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: Thibaut Collet <thibaut.collet@6wind.com> [Rebased and fixed checkpatch errors - Marc-André] Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt index e0292a0..e0d71e2 100644 --- a/docs/specs/vhost-user.txt +++ b/docs/specs/vhost-user.txt
@@ -194,6 +194,7 @@ #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 @@ 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.
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c index 840f443..d91b7b1 100644 --- a/hw/net/vhost_net.c +++ b/hw/net/vhost_net.c
@@ -388,6 +388,18 @@ 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 @@ { } +int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr) +{ + return -1; +} + VHostNetState *get_vhost_net(NetClientState *nc) { return 0;
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index 16d8e80..d804c5f 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c
@@ -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 @@ 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 @@ 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 @@ .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, };
diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h index ad19481..c59cc81 100644 --- a/include/hw/virtio/vhost-backend.h +++ b/include/hw/virtio/vhost-backend.h
@@ -68,6 +68,8 @@ 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 @@ 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;
diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h index 0188c4d..3389b41 100644 --- a/include/net/vhost_net.h +++ b/include/net/vhost_net.h
@@ -27,6 +27,7 @@ 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);
diff --git a/net/vhost-user.c b/net/vhost-user.c index b067524..17b5c2a 100644 --- a/net/vhost-user.c +++ b/net/vhost-user.c
@@ -106,9 +106,29 @@ static ssize_t vhost_user_receive(NetClientState *nc, const uint8_t *buf, size_t size) { - /* Discard the request that is received and managed by backend - * by an other way. + /* In case of RARP (message size is 60) notify backup to send a fake RARP. + This fake RARP will be sent by backend only for guest + without GUEST_ANNOUNCE capability. */ + if (size == 60) { + VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc); + int r; + static int display_rarp_failure = 1; + char mac_addr[6]; + + /* extract guest mac address from the RARP message */ + memcpy(mac_addr, &buf[6], 6); + + r = vhost_net_notify_migration_done(s->vhost_net, mac_addr); + + if ((r != 0) && (display_rarp_failure)) { + fprintf(stderr, + "Vhost user backend fails to broadcast fake RARP\n"); + fflush(stderr); + display_rarp_failure = 0; + } + } + return size; }