++
> >>>  1 file changed, 34 insertions(+)
> >>>
> >>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> >>> index 534d3051a078..6af3cde6d7d4 100644
> >>> --- a/virt/kvm/arm/vgic/vgic-v4.c
> >>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> >>> @@ -21,6 +21,19 @@
> >>>  
> >>>  #include "vgic.h"
> >>>  
> >>> +static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
> >>> +{
> >>> +	struct kvm_vcpu *vcpu = info;
> >>> +
> >>> +	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
> >>> +		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> >>> +		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> >>> +		kvm_vcpu_kick(vcpu);
> >>> +	}
> >>
> >> This code is so obviously broken that I completely overlooked it.
> >>
> >> If we have take a doorbell interrupt, then it means nothing was
> >> otherwise pending (because we'd have been kicked out of the blocking
> >> state, and will have masked the doorbell). So checking for pending
> >> interrupts is pointless.
> >>
> >> Furthermore, calling kvm_vgic_vcpu_pending_irq() takes the ap_list
> >> lock. If we take a doorbell interrupt while injecting a virtual
> >> interrupt (from userspace, for example) on the same CPU, we end-up
> >> in deadlock land. This would be solved by Christoffer's latest
> >> crop of timer patches, but there is no point getting there the first
> >> place.
> >>
> >> The patchlet below solves it:
> >>
> >> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> >> index 15feb1151797..48e4d6ebeaa8 100644
> >> --- a/virt/kvm/arm/vgic/vgic-v4.c
> >> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> >> @@ -94,11 +94,9 @@ static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
> >>  {
> >>  	struct kvm_vcpu *vcpu = info;
> >>  
> >> -	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
> >> -		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> >> -		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> >> -		kvm_vcpu_kick(vcpu);
> >> -	}
> >> +	vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> >> +	kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> >> +	kvm_vcpu_kick(vcpu);
> > 
> > I don't think you need the request and kick, because if you're getting
> > this doorbell, doesn't that also mean that the VCPU is not running in
> > the guest and you simply need to make sure the VCPU thread gets
> > scheduled again, so you could call kvm_vcpu_wake_up() instead.
> > 
> > Unless the request is there to ensure proper memory barriers around
> > setting pending_last?
> 
> We definitely need some form of barrier here (the write needs to be
> observed on the CPU we're waking up on), and I wanted to model this in a
> similar way to our injection path (where we do have the make_request +
> kick pattern).
> 
> After all, we really have an interrupt pending that deserves attention.
> Is there any reason why we'd want to model it differently from the rest
> of the injection path?
> 

The difference is that you'll never need this if the VCPU is running,
this is only when the VCPU is on a waitqueue and sleeping, and therefore
you don't actually need a kick, but you just need to wake up the VCPU
thread.

But kvm_vcpu_kick() also wakes up, it's just a question of using the
most appropriate hammer, making it clear what exactly is going on.

But, as Drew pointed out, we use the request framework to ensure proper
barriers (when he fixes it), after waking up a VCPU, so in this cae it's
to make sure the VCPU thread observed pending_last==true after being
woken up.

Interestingly, we don't need that for the timer, since we don't change
random in-memory values, but we read the physical counter which is the
thing that changes when waking up the thread.

So, sorry for a lot of noise, your code is fine, and Drew fixes KVM, I
think.

Thanks,
-Christoffer

^ permalink raw reply	[flat|nested] 118+ messages in thread

* Re: [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling
  2017-07-31 17:26 ` [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling Marc Zyngier
  2017-08-04  7:44   ` Marc Zyngier
  2017-08-28 18:18   ` Christoffer Dall
@ 2017-09-06  9:06   ` Shannon Zhao
  2 siblings, 0 replies; 118+ messages in thread
From: Shannon Zhao @ 2017-09-06  9:06 UTC (permalink / raw)
  To: Marc Zyngier, linux-kernel, linux-arm-kernel, kvmarm, kvm
  Cc: Jason Cooper, Thomas Gleixner



On 2017/8/1 1:26, Marc Zyngier wrote:
> When a vPE is not running, a VLPI being made pending results in a
> doorbell interrupt being delivered. Let's handle this interrupt
> and update the pending_last flag that indicates that VLPIs are
> pending. The corresponding vcpu is also kicked into action.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  virt/kvm/arm/vgic/vgic-v4.c | 34 ++++++++++++++++++++++++++++++++++
>  1 file changed, 34 insertions(+)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> index 534d3051a078..6af3cde6d7d4 100644
> --- a/virt/kvm/arm/vgic/vgic-v4.c
> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> @@ -21,6 +21,19 @@
>  
>  #include "vgic.h"
>  
> +static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
> +{
> +	struct kvm_vcpu *vcpu = info;
> +
> +	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
> +		vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
> +		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> +		kvm_vcpu_kick(vcpu);
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
>  int vgic_v4_init(struct kvm *kvm)
>  {
>  	struct vgic_dist *dist = &kvm->arch.vgic;
> @@ -57,16 +70,37 @@ int vgic_v4_init(struct kvm *kvm)
>  		return ret;
>  	}
>  
> +	kvm_for_each_vcpu(i, vcpu, kvm) {
> +		int irq = dist->its_vm.vpes[i]->irq;
> +
> +		ret = request_irq(irq, vgic_v4_doorbell_handler,
> +				  0, "vcpu", vcpu);
> +		if (ret) {
> +			kvm_err("failed to allocate vcpu IRQ%d\n", irq);
> +			dist->its_vm.nr_vpes = i;
This overwirtes the nr_vpes while it uses kvm->online_vcpus in
its_alloc_vcpu_irqs to alloc irqs and if this fails it uses the
overwirten nr_vpes other than kvm->online_vcpus in its_free_vcpu_irqs to
free the irqs. So there will be memory leak on error path.

