[PATCH v2 0/4] KVM: arm64: vgic-v3: MMIO-based LPI invalidation and co

[PATCH v2 0/4] KVM: arm64: vgic-v3: MMIO-based LPI invalidation and co

[Marc Zyngier]

Since revision IHI0069G of the GICv3 spec, an implementation is
allowed to implement MMIO-based LPI invalidation, without having to
support RVPEI (which is essentially a GICv4.1 feature).

This has the potential to make workloads using heavy LPI invalidation
fare a bit better, as they don't need to lock the access to the
command queue.

Similarly, an implementation can now expose that it allows LPIs to be
turned off, something that we always supported.

This series implements both these features, exposing the new
GICR_{INVLPIR,INVALLR,SYNCR} registers, transitions of the
GICR_CTLR.RWP bit on LPI disabling, and finally exposes these to
userspace and the guest with a new GICD_IIDR revision (and the ability
to save/restore it).

This series has been extremely useful to debug related GIC features,
and will be complemented by a few GIC driver patches.

* From v1 [1]:
  - Fixed CES and IR bit numbers (shrug...)
  - Plenty of small fixes all over the shop thanks to Oliver
  - Rebased on top of 5.18-rc1

[1] https://lore.kernel.org/r/20220314164044.772709-1-maz@kernel.org

Marc Zyngier (4):
  irqchip/gic-v3: Exposes bit values for GICR_CTLR.{IR,CES}
  KVM: arm64: vgic-v3: Expose GICR_CTLR.RWP when disabling LPIs
  KVM: arm64: vgic-v3: Implement MMIO-based LPI invalidation
  KVM: arm64: vgic-v3: Advertise GICR_CTLR.{IR,CES} as a new GICD_IIDR
    revision

 arch/arm64/kvm/vgic/vgic-init.c    |   7 +-
 arch/arm64/kvm/vgic/vgic-its.c     |  64 ++++++++++-----
 arch/arm64/kvm/vgic/vgic-mmio-v2.c |  18 ++++-
 arch/arm64/kvm/vgic/vgic-mmio-v3.c | 125 ++++++++++++++++++++++++++---
 arch/arm64/kvm/vgic/vgic.h         |  10 +++
 include/kvm/arm_vgic.h             |   8 +-
 include/linux/irqchip/arm-gic-v3.h |   2 +
 7 files changed, 195 insertions(+), 39 deletions(-)

-- 
2.34.1

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[PATCH v2 0/4] KVM: arm64: vgic-v3: MMIO-based LPI invalidation and co

[Marc Zyngier]

Since revision IHI0069G of the GICv3 spec, an implementation is
allowed to implement MMIO-based LPI invalidation, without having to
support RVPEI (which is essentially a GICv4.1 feature).

This has the potential to make workloads using heavy LPI invalidation
fare a bit better, as they don't need to lock the access to the
command queue.

Similarly, an implementation can now expose that it allows LPIs to be
turned off, something that we always supported.

This series implements both these features, exposing the new
GICR_{INVLPIR,INVALLR,SYNCR} registers, transitions of the
GICR_CTLR.RWP bit on LPI disabling, and finally exposes these to
userspace and the guest with a new GICD_IIDR revision (and the ability
to save/restore it).

This series has been extremely useful to debug related GIC features,
and will be complemented by a few GIC driver patches.

* From v1 [1]:
  - Fixed CES and IR bit numbers (shrug...)
  - Plenty of small fixes all over the shop thanks to Oliver
  - Rebased on top of 5.18-rc1

[1] https://lore.kernel.org/r/20220314164044.772709-1-maz@kernel.org

Marc Zyngier (4):
  irqchip/gic-v3: Exposes bit values for GICR_CTLR.{IR,CES}
  KVM: arm64: vgic-v3: Expose GICR_CTLR.RWP when disabling LPIs
  KVM: arm64: vgic-v3: Implement MMIO-based LPI invalidation
  KVM: arm64: vgic-v3: Advertise GICR_CTLR.{IR,CES} as a new GICD_IIDR
    revision

 arch/arm64/kvm/vgic/vgic-init.c    |   7 +-
 arch/arm64/kvm/vgic/vgic-its.c     |  64 ++++++++++-----
 arch/arm64/kvm/vgic/vgic-mmio-v2.c |  18 ++++-
 arch/arm64/kvm/vgic/vgic-mmio-v3.c | 125 ++++++++++++++++++++++++++---
 arch/arm64/kvm/vgic/vgic.h         |  10 +++
 include/kvm/arm_vgic.h             |   8 +-
 include/linux/irqchip/arm-gic-v3.h |   2 +
 7 files changed, 195 insertions(+), 39 deletions(-)

-- 
2.34.1


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linux-arm-kernel@lists.infradead.org
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[PATCH v2 0/4] KVM: arm64: vgic-v3: MMIO-based LPI invalidation and co

[Marc Zyngier]

Since revision IHI0069G of the GICv3 spec, an implementation is
allowed to implement MMIO-based LPI invalidation, without having to
support RVPEI (which is essentially a GICv4.1 feature).

This has the potential to make workloads using heavy LPI invalidation
fare a bit better, as they don't need to lock the access to the
command queue.

Similarly, an implementation can now expose that it allows LPIs to be
turned off, something that we always supported.

This series implements both these features, exposing the new
GICR_{INVLPIR,INVALLR,SYNCR} registers, transitions of the
GICR_CTLR.RWP bit on LPI disabling, and finally exposes these to
userspace and the guest with a new GICD_IIDR revision (and the ability
to save/restore it).

This series has been extremely useful to debug related GIC features,
and will be complemented by a few GIC driver patches.

* From v1 [1]:
  - Fixed CES and IR bit numbers (shrug...)
  - Plenty of small fixes all over the shop thanks to Oliver
  - Rebased on top of 5.18-rc1

[1] https://lore.kernel.org/r/20220314164044.772709-1-maz@kernel.org

Marc Zyngier (4):
  irqchip/gic-v3: Exposes bit values for GICR_CTLR.{IR,CES}
  KVM: arm64: vgic-v3: Expose GICR_CTLR.RWP when disabling LPIs
  KVM: arm64: vgic-v3: Implement MMIO-based LPI invalidation
  KVM: arm64: vgic-v3: Advertise GICR_CTLR.{IR,CES} as a new GICD_IIDR
    revision

 arch/arm64/kvm/vgic/vgic-init.c    |   7 +-
 arch/arm64/kvm/vgic/vgic-its.c     |  64 ++++++++++-----
 arch/arm64/kvm/vgic/vgic-mmio-v2.c |  18 ++++-
 arch/arm64/kvm/vgic/vgic-mmio-v3.c | 125 ++++++++++++++++++++++++++---
 arch/arm64/kvm/vgic/vgic.h         |  10 +++
 include/kvm/arm_vgic.h             |   8 +-
 include/linux/irqchip/arm-gic-v3.h |   2 +
 7 files changed, 195 insertions(+), 39 deletions(-)

-- 
2.34.1

[PATCH v2 1/4] irqchip/gic-v3: Exposes bit values for GICR_CTLR.{IR, CES}

[Marc Zyngier]

As we're about to expose GICR_CTLR.{IR,CES} to guests, populate
the include file with the architectural values.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 include/linux/irqchip/arm-gic-v3.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index 12d91f0dedf9..728691365464 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -127,6 +127,8 @@
 #define GICR_PIDR2			GICD_PIDR2
 
 #define GICR_CTLR_ENABLE_LPIS		(1UL << 0)
+#define GICR_CTLR_CES			(1UL << 1)
+#define GICR_CTLR_IR			(1UL << 2)
 #define GICR_CTLR_RWP			(1UL << 3)
 
 #define GICR_TYPER_CPU_NUMBER(r)	(((r) >> 8) & 0xffff)
-- 
2.34.1

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kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

[PATCH v2 1/4] irqchip/gic-v3: Exposes bit values for GICR_CTLR.{IR, CES}

[Marc Zyngier]

As we're about to expose GICR_CTLR.{IR,CES} to guests, populate
the include file with the architectural values.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 include/linux/irqchip/arm-gic-v3.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index 12d91f0dedf9..728691365464 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -127,6 +127,8 @@
 #define GICR_PIDR2			GICD_PIDR2
 
 #define GICR_CTLR_ENABLE_LPIS		(1UL << 0)
+#define GICR_CTLR_CES			(1UL << 1)
+#define GICR_CTLR_IR			(1UL << 2)
 #define GICR_CTLR_RWP			(1UL << 3)
 
 #define GICR_TYPER_CPU_NUMBER(r)	(((r) >> 8) & 0xffff)
-- 
2.34.1


_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v2 1/4] irqchip/gic-v3: Exposes bit values for GICR_CTLR.{IR,CES}

[Marc Zyngier]

As we're about to expose GICR_CTLR.{IR,CES} to guests, populate
the include file with the architectural values.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 include/linux/irqchip/arm-gic-v3.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index 12d91f0dedf9..728691365464 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -127,6 +127,8 @@
 #define GICR_PIDR2			GICD_PIDR2
 
 #define GICR_CTLR_ENABLE_LPIS		(1UL << 0)
+#define GICR_CTLR_CES			(1UL << 1)
+#define GICR_CTLR_IR			(1UL << 2)
 #define GICR_CTLR_RWP			(1UL << 3)
 
 #define GICR_TYPER_CPU_NUMBER(r)	(((r) >> 8) & 0xffff)
-- 
2.34.1

[PATCH v2 2/4] KVM: arm64: vgic-v3: Expose GICR_CTLR.RWP when disabling LPIs

[Marc Zyngier]

When disabling LPIs, a guest needs to poll GICR_CTLR.RWP in order
to be sure that the write has taken effect. We so far reported it
as 0, as we didn't advertise that LPIs could be turned off the
first place.

