[PATCH v7 13/14] iommu/arm-smmu-v3: Report events that belong to devices attached to vIOMMU

[Nicolin Chen <nicolinc@nvidia.com>]

Aside from the IOPF framework, iommufd provides an additional pathway to
report hardware events, via the vEVENTQ of vIOMMU infrastructure.

Define an iommu_vevent_arm_smmuv3 uAPI structure, and report stage-1 events
in the threaded IRQ handler. Also, add another four event record types that
can be forwarded to a VM.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   |  7 +++
 include/uapi/linux/iommufd.h                  | 23 +++++++
 .../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c     | 17 ++++++
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   | 60 +++++++++++--------
 4 files changed, 82 insertions(+), 25 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index 85352504343b..c8574969e700 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -1067,6 +1067,7 @@ int arm_smmu_attach_prepare_vmaster(struct arm_smmu_attach_state *state,
 				    struct iommu_domain *domain);
 void arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state);
 void arm_smmu_master_clear_vmaster(struct arm_smmu_master *master);
+int arm_vmaster_report_event(struct arm_smmu_vmaster *vmaster, u64 *evt);
 #else
 #define arm_smmu_hw_info NULL
 #define arm_vsmmu_alloc NULL
@@ -1085,6 +1086,12 @@ arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state)
 static inline void arm_smmu_master_clear_vmaster(struct arm_smmu_master *master)
 {
 }
+
+static inline int arm_vmaster_report_event(struct arm_smmu_vmaster *vmaster,
+					   u64 *evt)
+{
+	return -EOPNOTSUPP;
+}
 #endif /* CONFIG_ARM_SMMU_V3_IOMMUFD */
 
 #endif /* _ARM_SMMU_V3_H */
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 2ade4839880d..5fc7e27804b7 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -1054,9 +1054,32 @@ struct iommufd_vevent_header {
 /**
  * enum iommu_veventq_type - Virtual Event Queue Type
  * @IOMMU_VEVENTQ_TYPE_DEFAULT: Reserved for future use
+ * @IOMMU_VEVENTQ_TYPE_ARM_SMMUV3: ARM SMMUv3 Virtual Event Queue
  */
 enum iommu_veventq_type {
 	IOMMU_VEVENTQ_TYPE_DEFAULT = 0,
+	IOMMU_VEVENTQ_TYPE_ARM_SMMUV3 = 1,
+};
+
+/**
+ * struct iommu_vevent_arm_smmuv3 - ARM SMMUv3 Virtual Event
+ *                                  (IOMMU_VEVENTQ_TYPE_ARM_SMMUV3)
+ * @evt: 256-bit ARM SMMUv3 Event record, little-endian.
+ *       Reported event records: (Refer to "7.3 Event records" in SMMUv3 HW Spec)
+ *       - 0x04 C_BAD_STE
+ *       - 0x06 F_STREAM_DISABLED
+ *       - 0x08 C_BAD_SUBSTREAMID
+ *       - 0x0a C_BAD_CD
+ *       - 0x10 F_TRANSLATION
+ *       - 0x11 F_ADDR_SIZE
+ *       - 0x12 F_ACCESS
+ *       - 0x13 F_PERMISSION
+ *
+ * StreamID field reports a virtual device ID. To receive a virtual event for a
+ * device, a vDEVICE must be allocated via IOMMU_VDEVICE_ALLOC.
+ */
+struct iommu_vevent_arm_smmuv3 {
+	__aligned_le64 evt[4];
 };
 
 /**
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
index 364d8469a480..42c7daf4c8c7 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
@@ -445,4 +445,21 @@ struct iommufd_viommu *arm_vsmmu_alloc(struct device *dev,
 	return &vsmmu->core;
 }
 
+int arm_vmaster_report_event(struct arm_smmu_vmaster *vmaster, u64 *evt)
+{
+	struct iommu_vevent_arm_smmuv3 vevt;
+	int i;
+
+	lockdep_assert_held(&vmaster->vsmmu->smmu->streams_mutex);
+
+	vevt.evt[0] = cpu_to_le64((evt[0] & ~EVTQ_0_SID) |
+				  FIELD_PREP(EVTQ_0_SID, vmaster->vsid));
+	for (i = 1; i < EVTQ_ENT_DWORDS; i++)
+		vevt.evt[i] = cpu_to_le64(evt[i]);
+
+	return iommufd_viommu_report_event(&vmaster->vsmmu->core,
+					   IOMMU_VEVENTQ_TYPE_ARM_SMMUV3, &vevt,
+					   sizeof(vevt));
+}
+
 MODULE_IMPORT_NS("IOMMUFD");
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 9e50bcee69d1..fdf8bba14303 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1813,8 +1813,8 @@ static void arm_smmu_decode_event(struct arm_smmu_device *smmu, u64 *raw,
 	mutex_unlock(&smmu->streams_mutex);
 }
 
