Re: [Qemu-devel] [PATCH v2 3/5] vhost-user-test: add multiple queue test

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

On Wed, Oct 21, 2015 at 05:07:16PM +0800, Yuanhan Liu wrote:
> Setting VHOST_USER_PROTOCOL_F_MQ protocol feature bit to claim that we
> support MQ feature, and simply assume we support 0xff queue pairs at most.
> 
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
> 
> ---
> v2: use macro to define the max queues we support

Well this doesn't buy us anything - it's only used in
one place. I really meant the "2" which is the actual
# of queues.


> ---
>  tests/vhost-user-test.c | 21 +++++++++++++++++++--
>  1 file changed, 19 insertions(+), 2 deletions(-)
> 
> diff --git a/tests/vhost-user-test.c b/tests/vhost-user-test.c
> index f181391..8162e64 100644
> --- a/tests/vhost-user-test.c
> +++ b/tests/vhost-user-test.c
> @@ -29,11 +29,14 @@
>  #define HAVE_MONOTONIC_TIME
>  #endif
>  
> +#define MAX_QUEUS       0xff
> +
>  #define QEMU_CMD_ACCEL  " -machine accel=tcg"
>  #define QEMU_CMD_MEM    " -m 512 -object memory-backend-file,id=mem,size=512M,"\
>                          "mem-path=%s,share=on -numa node,memdev=mem"
>  #define QEMU_CMD_CHR    " -chardev socket,id=chr0,path=%s"
> -#define QEMU_CMD_NETDEV " -netdev vhost-user,id=net0,chardev=chr0,vhostforce"
> +#define QEMU_CMD_NETDEV " -netdev vhost-user,id=net0,chardev=chr0,vhostforce," \
> +                        "queues=2"
>  #define QEMU_CMD_NET    " -device virtio-net-pci,netdev=net0 "
>  #define QEMU_CMD_ROM    " -option-rom ../pc-bios/pxe-virtio.rom"
>  
> @@ -48,6 +51,8 @@
>  
>  #define VHOST_USER_F_PROTOCOL_FEATURES 30
>  
> +#define VHOST_USER_PROTOCOL_F_MQ 0
> +
>  typedef enum VhostUserRequest {
>      VHOST_USER_NONE = 0,
>      VHOST_USER_GET_FEATURES = 1,
> @@ -66,6 +71,8 @@ typedef enum VhostUserRequest {
>      VHOST_USER_SET_VRING_ERR = 14,
>      VHOST_USER_GET_PROTOCOL_FEATURES = 15,
>      VHOST_USER_SET_PROTOCOL_FEATURES = 16,
> +    VHOST_USER_GET_QUEUE_NUM = 17,
> +    VHOST_USER_SET_VRING_ENABLE = 18,
>      VHOST_USER_MAX
>  } VhostUserRequest;
>  
> @@ -232,7 +239,7 @@ 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 = 0;
> +        msg.u64 = (1ULL << VHOST_USER_PROTOCOL_F_MQ);
>          p = (uint8_t *) &msg;
>          qemu_chr_fe_write_all(chr, p, VHOST_USER_HDR_SIZE + msg.size);
>          break;
> @@ -266,6 +273,16 @@ static void chr_read(void *opaque, const uint8_t *buf, int size)
>           */
>          qemu_set_nonblock(fd);
>          break;
> +
> +    case VHOST_USER_GET_QUEUE_NUM:
> +         /* send back the number of queues we support (let it be 2) to qemu */
> +        msg.flags |= VHOST_USER_REPLY_MASK;
> +        msg.size = sizeof(m.u64);
> +        msg.u64 = MAX_QUEUS;
> +        p = (uint8_t *) &msg;
> +        qemu_chr_fe_write_all(chr, p, VHOST_USER_HDR_SIZE + msg.size);
> +        break;
> +
>      default:
>          break;
>      }
> -- 
> 1.9.0