Commit 7263a0ad authored by Changchun Ouyang's avatar Changchun Ouyang Committed by Michael S. Tsirkin
Browse files

vhost-user: add a new message to disable/enable a specific virt queue. 



Add a new message, VHOST_USER_SET_VRING_ENABLE, to enable or disable
a specific virt queue, which is similar to attach/detach queue for
tap device.

virtio driver on guest doesn't have to use max virt queue pair, it
could enable any number of virt queue ranging from 1 to max virt
queue pair.

Signed-off-by: default avatarChangchun Ouyang <changchun.ouyang@intel.com>
Signed-off-by: default avatarYuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarYuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: default avatarJason Wang <jasowang@redhat.com>
Tested-by: default avatarMarcel Apfelbaum <marcel@redhat.com>
parent b931bfbf

docs/specs/vhost-user.txt

+11 −1
Original line number Diff line number Diff line
@@ -148,7 +148,9 @@ VHOST_USER_GET_PROTOCOL_FEATURES. Master should stop when the number of 
requested queues is bigger than that.



As all queues share one connection, the master uses a unique index for each

queue in the sent message to identify a specified queue.

queue in the sent message to identify a specified queue. One queue pair

is enabled initially. More queues are enabled dynamically, by sending

message VHOST_USER_SET_VRING_ENABLE.



Message types

-------------
@@ -327,3 +329,11 @@ Message types 
      Query how many queues the backend supports. This request should be

      sent only when VHOST_USER_PROTOCOL_F_MQ is set in quried protocol

      features by VHOST_USER_GET_PROTOCOL_FEATURES.



 * VHOST_USER_SET_VRING_ENABLE



      Id: 18

      Equivalent ioctl: N/A

      Master payload: vring state description



      Signal slave to enable or disable corresponding vring.

hw/net/vhost_net.c

+18 −0
Original line number Diff line number Diff line
@@ -422,6 +422,19 @@ VHostNetState *get_vhost_net(NetClientState *nc) 


    return vhost_net;

}



int vhost_set_vring_enable(NetClientState *nc, int enable)

{

    VHostNetState *net = get_vhost_net(nc);

    const VhostOps *vhost_ops = net->dev.vhost_ops;



    if (vhost_ops->vhost_backend_set_vring_enable) {

        return vhost_ops->vhost_backend_set_vring_enable(&net->dev, enable);

    }



    return 0;

}



#else

uint64_t vhost_net_get_max_queues(VHostNetState *net)

{
@@ -472,4 +485,9 @@ VHostNetState *get_vhost_net(NetClientState *nc) 
{

    return 0;

}



int vhost_set_vring_enable(NetClientState *nc, int enable)

{

    return 0;

}

#endif

hw/net/virtio-net.c

+8 −0
Original line number Diff line number Diff line
@@ -406,6 +406,10 @@ static int peer_attach(VirtIONet *n, int index) 
        return 0;

    }



    if (nc->peer->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) {

        vhost_set_vring_enable(nc->peer, 1);

    }



    if (nc->peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {

        return 0;

    }
@@ -421,6 +425,10 @@ static int peer_detach(VirtIONet *n, int index) 
        return 0;

    }



    if (nc->peer->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) {

        vhost_set_vring_enable(nc->peer, 0);

    }



    if (nc->peer->info->type !=  NET_CLIENT_OPTIONS_KIND_TAP) {

        return 0;

    }

hw/virtio/vhost-user.c

+19 −0
Original line number Diff line number Diff line
@@ -48,6 +48,7 @@ typedef enum VhostUserRequest { 
    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;
@@ -290,6 +291,7 @@ static int vhost_user_call(struct vhost_dev *dev, unsigned long int request, 


    case VHOST_USER_SET_VRING_NUM:

    case VHOST_USER_SET_VRING_BASE:

    case VHOST_USER_SET_VRING_ENABLE:

        memcpy(&msg.state, arg, sizeof(struct vhost_vring_state));

        msg.size = sizeof(m.state);

        break;
@@ -406,6 +408,22 @@ static int vhost_user_init(struct vhost_dev *dev, void *opaque) 
    return 0;

}



static int vhost_user_set_vring_enable(struct vhost_dev *dev, int enable)

{

    struct vhost_vring_state state = {

        .index = dev->vq_index,

        .num   = enable,

    };



    assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);



    if (!(dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_MQ))) {

        return -1;

    }



    return vhost_user_call(dev, VHOST_USER_SET_VRING_ENABLE, &state);

}



static int vhost_user_cleanup(struct vhost_dev *dev)

{

    assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
@@ -428,4 +446,5 @@ const VhostOps user_ops = { 
        .vhost_backend_init = vhost_user_init,

        .vhost_backend_cleanup = vhost_user_cleanup,

        .vhost_backend_get_vq_index = vhost_user_get_vq_index,

        .vhost_backend_set_vring_enable = vhost_user_set_vring_enable,

};

include/hw/virtio/vhost-backend.h

+2 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ typedef int (*vhost_call)(struct vhost_dev *dev, unsigned long int request, 
typedef int (*vhost_backend_init)(struct vhost_dev *dev, void *opaque);

typedef int (*vhost_backend_cleanup)(struct vhost_dev *dev);

typedef int (*vhost_backend_get_vq_index)(struct vhost_dev *dev, int idx);

typedef int (*vhost_backend_set_vring_enable)(struct vhost_dev *dev, int enable);



typedef struct VhostOps {

    VhostBackendType backend_type;
@@ -32,6 +33,7 @@ typedef struct VhostOps { 
    vhost_backend_init vhost_backend_init;

    vhost_backend_cleanup vhost_backend_cleanup;

    vhost_backend_get_vq_index vhost_backend_get_vq_index;

    vhost_backend_set_vring_enable vhost_backend_set_vring_enable;

} VhostOps;



extern const VhostOps user_ops;