Re: [Qemu-devel] [PATCH v6 4/8] Add vhost-user skeleton

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

On Mon, Jan 13, 2014 at 03:25:15PM +0100, Antonios Motakis wrote:
> Add empty vhost_call, init and cleanup for the vhost-user backend.
> 
> Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
> Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>


I think the refactoring of VhostNetOptions should be in a separate
patch.

> ---
>  hw/net/vhost_net.c                | 57 ++++++++++++++++++++++-----------------
>  hw/virtio/vhost-backend.c         | 35 ++++++++++++++++++++++++
>  include/hw/virtio/vhost-backend.h |  3 ++-
>  include/net/vhost_net.h           | 13 ++++++++-
>  net/tap.c                         | 16 ++++++-----
>  5 files changed, 91 insertions(+), 33 deletions(-)
> 
> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> index 4aaf0b4..3614e6c 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -91,43 +91,51 @@ static int vhost_net_get_fd(NetClientState *backend)
>      }
>  }
>  
> -struct vhost_net *vhost_net_init(NetClientState *backend, int devfd,
> -                                 bool force)
> +struct vhost_net *vhost_net_init(VhostNetOptions *options)
>  {
> -    int r;
> +    int r = -1;
>      struct vhost_net *net = g_malloc(sizeof *net);
> -    if (!backend) {
> -        fprintf(stderr, "vhost-net requires backend to be setup\n");
> +
> +    if (!options->net_backend) {
> +        fprintf(stderr, "vhost-net requires net backend to be setup\n");
>          goto fail;
>      }
> -    r = vhost_net_get_fd(backend);
> -    if (r < 0) {
> -        goto fail;
> +
> +    if (options->backend_type == VHOST_BACKEND_TYPE_KERNEL) {
> +        r = vhost_net_get_fd(options->net_backend);
> +        if (r < 0) {
> +            goto fail;
> +        }
> +
> +        net->dev.backend_features =
> +                tap_has_vnet_hdr(options->net_backend) ? 0 :
> +                                (1 << VHOST_NET_F_VIRTIO_NET_HDR);
>      }
> -    net->nc = backend;
> -    net->dev.backend_features = tap_has_vnet_hdr(backend) ? 0 :
> -        (1 << VHOST_NET_F_VIRTIO_NET_HDR);
> +
> +    net->nc = options->net_backend;
>      net->backend = r;
>  
>      net->dev.nvqs = 2;
>      net->dev.vqs = net->vqs;
>  
> -    r = vhost_dev_init(&net->dev, devfd, "/dev/vhost-net",
> -                       VHOST_BACKEND_TYPE_KERNEL, force);
> +    r = vhost_dev_init(&net->dev, options->devfd, options->devpath,
> +                       options->backend_type, options->force);
>      if (r < 0) {
>          goto fail;
>      }
> -    if (!tap_has_vnet_hdr_len(backend,
> -                              sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
> -        net->dev.features &= ~(1 << VIRTIO_NET_F_MRG_RXBUF);
> -    }
> -    if (~net->dev.features & net->dev.backend_features) {
> -        fprintf(stderr, "vhost lacks feature mask %" PRIu64 " for backend\n",
> -                (uint64_t)(~net->dev.features & net->dev.backend_features));
> -        vhost_dev_cleanup(&net->dev);
> -        goto fail;
> +    if (options->backend_type == VHOST_BACKEND_TYPE_KERNEL) {
> +        if (!tap_has_vnet_hdr_len(options->net_backend,
> +                        sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
> +            net->dev.features &= ~(1 << VIRTIO_NET_F_MRG_RXBUF);
> +        }
> +        if (~net->dev.features & net->dev.backend_features) {
> +            fprintf(stderr, "vhost lacks feature mask %" PRIu64
> +                   " for backend\n",
> +                   (uint64_t)(~net->dev.features & net->dev.backend_features));
> +            vhost_dev_cleanup(&net->dev);
> +            goto fail;
> +        }
>      }
> -
>      /* Set sane init value. Override when guest acks. */
>      vhost_net_ack_features(net, 0);
>      return net;
> @@ -286,8 +294,7 @@ void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
>      vhost_virtqueue_mask(&net->dev, dev, idx, mask);
>  }
>  #else
> -struct vhost_net *vhost_net_init(NetClientState *backend, int devfd,
> -                                 bool force)
> +struct vhost_net *vhost_net_init(VhostNetOptions *options)
>  {
>      error_report("vhost-net support is not compiled in");
>      return NULL;
> diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
> index c0f11e4..1d83e1d 100644
