[PATCH v5 0/3] PCI: hv: Refactor hv_irq_unmask() to use hv_vpset and cpumask_to_vpset()

[PATCH v5 0/3] PCI: hv: Refactor hv_irq_unmask() to use hv_vpset and cpumask_to_vpset()

[Maya Nakamura]

This patchset removes a duplicate definition of VP set (hv_vp_set) and
uses the common definition (hv_vpset) that is used in other places. It
changes the order of the members in struct hv_pcibus_device due to
flexible array in hv_vpset.

It also removes the duplicate implementation of cpumask_to_vpset(), uses
the shared implementation, and exports hv_max_vp_index, which is
required by cpumask_to_vpset().

It adds __aligned(8) to struct retarget_msi_interrupt because Hyper-V
requires that hypercall arguments be aligned on an 8 byte boundary. This
is now a new patch, separate from one of the previous patches.

Maya Nakamura (3):
  PCI: hv: Add __aligned(8) to struct retarget_msi_interrupt
  PCI: hv: Replace hv_vp_set with hv_vpset
  PCI: hv: Refactor hv_irq_unmask() to use cpumask_to_vpset()

 arch/x86/hyperv/hv_init.c           |  1 +
 drivers/pci/controller/pci-hyperv.c | 61 +++++++++++++----------------
 2 files changed, 29 insertions(+), 33 deletions(-)

-- 
2.17.1

[PATCH v5 1/3] PCI: hv: Add __aligned(8) to struct retarget_msi_interrupt

[Maya Nakamura]

Because Hyper-V requires that hypercall arguments be aligned on an 8
byte boundary, add __aligned(8) to struct retarget_msi_interrupt.

Link: https://lore.kernel.org/lkml/87k1hlqlby.fsf@vitty.brq.redhat.com/
Signed-off-by: Maya Nakamura <m.maya.nakamura@gmail.com>
---
 drivers/pci/controller/pci-hyperv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 9ba4d12c179c..73862eef09ec 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -420,7 +420,7 @@ struct retarget_msi_interrupt {
 	struct hv_interrupt_entry int_entry;
 	u64	reserved2;
 	struct hv_device_interrupt_target int_target;
-} __packed;
+} __packed __aligned(8);
 
 /*
  * Driver specific state.
-- 
2.17.1

[PATCH v5 2/3] PCI: hv: Replace hv_vp_set with hv_vpset

[Maya Nakamura]

Remove a duplicate definition of VP set (hv_vp_set) and use the common
definition (hv_vpset) that is used in other places.

Change the order of the members in struct hv_pcibus_device so that the
declaration of retarget_msi_interrupt_params is the last member. Struct
hv_vpset, which contains a flexible array, is nested two levels deep in
struct hv_pcibus_device via retarget_msi_interrupt_params.

Add a comment that retarget_msi_interrupt_params should be the last
member of struct hv_pcibus_device.

Signed-off-by: Maya Nakamura <m.maya.nakamura@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
Changes in v5:
 - Remove the code added in v4.
 - Delete the v4 code change related comment from the commit message.
 - Add the Reviewed-by and Tested-by tags.

Changes in v4:
 - Add __aligned(8) to struct retarget_msi_interrupt.
 - Update the commit message.

Change in v3:
 - Correct the v2 change log.

Change in v2:
 - Update the commit message.

 drivers/pci/controller/pci-hyperv.c | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 73862eef09ec..d71695db1ba0 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -393,12 +393,6 @@ struct hv_interrupt_entry {
 
 #define HV_VP_SET_BANK_COUNT_MAX	5 /* current implementation limit */
 
-struct hv_vp_set {
-	u64	format;			/* 0 (HvGenericSetSparse4k) */
-	u64	valid_banks;
-	u64	masks[HV_VP_SET_BANK_COUNT_MAX];
-};
-
 /*
  * flags for hv_device_interrupt_target.flags
  */
@@ -410,7 +404,7 @@ struct hv_device_interrupt_target {
 	u32	flags;
 	union {
 		u64		 vp_mask;
-		struct hv_vp_set vp_set;
+		struct hv_vpset vp_set;
 	};
 };
 
