[Qemu-devel] [RFC v2 1/4] vhost: propagate errors in vhost_device_iotlb_miss()

[Maxime Coquelin]

Some backends might want to know when things went wrong.

Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
---
 hw/virtio/vhost.c         | 15 ++++++++++-----
 include/hw/virtio/vhost.h |  2 +-
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 613494d..c490cf9 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -964,18 +964,20 @@ static int vhost_memory_region_lookup(struct vhost_dev 
*hdev,
     return -EFAULT;
 }
 
-void vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write)
+int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write)
 {
     IOMMUTLBEntry iotlb;
     uint64_t uaddr, len;
+    int ret = -EFAULT;
 
     rcu_read_lock();
 
     iotlb = address_space_get_iotlb_entry(dev->vdev->dma_as,
                                           iova, write);
     if (iotlb.target_as != NULL) {
-        if (vhost_memory_region_lookup(dev, iotlb.translated_addr,
-                                       &uaddr, &len)) {
+        ret = vhost_memory_region_lookup(dev, iotlb.translated_addr,
+                                         &uaddr, &len);
+        if (ret) {
             error_report("Fail to lookup the translated address "
                          "%"PRIx64, iotlb.translated_addr);
             goto out;
@@ -984,14 +986,17 @@ void vhost_device_iotlb_miss(struct vhost_dev *dev, 
uint64_t iova, int write)
         len = MIN(iotlb.addr_mask + 1, len);
         iova = iova & ~iotlb.addr_mask;
 
-        if (dev->vhost_ops->vhost_update_device_iotlb(dev, iova, uaddr,
-                                                      len, iotlb.perm)) {
+        ret = dev->vhost_ops->vhost_update_device_iotlb(dev, iova, uaddr,
+                                                      len, iotlb.perm);
+        if (ret) {
             error_report("Fail to update device iotlb");
             goto out;
         }
     }
 out:
     rcu_read_unlock();
+
+    return ret;
 }
 
 static int vhost_virtqueue_start(struct vhost_dev *dev,
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index a450321..467dc77 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -105,5 +105,5 @@ bool vhost_has_free_slot(void);
 int vhost_net_set_backend(struct vhost_dev *hdev,
                           struct vhost_vring_file *file);
 
-void vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write);
+int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write);
 #endif
-- 
2.9.3