-static int arm_smmu_handle_event(struct arm_smmu_device *smmu,
-			       struct arm_smmu_event *event)
+static int arm_smmu_handle_event(struct arm_smmu_device *smmu, u64 *evt,
+				 struct arm_smmu_event *event)
 {
 	int ret = 0;
 	u32 perm = 0;
@@ -1823,6 +1823,10 @@ static int arm_smmu_handle_event(struct arm_smmu_device *smmu,
 	struct iommu_fault *flt = &fault_evt.fault;
 
 	switch (event->id) {
+	case EVT_ID_BAD_STE_CONFIG:
+	case EVT_ID_STREAM_DISABLED_FAULT:
+	case EVT_ID_BAD_SUBSTREAMID_CONFIG:
+	case EVT_ID_BAD_CD_CONFIG:
 	case EVT_ID_TRANSLATION_FAULT:
 	case EVT_ID_ADDR_SIZE_FAULT:
 	case EVT_ID_ACCESS_FAULT:
@@ -1832,31 +1836,30 @@ static int arm_smmu_handle_event(struct arm_smmu_device *smmu,
 		return -EOPNOTSUPP;
 	}
 
-	if (!event->stall)
-		return -EOPNOTSUPP;
-
-	if (event->read)
-		perm |= IOMMU_FAULT_PERM_READ;
-	else
-		perm |= IOMMU_FAULT_PERM_WRITE;
+	if (event->stall) {
+		if (event->read)
+			perm |= IOMMU_FAULT_PERM_READ;
+		else
+			perm |= IOMMU_FAULT_PERM_WRITE;
 
-	if (event->instruction)
-		perm |= IOMMU_FAULT_PERM_EXEC;
+		if (event->instruction)
+			perm |= IOMMU_FAULT_PERM_EXEC;
 
-	if (event->privileged)
-		perm |= IOMMU_FAULT_PERM_PRIV;
+		if (event->privileged)
+			perm |= IOMMU_FAULT_PERM_PRIV;
 
-	flt->type = IOMMU_FAULT_PAGE_REQ;
-	flt->prm = (struct iommu_fault_page_request) {
-		.flags = IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE,
-		.grpid = event->stag,
-		.perm = perm,
-		.addr = event->iova,
-	};
+		flt->type = IOMMU_FAULT_PAGE_REQ;
+		flt->prm = (struct iommu_fault_page_request){
+			.flags = IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE,
+			.grpid = event->stag,
+			.perm = perm,
+			.addr = event->iova,
+		};
 
-	if (event->ssv) {
-		flt->prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PASID_VALID;
-		flt->prm.pasid = event->ssid;
+		if (event->ssv) {
+			flt->prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PASID_VALID;
+			flt->prm.pasid = event->ssid;
+		}
 	}
 
 	mutex_lock(&smmu->streams_mutex);
@@ -1866,7 +1869,14 @@ static int arm_smmu_handle_event(struct arm_smmu_device *smmu,
 		goto out_unlock;
 	}
 
-	ret = iommu_report_device_fault(master->dev, &fault_evt);
+	if (event->stall) {
+		ret = iommu_report_device_fault(master->dev, &fault_evt);
+	} else {
+		if (master->vmaster && !event->s2)
+			ret = arm_vmaster_report_event(master->vmaster, evt);
+		else
+			ret = -EFAULT; /* Unhandled events should be pinned */
+	}
 out_unlock:
 	mutex_unlock(&smmu->streams_mutex);
 	return ret;
@@ -1944,7 +1954,7 @@ static irqreturn_t arm_smmu_evtq_thread(int irq, void *dev)
 	do {
 		while (!queue_remove_raw(q, evt)) {
 			arm_smmu_decode_event(smmu, evt, &event);
-			if (arm_smmu_handle_event(smmu, &event))
+			if (arm_smmu_handle_event(smmu, evt, &event))
 				arm_smmu_dump_event(smmu, evt, &event, &rs);
 
 			put_device(event.dev);
-- 
2.43.0