@@ -460,12 +454,16 @@ struct hv_pcibus_device {
 	struct msi_controller msi_chip;
 	struct irq_domain *irq_domain;
 
-	/* hypercall arg, must not cross page boundary */
-	struct retarget_msi_interrupt retarget_msi_interrupt_params;
-
 	spinlock_t retarget_msi_interrupt_lock;
 
 	struct workqueue_struct *wq;
+
+	/* hypercall arg, must not cross page boundary */
+	struct retarget_msi_interrupt retarget_msi_interrupt_params;
+
+	/*
+	 * Don't put anything here: retarget_msi_interrupt_params must be last
+	 */
 };
 
 /*
@@ -955,12 +953,13 @@ static void hv_irq_unmask(struct irq_data *data)
 		 */
 		params->int_target.flags |=
 			HV_DEVICE_INTERRUPT_TARGET_PROCESSOR_SET;
-		params->int_target.vp_set.valid_banks =
+		params->int_target.vp_set.valid_bank_mask =
 			(1ull << HV_VP_SET_BANK_COUNT_MAX) - 1;
 
 		/*
 		 * var-sized hypercall, var-size starts after vp_mask (thus
-		 * vp_set.format does not count, but vp_set.valid_banks does).
+		 * vp_set.format does not count, but vp_set.valid_bank_mask
+		 * does).
 		 */
 		var_size = 1 + HV_VP_SET_BANK_COUNT_MAX;
 
@@ -974,7 +973,7 @@ static void hv_irq_unmask(struct irq_data *data)
 				goto exit_unlock;
 			}
 
-			params->int_target.vp_set.masks[cpu_vmbus / 64] |=
+			params->int_target.vp_set.bank_contents[cpu_vmbus / 64]	|=
 				(1ULL << (cpu_vmbus & 63));
 		}
 	} else {
-- 
2.17.1

[PATCH v5 3/3] PCI: hv: Refactor hv_irq_unmask() to use cpumask_to_vpset()

[Maya Nakamura]

Remove the duplicate implementation of cpumask_to_vpset() and use the
shared implementation. Export hv_max_vp_index, which is required by
cpumask_to_vpset().

Signed-off-by: Maya Nakamura <m.maya.nakamura@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
Changes in v5:
 - Revise the commit message to clarify the changes based on feedback.
 - Add the Reviewed-by and Tested-by tags.

Changes in v4:
 - Replace GFP_KERNEL with GFP_ATOMIC for alloc_cpumask_var().
 - Update the commit message.

Changes in v3:
 - Modify to catch all failures from cpumask_to_vpset().
 - Correct the v2 change log about the commit message.

Changes in v2:
 - Remove unnecessary nr_bank initialization.
 - Delete two unnecessary dev_err()'s.
 - Unlock before returning.
 - Update the commit message.

 arch/x86/hyperv/hv_init.c           |  1 +
 drivers/pci/controller/pci-hyperv.c | 38 +++++++++++++----------------
 2 files changed, 18 insertions(+), 21 deletions(-)

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 7abb09e2eeb8..7f2eed1fc81b 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -96,6 +96,7 @@ void  __percpu **hyperv_pcpu_input_arg;
 EXPORT_SYMBOL_GPL(hyperv_pcpu_input_arg);
 
 u32 hv_max_vp_index;
+EXPORT_SYMBOL_GPL(hv_max_vp_index);
 
 static int hv_cpu_init(unsigned int cpu)
 {
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index d71695db1ba0..95441a35eceb 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -391,8 +391,6 @@ struct hv_interrupt_entry {
 	u32	data;
 };
 