Start tracking this state during which LPIs are being disabled,
and expose the 'in progress' state via the RWP bit.

We also take this opportunity to disallow enabling LPIs and programming
GICR_{PEND,PROP}BASER while LPI disabling is in progress, as allowed by
the architecture (UNPRED behaviour).

We don't advertise the feature to the guest yet (which is allowed by
the architecture).

Reviewed-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/vgic/vgic-its.c     |  2 +-
 arch/arm64/kvm/vgic/vgic-mmio-v3.c | 36 ++++++++++++++++++++++--------
 arch/arm64/kvm/vgic/vgic.h         |  1 +
 include/kvm/arm_vgic.h             |  4 ++--
 4 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c
index 089fc2ffcb43..8371c5a9639c 100644
--- a/arch/arm64/kvm/vgic/vgic-its.c
+++ b/arch/arm64/kvm/vgic/vgic-its.c
@@ -683,7 +683,7 @@ int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
 	if (!vcpu)
 		return E_ITS_INT_UNMAPPED_INTERRUPT;
 
-	if (!vcpu->arch.vgic_cpu.lpis_enabled)
+	if (!vgic_lpis_enabled(vcpu))
 		return -EBUSY;
 
 	vgic_its_cache_translation(kvm, its, devid, eventid, ite->irq);
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
index 58e40b4874f8..b5ef7e15bb66 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
@@ -221,6 +221,13 @@ static void vgic_mmio_write_irouter(struct kvm_vcpu *vcpu,
 	vgic_put_irq(vcpu->kvm, irq);
 }
 
+bool vgic_lpis_enabled(struct kvm_vcpu *vcpu)
+{
+	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+
+	return atomic_read(&vgic_cpu->ctlr) == GICR_CTLR_ENABLE_LPIS;
+}
+
 static unsigned long vgic_mmio_read_v3r_ctlr(struct kvm_vcpu *vcpu,
 					     gpa_t addr, unsigned int len)
 {
@@ -229,26 +236,38 @@ static unsigned long vgic_mmio_read_v3r_ctlr(struct kvm_vcpu *vcpu,
 	return vgic_cpu->lpis_enabled ? GICR_CTLR_ENABLE_LPIS : 0;
 }
 
-
 static void vgic_mmio_write_v3r_ctlr(struct kvm_vcpu *vcpu,
 				     gpa_t addr, unsigned int len,
 				     unsigned long val)
 {
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
-	bool was_enabled = vgic_cpu->lpis_enabled;
+	u32 ctlr;
 
 	if (!vgic_has_its(vcpu->kvm))
 		return;
 
-	vgic_cpu->lpis_enabled = val & GICR_CTLR_ENABLE_LPIS;
+	if (!(val & GICR_CTLR_ENABLE_LPIS)) {
+		/*
+		 * Don't disable if RWP is set, as there already an
+		 * ongoing disable. Funky guest...
+		 */
+		ctlr = atomic_cmpxchg_acquire(&vgic_cpu->ctlr,
+					      GICR_CTLR_ENABLE_LPIS,
+					      GICR_CTLR_RWP);
+		if (ctlr != GICR_CTLR_ENABLE_LPIS)
+			return;
 
-	if (was_enabled && !vgic_cpu->lpis_enabled) {
 		vgic_flush_pending_lpis(vcpu);
 		vgic_its_invalidate_cache(vcpu->kvm);
-	}
+		atomic_set_release(&vgic_cpu->ctlr, 0);
+	} else {
+		ctlr = atomic_cmpxchg_acquire(&vgic_cpu->ctlr, 0,
+					      GICR_CTLR_ENABLE_LPIS);
+		if (ctlr != 0)
+			return;
 
-	if (!was_enabled && vgic_cpu->lpis_enabled)
 		vgic_enable_lpis(vcpu);
+	}
 }
 
 static bool vgic_mmio_vcpu_rdist_is_last(struct kvm_vcpu *vcpu)
@@ -478,11 +497,10 @@ static void vgic_mmio_write_propbase(struct kvm_vcpu *vcpu,
 				     unsigned long val)
 {
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
-	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 	u64 old_propbaser, propbaser;
 
 	/* Storing a value with LPIs already enabled is undefined */
-	if (vgic_cpu->lpis_enabled)
+	if (vgic_lpis_enabled(vcpu))
 		return;
 
 	do {
@@ -513,7 +531,7 @@ static void vgic_mmio_write_pendbase(struct kvm_vcpu *vcpu,
 	u64 old_pendbaser, pendbaser;
 
 	/* Storing a value with LPIs already enabled is undefined */
-	if (vgic_cpu->lpis_enabled)
+	if (vgic_lpis_enabled(vcpu))
 		return;
 
 	do {
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index 3fd6c86a7ef3..a21e9b602ff2 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -308,6 +308,7 @@ static inline bool vgic_dist_overlap(struct kvm *kvm, gpa_t base, size_t size)
 		(base < d->vgic_dist_base + KVM_VGIC_V3_DIST_SIZE);
 }
 
+bool vgic_lpis_enabled(struct kvm_vcpu *vcpu);
 int vgic_copy_lpi_list(struct kvm *kvm, struct kvm_vcpu *vcpu, u32 **intid_ptr);
 int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
 			 u32 devid, u32 eventid, struct vgic_irq **irq);
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index bb30a6803d9f..fdf1c2c322e5 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -347,8 +347,8 @@ struct vgic_cpu {
 
 	/* Contains the attributes and gpa of the LPI pending tables. */
 	u64 pendbaser;
-
-	bool lpis_enabled;
+	/* GICR_CTLR.{ENABLE_LPIS,RWP} */
+	atomic_t ctlr;
 
 	/* Cache guest priority bits */
 	u32 num_pri_bits;
-- 
2.34.1

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[PATCH v2 2/4] KVM: arm64: vgic-v3: Expose GICR_CTLR.RWP when disabling LPIs

[Marc Zyngier]

When disabling LPIs, a guest needs to poll GICR_CTLR.RWP in order
to be sure that the write has taken effect. We so far reported it
as 0, as we didn't advertise that LPIs could be turned off the
first place.

Start tracking this state during which LPIs are being disabled,
and expose the 'in progress' state via the RWP bit.

We also take this opportunity to disallow enabling LPIs and programming
GICR_{PEND,PROP}BASER while LPI disabling is in progress, as allowed by
the architecture (UNPRED behaviour).

We don't advertise the feature to the guest yet (which is allowed by
the architecture).

Reviewed-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/vgic/vgic-its.c     |  2 +-
 arch/arm64/kvm/vgic/vgic-mmio-v3.c | 36 ++++++++++++++++++++++--------
 arch/arm64/kvm/vgic/vgic.h         |  1 +
 include/kvm/arm_vgic.h             |  4 ++--
 4 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c
index 089fc2ffcb43..8371c5a9639c 100644
--- a/arch/arm64/kvm/vgic/vgic-its.c
+++ b/arch/arm64/kvm/vgic/vgic-its.c
@@ -683,7 +683,7 @@ int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
 	if (!vcpu)
 		return E_ITS_INT_UNMAPPED_INTERRUPT;
 
-	if (!vcpu->arch.vgic_cpu.lpis_enabled)
+	if (!vgic_lpis_enabled(vcpu))
 		return -EBUSY;
 
 	vgic_its_cache_translation(kvm, its, devid, eventid, ite->irq);
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
index 58e40b4874f8..b5ef7e15bb66 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
@@ -221,6 +221,13 @@ static void vgic_mmio_write_irouter(struct kvm_vcpu *vcpu,
 	vgic_put_irq(vcpu->kvm, irq);
 }
 
+bool vgic_lpis_enabled(struct kvm_vcpu *vcpu)
+{
+	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+
+	return atomic_read(&vgic_cpu->ctlr) == GICR_CTLR_ENABLE_LPIS;
+}
+
 static unsigned long vgic_mmio_read_v3r_ctlr(struct kvm_vcpu *vcpu,
 					     gpa_t addr, unsigned int len)
 {
@@ -229,26 +236,38 @@ static unsigned long vgic_mmio_read_v3r_ctlr(struct kvm_vcpu *vcpu,
 	return vgic_cpu->lpis_enabled ? GICR_CTLR_ENABLE_LPIS : 0;
 }
 
-
 static void vgic_mmio_write_v3r_ctlr(struct kvm_vcpu *vcpu,
 				     gpa_t addr, unsigned int len,
 				     unsigned long val)
 {
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
-	bool was_enabled = vgic_cpu->lpis_enabled;
+	u32 ctlr;
 
 	if (!vgic_has_its(vcpu->kvm))
 		return;
 
-	vgic_cpu->lpis_enabled = val & GICR_CTLR_ENABLE_LPIS;
+	if (!(val & GICR_CTLR_ENABLE_LPIS)) {
+		/*
+		 * Don't disable if RWP is set, as there already an
+		 * ongoing disable. Funky guest...
+		 */
+		ctlr = atomic_cmpxchg_acquire(&vgic_cpu->ctlr,
+					      GICR_CTLR_ENABLE_LPIS,
+					      GICR_CTLR_RWP);
+		if (ctlr != GICR_CTLR_ENABLE_LPIS)
+			return;
 
-	if (was_enabled && !vgic_cpu->lpis_enabled) {
 		vgic_flush_pending_lpis(vcpu);
 		vgic_its_invalidate_cache(vcpu->kvm);
-	}
+		atomic_set_release(&vgic_cpu->ctlr, 0);
+	} else {
+		ctlr = atomic_cmpxchg_acquire(&vgic_cpu->ctlr, 0,
+					      GICR_CTLR_ENABLE_LPIS);
+		if (ctlr != 0)
+			return;
 
