On Thu, Sep 24, 2015 at 6:22 PM, <marcandre.lur...@redhat.com> wrote:
> From: Thibaut Collet <thibaut.col...@6wind.com>
>
> 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.col...@6wind.com>
> [Rebased and fixed checkpatch errors - Marc-André]
> Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> ---
> docs/specs/vhost-user.txt | 15 +++++++++++++++
> hw/net/vhost_net.c | 17 +++++++++++++++++
> hw/virtio/vhost-user.c | 30 ++++++++++++++++++++++++++++++
> include/hw/virtio/vhost-backend.h | 3 +++
> include/net/vhost_net.h | 1 +
> net/vhost-user.c | 24 ++++++++++++++++++++++--
> 6 files changed, 88 insertions(+), 2 deletions(-)
>
> 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 @@ 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.
> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> index 840f443..da66b64 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -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)
> +{
> + 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 455caba..b7f3699 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"
> @@ -30,6 +31,7 @@
> #define VHOST_USER_PROTOCOL_FEATURE_MASK 0x3ULL
> #define VHOST_USER_PROTOCOL_F_MQ 0
> #define VHOST_USER_PROTOCOL_F_LOG_SHMFD 1
> +#define VHOST_USER_PROTOCOL_F_RARP 2
The VHOST_USER_PROTOCOL_FEATURE_MASK must be changed and set to 0x7ULL
>
> 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;
>
> @@ -561,6 +564,32 @@ 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,
> @@ -582,4 +611,5 @@ 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,
> };
> diff --git a/include/hw/virtio/vhost-backend.h
> b/include/hw/virtio/vhost-backend.h
> index e07118c..5918c01 100644
> --- a/include/hw/virtio/vhost-backend.h
> +++ b/include/hw/virtio/vhost-backend.h
> @@ -67,6 +67,8 @@ 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;
> 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 @@ 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);
> diff --git a/net/vhost-user.c b/net/vhost-user.c
> index 87917a5..cfe11b8 100644
> --- a/net/vhost-user.c
> +++ b/net/vhost-user.c
> @@ -106,9 +106,29 @@ err:
> 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;
> }
>
> --
> 2.4.3
>
