vhost-user: Don't pass file descriptor for VHOST_USER_REM_MEM_REG

The spec clarifies now that QEMU should not send a file descriptor in a
request to remove a memory region. Change it accordingly.

For libvhost-user, this is a bug fix that makes it compatible with
rust-vmm's implementation that doesn't send a file descriptor. Keep
accepting, but ignoring a file descriptor for compatibility with older
QEMU versions.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20220407133657.155281-4-kwolf@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index a80315ecfc..2d434ff0bc 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -751,7 +751,7 @@ static int send_remove_regions(struct vhost_dev *dev,
             vhost_user_fill_msg_region(&region_buffer, shadow_reg, 0);
             msg->payload.mem_reg.region = region_buffer;
 
-            ret = vhost_user_write(dev, msg, &fd, 1);
+            ret = vhost_user_write(dev, msg, NULL, 0);
             if (ret < 0) {
                 return ret;
             }