[PART2 PATCH v4 07/11] iommu/amd: Introduce amd_iommu_update_ga()

[Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>]

From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>

Introduces a new IOMMU API, amd_iommu_update_ga(), which allows
KVM (SVM) to update existing posted interrupt IOMMU IRTE when
load/unload vcpu.

Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
---
 drivers/iommu/amd_iommu.c       | 65 +++++++++++++++++++++++++++++++++++++++++
 drivers/iommu/amd_iommu_types.h |  1 +
 include/linux/amd-iommu.h       |  9 ++++++
 3 files changed, 75 insertions(+)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index fe9b005..4a337dc 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -4461,4 +4461,69 @@ int amd_iommu_create_irq_domain(struct amd_iommu *iommu)
 
 	return 0;
 }
+
+static int
+update_irte_ga(struct irte_ga *irte, unsigned int devid,
+	       u64 base, int cpu, bool is_run)
+{
+	struct irq_remap_table *irt = get_irq_table(devid, false);
+	unsigned long flags;
+
+	if (!irt)
+		return -ENODEV;
+
+	spin_lock_irqsave(&irt->lock, flags);
+
+	if (irte->lo.fields_vapic.guest_mode) {
+		irte->hi.fields.ga_root_ptr = (base >> 12);
+		if (cpu >= 0)
+			irte->lo.fields_vapic.destination = cpu;
+		irte->lo.fields_vapic.is_run = is_run;
+		barrier();
+	}
+
+	spin_unlock_irqrestore(&irt->lock, flags);
+
+	return 0;
+}
+
+int amd_iommu_update_ga(u32 vcpu_id, u32 cpu, u32 vm_id,
+			u64 base, bool is_run)
+{
+	unsigned long flags;
+	struct amd_iommu *iommu;
+
+	if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir))
+		return 0;
+
+	for_each_iommu(iommu) {
+		struct amd_ir_data *ir_data;
+
+		spin_lock_irqsave(&iommu->gatag_ir_hash_lock, flags);
+
+		/* Note:
+		 * We need to update all interrupt remapping table entries
+		 * for targeting the specified vcpu. Here, we use gatag
+		 * as a hash key and iterate through all entries in the bucket.
+		 */
+		hash_for_each_possible(iommu->gatag_ir_hash, ir_data, hnode,
+				       AMD_IOMMU_GATAG(vm_id, vcpu_id)) {
+			struct irte_ga *irte = (struct irte_ga *) ir_data->entry;
+
+			if (!irte->lo.fields_vapic.guest_mode)
+				continue;
+
+			update_irte_ga((struct irte_ga *)ir_data->ref,
+					ir_data->irq_2_irte.devid,
+					base, cpu, is_run);
+			iommu_flush_irt(iommu, ir_data->irq_2_irte.devid);
+			iommu_completion_wait(iommu);
+		}
+
+		spin_unlock_irqrestore(&iommu->gatag_ir_hash_lock, flags);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(amd_iommu_update_ga);
 #endif
diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index 2ed353b..52160c8 100644
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -844,6 +844,7 @@ struct amd_ir_data {
 	union {
 		struct msi_msg msi_entry;
 	};
+	void *ref;	/* Pointer to the actual irte */
 };
 
 #ifdef CONFIG_IRQ_REMAP
diff --git a/include/linux/amd-iommu.h b/include/linux/amd-iommu.h
index 940fdd8..a6fc022 100644
--- a/include/linux/amd-iommu.h
+++ b/include/linux/amd-iommu.h
@@ -179,6 +179,9 @@ static inline int amd_iommu_detect(void) { return -ENODEV; }
 /* IOMMU AVIC Function */
 extern int amd_iommu_register_ga_log_notifier(int (*notifier)(int, int));
 
+extern int
+amd_iommu_update_ga(u32 vcpu_id, u32 cpu, u32 vm_id, u64 base, bool is_run);
+
 #else /* defined(CONFIG_AMD_IOMMU) && defined(CONFIG_IRQ_REMAP) */
 
 static inline int
@@ -187,6 +190,12 @@ amd_iommu_register_ga_log_notifier(int (*notifier)(int, int))
 	return 0;
 }
 
+static inline int
+amd_iommu_update_ga(u32 vcpu_id, u32 cpu, u32 vm_id, u64 base, bool is_run)
+{
+	return 0;
+}
+
 #endif /* defined(CONFIG_AMD_IOMMU) && defined(CONFIG_IRQ_REMAP) */
 
 #endif /* _ASM_X86_AMD_IOMMU_H */
-- 
1.9.1