> --- a/hw/virtio/vhost-backend.c
> +++ b/hw/virtio/vhost-backend.c
> @@ -16,6 +16,38 @@
>  #include <unistd.h>
>  #include <sys/ioctl.h>
>  
> +static int vhost_user_call(struct vhost_dev *dev, unsigned long int request,
> +        void *arg)
> +{
> +    assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
> +    error_report("vhost_user_call not implemented\n");
> +
> +    return -1;
> +}
> +
> +static int vhost_user_init(struct vhost_dev *dev, const char *devpath)
> +{
> +    assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
> +    error_report("vhost_user_init not implemented\n");
> +
> +    return -1;
> +}
> +
> +static int vhost_user_cleanup(struct vhost_dev *dev)
> +{
> +    assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
> +    error_report("vhost_user_cleanup not implemented\n");
> +
> +    return -1;
> +}
> +
> +static const VhostOps user_ops = {
> +        .backend_type = VHOST_BACKEND_TYPE_USER,
> +        .vhost_call = vhost_user_call,
> +        .vhost_backend_init = vhost_user_init,
> +        .vhost_backend_cleanup = vhost_user_cleanup
> +};
> +
>  static int vhost_kernel_call(struct vhost_dev *dev, unsigned long int request,
>                               void *arg)
>  {
> @@ -56,6 +88,9 @@ int vhost_set_backend_type(struct vhost_dev *dev, VhostBackendType backend_type)
>      case VHOST_BACKEND_TYPE_KERNEL:
>          dev->vhost_ops = &kernel_ops;
>          break;
> +    case VHOST_BACKEND_TYPE_USER:
> +        dev->vhost_ops = &user_ops;
> +        break;
>      default:
>          error_report("Unknown vhost backend type\n");
>          r = -1;
> diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
> index 93fc55b..ef87ffa 100644
> --- a/include/hw/virtio/vhost-backend.h
> +++ b/include/hw/virtio/vhost-backend.h
> @@ -14,7 +14,8 @@
>  typedef enum VhostBackendType {
>      VHOST_BACKEND_TYPE_NONE = 0,
>      VHOST_BACKEND_TYPE_KERNEL = 1,
> -    VHOST_BACKEND_TYPE_MAX = 2,
> +    VHOST_BACKEND_TYPE_USER = 2,
> +    VHOST_BACKEND_TYPE_MAX = 3,
>  } VhostBackendType;
>  
>  struct vhost_dev;
> diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h
> index 2d936bb..1169562 100644
> --- a/include/net/vhost_net.h
> +++ b/include/net/vhost_net.h
> @@ -2,11 +2,22 @@
>  #define VHOST_NET_H
>  
>  #include "net/net.h"
> +#include "hw/virtio/vhost-backend.h"
> +
> +#define VHOST_NET_DEFAULT_PATH  "/dev/vhost-net"
>  
>  struct vhost_net;
>  typedef struct vhost_net VHostNetState;
>  
> -VHostNetState *vhost_net_init(NetClientState *backend, int devfd, bool force);
> +typedef struct VhostNetOptions {
> +    VhostBackendType backend_type;
> +    NetClientState *net_backend;
> +    const char *devpath;
> +    int devfd;
> +    bool force;
> +} VhostNetOptions;
> +
> +struct vhost_net *vhost_net_init(VhostNetOptions *options);
>  
>  bool vhost_net_query(VHostNetState *net, VirtIODevice *dev);
>  int vhost_net_start(VirtIODevice *dev, NetClientState *ncs, int total_queues);
> diff --git a/net/tap.c b/net/tap.c
> index 39c1cda..776dbc4 100644
> --- a/net/tap.c
> +++ b/net/tap.c
> @@ -621,19 +621,23 @@ static int net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
>  
>      if (tap->has_vhost ? tap->vhost :
>          vhostfdname || (tap->has_vhostforce && tap->vhostforce)) {
> -        int vhostfd;
> +        VhostNetOptions options;
> +
> +        options.backend_type = VHOST_BACKEND_TYPE_KERNEL;
> +        options.net_backend = &s->nc;
> +        options.devpath = VHOST_NET_DEFAULT_PATH;
> +        options.force = tap->has_vhostforce && tap->vhostforce;
>  
>          if (tap->has_vhostfd || tap->has_vhostfds) {
> -            vhostfd = monitor_handle_fd_param(cur_mon, vhostfdname);
> -            if (vhostfd == -1) {
> +            options.devfd = monitor_handle_fd_param(cur_mon, vhostfdname);
> +            if (options.devfd == -1) {
>                  return -1;
>              }
>          } else {
> -            vhostfd = -1;
> +            options.devfd = -1;
>          }
>  
> -        s->vhost_net = vhost_net_init(&s->nc, vhostfd,
> -                                      tap->has_vhostforce && tap->vhostforce);
> +        s->vhost_net = vhost_net_init(&options);
>          if (!s->vhost_net) {
>              error_report("vhost-net requested but could not be initialized");
>              return -1;
> -- 
> 1.8.3.2
>