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>

1 files changed, 39 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