[PART2 PATCH v5 07/12] 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       | 50 +++++++++++++++++++++++++++++++++++++++++
 drivers/iommu/amd_iommu_types.h |  1 +
 include/linux/amd-iommu.h       | 22 ++++++++++++++++++
 3 files changed, 73 insertions(+)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 861d723..e6a271c 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -4458,4 +4458,54 @@ 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 cpu, u64 base, bool is_run,
+			struct amd_iommu_pi_data *pi)
+{
+	struct amd_ir_data *ir_data = pi->ir_data;
+	int devid = ir_data->irq_2_irte.devid;
+	struct irte_ga *irte = (struct irte_ga *) ir_data->entry;
+	struct amd_iommu *iommu;
+
+	if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir))
+		return 0;
+
+	iommu = amd_iommu_rlookup_table[devid];
+	if (!iommu)
+		return -ENODEV;
+
+	if (!irte->lo.fields_vapic.guest_mode)
+		return 0;
+
+	update_irte_ga((struct irte_ga *)ir_data->ref, devid, base, cpu, is_run);
+	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 947c74a..623ee9e 100644
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -824,6 +824,7 @@ 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 465d096..2094d90 100644
--- a/include/linux/amd-iommu.h
+++ b/include/linux/amd-iommu.h
@@ -22,6 +22,19 @@
 
 #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 {
+	struct list_head node;		/* For per-vcpu pi_list */
+	u32 ga_tag;
+	bool is_guest_mode;
+	struct vcpu_data *vcpu_data;
+	struct amd_ir_data *ir_data;
+};
+
 #ifdef CONFIG_AMD_IOMMU
 
 struct task_struct;
@@ -179,6 +192,9 @@ 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(u32 cpu, u64 base, bool is_run, struct amd_iommu_pi_data *pi);
+
 #else /* defined(CONFIG_AMD_IOMMU) && defined(CONFIG_IRQ_REMAP) */
 
 static inline int
@@ -187,6 +203,12 @@ amd_iommu_register_ga_log_notifier(int (*notifier)(u32))
 	return 0;
 }
 
+static inline int
+amd_iommu_update_ga(u32 cpu, u64 base, bool is_run, struct amd_iommu_pi_data *pi)
+{
+	return 0;
+}
+
 #endif /* defined(CONFIG_AMD_IOMMU) && defined(CONFIG_IRQ_REMAP) */
 
 #endif /* _ASM_X86_AMD_IOMMU_H */
-- 
1.9.1