> +			break;
> +		}
> +	}
> +
> +	if (ret)
> +		vgic_v4_teardown(kvm);
> +
>  	return ret;
>  }
>  
>  void vgic_v4_teardown(struct kvm *kvm)
>  {
>  	struct its_vm *its_vm = &kvm->arch.vgic.its_vm;
> +	int i;
>  
>  	if (!its_vm->vpes)
>  		return;
>  
> +	for (i = 0; i < its_vm->nr_vpes; i++) {
> +		struct kvm_vcpu *vcpu = kvm_get_vcpu(kvm, i);
> +		free_irq(its_vm->vpes[i]->irq, vcpu);
> +	}
> +
>  	its_free_vcpu_irqs(its_vm);
>  	kfree(its_vm->vpes);
>  	its_vm->nr_vpes = 0;
> 

Thanks,
-- 
Shannon

^ permalink raw reply	[flat|nested] 118+ messages in thread

end of thread, other threads:[~2017-09-06  9:06 UTC | newest]

Thread overview: 118+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 01/59] genirq: Let irq_set_vcpu_affinity() iterate over hierarchy Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 02/59] irqchip/gic-v3: Add redistributor iterator Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 03/59] irqchip/gic-v3: Add VLPI/DirectLPI discovery Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 04/59] irqchip/gic-v3-its: Move LPI definitions around Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 05/59] irqchip/gic-v3-its: Add probing for VLPI properties Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 06/59] irqchip/gic-v3-its: Macro-ize its_send_single_command Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 07/59] irqchip/gic-v3-its: Implement irq_set_irqchip_state for pending state Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 08/59] irqchip/gic-v3-its: Split out property table allocation Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 09/59] irqchip/gic-v3-its: Allow use of indirect VCPU tables Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 10/59] irqchip/gic-v3-its: Split out pending table allocation Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 11/59] irqchip/gic-v3-its: Rework LPI freeing Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 12/59] irqchip/gic-v3-its: Generalize device table allocation Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 13/59] irqchip/gic-v3-its: Generalize LPI configuration Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 14/59] irqchip/gic-v4: Add management structure definitions Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 15/59] irqchip/gic-v3-its: Add GICv4 ITS command definitions Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 16/59] irqchip/gic-v3-its: Add VLPI configuration hook Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 17/59] irqchip/gic-v3-its: Add VLPI map/unmap operations Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 18/59] irqchip/gic-v3-its: Add VLPI configuration handling Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 19/59] irqchip/gic-v3-its: Add VPE domain infrastructure Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 20/59] irqchip/gic-v3-its: Add VPE irq domain allocation/teardown Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 21/59] irqchip/gic-v3-its: Add VPE irq domain [de]activation Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 22/59] irqchip/gic-v3-its: Add VPENDBASER/VPROPBASER accessors Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 23/59] irqchip/gic-v3-its: Add VPE scheduling Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 24/59] irqchip/gic-v3-its: Add VPE invalidation hook Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 25/59] irqchip/gic-v3-its: Add VPE affinity changes Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 26/59] irqchip/gic-v3-its: Add VPE interrupt masking Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 27/59] irqchip/gic-v3-its: Support VPE doorbell invalidation even when !DirectLPI Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 28/59] irqchip/gic-v3-its: Allow doorbell interrupts to be injected/cleared Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 29/59] irqchip/gic-v3-its: Set implementation defined bit to enable VLPIs Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 30/59] irqchip/gic-v4: Add per-VM VPE domain creation Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 31/59] irqchip/gic-v4: Add VPE command interface Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 32/59] irqchip/gic-v4: Add VLPI configuration interface Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 33/59] irqchip/gic-v4: Add some basic documentation Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 34/59] irqchip/gic-v4: Enable low-level GICv4 operations Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 35/59] irqchip/gic-v3: Advertise GICv4 support to KVM Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 36/59] KVM: arm: Select ARM_GIC_V3 and ARM_GIC_V3_ITS Marc Zyngier