-	if (!was_enabled && vgic_cpu->lpis_enabled)
 		vgic_enable_lpis(vcpu);
+	}
 }
 
 static bool vgic_mmio_vcpu_rdist_is_last(struct kvm_vcpu *vcpu)
@@ -478,11 +497,10 @@ static void vgic_mmio_write_propbase(struct kvm_vcpu *vcpu,
 				     unsigned long val)
 {
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
-	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 	u64 old_propbaser, propbaser;
 
 	/* Storing a value with LPIs already enabled is undefined */
-	if (vgic_cpu->lpis_enabled)
+	if (vgic_lpis_enabled(vcpu))
 		return;
 
 	do {
@@ -513,7 +531,7 @@ static void vgic_mmio_write_pendbase(struct kvm_vcpu *vcpu,
 	u64 old_pendbaser, pendbaser;
 
 	/* Storing a value with LPIs already enabled is undefined */
-	if (vgic_cpu->lpis_enabled)
+	if (vgic_lpis_enabled(vcpu))
 		return;
 
 	do {
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index 3fd6c86a7ef3..a21e9b602ff2 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -308,6 +308,7 @@ static inline bool vgic_dist_overlap(struct kvm *kvm, gpa_t base, size_t size)
 		(base < d->vgic_dist_base + KVM_VGIC_V3_DIST_SIZE);
 }
 
+bool vgic_lpis_enabled(struct kvm_vcpu *vcpu);
 int vgic_copy_lpi_list(struct kvm *kvm, struct kvm_vcpu *vcpu, u32 **intid_ptr);
 int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
 			 u32 devid, u32 eventid, struct vgic_irq **irq);
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index bb30a6803d9f..fdf1c2c322e5 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -347,8 +347,8 @@ struct vgic_cpu {
 
 	/* Contains the attributes and gpa of the LPI pending tables. */
 	u64 pendbaser;
-
-	bool lpis_enabled;
+	/* GICR_CTLR.{ENABLE_LPIS,RWP} */
+	atomic_t ctlr;
 
 	/* Cache guest priority bits */
 	u32 num_pri_bits;
-- 
2.34.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v2 2/4] KVM: arm64: vgic-v3: Expose GICR_CTLR.RWP when disabling LPIs

[Marc Zyngier]

When disabling LPIs, a guest needs to poll GICR_CTLR.RWP in order
to be sure that the write has taken effect. We so far reported it
as 0, as we didn't advertise that LPIs could be turned off the
first place.

Start tracking this state during which LPIs are being disabled,
and expose the 'in progress' state via the RWP bit.

We also take this opportunity to disallow enabling LPIs and programming
GICR_{PEND,PROP}BASER while LPI disabling is in progress, as allowed by
the architecture (UNPRED behaviour).

We don't advertise the feature to the guest yet (which is allowed by
the architecture).

Reviewed-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/vgic/vgic-its.c     |  2 +-
 arch/arm64/kvm/vgic/vgic-mmio-v3.c | 36 ++++++++++++++++++++++--------
 arch/arm64/kvm/vgic/vgic.h         |  1 +
 include/kvm/arm_vgic.h             |  4 ++--
 4 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c
index 089fc2ffcb43..8371c5a9639c 100644
--- a/arch/arm64/kvm/vgic/vgic-its.c
+++ b/arch/arm64/kvm/vgic/vgic-its.c
@@ -683,7 +683,7 @@ int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
 	if (!vcpu)
 		return E_ITS_INT_UNMAPPED_INTERRUPT;
 
-	if (!vcpu->arch.vgic_cpu.lpis_enabled)
+	if (!vgic_lpis_enabled(vcpu))
 		return -EBUSY;
 
 	vgic_its_cache_translation(kvm, its, devid, eventid, ite->irq);
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
index 58e40b4874f8..b5ef7e15bb66 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
@@ -221,6 +221,13 @@ static void vgic_mmio_write_irouter(struct kvm_vcpu *vcpu,
 	vgic_put_irq(vcpu->kvm, irq);
 }
 
+bool vgic_lpis_enabled(struct kvm_vcpu *vcpu)
+{
+	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+
+	return atomic_read(&vgic_cpu->ctlr) == GICR_CTLR_ENABLE_LPIS;
+}
+
 static unsigned long vgic_mmio_read_v3r_ctlr(struct kvm_vcpu *vcpu,
 					     gpa_t addr, unsigned int len)
 {
@@ -229,26 +236,38 @@ static unsigned long vgic_mmio_read_v3r_ctlr(struct kvm_vcpu *vcpu,
 	return vgic_cpu->lpis_enabled ? GICR_CTLR_ENABLE_LPIS : 0;
 }
 
-
 static void vgic_mmio_write_v3r_ctlr(struct kvm_vcpu *vcpu,
 				     gpa_t addr, unsigned int len,
 				     unsigned long val)
 {
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
-	bool was_enabled = vgic_cpu->lpis_enabled;
+	u32 ctlr;
 
 	if (!vgic_has_its(vcpu->kvm))
 		return;
 
-	vgic_cpu->lpis_enabled = val & GICR_CTLR_ENABLE_LPIS;
+	if (!(val & GICR_CTLR_ENABLE_LPIS)) {
+		/*
+		 * Don't disable if RWP is set, as there already an
+		 * ongoing disable. Funky guest...
+		 */
+		ctlr = atomic_cmpxchg_acquire(&vgic_cpu->ctlr,
+					      GICR_CTLR_ENABLE_LPIS,
+					      GICR_CTLR_RWP);
+		if (ctlr != GICR_CTLR_ENABLE_LPIS)
+			return;
 
-	if (was_enabled && !vgic_cpu->lpis_enabled) {
 		vgic_flush_pending_lpis(vcpu);
 		vgic_its_invalidate_cache(vcpu->kvm);
-	}
+		atomic_set_release(&vgic_cpu->ctlr, 0);
+	} else {
+		ctlr = atomic_cmpxchg_acquire(&vgic_cpu->ctlr, 0,
+					      GICR_CTLR_ENABLE_LPIS);
+		if (ctlr != 0)
+			return;
 
-	if (!was_enabled && vgic_cpu->lpis_enabled)
 		vgic_enable_lpis(vcpu);
+	}
 }
 
 static bool vgic_mmio_vcpu_rdist_is_last(struct kvm_vcpu *vcpu)
@@ -478,11 +497,10 @@ static void vgic_mmio_write_propbase(struct kvm_vcpu *vcpu,
 				     unsigned long val)
 {
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
-	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 	u64 old_propbaser, propbaser;
 
 	/* Storing a value with LPIs already enabled is undefined */
-	if (vgic_cpu->lpis_enabled)
+	if (vgic_lpis_enabled(vcpu))
 		return;
 
 	do {
@@ -513,7 +531,7 @@ static void vgic_mmio_write_pendbase(struct kvm_vcpu *vcpu,
 	u64 old_pendbaser, pendbaser;
 
 	/* Storing a value with LPIs already enabled is undefined */
-	if (vgic_cpu->lpis_enabled)
+	if (vgic_lpis_enabled(vcpu))
 		return;
 
 	do {
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index 3fd6c86a7ef3..a21e9b602ff2 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -308,6 +308,7 @@ static inline bool vgic_dist_overlap(struct kvm *kvm, gpa_t base, size_t size)
 		(base < d->vgic_dist_base + KVM_VGIC_V3_DIST_SIZE);
 }
 
+bool vgic_lpis_enabled(struct kvm_vcpu *vcpu);
 int vgic_copy_lpi_list(struct kvm *kvm, struct kvm_vcpu *vcpu, u32 **intid_ptr);
 int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
 			 u32 devid, u32 eventid, struct vgic_irq **irq);
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index bb30a6803d9f..fdf1c2c322e5 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -347,8 +347,8 @@ struct vgic_cpu {
 
 	/* Contains the attributes and gpa of the LPI pending tables. */
 	u64 pendbaser;
-
-	bool lpis_enabled;
+	/* GICR_CTLR.{ENABLE_LPIS,RWP} */
+	atomic_t ctlr;
 
 	/* Cache guest priority bits */
 	u32 num_pri_bits;
-- 
2.34.1

[PATCH v2 3/4] KVM: arm64: vgic-v3: Implement MMIO-based LPI invalidation

[Marc Zyngier]

Since GICv4.1, it has become legal for an implementation to advertise
GICR_{INVLPIR,INVALLR,SYNCR} while having an ITS, allowing for a more
efficient invalidation scheme (no guest command queue contention when
multiple CPUs are generating invalidations).

Provide the invalidation registers as a primitive to their ITS
counterpart. Note that we don't advertise them to the guest yet
(the architecture allows an implementation to do this).

