Commit 3e866365 authored by Thibaut Collet's avatar Thibaut Collet Committed by Michael S. Tsirkin
Browse files

vhost user: add rarp sending after live migration for legacy guest 



A new vhost user message is added to allow QEMU to ask to vhost user backend to
broadcast a fake RARP after live migration for guest without GUEST_ANNOUNCE
capability.

This new message is sent only if the backend supports the new
VHOST_USER_PROTOCOL_F_RARP protocol feature.
The payload of this new message is the MAC address of the guest (not known by
the backend). The MAC address is copied in the first 6 bytes of a u64 to avoid
to create a new payload message type.

This new message has no equivalent ioctl so a new callback is added in the
userOps structure to send the request.

Upon reception of this new message the vhost user backend must generate and
broadcast a fake RARP request to notify the migration is terminated.

Signed-off-by: default avatarThibaut Collet <thibaut.collet@6wind.com>
[Rebased and fixed checkpatch errors - Marc-André]
Signed-off-by: default avatarMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Tested-by: default avatarThibaut Collet <thibaut.collet@6wind.com>
parent f6f56291

docs/specs/vhost-user.txt

+15 −0
Original line number Diff line number Diff line
@@ -194,6 +194,7 @@ Protocol features 


#define VHOST_USER_PROTOCOL_F_MQ             0

#define VHOST_USER_PROTOCOL_F_LOG_SHMFD      1

#define VHOST_USER_PROTOCOL_F_RARP           2



Message types

-------------
@@ -381,3 +382,17 @@ Message types 
      Master payload: vring state description



      Signal slave to enable or disable corresponding vring.



 * VHOST_USER_SEND_RARP



      Id: 19

      Equivalent ioctl: N/A

      Master payload: u64



      Ask vhost user backend to broadcast a fake RARP to notify the migration

      is terminated for guest that does not support GUEST_ANNOUNCE.

      Only legal if feature bit VHOST_USER_F_PROTOCOL_FEATURES is present in

      VHOST_USER_GET_FEATURES and protocol feature bit VHOST_USER_PROTOCOL_F_RARP

      is present in VHOST_USER_GET_PROTOCOL_FEATURES.

      The first 6 bytes of the payload contain the mac address of the guest to

      allow the vhost user backend to construct and broadcast the fake RARP.

hw/net/vhost_net.c

+17 −0
Original line number Diff line number Diff line
@@ -388,6 +388,18 @@ void vhost_net_cleanup(struct vhost_net *net) 
    g_free(net);

}



int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)

{

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

    int r = -1;



    if (vhost_ops->vhost_migration_done) {

        r = vhost_ops->vhost_migration_done(&net->dev, mac_addr);

    }



    return r;

}



bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)

{

    return vhost_virtqueue_pending(&net->dev, idx);
@@ -479,6 +491,11 @@ void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev, 
{

}



int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)

{

    return -1;

}



VHostNetState *get_vhost_net(NetClientState *nc)

{

    return 0;

hw/virtio/vhost-user.c

+31 −1
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 


#include "hw/virtio/vhost.h"

#include "hw/virtio/vhost-backend.h"

#include "hw/virtio/virtio-net.h"

#include "sysemu/char.h"

#include "sysemu/kvm.h"

#include "qemu/error-report.h"
@@ -27,9 +28,10 @@ 
#define VHOST_MEMORY_MAX_NREGIONS    8

#define VHOST_USER_F_PROTOCOL_FEATURES 30



#define VHOST_USER_PROTOCOL_FEATURE_MASK 0x3ULL

#define VHOST_USER_PROTOCOL_FEATURE_MASK 0x7ULL

#define VHOST_USER_PROTOCOL_F_MQ         0

#define VHOST_USER_PROTOCOL_F_LOG_SHMFD  1

#define VHOST_USER_PROTOCOL_F_RARP       2



typedef enum VhostUserRequest {

    VHOST_USER_NONE = 0,
@@ -51,6 +53,7 @@ typedef enum VhostUserRequest { 
    VHOST_USER_SET_PROTOCOL_FEATURES = 16,

    VHOST_USER_GET_QUEUE_NUM = 17,

    VHOST_USER_SET_VRING_ENABLE = 18,

    VHOST_USER_SEND_RARP = 19,

    VHOST_USER_MAX

} VhostUserRequest;
@@ -566,6 +569,32 @@ static bool vhost_user_requires_shm_log(struct vhost_dev *dev) 
                              VHOST_USER_PROTOCOL_F_LOG_SHMFD);

}



static int vhost_user_migration_done(struct vhost_dev *dev, char* mac_addr)

{

    VhostUserMsg msg = { 0 };

    int err;



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



    /* If guest supports GUEST_ANNOUNCE do nothing */

    if (virtio_has_feature(dev->acked_features, VIRTIO_NET_F_GUEST_ANNOUNCE)) {

        return 0;

    }



    /* if backend supports VHOST_USER_PROTOCOL_F_RARP ask it to send the RARP */

    if (virtio_has_feature(dev->protocol_features,

                           VHOST_USER_PROTOCOL_F_RARP)) {

        msg.request = VHOST_USER_SEND_RARP;

        msg.flags = VHOST_USER_VERSION;

        memcpy((char *)&msg.u64, mac_addr, 6);

        msg.size = sizeof(m.u64);



        err = vhost_user_write(dev, &msg, NULL, 0);

        return err;

    }

    return -1;

}



const VhostOps user_ops = {

        .backend_type = VHOST_BACKEND_TYPE_USER,

        .vhost_backend_init = vhost_user_init,
@@ -587,4 +616,5 @@ const VhostOps user_ops = { 
        .vhost_get_vq_index = vhost_user_get_vq_index,

        .vhost_set_vring_enable = vhost_user_set_vring_enable,

        .vhost_requires_shm_log = vhost_user_requires_shm_log,

        .vhost_migration_done = vhost_user_migration_done,

};

include/hw/virtio/vhost-backend.h

+3 −0
Original line number Diff line number Diff line
@@ -68,6 +68,8 @@ typedef int (*vhost_get_vq_index_op)(struct vhost_dev *dev, int idx); 
typedef int (*vhost_set_vring_enable_op)(struct vhost_dev *dev,

                                         int enable);

typedef bool (*vhost_requires_shm_log_op)(struct vhost_dev *dev);

typedef int (*vhost_migration_done_op)(struct vhost_dev *dev,

                                       char *mac_addr);



typedef struct VhostOps {

    VhostBackendType backend_type;
@@ -94,6 +96,7 @@ typedef struct VhostOps { 
    vhost_get_vq_index_op vhost_get_vq_index;

    vhost_set_vring_enable_op vhost_set_vring_enable;

    vhost_requires_shm_log_op vhost_requires_shm_log;

    vhost_migration_done_op vhost_migration_done;

} VhostOps;



extern const VhostOps user_ops;

include/net/vhost_net.h

+1 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ void vhost_net_ack_features(VHostNetState *net, uint64_t features); 
bool vhost_net_virtqueue_pending(VHostNetState *net, int n);

void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,

                              int idx, bool mask);

int vhost_net_notify_migration_done(VHostNetState *net, char* mac_addr);

VHostNetState *get_vhost_net(NetClientState *nc);



int vhost_set_vring_enable(NetClientState * nc, int enable);