diff mbox series

[v13,06/10] virtio-iommu: Implement fault reporting

Message ID 20200125171955.12825-7-eric.auger@redhat.com
State New
Headers show
Series VIRTIO-IOMMU device | expand

Commit Message

Eric Auger Jan. 25, 2020, 5:19 p.m. UTC 
The event queue allows to report asynchronous errors.
The translate function now injects faults when relevant.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---
v12 -> v13:
- return on virtio_error()

v11 -> v12:
- reporting the addr associated with the fault and set the
  VIRTIO_IOMMU_FAULT_F_ADDRESS flag.
- added cpu_to_le<n>

v10 -> v11:
- change a virtio_error into an error_report_once
  (no buffer available for output faults)
---
 hw/virtio/trace-events   |  1 +
 hw/virtio/virtio-iommu.c | 73 +++++++++++++++++++++++++++++++++++++---
 2 files changed, 69 insertions(+), 5 deletions(-)

Comments

Peter Xu Feb. 3, 2020, 1:55 p.m. UTC | #1 
On Sat, Jan 25, 2020 at 06:19:51PM +0100, Eric Auger wrote:

[...]

> +static void virtio_iommu_report_fault(VirtIOIOMMU *viommu, uint8_t reason,
> +                                      int flags, uint32_t endpoint,
> +                                      uint64_t address)
> +{
> +    VirtIODevice *vdev = &viommu->parent_obj;
> +    VirtQueue *vq = viommu->event_vq;
> +    struct virtio_iommu_fault fault;
> +    VirtQueueElement *elem;
> +    size_t sz;
> +
> +    memset(&fault, 0, sizeof(fault));
> +    fault.reason = reason;
> +    fault.flags = cpu_to_le32(flags);
> +    fault.endpoint = cpu_to_le32(endpoint);
> +    fault.address = cpu_to_le64(address);
> +
> +    for (;;) {
> +        elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
> +
> +        if (!elem) {
> +            error_report_once(
> +                "no buffer available in event queue to report event");
> +            return;
> +        }
> +
> +        if (iov_size(elem->in_sg, elem->in_num) < sizeof(fault)) {
> +            virtio_error(vdev, "error buffer of wrong size");
> +            virtqueue_detach_element(vq, elem, 0);
> +            g_free(elem);
> +            return;
> +        }
> +        break;

This for loop is not needed any more?  Other than that:

Reviewed-by: Peter Xu <peterx@redhat.com>
Eric Auger Feb. 3, 2020, 3:01 p.m. UTC | #2 
Hi Peter,

On 2/3/20 2:55 PM, Peter Xu wrote:
> On Sat, Jan 25, 2020 at 06:19:51PM +0100, Eric Auger wrote:
> 
> [...]
> 
>> +static void virtio_iommu_report_fault(VirtIOIOMMU *viommu, uint8_t reason,
>> +                                      int flags, uint32_t endpoint,
>> +                                      uint64_t address)
>> +{
>> +    VirtIODevice *vdev = &viommu->parent_obj;
>> +    VirtQueue *vq = viommu->event_vq;
>> +    struct virtio_iommu_fault fault;
>> +    VirtQueueElement *elem;
>> +    size_t sz;
>> +
>> +    memset(&fault, 0, sizeof(fault));
>> +    fault.reason = reason;
>> +    fault.flags = cpu_to_le32(flags);
>> +    fault.endpoint = cpu_to_le32(endpoint);
>> +    fault.address = cpu_to_le64(address);
>> +
>> +    for (;;) {
>> +        elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
>> +
>> +        if (!elem) {
>> +            error_report_once(
>> +                "no buffer available in event queue to report event");
>> +            return;
>> +        }
>> +
>> +        if (iov_size(elem->in_sg, elem->in_num) < sizeof(fault)) {
>> +            virtio_error(vdev, "error buffer of wrong size");
>> +            virtqueue_detach_element(vq, elem, 0);
>> +            g_free(elem);
>> +            return;
>> +        }
>> +        break;
> 
> This for loop is not needed any more?  Other than that:
hum yes indeed.
> 
> Reviewed-by: Peter Xu <peterx@redhat.com>

Thanks!

Eric
>
diff mbox series

Patch

diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index 095aa8b509..e83500bee9 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -72,3 +72,4 @@  virtio_iommu_put_endpoint(uint32_t ep_id) "Free endpoint=%d"
 virtio_iommu_get_domain(uint32_t domain_id) "Alloc domain=%d"
 virtio_iommu_put_domain(uint32_t domain_id) "Free domain=%d"
 virtio_iommu_translate_out(uint64_t virt_addr, uint64_t phys_addr, uint32_t sid) "0x%"PRIx64" -> 0x%"PRIx64 " for sid=%d"
+virtio_iommu_report_fault(uint8_t reason, uint32_t flags, uint32_t endpoint, uint64_t addr) "FAULT reason=%d flags=%d endpoint=%d address =0x%"PRIx64
diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
index cc0715284f..ec8f42e167 100644
--- a/hw/virtio/virtio-iommu.c
+++ b/hw/virtio/virtio-iommu.c
@@ -472,6 +472,51 @@  out:
     }
 }
 