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/vgic/vgic-its.c     | 62 ++++++++++++++++++----------
 arch/arm64/kvm/vgic/vgic-mmio-v3.c | 66 ++++++++++++++++++++++++++++++
 arch/arm64/kvm/vgic/vgic.h         |  4 ++
 include/kvm/arm_vgic.h             |  1 +
 4 files changed, 112 insertions(+), 21 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c
index 8371c5a9639c..9f51d624730f 100644
--- a/arch/arm64/kvm/vgic/vgic-its.c
+++ b/arch/arm64/kvm/vgic/vgic-its.c
@@ -1272,6 +1272,11 @@ static int vgic_its_cmd_handle_clear(struct kvm *kvm, struct vgic_its *its,
 	return 0;
 }
 
+int vgic_its_inv_lpi(struct kvm *kvm, struct vgic_irq *irq)
+{
+	return update_lpi_config(kvm, irq, NULL, true);
+}
+
 /*
  * The INV command syncs the configuration bits from the memory table.
  * Must be called with the its_lock mutex held.
@@ -1288,7 +1293,41 @@ 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, true);
+	return vgic_its_inv_lpi(kvm, ite->irq);
+}
+
+/**
+ * vgic_its_invall - invalidate all LPIs targetting a given vcpu
+ * @vcpu: the vcpu for which the RD is targetted by an invalidation
+ *
+ * Contrary to the INVALL command, this targets a RD instead of a
+ * collection, and we don't need to hold the its_lock, since no ITS is
+ * involved here.
+ */
+int vgic_its_invall(struct kvm_vcpu *vcpu)
+{
+	struct kvm *kvm = vcpu->kvm;
+	int irq_count, i = 0;
+	u32 *intids;
+
+	irq_count = vgic_copy_lpi_list(kvm, vcpu, &intids);
+	if (irq_count < 0)
+		return irq_count;
+
+	for (i = 0; i < irq_count; i++) {
+		struct vgic_irq *irq = vgic_get_irq(kvm, NULL, intids[i]);
+		if (!irq)
+			continue;
+		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;
 }
 
 /*
@@ -1305,32 +1344,13 @@ static int vgic_its_cmd_handle_invall(struct kvm *kvm, struct vgic_its *its,
 	u32 coll_id = its_cmd_get_collection(its_cmd);
 	struct its_collection *collection;
 	struct kvm_vcpu *vcpu;
-	struct vgic_irq *irq;
-	u32 *intids;
-	int irq_count, i;
 
 	collection = find_collection(its, coll_id);
 	if (!its_is_collection_mapped(collection))
 		return E_ITS_INVALL_UNMAPPED_COLLECTION;
 
 	vcpu = kvm_get_vcpu(kvm, collection->target_addr);
-
-	irq_count = vgic_copy_lpi_list(kvm, vcpu, &intids);
-	if (irq_count < 0)
-		return irq_count;
-
-	for (i = 0; i < irq_count; i++) {
-		irq = vgic_get_irq(kvm, NULL, intids[i]);
-		if (!irq)
-			continue;
-		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);
+	vgic_its_invall(vcpu);
 
 	return 0;
 }
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
index b5ef7e15bb66..9824c773427d 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
@@ -543,6 +543,63 @@ static void vgic_mmio_write_pendbase(struct kvm_vcpu *vcpu,
 			   pendbaser) != old_pendbaser);
 }
 
+static unsigned long vgic_mmio_read_sync(struct kvm_vcpu *vcpu,
+					 gpa_t addr, unsigned int len)
+{
+	return !!atomic_read(&vcpu->arch.vgic_cpu.syncr_busy);
+}
+
+static void vgic_set_rdist_busy(struct kvm_vcpu *vcpu, bool busy)
+{
+	if (busy) {
+		atomic_inc(&vcpu->arch.vgic_cpu.syncr_busy);
+		smp_mb__after_atomic();
+	} else {
+		smp_mb__before_atomic();
+		atomic_dec(&vcpu->arch.vgic_cpu.syncr_busy);
+	}
+}
+
+static void vgic_mmio_write_invlpi(struct kvm_vcpu *vcpu,
+				   gpa_t addr, unsigned int len,
+				   unsigned long val)
+{
+	struct vgic_irq *irq;
+
+	/*
+	 * If the guest wrote only to the upper 32bit part of the
+	 * register, drop the write on the floor, as it is only for
+	 * vPEs (which we don't support for obvious reasons).
+	 *
+	 * Also discard the access if LPIs are not enabled.
+	 */
+	if ((addr & 4) || !vgic_lpis_enabled(vcpu))
+		return;
+
+	vgic_set_rdist_busy(vcpu, true);
+
+	irq = vgic_get_irq(vcpu->kvm, NULL, lower_32_bits(val));
+	if (irq) {
+		vgic_its_inv_lpi(vcpu->kvm, irq);
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+
+	vgic_set_rdist_busy(vcpu, false);
+}
+
+static void vgic_mmio_write_invall(struct kvm_vcpu *vcpu,
+				   gpa_t addr, unsigned int len,
+				   unsigned long val)
+{
+	/* See vgic_mmio_write_invlpi() for the early return rationale */
+	if ((addr & 4) || !vgic_lpis_enabled(vcpu))
+		return;
+
+	vgic_set_rdist_busy(vcpu, true);
+	vgic_its_invall(vcpu);
+	vgic_set_rdist_busy(vcpu, false);
+}
+
 /*
  * The GICv3 per-IRQ registers are split to control PPIs and SGIs in the
  * redistributors, while SPIs are covered by registers in the distributor
@@ -648,6 +705,15 @@ static const struct vgic_register_region vgic_v3_rd_registers[] = {
 	REGISTER_DESC_WITH_LENGTH(GICR_PENDBASER,
 		vgic_mmio_read_pendbase, vgic_mmio_write_pendbase, 8,
 		VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
+	REGISTER_DESC_WITH_LENGTH(GICR_INVLPIR,
+		vgic_mmio_read_raz, vgic_mmio_write_invlpi, 8,
+		VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
+	REGISTER_DESC_WITH_LENGTH(GICR_INVALLR,
+		vgic_mmio_read_raz, vgic_mmio_write_invall, 8,
+		VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
+	REGISTER_DESC_WITH_LENGTH(GICR_SYNCR,
+		vgic_mmio_read_sync, vgic_mmio_write_wi, 4,
+		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_LENGTH(GICR_IDREGS,
 		vgic_mmio_read_v3_idregs, vgic_mmio_write_wi, 48,
 		VGIC_ACCESS_32bit),
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index a21e9b602ff2..1d04a900f3e3 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -318,6 +318,10 @@ void vgic_lpi_translation_cache_init(struct kvm *kvm);
 void vgic_lpi_translation_cache_destroy(struct kvm *kvm);
 void vgic_its_invalidate_cache(struct kvm *kvm);
 
+/* GICv4.1 MMIO interface */
+int vgic_its_inv_lpi(struct kvm *kvm, struct vgic_irq *irq);
+int vgic_its_invall(struct kvm_vcpu *vcpu);
+
 bool vgic_supports_direct_msis(struct kvm *kvm);
 int vgic_v4_init(struct kvm *kvm);
 void vgic_v4_teardown(struct kvm *kvm);
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index fdf1c2c322e5..401236f97cf2 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -344,6 +344,7 @@ struct vgic_cpu {
 	struct vgic_io_device	rd_iodev;
 	struct vgic_redist_region *rdreg;
 	u32 rdreg_index;
+	atomic_t syncr_busy;
 
 	/* Contains the attributes and gpa of the LPI pending tables. */
 	u64 pendbaser;
-- 
2.34.1

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

[PATCH v2 3/4] KVM: arm64: vgic-v3: Implement MMIO-based LPI invalidation

[Marc Zyngier]

Since GICv4.1, it has become legal for an implementation to advertise
GICR_{INVLPIR,INVALLR,SYNCR} while having an ITS, allowing for a more
efficient invalidation scheme (no guest command queue contention when
multiple CPUs are generating invalidations).

Provide the invalidation registers as a primitive to their ITS
counterpart. Note that we don't advertise them to the guest yet
(the architecture allows an implementation to do this).

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/vgic/vgic-its.c     | 62 ++++++++++++++++++----------
 arch/arm64/kvm/vgic/vgic-mmio-v3.c | 66 ++++++++++++++++++++++++++++++
 arch/arm64/kvm/vgic/vgic.h         |  4 ++
 include/kvm/arm_vgic.h             |  1 +
 4 files changed, 112 insertions(+), 21 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c
index 8371c5a9639c..9f51d624730f 100644
--- a/arch/arm64/kvm/vgic/vgic-its.c
+++ b/arch/arm64/kvm/vgic/vgic-its.c
@@ -1272,6 +1272,11 @@ static int vgic_its_cmd_handle_clear(struct kvm *kvm, struct vgic_its *its,
 	return 0;
 }
 
+int vgic_its_inv_lpi(struct kvm *kvm, struct vgic_irq *irq)
+{
+	return update_lpi_config(kvm, irq, NULL, true);
+}
+
 /*
  * The INV command syncs the configuration bits from the memory table.
  * Must be called with the its_lock mutex held.
@@ -1288,7 +1293,41 @@ 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, true);
+	return vgic_its_inv_lpi(kvm, ite->irq);
+}
+
+/**
+ * vgic_its_invall - invalidate all LPIs targetting a given vcpu
+ * @vcpu: the vcpu for which the RD is targetted by an invalidation
+ *
+ * Contrary to the INVALL command, this targets a RD instead of a
+ * collection, and we don't need to hold the its_lock, since no ITS is
+ * involved here.
+ */
+int vgic_its_invall(struct kvm_vcpu *vcpu)
+{
+	struct kvm *kvm = vcpu->kvm;
+	int irq_count, i = 0;
+	u32 *intids;
+
+	irq_count = vgic_copy_lpi_list(kvm, vcpu, &intids);
+	if (irq_count < 0)
+		return irq_count;
+
+	for (i = 0; i < irq_count; i++) {
+		struct vgic_irq *irq = vgic_get_irq(kvm, NULL, intids[i]);
+		if (!irq)
+			continue;
+		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;
 }
 
