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.

Signed-off-by: Nicolin Chen <nicol...@nvidia.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   |  7 +++
 include/uapi/linux/iommufd.h                  | 15 +++++
 .../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c     | 15 +++++
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   | 58 +++++++++++--------
 4 files changed, 70 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 4435ad7db776..d24c3d8ee397 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -1066,6 +1066,7 @@ struct iommufd_viommu *arm_vsmmu_alloc(struct device *dev,
 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);
+int arm_vmaster_report_event(struct arm_smmu_vmaster *vmaster, u64 *evt);
 #else
 #define arm_smmu_hw_info NULL
 #define arm_vsmmu_alloc NULL
@@ -1081,6 +1082,12 @@ static inline void
 arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state)
 {
 }
+
+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 08cbc6bc3725..cbc30eff302d 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -1058,9 +1058,24 @@ 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.
+ *       (Refer to "7.3 Event records" in SMMUv3 HW Spec)
+ *
+ * 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 98138088fd16..ceeed907a714 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
@@ -443,4 +443,19 @@ 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;
+
+       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 686c171dd273..59fbc342a095 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1812,8 +1812,8 @@ 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;
@@ -1831,31 +1831,30 @@ 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);
@@ -1865,7 +1864,16 @@ 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 {
+               down_read(&master->vmaster_rwsem);
+               if (master->vmaster && !event->s2)
+                       ret = arm_vmaster_report_event(master->vmaster, evt);
+               else
+                       ret = -EFAULT; /* Unhandled events should be pinned */
+               up_read(&master->vmaster_rwsem);
+       }
 out_unlock:
        mutex_unlock(&smmu->streams_mutex);
        return ret;
@@ -1943,7 +1951,7 @@ 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


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