Re: [Qemu-devel] [PATCH 4/4] libvhost-user: Support VHOST_USER_SET_SLAVE_REQ_FD

[Marc-André Lureau]

On Mon, Oct 2, 2017 at 9:15 PM, Dr. David Alan Gilbert (git)
<address@hidden> wrote:
> From: "Dr. David Alan Gilbert" <address@hidden>
>
> Allow the qemu to pass us a slave fd.  We don't do anything
> with it yet.
>
> Signed-off-by: Dr. David Alan Gilbert <address@hidden>

Reviewed-by: Marc-André Lureau <address@hidden>


> ---
>  contrib/libvhost-user/libvhost-user.c | 27 ++++++++++++++++++++++++++-
>  contrib/libvhost-user/libvhost-user.h |  1 +
>  2 files changed, 27 insertions(+), 1 deletion(-)
>
> diff --git a/contrib/libvhost-user/libvhost-user.c 
> b/contrib/libvhost-user/libvhost-user.c
> index 1901311a70..756b60c4b3 100644
> --- a/contrib/libvhost-user/libvhost-user.c
> +++ b/contrib/libvhost-user/libvhost-user.c
> @@ -703,7 +703,8 @@ vu_set_vring_err_exec(VuDev *dev, VhostUserMsg *vmsg)
>  static bool
>  vu_get_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg)
>  {
> -    uint64_t features = 1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD;
> +    uint64_t features = 1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD |
> +                        1ULL << VHOST_USER_PROTOCOL_F_SLAVE_REQ;
>
>      if (dev->iface->get_protocol_features) {
>          features |= dev->iface->get_protocol_features(dev);
> @@ -757,6 +758,23 @@ vu_set_vring_enable_exec(VuDev *dev, VhostUserMsg *vmsg)
>  }
>
>  static bool
> +vu_set_slave_req_fd(VuDev *dev, VhostUserMsg *vmsg)
> +{
> +    if (vmsg->fd_num != 1) {
> +        vu_panic(dev, "Invalid slave_req_fd message (%d fd's)", 
> vmsg->fd_num);
> +        return false;
> +    }
> +
> +    if (dev->slave_fd != -1) {
> +        close(dev->slave_fd);
> +    }
> +    dev->slave_fd = vmsg->fds[0];
> +    DPRINT("Got slave_fd: %d\n", vmsg->fds[0]);
> +
> +    return false;
> +}
> +
> +static bool
>  vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
>  {
>      int do_reply = 0;
> @@ -819,6 +837,8 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
>          return vu_get_queue_num_exec(dev, vmsg);
>      case VHOST_USER_SET_VRING_ENABLE:
>          return vu_set_vring_enable_exec(dev, vmsg);
> +    case VHOST_USER_SET_SLAVE_REQ_FD:
> +        return vu_set_slave_req_fd(dev, vmsg);
>      case VHOST_USER_NONE:
>          break;
>      default:
> @@ -892,6 +912,10 @@ vu_deinit(VuDev *dev)
>
>
>      vu_close_log(dev);
> +    if (dev->slave_fd != -1) {
> +        close(dev->slave_fd);
> +        dev->slave_fd = -1;
> +    }
>
>      if (dev->sock != -1) {
>          close(dev->sock);
> @@ -922,6 +946,7 @@ vu_init(VuDev *dev,
>      dev->remove_watch = remove_watch;
>      dev->iface = iface;
>      dev->log_call_fd = -1;
> +    dev->slave_fd = -1;
>      for (i = 0; i < VHOST_MAX_NR_VIRTQUEUE; i++) {
>          dev->vq[i] = (VuVirtq) {
>              .call_fd = -1, .kick_fd = -1, .err_fd = -1,
> diff --git a/contrib/libvhost-user/libvhost-user.h 
> b/contrib/libvhost-user/libvhost-user.h
> index c2fc6da720..7534e97f92 100644
> --- a/contrib/libvhost-user/libvhost-user.h
> +++ b/contrib/libvhost-user/libvhost-user.h
> @@ -226,6 +226,7 @@ struct VuDev {
>      VuDevRegion regions[VHOST_MEMORY_MAX_NREGIONS];
>      VuVirtq vq[VHOST_MAX_NR_VIRTQUEUE];
>      int log_call_fd;
> +    int slave_fd;
>      uint64_t log_size;
>      uint8_t *log_table;
>      uint64_t features;
> --
> 2.13.6
>
>



-- 
Marc-André Lureau