 /*
@@ -1305,32 +1344,13 @@ static int vgic_its_cmd_handle_invall(struct kvm *kvm, struct vgic_its *its,
 	u32 coll_id = its_cmd_get_collection(its_cmd);
 	struct its_collection *collection;
 	struct kvm_vcpu *vcpu;
-	struct vgic_irq *irq;
-	u32 *intids;
-	int irq_count, i;
 
 	collection = find_collection(its, coll_id);
 	if (!its_is_collection_mapped(collection))
 		return E_ITS_INVALL_UNMAPPED_COLLECTION;
 
 	vcpu = kvm_get_vcpu(kvm, collection->target_addr);
-
-	irq_count = vgic_copy_lpi_list(kvm, vcpu, &intids);
-	if (irq_count < 0)
-		return irq_count;
-
-	for (i = 0; i < irq_count; i++) {
-		irq = vgic_get_irq(kvm, NULL, intids[i]);
-		if (!irq)
-			continue;
-		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);
+	vgic_its_invall(vcpu);
 
 	return 0;
 }
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
index b5ef7e15bb66..9824c773427d 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
@@ -543,6 +543,63 @@ static void vgic_mmio_write_pendbase(struct kvm_vcpu *vcpu,
 			   pendbaser) != old_pendbaser);
 }
 
+static unsigned long vgic_mmio_read_sync(struct kvm_vcpu *vcpu,
+					 gpa_t addr, unsigned int len)
+{
+	return !!atomic_read(&vcpu->arch.vgic_cpu.syncr_busy);
+}
+
+static void vgic_set_rdist_busy(struct kvm_vcpu *vcpu, bool busy)
+{
+	if (busy) {
+		atomic_inc(&vcpu->arch.vgic_cpu.syncr_busy);
+		smp_mb__after_atomic();
+	} else {
+		smp_mb__before_atomic();
+		atomic_dec(&vcpu->arch.vgic_cpu.syncr_busy);
+	}
+}
+
+static void vgic_mmio_write_invlpi(struct kvm_vcpu *vcpu,
+				   gpa_t addr, unsigned int len,
+				   unsigned long val)
+{
+	struct vgic_irq *irq;
+
+	/*
+	 * If the guest wrote only to the upper 32bit part of the
+	 * register, drop the write on the floor, as it is only for
+	 * vPEs (which we don't support for obvious reasons).
+	 *
+	 * Also discard the access if LPIs are not enabled.
+	 */
+	if ((addr & 4) || !vgic_lpis_enabled(vcpu))
+		return;
+
+	vgic_set_rdist_busy(vcpu, true);
+
+	irq = vgic_get_irq(vcpu->kvm, NULL, lower_32_bits(val));
+	if (irq) {
+		vgic_its_inv_lpi(vcpu->kvm, irq);
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+
+	vgic_set_rdist_busy(vcpu, false);
+}
+
+static void vgic_mmio_write_invall(struct kvm_vcpu *vcpu,
+				   gpa_t addr, unsigned int len,
+				   unsigned long val)
+{
+	/* See vgic_mmio_write_invlpi() for the early return rationale */
+	if ((addr & 4) || !vgic_lpis_enabled(vcpu))
+		return;
+
+	vgic_set_rdist_busy(vcpu, true);
+	vgic_its_invall(vcpu);
+	vgic_set_rdist_busy(vcpu, false);
+}
+
 /*
  * The GICv3 per-IRQ registers are split to control PPIs and SGIs in the
  * redistributors, while SPIs are covered by registers in the distributor
@@ -648,6 +705,15 @@ static const struct vgic_register_region vgic_v3_rd_registers[] = {
 	REGISTER_DESC_WITH_LENGTH(GICR_PENDBASER,
 		vgic_mmio_read_pendbase, vgic_mmio_write_pendbase, 8,
 		VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
+	REGISTER_DESC_WITH_LENGTH(GICR_INVLPIR,
+		vgic_mmio_read_raz, vgic_mmio_write_invlpi, 8,
+		VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
+	REGISTER_DESC_WITH_LENGTH(GICR_INVALLR,
+		vgic_mmio_read_raz, vgic_mmio_write_invall, 8,
+		VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
+	REGISTER_DESC_WITH_LENGTH(GICR_SYNCR,
+		vgic_mmio_read_sync, vgic_mmio_write_wi, 4,
+		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_LENGTH(GICR_IDREGS,
 		vgic_mmio_read_v3_idregs, vgic_mmio_write_wi, 48,
 		VGIC_ACCESS_32bit),
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index a21e9b602ff2..1d04a900f3e3 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -318,6 +318,10 @@ void vgic_lpi_translation_cache_init(struct kvm *kvm);
 void vgic_lpi_translation_cache_destroy(struct kvm *kvm);
 void vgic_its_invalidate_cache(struct kvm *kvm);
 
+/* GICv4.1 MMIO interface */
+int vgic_its_inv_lpi(struct kvm *kvm, struct vgic_irq *irq);
+int vgic_its_invall(struct kvm_vcpu *vcpu);
+
 bool vgic_supports_direct_msis(struct kvm *kvm);
 int vgic_v4_init(struct kvm *kvm);
 void vgic_v4_teardown(struct kvm *kvm);
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index fdf1c2c322e5..401236f97cf2 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -344,6 +344,7 @@ struct vgic_cpu {
 	struct vgic_io_device	rd_iodev;
 	struct vgic_redist_region *rdreg;
 	u32 rdreg_index;
+	atomic_t syncr_busy;
 
 	/* Contains the attributes and gpa of the LPI pending tables. */
 	u64 pendbaser;
-- 
2.34.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v2 3/4] KVM: arm64: vgic-v3: Implement MMIO-based LPI invalidation

[Marc Zyngier]

Since GICv4.1, it has become legal for an implementation to advertise
GICR_{INVLPIR,INVALLR,SYNCR} while having an ITS, allowing for a more
efficient invalidation scheme (no guest command queue contention when
multiple CPUs are generating invalidations).

Provide the invalidation registers as a primitive to their ITS
counterpart. Note that we don't advertise them to the guest yet
(the architecture allows an implementation to do this).

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/vgic/vgic-its.c     | 62 ++++++++++++++++++----------
 arch/arm64/kvm/vgic/vgic-mmio-v3.c | 66 ++++++++++++++++++++++++++++++
 arch/arm64/kvm/vgic/vgic.h         |  4 ++
 include/kvm/arm_vgic.h             |  1 +
 4 files changed, 112 insertions(+), 21 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c
index 8371c5a9639c..9f51d624730f 100644
--- a/arch/arm64/kvm/vgic/vgic-its.c
+++ b/arch/arm64/kvm/vgic/vgic-its.c
@@ -1272,6 +1272,11 @@ static int vgic_its_cmd_handle_clear(struct kvm *kvm, struct vgic_its *its,
 	return 0;
 }
 
+int vgic_its_inv_lpi(struct kvm *kvm, struct vgic_irq *irq)
+{
+	return update_lpi_config(kvm, irq, NULL, true);
+}
+
 /*
  * The INV command syncs the configuration bits from the memory table.
  * Must be called with the its_lock mutex held.
@@ -1288,7 +1293,41 @@ 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, true);
+	return vgic_its_inv_lpi(kvm, ite->irq);
+}
+
+/**
+ * vgic_its_invall - invalidate all LPIs targetting a given vcpu
+ * @vcpu: the vcpu for which the RD is targetted by an invalidation
+ *
+ * Contrary to the INVALL command, this targets a RD instead of a
+ * collection, and we don't need to hold the its_lock, since no ITS is
+ * involved here.
+ */
+int vgic_its_invall(struct kvm_vcpu *vcpu)
+{
+	struct kvm *kvm = vcpu->kvm;
+	int irq_count, i = 0;
+	u32 *intids;
+
+	irq_count = vgic_copy_lpi_list(kvm, vcpu, &intids);
+	if (irq_count < 0)
+		return irq_count;
+
+	for (i = 0; i < irq_count; i++) {
+		struct vgic_irq *irq = vgic_get_irq(kvm, NULL, intids[i]);
+		if (!irq)
+			continue;
+		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;
 }
 
 /*
@@ -1305,32 +1344,13 @@ static int vgic_its_cmd_handle_invall(struct kvm *kvm, struct vgic_its *its,
 	u32 coll_id = its_cmd_get_collection(its_cmd);
 	struct its_collection *collection;
 	struct kvm_vcpu *vcpu;
-	struct vgic_irq *irq;
-	u32 *intids;
-	int irq_count, i;
 
 	collection = find_collection(its, coll_id);
 	if (!its_is_collection_mapped(collection))
 		return E_ITS_INVALL_UNMAPPED_COLLECTION;
 
 	vcpu = kvm_get_vcpu(kvm, collection->target_addr);
-
-	irq_count = vgic_copy_lpi_list(kvm, vcpu, &intids);
-	if (irq_count < 0)
-		return irq_count;
-
-	for (i = 0; i < irq_count; i++) {
-		irq = vgic_get_irq(kvm, NULL, intids[i]);
-		if (!irq)
-			continue;
-		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);
+	vgic_its_invall(vcpu);
 
 	return 0;
 }
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
index b5ef7e15bb66..9824c773427d 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
@@ -543,6 +543,63 @@ static void vgic_mmio_write_pendbase(struct kvm_vcpu *vcpu,
 			   pendbaser) != old_pendbaser);
 }
 
