[PATCH] vdpa: Remove shadow CVQ command check

[PATCH] vdpa: Remove shadow CVQ command check

[Eugenio Pérez]

The guest will see undefined behavior if it issue not negotiate
commands, bit it is expected somehow.

Simplify code deleting this check.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 net/vhost-vdpa.c | 48 ------------------------------------------------
 1 file changed, 48 deletions(-)

diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index eebf29f5c1..6d64000202 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -461,48 +461,6 @@ static NetClientInfo net_vhost_vdpa_cvq_info = {
     .check_peer_type = vhost_vdpa_check_peer_type,
 };
 
-/**
- * Do not forward commands not supported by SVQ. Otherwise, the device could
- * accept it and qemu would not know how to update the device model.
- */
-static bool vhost_vdpa_net_cvq_validate_cmd(const void *out_buf, size_t len)
-{
-    struct virtio_net_ctrl_hdr ctrl;
-
-    if (unlikely(len < sizeof(ctrl))) {
-        qemu_log_mask(LOG_GUEST_ERROR,
-                      "%s: invalid legnth of out buffer %zu\n", __func__, len);
-        return false;
-    }
-
-    memcpy(&ctrl, out_buf, sizeof(ctrl));
-    switch (ctrl.class) {
-    case VIRTIO_NET_CTRL_MAC:
-        switch (ctrl.cmd) {
-        case VIRTIO_NET_CTRL_MAC_ADDR_SET:
-            return true;
-        default:
-            qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid mac cmd %u\n",
-                          __func__, ctrl.cmd);
-        };
-        break;
-    case VIRTIO_NET_CTRL_MQ:
-        switch (ctrl.cmd) {
-        case VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET:
-            return true;
-        default:
-            qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid mq cmd %u\n",
-                          __func__, ctrl.cmd);
-        };
-        break;
-    default:
-        qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid control class %u\n",
-                      __func__, ctrl.class);
-    };
-
-    return false;
-}
-
 /**
  * Validate and copy control virtqueue commands.
  *
@@ -526,16 +484,10 @@ static int vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,
         .iov_len = sizeof(status),
     };
     ssize_t dev_written = -EINVAL;
-    bool ok;
 
     out.iov_len = iov_to_buf(elem->out_sg, elem->out_num, 0,
                              s->cvq_cmd_out_buffer,
                              vhost_vdpa_net_cvq_cmd_len());
-    ok = vhost_vdpa_net_cvq_validate_cmd(s->cvq_cmd_out_buffer, out.iov_len);
-    if (unlikely(!ok)) {
-        goto out;
-    }
-
     dev_written = vhost_vdpa_net_cvq_add(s, out.iov_len, sizeof(status));
     if (unlikely(dev_written < 0)) {
         goto out;
-- 
2.31.1

Re: [PATCH] vdpa: Remove shadow CVQ command check

[Jason Wang]

On Thu, Oct 20, 2022 at 4:02 PM Eugenio Pérez <eperezma@redhat.com> wrote:
>
> The guest will see undefined behavior if it issue not negotiate
> commands, bit it is expected somehow.
>
> Simplify code deleting this check.
>
> Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> Acked-by: Jason Wang <jasowang@redhat.com>

Applied.

Thanks

> ---
>  net/vhost-vdpa.c | 48 ------------------------------------------------
>  1 file changed, 48 deletions(-)
>
> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> index eebf29f5c1..6d64000202 100644
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -461,48 +461,6 @@ static NetClientInfo net_vhost_vdpa_cvq_info = {
>      .check_peer_type = vhost_vdpa_check_peer_type,
>  };
>
> -/**
> - * Do not forward commands not supported by SVQ. Otherwise, the device could
> - * accept it and qemu would not know how to update the device model.
> - */
> -static bool vhost_vdpa_net_cvq_validate_cmd(const void *out_buf, size_t len)
> -{
> -    struct virtio_net_ctrl_hdr ctrl;
> -
> -    if (unlikely(len < sizeof(ctrl))) {
> -        qemu_log_mask(LOG_GUEST_ERROR,
> -                      "%s: invalid legnth of out buffer %zu\n", __func__, len);
> -        return false;
> -    }
> -
> -    memcpy(&ctrl, out_buf, sizeof(ctrl));
> -    switch (ctrl.class) {
> -    case VIRTIO_NET_CTRL_MAC:
> -        switch (ctrl.cmd) {
> -        case VIRTIO_NET_CTRL_MAC_ADDR_SET:
> -            return true;
> -        default:
> -            qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid mac cmd %u\n",
> -                          __func__, ctrl.cmd);
> -        };
> -        break;
> -    case VIRTIO_NET_CTRL_MQ:
> -        switch (ctrl.cmd) {
> -        case VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET:
> -            return true;
> -        default:
> -            qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid mq cmd %u\n",
> -                          __func__, ctrl.cmd);
> -        };
> -        break;
> -    default:
> -        qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid control class %u\n",
> -                      __func__, ctrl.class);
> -    };
> -
> -    return false;
> -}
> -
>  /**
>   * Validate and copy control virtqueue commands.
>   *
> @@ -526,16 +484,10 @@ static int vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,
>          .iov_len = sizeof(status),
>      };
>      ssize_t dev_written = -EINVAL;
> -    bool ok;
>
>      out.iov_len = iov_to_buf(elem->out_sg, elem->out_num, 0,
>                               s->cvq_cmd_out_buffer,
>                               vhost_vdpa_net_cvq_cmd_len());
> -    ok = vhost_vdpa_net_cvq_validate_cmd(s->cvq_cmd_out_buffer, out.iov_len);
> -    if (unlikely(!ok)) {
> -        goto out;
> -    }
> -
>      dev_written = vhost_vdpa_net_cvq_add(s, out.iov_len, sizeof(status));
>      if (unlikely(dev_written < 0)) {
>          goto out;
> --
> 2.31.1
>