iommu/amd: Introduce amd_iommu_update_ga()

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>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

3 files changed, 49 insertions, 0 deletions

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index eec37b2f54df..089e1ed4deec 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -4269,4 +4269,43 @@ int amd_iommu_create_irq_domain(struct amd_iommu *iommu)
 
         return 0;
 }
+
+int amd_iommu_update_ga(int cpu, bool is_run, void *data)
+{
+        unsigned long flags;
+        struct amd_iommu *iommu;
+        struct irq_remap_table *irt;
+        struct amd_ir_data *ir_data = (struct amd_ir_data *)data;
+        int devid = ir_data->irq_2_irte.devid;
+        struct irte_ga *entry = (struct irte_ga *) ir_data->entry;
+        struct irte_ga *ref = (struct irte_ga *) ir_data->ref;
+
+        if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) ||
+            !ref || !entry || !entry->lo.fields_vapic.guest_mode)
+                return 0;
+
+        iommu = amd_iommu_rlookup_table[devid];
+        if (!iommu)
+                return -ENODEV;
+
+        irt = get_irq_table(devid, false);
+        if (!irt)
+                return -ENODEV;
+
+        spin_lock_irqsave(&irt->lock, flags);
+
+        if (ref->lo.fields_vapic.guest_mode) {
+                if (cpu >= 0)
+                        ref->lo.fields_vapic.destination = cpu;
+                ref->lo.fields_vapic.is_run = is_run;
+                barrier();
+        }
+
+        spin_unlock_irqrestore(&irt->lock, flags);
+
+        iommu_flush_irt(iommu, devid);
+        iommu_completion_wait(iommu);
+        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 8a7a93d40063..60018a8fb655 100644
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -810,6 +810,7 @@ struct amd_ir_data {
         struct irq_2_irte irq_2_irte;
         struct msi_msg msi_entry;
         void *entry;    /* Pointer to union irte or struct irte_ga */
+        void *ref;      /* Pointer to the actual irte */
 };
 
 struct amd_irte_ops {
diff --git a/include/linux/amd-iommu.h b/include/linux/amd-iommu.h
index 465d096a5f4b..d8d48aca0eb7 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)(u32));
 
+extern int
+amd_iommu_update_ga(int cpu, bool is_run, void *data);
+
 #else /* defined(CONFIG_AMD_IOMMU) && defined(CONFIG_IRQ_REMAP) */
 
 static inline int
@@ -187,6 +190,12 @@ amd_iommu_register_ga_log_notifier(int (*notifier)(u32))
         return 0;
 }
 
+static inline int
+amd_iommu_update_ga(int cpu, bool is_run, void *data)
+{
+        return 0;
+}
+
 #endif /* defined(CONFIG_AMD_IOMMU) && defined(CONFIG_IRQ_REMAP) */
 
 #endif /* _ASM_X86_AMD_IOMMU_H */