+static unsigned long vgic_mmio_read_sync(struct kvm_vcpu *vcpu,
+					 gpa_t addr, unsigned int len)
+{
+	return !!atomic_read(&vcpu->arch.vgic_cpu.syncr_busy);
+}
+
+static void vgic_set_rdist_busy(struct kvm_vcpu *vcpu, bool busy)
+{
+	if (busy) {
+		atomic_inc(&vcpu->arch.vgic_cpu.syncr_busy);
+		smp_mb__after_atomic();
+	} else {
+		smp_mb__before_atomic();
+		atomic_dec(&vcpu->arch.vgic_cpu.syncr_busy);
+	}
+}
+
+static void vgic_mmio_write_invlpi(struct kvm_vcpu *vcpu,
+				   gpa_t addr, unsigned int len,
+				   unsigned long val)
+{
+	struct vgic_irq *irq;
+
+	/*
+	 * If the guest wrote only to the upper 32bit part of the
+	 * register, drop the write on the floor, as it is only for
+	 * vPEs (which we don't support for obvious reasons).
+	 *
+	 * Also discard the access if LPIs are not enabled.
+	 */
+	if ((addr & 4) || !vgic_lpis_enabled(vcpu))
+		return;
+
+	vgic_set_rdist_busy(vcpu, true);
+
+	irq = vgic_get_irq(vcpu->kvm, NULL, lower_32_bits(val));
+	if (irq) {
+		vgic_its_inv_lpi(vcpu->kvm, irq);
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+
+	vgic_set_rdist_busy(vcpu, false);
+}
+
+static void vgic_mmio_write_invall(struct kvm_vcpu *vcpu,
+				   gpa_t addr, unsigned int len,
+				   unsigned long val)
+{
+	/* See vgic_mmio_write_invlpi() for the early return rationale */
+	if ((addr & 4) || !vgic_lpis_enabled(vcpu))
+		return;
+
+	vgic_set_rdist_busy(vcpu, true);
+	vgic_its_invall(vcpu);
+	vgic_set_rdist_busy(vcpu, false);
+}
+
 /*
  * The GICv3 per-IRQ registers are split to control PPIs and SGIs in the
  * redistributors, while SPIs are covered by registers in the distributor
@@ -648,6 +705,15 @@ static const struct vgic_register_region vgic_v3_rd_registers[] = {
 	REGISTER_DESC_WITH_LENGTH(GICR_PENDBASER,
 		vgic_mmio_read_pendbase, vgic_mmio_write_pendbase, 8,
 		VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
+	REGISTER_DESC_WITH_LENGTH(GICR_INVLPIR,
+		vgic_mmio_read_raz, vgic_mmio_write_invlpi, 8,
+		VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
+	REGISTER_DESC_WITH_LENGTH(GICR_INVALLR,
+		vgic_mmio_read_raz, vgic_mmio_write_invall, 8,
+		VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
+	REGISTER_DESC_WITH_LENGTH(GICR_SYNCR,
+		vgic_mmio_read_sync, vgic_mmio_write_wi, 4,
+		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_LENGTH(GICR_IDREGS,
 		vgic_mmio_read_v3_idregs, vgic_mmio_write_wi, 48,
 		VGIC_ACCESS_32bit),
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index a21e9b602ff2..1d04a900f3e3 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -318,6 +318,10 @@ void vgic_lpi_translation_cache_init(struct kvm *kvm);
 void vgic_lpi_translation_cache_destroy(struct kvm *kvm);
 void vgic_its_invalidate_cache(struct kvm *kvm);
 
+/* GICv4.1 MMIO interface */
+int vgic_its_inv_lpi(struct kvm *kvm, struct vgic_irq *irq);
+int vgic_its_invall(struct kvm_vcpu *vcpu);
+
 bool vgic_supports_direct_msis(struct kvm *kvm);
 int vgic_v4_init(struct kvm *kvm);
 void vgic_v4_teardown(struct kvm *kvm);
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index fdf1c2c322e5..401236f97cf2 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -344,6 +344,7 @@ struct vgic_cpu {
 	struct vgic_io_device	rd_iodev;
 	struct vgic_redist_region *rdreg;
 	u32 rdreg_index;
+	atomic_t syncr_busy;
 
 	/* Contains the attributes and gpa of the LPI pending tables. */
 	u64 pendbaser;
-- 
2.34.1

[PATCH v2 4/4] KVM: arm64: vgic-v3: Advertise GICR_CTLR.{IR, CES} as a new GICD_IIDR revision

[Marc Zyngier]

Since adversising GICR_CTLR.{IC,CES} is directly observable from
a guest, we need to make it selectable from userspace.

For that, bump the default GICD_IIDR revision and let userspace
downgrade it to the previous default. For GICv2, the two distributor
revisions are strictly equivalent.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/vgic/vgic-init.c    |  7 ++++++-
 arch/arm64/kvm/vgic/vgic-mmio-v2.c | 18 +++++++++++++++---
 arch/arm64/kvm/vgic/vgic-mmio-v3.c | 23 +++++++++++++++++++++--
 arch/arm64/kvm/vgic/vgic.h         |  5 +++++
 include/kvm/arm_vgic.h             |  3 +++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index fc00304fe7d8..f84e04f334c6 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -319,7 +319,12 @@ int vgic_init(struct kvm *kvm)
 
 	vgic_debug_init(kvm);
 
-	dist->implementation_rev = 2;
+	/*
+	 * If userspace didn't set the GIC implementation revision,
+	 * default to the latest and greatest. You know want it.
+	 */
+	if (!dist->implementation_rev)
+		dist->implementation_rev = KVM_VGIC_IMP_REV_LATEST;
 	dist->initialized = true;
 
 out:
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v2.c b/arch/arm64/kvm/vgic/vgic-mmio-v2.c
index 12e4c223e6b8..77a67e9d3d14 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v2.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v2.c
@@ -73,9 +73,13 @@ static int vgic_mmio_uaccess_write_v2_misc(struct kvm_vcpu *vcpu,
 					   gpa_t addr, unsigned int len,
 					   unsigned long val)
 {
+	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+	u32 reg;
+
 	switch (addr & 0x0c) {
 	case GIC_DIST_IIDR:
-		if (val != vgic_mmio_read_v2_misc(vcpu, addr, len))
+		reg = vgic_mmio_read_v2_misc(vcpu, addr, len);
+		if ((reg ^ val) & ~GICD_IIDR_REVISION_MASK)
 			return -EINVAL;
 
 		/*
@@ -87,8 +91,16 @@ static int vgic_mmio_uaccess_write_v2_misc(struct kvm_vcpu *vcpu,
 		 * migration from old kernels to new kernels with legacy
 		 * userspace.
 		 */
-		vcpu->kvm->arch.vgic.v2_groups_user_writable = true;
-		return 0;
+		reg = FIELD_GET(GICD_IIDR_REVISION_MASK, reg);
+		switch (reg) {
+		case KVM_VGIC_IMP_REV_2:
+		case KVM_VGIC_IMP_REV_3:
+			vcpu->kvm->arch.vgic.v2_groups_user_writable = true;
+			dist->implementation_rev = reg;
+			return 0;
+		default:
+			return -EINVAL;
+		}
 	}
 
 	vgic_mmio_write_v2_misc(vcpu, addr, len, val);
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
index 9824c773427d..f7aa7bcd6fb8 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
@@ -155,13 +155,27 @@ static int vgic_mmio_uaccess_write_v3_misc(struct kvm_vcpu *vcpu,
 					   unsigned long val)
 {
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+	u32 reg;
 
 	switch (addr & 0x0c) {
 	case GICD_TYPER2:
-	case GICD_IIDR:
 		if (val != vgic_mmio_read_v3_misc(vcpu, addr, len))
 			return -EINVAL;
 		return 0;
+	case GICD_IIDR:
+		reg = vgic_mmio_read_v3_misc(vcpu, addr, len);
+		if ((reg ^ val) & ~GICD_IIDR_REVISION_MASK)
+			return -EINVAL;
+
+		reg = FIELD_GET(GICD_IIDR_REVISION_MASK, reg);
+		switch (reg) {
+		case KVM_VGIC_IMP_REV_2:
+		case KVM_VGIC_IMP_REV_3:
+			dist->implementation_rev = reg;
+			return 0;
+		default:
+			return -EINVAL;
+		}
 	case GICD_CTLR:
 		/* Not a GICv4.1? No HW SGIs */
 		if (!kvm_vgic_global_state.has_gicv4_1)
@@ -232,8 +246,13 @@ static unsigned long vgic_mmio_read_v3r_ctlr(struct kvm_vcpu *vcpu,
 					     gpa_t addr, unsigned int len)
 {
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+	unsigned long val;
+
+	val = atomic_read(&vgic_cpu->ctlr);
+	if (vgic_get_implementation_rev(vcpu) >= KVM_VGIC_IMP_REV_3)
+		val |= GICR_CTLR_IR | GICR_CTLR_CES;
 
-	return vgic_cpu->lpis_enabled ? GICR_CTLR_ENABLE_LPIS : 0;
+	return val;
 }
 
 static void vgic_mmio_write_v3r_ctlr(struct kvm_vcpu *vcpu,
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index 1d04a900f3e3..4c6bdd321faa 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -98,6 +98,11 @@
 #define DEBUG_SPINLOCK_BUG_ON(p)
 #endif
 
+static inline u32 vgic_get_implementation_rev(struct kvm_vcpu *vcpu)
+{
+	return vcpu->kvm->arch.vgic.implementation_rev;
+}
+
 /* Requires the irq_lock to be held by the caller. */
 static inline bool irq_is_pending(struct vgic_irq *irq)
 {
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 401236f97cf2..2d8f2e90edc2 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -231,6 +231,9 @@ struct vgic_dist {
 
 	/* Implementation revision as reported in the GICD_IIDR */
 	u32			implementation_rev;
+#define KVM_VGIC_IMP_REV_2	2 /* GICv2 restorable groups */
+#define KVM_VGIC_IMP_REV_3	3 /* GICv3 GICR_CTLR.{IW,CES,RWP} */
+#define KVM_VGIC_IMP_REV_LATEST	KVM_VGIC_IMP_REV_3
 
 	/* Userspace can write to GICv2 IGROUPR */
 	bool			v2_groups_user_writable;
-- 
2.34.1

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

[PATCH v2 4/4] KVM: arm64: vgic-v3: Advertise GICR_CTLR.{IR, CES} as a new GICD_IIDR revision

[Marc Zyngier]

Since adversising GICR_CTLR.{IC,CES} is directly observable from
a guest, we need to make it selectable from userspace.