+static void virtio_iommu_report_fault(VirtIOIOMMU *viommu, uint8_t reason,
+                                      int flags, uint32_t endpoint,
+                                      uint64_t address)
+{
+    VirtIODevice *vdev = &viommu->parent_obj;
+    VirtQueue *vq = viommu->event_vq;
+    struct virtio_iommu_fault fault;
+    VirtQueueElement *elem;
+    size_t sz;
+
+    memset(&fault, 0, sizeof(fault));
+    fault.reason = reason;
+    fault.flags = cpu_to_le32(flags);
+    fault.endpoint = cpu_to_le32(endpoint);
+    fault.address = cpu_to_le64(address);
+
+    for (;;) {
+        elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
+
+        if (!elem) {
+            error_report_once(
+                "no buffer available in event queue to report event");
+            return;
+        }
+
+        if (iov_size(elem->in_sg, elem->in_num) < sizeof(fault)) {
+            virtio_error(vdev, "error buffer of wrong size");
+            virtqueue_detach_element(vq, elem, 0);
+            g_free(elem);
+            return;
+        }
+        break;
+    }
+    /* we have a buffer to fill in */
+    sz = iov_from_buf(elem->in_sg, elem->in_num, 0,
+                      &fault, sizeof(fault));
+    assert(sz == sizeof(fault));
+
+    trace_virtio_iommu_report_fault(reason, flags, endpoint, address);
+    virtqueue_push(vq, elem, sz);
+    virtio_notify(vdev, vq);
+    g_free(elem);
+
+}
+
 static IOMMUTLBEntry virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr,
                                             IOMMUAccessFlags flag,
                                             int iommu_idx)
@@ -480,9 +525,10 @@  static IOMMUTLBEntry virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr,
     VirtIOIOMMUInterval interval, *mapping_key;
     VirtIOIOMMUMapping *mapping_value;
     VirtIOIOMMU *s = sdev->viommu;
+    bool read_fault, write_fault;
     VirtIOIOMMUEndpoint *ep;
+    uint32_t sid, flags;
     bool bypass_allowed;
-    uint32_t sid;
     bool found;
 
     interval.low = addr;
@@ -508,6 +554,9 @@  static IOMMUTLBEntry virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr,
     if (!ep) {
         if (!bypass_allowed) {
             error_report_once("%s sid=%d is not known!!", __func__, sid);
+            virtio_iommu_report_fault(s, VIRTIO_IOMMU_FAULT_R_UNKNOWN,
+                                      VIRTIO_IOMMU_FAULT_F_ADDRESS,
+                                      sid, addr);
         } else {
             entry.perm = flag;
         }
@@ -519,6 +568,9 @@  static IOMMUTLBEntry virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr,
             error_report_once("%s %02x:%02x.%01x not attached to any domain",
                               __func__, PCI_BUS_NUM(sid),
                               PCI_SLOT(sid), PCI_FUNC(sid));
+            virtio_iommu_report_fault(s, VIRTIO_IOMMU_FAULT_R_DOMAIN,
+                                      VIRTIO_IOMMU_FAULT_F_ADDRESS,
+                                      sid, addr);
         } else {
             entry.perm = flag;
         }
@@ -531,15 +583,26 @@  static IOMMUTLBEntry virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr,
     if (!found) {
         error_report_once("%s no mapping for 0x%"PRIx64" for sid=%d",
                           __func__, addr, sid);
+        virtio_iommu_report_fault(s, VIRTIO_IOMMU_FAULT_R_MAPPING,
+                                  VIRTIO_IOMMU_FAULT_F_ADDRESS,
+                                  sid, addr);
         goto unlock;
     }
 
-    if (((flag & IOMMU_RO) &&
-            !(mapping_value->flags & VIRTIO_IOMMU_MAP_F_READ)) ||
-        ((flag & IOMMU_WO) &&
-            !(mapping_value->flags & VIRTIO_IOMMU_MAP_F_WRITE))) {
+    read_fault = (flag & IOMMU_RO) &&
+                    !(mapping_value->flags & VIRTIO_IOMMU_MAP_F_READ);
+    write_fault = (flag & IOMMU_WO) &&
+                    !(mapping_value->flags & VIRTIO_IOMMU_MAP_F_WRITE);
+
+    flags = read_fault ? VIRTIO_IOMMU_FAULT_F_READ : 0;
+    flags |= write_fault ? VIRTIO_IOMMU_FAULT_F_WRITE : 0;
+    if (flags) {
         error_report_once("%s permission error on 0x%"PRIx64"(%d): allowed=%d",
                           __func__, addr, flag, mapping_value->flags);
+        flags |= VIRTIO_IOMMU_FAULT_F_ADDRESS;
+        virtio_iommu_report_fault(s, VIRTIO_IOMMU_FAULT_R_MAPPING,
+                                  flags | VIRTIO_IOMMU_FAULT_F_ADDRESS,
+                                  sid, addr);
         goto unlock;
     }
     entry.translated_addr = addr - mapping_key->low + mapping_value->phys_addr;