2017-08-26 19:49   ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 37/59] KVM: arm/arm64: vgic: Move kvm_vgic_destroy call around Marc Zyngier
2017-08-26 19:49   ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 38/59] KVM: arm/arm64: vITS: Add MSI translation helpers Marc Zyngier
2017-08-26 19:49   ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 39/59] KVM: arm/arm64: GICv4: Add property field and per-VM predicate Marc Zyngier
2017-08-26 19:49   ` Christoffer Dall
2017-08-30  9:46     ` Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 40/59] KVM: arm/arm64: GICv4: Add init/teardown of the per-VM vPE irq domain Marc Zyngier
2017-08-26 19:49   ` Christoffer Dall
2017-08-30  9:50     ` Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass Marc Zyngier
2017-08-26 19:48   ` Christoffer Dall
2017-08-30  9:42     ` Marc Zyngier
2017-08-30 10:20       ` Auger Eric
2017-08-30 10:42         ` Marc Zyngier
2017-08-30 12:54           ` Auger Eric
2017-08-30 10:28     ` Marc Zyngier
2017-08-30 11:46       ` Christoffer Dall
2017-08-30 12:53         ` Marc Zyngier
2017-08-30 19:59           ` Christoffer Dall
2017-08-31 10:24             ` Marc Zyngier
2017-08-31 12:36               ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 42/59] KVM: arm/arm64: GICv4: Handle INT command applied to a VLPI Marc Zyngier
2017-08-28 18:18   ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 43/59] KVM: arm/arm64: GICv4: Unmap VLPI when freeing an LPI Marc Zyngier
2017-08-28 18:18   ` Christoffer Dall
2017-08-30 11:03     ` Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 44/59] KVM: arm/arm64: GICv4: Handle MOVI applied to a VLPI Marc Zyngier
2017-08-28 18:18   ` Christoffer Dall
2017-08-30 14:08     ` Marc Zyngier
2017-08-30 20:04       ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 45/59] KVM: arm/arm64: GICv4: Handle CLEAR " Marc Zyngier
2017-08-28 18:18   ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 46/59] KVM: arm/arm64: GICv4: Handle MOVALL applied to a vPE Marc Zyngier
2017-08-28 18:18   ` Christoffer Dall
2017-08-30 14:46     ` Marc Zyngier
2017-08-30 20:10       ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 47/59] KVM: arm/arm64: GICv4: Propagate property updates to VLPIs Marc Zyngier
2017-08-28 18:18   ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 48/59] KVM: arm/arm64: GICv4: Handle INVALL applied to a vPE Marc Zyngier
2017-08-28 18:18   ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 49/59] KVM: arm/arm64: GICv4: Propagate VLPI properties at map time Marc Zyngier
2017-08-28 18:18   ` Christoffer Dall
2017-08-30 14:56     ` Marc Zyngier
2017-08-30 20:12       ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 50/59] KVM: arm/arm64: GICv4: Use pending_last as a scheduling hint Marc Zyngier
2017-08-28 18:18   ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling Marc Zyngier
2017-08-04  7:44   ` Marc Zyngier
2017-08-28 18:18     ` Christoffer Dall
2017-08-30 10:31       ` Andrew Jones
2017-08-30 11:55         ` Christoffer Dall
2017-08-30 12:28           ` Andrew Jones
2017-08-31 12:18       ` Marc Zyngier
2017-08-31 12:41         ` Christoffer Dall
2017-08-28 18:18   ` Christoffer Dall
2017-08-30 15:36     ` Marc Zyngier
2017-08-30 20:58       ` Christoffer Dall
2017-08-31  8:19         ` Marc Zyngier
2017-09-06  9:06   ` Shannon Zhao
2017-07-31 17:26 ` [PATCH v3 52/59] KVM: arm/arm64: GICv4: Use the doorbell interrupt as an unblocking source Marc Zyngier
2017-08-28 18:19   ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 53/59] KVM: arm/arm64: GICv4: Hook vPE scheduling into vgic flush/sync Marc Zyngier
2017-08-28 18:17   ` Christoffer Dall
2017-08-30  9:59     ` Marc Zyngier
2017-08-30 11:56       ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 54/59] KVM: arm/arm64: GICv4: Enable virtual cpuif if VLPIs can be delivered Marc Zyngier
2017-08-28 18:20   ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 55/59] KVM: arm/arm64: GICv4: Enable VLPI support Marc Zyngier
2017-08-28 18:25   ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 56/59] KVM: arm/arm64: GICv4: Prevent heterogenous systems from using GICv4 Marc Zyngier
2017-08-28 18:35   ` Christoffer Dall
2017-08-30 16:03     ` Marc Zyngier
2017-08-30 21:00       ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 57/59] KVM: arm/arm64: GICv4: Theory of operations Marc Zyngier
2017-08-28 18:18   ` Christoffer Dall
2017-08-30 11:30     ` Marc Zyngier
2017-08-30 11:58       ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 58/59] irqchip/gic-v3-its: Pass its_node pointer to each command bulder Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 59/59] irqchip/gic-v3-its: Workaround Huawei D05 redistributor addressing Marc Zyngier

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