For that, bump the default GICD_IIDR revision and let userspace
downgrade it to the previous default. For GICv2, the two distributor
revisions are strictly equivalent.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/vgic/vgic-init.c    |  7 ++++++-
 arch/arm64/kvm/vgic/vgic-mmio-v2.c | 18 +++++++++++++++---
 arch/arm64/kvm/vgic/vgic-mmio-v3.c | 23 +++++++++++++++++++++--
 arch/arm64/kvm/vgic/vgic.h         |  5 +++++
 include/kvm/arm_vgic.h             |  3 +++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index fc00304fe7d8..f84e04f334c6 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -319,7 +319,12 @@ int vgic_init(struct kvm *kvm)
 
 	vgic_debug_init(kvm);
 
-	dist->implementation_rev = 2;
+	/*
+	 * If userspace didn't set the GIC implementation revision,
+	 * default to the latest and greatest. You know want it.
+	 */
+	if (!dist->implementation_rev)
+		dist->implementation_rev = KVM_VGIC_IMP_REV_LATEST;
 	dist->initialized = true;
 
 out:
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v2.c b/arch/arm64/kvm/vgic/vgic-mmio-v2.c
index 12e4c223e6b8..77a67e9d3d14 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v2.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v2.c
@@ -73,9 +73,13 @@ static int vgic_mmio_uaccess_write_v2_misc(struct kvm_vcpu *vcpu,
 					   gpa_t addr, unsigned int len,
 					   unsigned long val)
 {
+	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+	u32 reg;
+
 	switch (addr & 0x0c) {
 	case GIC_DIST_IIDR:
-		if (val != vgic_mmio_read_v2_misc(vcpu, addr, len))
+		reg = vgic_mmio_read_v2_misc(vcpu, addr, len);
+		if ((reg ^ val) & ~GICD_IIDR_REVISION_MASK)
 			return -EINVAL;
 
 		/*
@@ -87,8 +91,16 @@ static int vgic_mmio_uaccess_write_v2_misc(struct kvm_vcpu *vcpu,
 		 * migration from old kernels to new kernels with legacy
 		 * userspace.
 		 */
-		vcpu->kvm->arch.vgic.v2_groups_user_writable = true;
-		return 0;
+		reg = FIELD_GET(GICD_IIDR_REVISION_MASK, reg);
+		switch (reg) {
+		case KVM_VGIC_IMP_REV_2:
+		case KVM_VGIC_IMP_REV_3:
+			vcpu->kvm->arch.vgic.v2_groups_user_writable = true;
+			dist->implementation_rev = reg;
+			return 0;
+		default:
+			return -EINVAL;
+		}
 	}
 
 	vgic_mmio_write_v2_misc(vcpu, addr, len, val);
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
index 9824c773427d..f7aa7bcd6fb8 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
@@ -155,13 +155,27 @@ static int vgic_mmio_uaccess_write_v3_misc(struct kvm_vcpu *vcpu,
 					   unsigned long val)
 {
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+	u32 reg;
 
 	switch (addr & 0x0c) {
 	case GICD_TYPER2:
-	case GICD_IIDR:
 		if (val != vgic_mmio_read_v3_misc(vcpu, addr, len))
 			return -EINVAL;
 		return 0;
+	case GICD_IIDR:
+		reg = vgic_mmio_read_v3_misc(vcpu, addr, len);
+		if ((reg ^ val) & ~GICD_IIDR_REVISION_MASK)
+			return -EINVAL;
+
+		reg = FIELD_GET(GICD_IIDR_REVISION_MASK, reg);
+		switch (reg) {
+		case KVM_VGIC_IMP_REV_2:
+		case KVM_VGIC_IMP_REV_3:
+			dist->implementation_rev = reg;
+			return 0;
+		default:
+			return -EINVAL;
+		}
 	case GICD_CTLR:
 		/* Not a GICv4.1? No HW SGIs */
 		if (!kvm_vgic_global_state.has_gicv4_1)
@@ -232,8 +246,13 @@ static unsigned long vgic_mmio_read_v3r_ctlr(struct kvm_vcpu *vcpu,
 					     gpa_t addr, unsigned int len)
 {
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+	unsigned long val;
+
+	val = atomic_read(&vgic_cpu->ctlr);
+	if (vgic_get_implementation_rev(vcpu) >= KVM_VGIC_IMP_REV_3)
+		val |= GICR_CTLR_IR | GICR_CTLR_CES;
 
-	return vgic_cpu->lpis_enabled ? GICR_CTLR_ENABLE_LPIS : 0;
+	return val;
 }
 
 static void vgic_mmio_write_v3r_ctlr(struct kvm_vcpu *vcpu,
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index 1d04a900f3e3..4c6bdd321faa 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -98,6 +98,11 @@
 #define DEBUG_SPINLOCK_BUG_ON(p)
 #endif
 
+static inline u32 vgic_get_implementation_rev(struct kvm_vcpu *vcpu)
+{
+	return vcpu->kvm->arch.vgic.implementation_rev;
+}
+
 /* Requires the irq_lock to be held by the caller. */
 static inline bool irq_is_pending(struct vgic_irq *irq)
 {
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 401236f97cf2..2d8f2e90edc2 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -231,6 +231,9 @@ struct vgic_dist {
 
 	/* Implementation revision as reported in the GICD_IIDR */
 	u32			implementation_rev;
+#define KVM_VGIC_IMP_REV_2	2 /* GICv2 restorable groups */
+#define KVM_VGIC_IMP_REV_3	3 /* GICv3 GICR_CTLR.{IW,CES,RWP} */
+#define KVM_VGIC_IMP_REV_LATEST	KVM_VGIC_IMP_REV_3
 
 	/* Userspace can write to GICv2 IGROUPR */
 	bool			v2_groups_user_writable;
-- 
2.34.1


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[PATCH v2 4/4] KVM: arm64: vgic-v3: Advertise GICR_CTLR.{IR,CES} as a new GICD_IIDR revision

[Marc Zyngier]

Since adversising GICR_CTLR.{IC,CES} is directly observable from
a guest, we need to make it selectable from userspace.

For that, bump the default GICD_IIDR revision and let userspace
downgrade it to the previous default. For GICv2, the two distributor
revisions are strictly equivalent.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/vgic/vgic-init.c    |  7 ++++++-
 arch/arm64/kvm/vgic/vgic-mmio-v2.c | 18 +++++++++++++++---
 arch/arm64/kvm/vgic/vgic-mmio-v3.c | 23 +++++++++++++++++++++--
 arch/arm64/kvm/vgic/vgic.h         |  5 +++++
 include/kvm/arm_vgic.h             |  3 +++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index fc00304fe7d8..f84e04f334c6 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -319,7 +319,12 @@ int vgic_init(struct kvm *kvm)
 
 	vgic_debug_init(kvm);
 
-	dist->implementation_rev = 2;
+	/*
+	 * If userspace didn't set the GIC implementation revision,
+	 * default to the latest and greatest. You know want it.
+	 */
+	if (!dist->implementation_rev)
+		dist->implementation_rev = KVM_VGIC_IMP_REV_LATEST;
 	dist->initialized = true;
 
 out:
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v2.c b/arch/arm64/kvm/vgic/vgic-mmio-v2.c
index 12e4c223e6b8..77a67e9d3d14 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v2.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v2.c
@@ -73,9 +73,13 @@ static int vgic_mmio_uaccess_write_v2_misc(struct kvm_vcpu *vcpu,
 					   gpa_t addr, unsigned int len,
 					   unsigned long val)
 {
+	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+	u32 reg;
+
 	switch (addr & 0x0c) {
 	case GIC_DIST_IIDR:
-		if (val != vgic_mmio_read_v2_misc(vcpu, addr, len))
+		reg = vgic_mmio_read_v2_misc(vcpu, addr, len);
+		if ((reg ^ val) & ~GICD_IIDR_REVISION_MASK)
 			return -EINVAL;
 
 		/*
@@ -87,8 +91,16 @@ static int vgic_mmio_uaccess_write_v2_misc(struct kvm_vcpu *vcpu,
 		 * migration from old kernels to new kernels with legacy
 		 * userspace.
 		 */
-		vcpu->kvm->arch.vgic.v2_groups_user_writable = true;
-		return 0;
+		reg = FIELD_GET(GICD_IIDR_REVISION_MASK, reg);
+		switch (reg) {
+		case KVM_VGIC_IMP_REV_2:
+		case KVM_VGIC_IMP_REV_3:
+			vcpu->kvm->arch.vgic.v2_groups_user_writable = true;
+			dist->implementation_rev = reg;
+			return 0;
+		default:
+			return -EINVAL;
+		}
 	}
 
 	vgic_mmio_write_v2_misc(vcpu, addr, len, val);
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
index 9824c773427d..f7aa7bcd6fb8 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
@@ -155,13 +155,27 @@ static int vgic_mmio_uaccess_write_v3_misc(struct kvm_vcpu *vcpu,
 					   unsigned long val)
 {
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+	u32 reg;
 
 	switch (addr & 0x0c) {
 	case GICD_TYPER2:
-	case GICD_IIDR:
 		if (val != vgic_mmio_read_v3_misc(vcpu, addr, len))
 			return -EINVAL;
 		return 0;
+	case GICD_IIDR:
+		reg = vgic_mmio_read_v3_misc(vcpu, addr, len);
+		if ((reg ^ val) & ~GICD_IIDR_REVISION_MASK)
+			return -EINVAL;
+
+		reg = FIELD_GET(GICD_IIDR_REVISION_MASK, reg);
+		switch (reg) {
+		case KVM_VGIC_IMP_REV_2:
+		case KVM_VGIC_IMP_REV_3:
+			dist->implementation_rev = reg;
+			return 0;
+		default:
+			return -EINVAL;
+		}
 	case GICD_CTLR:
 		/* Not a GICv4.1? No HW SGIs */
 		if (!kvm_vgic_global_state.has_gicv4_1)
@@ -232,8 +246,13 @@ static unsigned long vgic_mmio_read_v3r_ctlr(struct kvm_vcpu *vcpu,
 					     gpa_t addr, unsigned int len)
 {
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+	unsigned long val;
+
+	val = atomic_read(&vgic_cpu->ctlr);
+	if (vgic_get_implementation_rev(vcpu) >= KVM_VGIC_IMP_REV_3)
+		val |= GICR_CTLR_IR | GICR_CTLR_CES;
 
