Re: [PATCH 03/18] vhost_net: do not assume nvqs is always 2

[Eli Cohen]

On Mon, Jun 21, 2021 at 12:16:35PM +0800, Jason Wang wrote:
> This patch switches to initialize dev.nvqs from the VhostNetOptions
> instead of assuming it was 2. This is useful for implementing control
> virtqueue support which will be a single vhost_net structure with a
> single cvq.

Maybe worth mentioning in the changelog that nvqs is still set to 2 for
all users and this patch does not change functionality.

Reviewed-by: Eli Cohen <elic@nvidia.com>

> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
>  hw/net/vhost_net.c      | 2 +-
>  include/net/vhost_net.h | 1 +
>  net/tap.c               | 1 +
>  net/vhost-user.c        | 1 +
>  net/vhost-vdpa.c        | 1 +
>  5 files changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> index 6bd4184f96..ef1370bd92 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -163,9 +163,9 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
>          goto fail;
>      }
>      net->nc = options->net_backend;
> +    net->dev.nvqs = options->nvqs;
>  
>      net->dev.max_queues = 1;
> -    net->dev.nvqs = 2;
>      net->dev.vqs = net->vqs;
>  
>      if (backend_kernel) {
> diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h
> index 172b0051d8..fba40cf695 100644
> --- a/include/net/vhost_net.h
> +++ b/include/net/vhost_net.h
> @@ -14,6 +14,7 @@ typedef struct VhostNetOptions {
>      VhostBackendType backend_type;
>      NetClientState *net_backend;
>      uint32_t busyloop_timeout;
> +    unsigned int nvqs;
>      void *opaque;
>  } VhostNetOptions;
>  
> diff --git a/net/tap.c b/net/tap.c
> index f5686bbf77..f716be3e3f 100644
> --- a/net/tap.c
> +++ b/net/tap.c
> @@ -749,6 +749,7 @@ static void net_init_tap_one(const NetdevTapOptions *tap, 
> NetClientState *peer,
>              qemu_set_nonblock(vhostfd);
>          }
>          options.opaque = (void *)(uintptr_t)vhostfd;
> +        options.nvqs = 2;
>  
>          s->vhost_net = vhost_net_init(&options);
>          if (!s->vhost_net) {
> diff --git a/net/vhost-user.c b/net/vhost-user.c
> index ffbd94d944..b93918c5a4 100644
> --- a/net/vhost-user.c
> +++ b/net/vhost-user.c
> @@ -85,6 +85,7 @@ static int vhost_user_start(int queues, NetClientState 
> *ncs[],
>          options.net_backend = ncs[i];
>          options.opaque      = be;
>          options.busyloop_timeout = 0;
> +        options.nvqs = 2;
>          net = vhost_net_init(&options);
>          if (!net) {
>              error_report("failed to init vhost_net for queue %d", i);
> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> index 19187dce8c..18b45ad777 100644
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -105,6 +105,7 @@ static int vhost_vdpa_add(NetClientState *ncs, void *be)
>      options.net_backend = ncs;
>      options.opaque      = be;
>      options.busyloop_timeout = 0;
> +    options.nvqs = 2;
>  
>      net = vhost_net_init(&options);
>      if (!net) {
> -- 
> 2.25.1
>