-#define HV_VP_SET_BANK_COUNT_MAX	5 /* current implementation limit */
-
 /*
  * flags for hv_device_interrupt_target.flags
  */
@@ -908,12 +906,12 @@ static void hv_irq_unmask(struct irq_data *data)
 	struct retarget_msi_interrupt *params;
 	struct hv_pcibus_device *hbus;
 	struct cpumask *dest;
+	cpumask_var_t tmp;
 	struct pci_bus *pbus;
 	struct pci_dev *pdev;
 	unsigned long flags;
 	u32 var_size = 0;
-	int cpu_vmbus;
-	int cpu;
+	int cpu, nr_bank;
 	u64 res;
 
 	dest = irq_data_get_effective_affinity_mask(data);
@@ -953,29 +951,27 @@ static void hv_irq_unmask(struct irq_data *data)
 		 */
 		params->int_target.flags |=
 			HV_DEVICE_INTERRUPT_TARGET_PROCESSOR_SET;
-		params->int_target.vp_set.valid_bank_mask =
-			(1ull << HV_VP_SET_BANK_COUNT_MAX) - 1;
+
+		if (!alloc_cpumask_var(&tmp, GFP_ATOMIC)) {
+			res = 1;
+			goto exit_unlock;
+		}
+
+		cpumask_and(tmp, dest, cpu_online_mask);
+		nr_bank = cpumask_to_vpset(&params->int_target.vp_set, tmp);
+		free_cpumask_var(tmp);
+
+		if (nr_bank <= 0) {
+			res = 1;
+			goto exit_unlock;
+		}
 
 		/*
 		 * var-sized hypercall, var-size starts after vp_mask (thus
 		 * vp_set.format does not count, but vp_set.valid_bank_mask
 		 * does).
 		 */
-		var_size = 1 + HV_VP_SET_BANK_COUNT_MAX;
-
-		for_each_cpu_and(cpu, dest, cpu_online_mask) {
-			cpu_vmbus = hv_cpu_number_to_vp_number(cpu);
-
-			if (cpu_vmbus >= HV_VP_SET_BANK_COUNT_MAX * 64) {
-				dev_err(&hbus->hdev->device,
-					"too high CPU %d", cpu_vmbus);
-				res = 1;
-				goto exit_unlock;
-			}
-
-			params->int_target.vp_set.bank_contents[cpu_vmbus / 64]	|=
-				(1ULL << (cpu_vmbus & 63));
-		}
+		var_size = 1 + nr_bank;
 	} else {
 		for_each_cpu_and(cpu, dest, cpu_online_mask) {
 			params->int_target.vp_mask |=
-- 
2.17.1

Re: [PATCH v5 0/3] PCI: hv: Refactor hv_irq_unmask() to use hv_vpset and cpumask_to_vpset()

[Lorenzo Pieralisi]

On Fri, Mar 01, 2019 at 06:54:45AM +0000, Maya Nakamura wrote:
> This patchset removes a duplicate definition of VP set (hv_vp_set) and
> uses the common definition (hv_vpset) that is used in other places. It
> changes the order of the members in struct hv_pcibus_device due to
> flexible array in hv_vpset.
> 
> It also removes the duplicate implementation of cpumask_to_vpset(), uses
> the shared implementation, and exports hv_max_vp_index, which is
> required by cpumask_to_vpset().
> 
> It adds __aligned(8) to struct retarget_msi_interrupt because Hyper-V
> requires that hypercall arguments be aligned on an 8 byte boundary. This
> is now a new patch, separate from one of the previous patches.
> 
> Maya Nakamura (3):
>   PCI: hv: Add __aligned(8) to struct retarget_msi_interrupt
>   PCI: hv: Replace hv_vp_set with hv_vpset
>   PCI: hv: Refactor hv_irq_unmask() to use cpumask_to_vpset()
> 
>  arch/x86/hyperv/hv_init.c           |  1 +
>  drivers/pci/controller/pci-hyperv.c | 61 +++++++++++++----------------
>  2 files changed, 29 insertions(+), 33 deletions(-)

It looks all good, applied to pci/hv for v5.1, pending kbot checks.

Thanks,
Lorenzo