-	return vgic_cpu->lpis_enabled ? GICR_CTLR_ENABLE_LPIS : 0;
+	return val;
 }
 
 static void vgic_mmio_write_v3r_ctlr(struct kvm_vcpu *vcpu,
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index 1d04a900f3e3..4c6bdd321faa 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -98,6 +98,11 @@
 #define DEBUG_SPINLOCK_BUG_ON(p)
 #endif
 
+static inline u32 vgic_get_implementation_rev(struct kvm_vcpu *vcpu)
+{
+	return vcpu->kvm->arch.vgic.implementation_rev;
+}
+
 /* Requires the irq_lock to be held by the caller. */
 static inline bool irq_is_pending(struct vgic_irq *irq)
 {
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 401236f97cf2..2d8f2e90edc2 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -231,6 +231,9 @@ struct vgic_dist {
 
 	/* Implementation revision as reported in the GICD_IIDR */
 	u32			implementation_rev;
+#define KVM_VGIC_IMP_REV_2	2 /* GICv2 restorable groups */
+#define KVM_VGIC_IMP_REV_3	3 /* GICv3 GICR_CTLR.{IW,CES,RWP} */
+#define KVM_VGIC_IMP_REV_LATEST	KVM_VGIC_IMP_REV_3
 
 	/* Userspace can write to GICv2 IGROUPR */
 	bool			v2_groups_user_writable;
-- 
2.34.1

Re: [PATCH v2 1/4] irqchip/gic-v3: Exposes bit values for GICR_CTLR.{IR,CES}

[Oliver Upton]

On Tue, Apr 05, 2022 at 07:23:24PM +0100, Marc Zyngier wrote:
> As we're about to expose GICR_CTLR.{IR,CES} to guests, populate
> the include file with the architectural values.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>

Reviewed-by: Oliver Upton <oupton@google.com>

> ---
>  include/linux/irqchip/arm-gic-v3.h | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
> index 12d91f0dedf9..728691365464 100644
> --- a/include/linux/irqchip/arm-gic-v3.h
> +++ b/include/linux/irqchip/arm-gic-v3.h
> @@ -127,6 +127,8 @@
>  #define GICR_PIDR2			GICD_PIDR2
>  
>  #define GICR_CTLR_ENABLE_LPIS		(1UL << 0)
> +#define GICR_CTLR_CES			(1UL << 1)
> +#define GICR_CTLR_IR			(1UL << 2)
>  #define GICR_CTLR_RWP			(1UL << 3)
>  
>  #define GICR_TYPER_CPU_NUMBER(r)	(((r) >> 8) & 0xffff)
> -- 
> 2.34.1
> 
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Re: [PATCH v2 1/4] irqchip/gic-v3: Exposes bit values for GICR_CTLR.{IR,CES}

[Oliver Upton]

On Tue, Apr 05, 2022 at 07:23:24PM +0100, Marc Zyngier wrote:
> As we're about to expose GICR_CTLR.{IR,CES} to guests, populate
> the include file with the architectural values.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>

Reviewed-by: Oliver Upton <oupton@google.com>

> ---
>  include/linux/irqchip/arm-gic-v3.h | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
> index 12d91f0dedf9..728691365464 100644
> --- a/include/linux/irqchip/arm-gic-v3.h
> +++ b/include/linux/irqchip/arm-gic-v3.h
> @@ -127,6 +127,8 @@
>  #define GICR_PIDR2			GICD_PIDR2
>  
>  #define GICR_CTLR_ENABLE_LPIS		(1UL << 0)
> +#define GICR_CTLR_CES			(1UL << 1)
> +#define GICR_CTLR_IR			(1UL << 2)
>  #define GICR_CTLR_RWP			(1UL << 3)
>  
>  #define GICR_TYPER_CPU_NUMBER(r)	(((r) >> 8) & 0xffff)
> -- 
> 2.34.1
> 

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Re: [PATCH v2 1/4] irqchip/gic-v3: Exposes bit values for GICR_CTLR.{IR,CES}

[Oliver Upton]

On Tue, Apr 05, 2022 at 07:23:24PM +0100, Marc Zyngier wrote:
> As we're about to expose GICR_CTLR.{IR,CES} to guests, populate
> the include file with the architectural values.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>

Reviewed-by: Oliver Upton <oupton@google.com>

> ---
>  include/linux/irqchip/arm-gic-v3.h | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
> index 12d91f0dedf9..728691365464 100644
> --- a/include/linux/irqchip/arm-gic-v3.h
> +++ b/include/linux/irqchip/arm-gic-v3.h
> @@ -127,6 +127,8 @@
>  #define GICR_PIDR2			GICD_PIDR2
>  
>  #define GICR_CTLR_ENABLE_LPIS		(1UL << 0)
> +#define GICR_CTLR_CES			(1UL << 1)
> +#define GICR_CTLR_IR			(1UL << 2)
>  #define GICR_CTLR_RWP			(1UL << 3)
>  
>  #define GICR_TYPER_CPU_NUMBER(r)	(((r) >> 8) & 0xffff)
> -- 
> 2.34.1
> 

Re: [PATCH v2 3/4] KVM: arm64: vgic-v3: Implement MMIO-based LPI invalidation

[Oliver Upton]

On Tue, Apr 05, 2022 at 07:23:26PM +0100, Marc Zyngier wrote:
> Since GICv4.1, it has become legal for an implementation to advertise
> GICR_{INVLPIR,INVALLR,SYNCR} while having an ITS, allowing for a more
> efficient invalidation scheme (no guest command queue contention when
> multiple CPUs are generating invalidations).
> 
> Provide the invalidation registers as a primitive to their ITS
> counterpart. Note that we don't advertise them to the guest yet
> (the architecture allows an implementation to do this).
> 

I'll admit that this part tripped me up a bit, odd stuff.

> Signed-off-by: Marc Zyngier <maz@kernel.org>

Reviewed-by: Oliver Upton <oupton@google.com>

Re: [PATCH v2 3/4] KVM: arm64: vgic-v3: Implement MMIO-based LPI invalidation

[Oliver Upton]

On Tue, Apr 05, 2022 at 07:23:26PM +0100, Marc Zyngier wrote:
> Since GICv4.1, it has become legal for an implementation to advertise
> GICR_{INVLPIR,INVALLR,SYNCR} while having an ITS, allowing for a more
> efficient invalidation scheme (no guest command queue contention when
> multiple CPUs are generating invalidations).
> 
> Provide the invalidation registers as a primitive to their ITS
> counterpart. Note that we don't advertise them to the guest yet
> (the architecture allows an implementation to do this).
> 

I'll admit that this part tripped me up a bit, odd stuff.

> Signed-off-by: Marc Zyngier <maz@kernel.org>

Reviewed-by: Oliver Upton <oupton@google.com>
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Re: [PATCH v2 3/4] KVM: arm64: vgic-v3: Implement MMIO-based LPI invalidation

[Oliver Upton]

On Tue, Apr 05, 2022 at 07:23:26PM +0100, Marc Zyngier wrote:
> Since GICv4.1, it has become legal for an implementation to advertise
> GICR_{INVLPIR,INVALLR,SYNCR} while having an ITS, allowing for a more
> efficient invalidation scheme (no guest command queue contention when
> multiple CPUs are generating invalidations).
> 
> Provide the invalidation registers as a primitive to their ITS
> counterpart. Note that we don't advertise them to the guest yet
> (the architecture allows an implementation to do this).
> 

I'll admit that this part tripped me up a bit, odd stuff.

> Signed-off-by: Marc Zyngier <maz@kernel.org>

Reviewed-by: Oliver Upton <oupton@google.com>

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[irqchip: irq/irqchip-next] irqchip/gic-v3: Exposes bit values for GICR_CTLR.{IR, CES}

[irqchip-bot for Marc Zyngier]

The following commit has been merged into the irq/irqchip-next branch of irqchip:

Commit-ID:     34453c2e9f799d02f5f379519495208bbd96a935
Gitweb:        https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms/34453c2e9f799d02f5f379519495208bbd96a935
Author:        Marc Zyngier <maz@kernel.org>
AuthorDate:    Tue, 05 Apr 2022 19:23:24 +01:00
Committer:     Marc Zyngier <maz@kernel.org>
CommitterDate: Wed, 04 May 2022 14:09:52 +01:00

irqchip/gic-v3: Exposes bit values for GICR_CTLR.{IR, CES}

As we're about to expose GICR_CTLR.{IR,CES} to guests, populate
the include file with the architectural values.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Oliver Upton <oupton@google.com>
Link: https://lore.kernel.org/r/20220405182327.205520-2-maz@kernel.org
---
 include/linux/irqchip/arm-gic-v3.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index 12d91f0..7286913 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -127,6 +127,8 @@
 #define GICR_PIDR2			GICD_PIDR2
 
 #define GICR_CTLR_ENABLE_LPIS		(1UL << 0)
+#define GICR_CTLR_CES			(1UL << 1)
+#define GICR_CTLR_IR			(1UL << 2)
 #define GICR_CTLR_RWP			(1UL << 3)
 
 #define GICR_TYPER_CPU_NUMBER(r)	(((r) >> 8) & 0xffff)