Re: [PATCH 16/31] vhost: pass queue index to vhost_vq_get_addr

[Jason Wang]

在 2022/1/22 上午4:27, Eugenio Pérez 写道:
Doing that way allows vhost backend to know what address to return.

Signed-off-by: Eugenio Pérez <epere...@redhat.com>
---
  hw/virtio/vhost.c | 6 +++---
  1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 7b03efccec..64b955ba0c 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -798,9 +798,10 @@ static int vhost_virtqueue_set_addr(struct vhost_dev *dev,
                                      struct vhost_virtqueue *vq,
                                      unsigned idx, bool enable_log)
  {
-    struct vhost_vring_addr addr;
+    struct vhost_vring_addr addr = {
+        .index = idx,
+    };
      int r;
-    memset(&addr, 0, sizeof(struct vhost_vring_addr));
  
      if (dev->vhost_ops->vhost_vq_get_addr) {
          r = dev->vhost_ops->vhost_vq_get_addr(dev, &addr, vq);
@@ -813,7 +814,6 @@ static int vhost_virtqueue_set_addr(struct vhost_dev *dev,
          addr.avail_user_addr = (uint64_t)(unsigned long)vq->avail;
          addr.used_user_addr = (uint64_t)(unsigned long)vq->used;
      }


I'm a bit lost in the logic above, any reason we need call 
vhost_vq_get_addr() :) ?

Thanks


-    addr.index = idx;
      addr.log_guest_addr = vq->used_phys;
      addr.flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0;
      r = dev->vhost_ops->vhost_set_vring_addr(dev, &addr);