iommu/amd: Implements irq_set_vcpu_affinity() hook to setup vapic mode for pass-through devices

This patch implements irq_set_vcpu_affinity() function to set up interrupt
remapping table entry with vapic mode for pass-through devices.

In case requirements for vapic mode are not met, it falls back to set up
the IRTE in legacy mode.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

include/linux/amd-iommu.h

@@ -22,6 +22,20 @@
 
 #include <linux/types.h>
 
+/*
+ * This is mainly used to communicate information back-and-forth
+ * between SVM and IOMMU for setting up and tearing down posted
+ * interrupt
+ */
+struct amd_iommu_pi_data {
+	u32 ga_tag;
+	u32 prev_ga_tag;
+	u64 base;
+	bool is_guest_mode;
+	struct vcpu_data *vcpu_data;
+	void *ir_data;
+};
+
 #ifdef CONFIG_AMD_IOMMU
 
 struct task_struct;