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>
diff --git a/include/linux/amd-iommu.h b/include/linux/amd-iommu.h
index 465d096..d8d48ac 100644
--- a/include/linux/amd-iommu.h
+++ b/include/linux/amd-iommu.h
@@ -179,6 +179,9 @@
 /* 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 @@
 	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 */