Re: [Qemu-devel] [PATCH V2 2/2] tests/vhost-user: check vhost-user feature negotiation

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Jul 29, 2015 at 11:06:49PM +0300, Marcel Apfelbaum wrote:
> Check the backend receives all declared virtio features
> that are also supported by QEMU virtio.
> 
> Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
> ---
>  tests/vhost-user-test.c | 19 ++++++++++++++++---
>  1 file changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/tests/vhost-user-test.c b/tests/vhost-user-test.c
> index 228acb6..019b880 100644
> --- a/tests/vhost-user-test.c
> +++ b/tests/vhost-user-test.c
> @@ -17,6 +17,7 @@
>  #include "sysemu/sysemu.h"
>  
>  #include <linux/vhost.h>
> +#include <linux/virtio_net.h>
>  #include <sys/mman.h>
>  #include <sys/vfs.h>
>  #include <qemu/sockets.h>
> @@ -297,14 +298,26 @@ static void chr_read(void *opaque, const uint8_t *buf, int size)
>          /* send back features to qemu */
>          msg.flags |= VHOST_USER_REPLY_MASK;
>          msg.size = sizeof(m.u64);
> -        msg.u64 = 0x1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
> +        msg.u64 = (0x1ULL << VHOST_USER_F_PROTOCOL_FEATURES) |
> +                  (0x1ULL << VIRTIO_F_ANY_LAYOUT) |
> +                  (0x1ULL << VIRTIO_F_VERSION_1)  |
> +                  (0x1ULL << VIRTIO_NET_F_MRG_RXBUF) |
> +                  (0x1ULL << VIRTIO_NET_F_MQ);
>          p = (uint8_t *) &msg;
>          qemu_chr_fe_write_all(chr, p, VHOST_USER_HDR_SIZE + msg.size);
>          break;
>  

No, this mixes protocol features and virtio features.
It's not what was intended.

>      case VHOST_USER_SET_FEATURES:
> -	g_assert_cmpint(msg.u64 & (0x1ULL << VHOST_USER_F_PROTOCOL_FEATURES),
> -			!=, 0ULL);
> +        g_assert_cmpint(msg.u64 & (0x1ULL << VHOST_USER_F_PROTOCOL_FEATURES),
> +            !=, 0ULL);
> +        g_assert_cmpint(msg.u64 & (0x1ULL << VIRTIO_F_ANY_LAYOUT),
> +            !=, 0ULL);
> +        g_assert_cmpint(msg.u64 & (0x1ULL << VIRTIO_F_VERSION_1),
> +            !=, 0ULL);
> +        g_assert_cmpint(msg.u64 & (0x1ULL << VIRTIO_NET_F_MRG_RXBUF),
> +            !=, 0ULL);
> +        g_assert_cmpint(msg.u64 & (0x1ULL << VIRTIO_NET_F_MQ),
> +            !=, 0ULL);
>          break;
>  
>      case VHOST_USER_GET_PROTOCOL_FEATURES:
> -- 
> 2.1.0