Re: [RFC PATCH v4 09/20] vdpa: Save call_fd in vhost-vdpa

[Jason Wang]

在 2021/10/1 下午3:05, Eugenio Pérez 写道:
We need to know it to switch to Shadow VirtQueue.

Signed-off-by: Eugenio Pérez <epere...@redhat.com>
---
  include/hw/virtio/vhost-vdpa.h | 2 ++
  hw/virtio/vhost-vdpa.c         | 5 +++++
  2 files changed, 7 insertions(+)

diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
index 48aae59d8e..fddac248b3 100644
--- a/include/hw/virtio/vhost-vdpa.h
+++ b/include/hw/virtio/vhost-vdpa.h
@@ -30,6 +30,8 @@ typedef struct vhost_vdpa {
      GPtrArray *shadow_vqs;
      struct vhost_dev *dev;
      QLIST_ENTRY(vhost_vdpa) entry;
+    /* File descriptor the device uses to call VM/SVQ */
+    int call_fd[VIRTIO_QUEUE_MAX];


Any reason we don't do this for kick_fd or why 
virtio_queue_get_guest_notifier() can't work here? Need a comment or 
commit log.

I think we need to have a consistent way to handle both kick and call fd.

Thanks


      VhostVDPAHostNotifier notifier[VIRTIO_QUEUE_MAX];
  } VhostVDPA;
  
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 36c954a779..57a857444a 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -652,7 +652,12 @@ static int vhost_vdpa_set_vring_kick(struct vhost_dev *dev,
  static int vhost_vdpa_set_vring_call(struct vhost_dev *dev,
                                         struct vhost_vring_file *file)
  {
+    struct vhost_vdpa *v = dev->opaque;
+    int vdpa_idx = vhost_vdpa_get_vq_index(dev, file->index);
+
      trace_vhost_vdpa_set_vring_call(dev, file->index, file->fd);
+
+    v->call_fd[vdpa_idx] = file->fd;
      return vhost_vdpa_call(dev, VHOST_SET_VRING_CALL, file);
  }