libvhost-user: Allow vu_message_read to be replaced

Allow vu_message_read to be replaced by one which will make use of the
QIOChannel functions. Thus reading vhost-user message won't stall the
guest. For slave channel, we still use the default vu_message_read.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200918080912.321299-2-coiby.xu@gmail.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Coiby Xu 2020-09-18 16:09:06 +08:00 committed by Stefan Hajnoczi
parent f25e7ab2b0
commit 049f55502a
5 changed files with 33 additions and 10 deletions

View file

@ -147,7 +147,7 @@ vug_init(VugDev *dev, uint16_t max_queues, int socket,
g_assert(dev);
g_assert(iface);
if (!vu_init(&dev->parent, max_queues, socket, panic, set_watch,
if (!vu_init(&dev->parent, max_queues, socket, panic, NULL, set_watch,
remove_watch, iface)) {
return false;
}

View file

@ -68,8 +68,6 @@
/* The version of inflight buffer */
#define INFLIGHT_VERSION 1
#define VHOST_USER_HDR_SIZE offsetof(VhostUserMsg, payload.u64)
/* The version of the protocol we support */
#define VHOST_USER_VERSION 1
#define LIBVHOST_USER_DEBUG 0
@ -268,7 +266,7 @@ have_userfault(void)
}
static bool
vu_message_read(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
vu_message_read_default(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
{
char control[CMSG_SPACE(VHOST_MEMORY_BASELINE_NREGIONS * sizeof(int))] = {};
struct iovec iov = {
@ -416,7 +414,7 @@ vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg)
goto out;
}
if (!vu_message_read(dev, dev->slave_fd, &msg_reply)) {
if (!vu_message_read_default(dev, dev->slave_fd, &msg_reply)) {
goto out;
}
@ -907,7 +905,7 @@ vu_set_mem_table_exec_postcopy(VuDev *dev, VhostUserMsg *vmsg)
/* Wait for QEMU to confirm that it's registered the handler for the
* faults.
*/
if (!vu_message_read(dev, dev->sock, vmsg) ||
if (!dev->read_msg(dev, dev->sock, vmsg) ||
vmsg->size != sizeof(vmsg->payload.u64) ||
vmsg->payload.u64 != 0) {
vu_panic(dev, "failed to receive valid ack for postcopy set-mem-table");
@ -1869,7 +1867,7 @@ vu_dispatch(VuDev *dev)
int reply_requested;
bool need_reply, success = false;
if (!vu_message_read(dev, dev->sock, &vmsg)) {
if (!dev->read_msg(dev, dev->sock, &vmsg)) {
goto end;
}
@ -1967,6 +1965,7 @@ vu_init(VuDev *dev,
uint16_t max_queues,
int socket,
vu_panic_cb panic,
vu_read_msg_cb read_msg,
vu_set_watch_cb set_watch,
vu_remove_watch_cb remove_watch,
const VuDevIface *iface)
@ -1984,6 +1983,7 @@ vu_init(VuDev *dev,
dev->sock = socket;
dev->panic = panic;
dev->read_msg = read_msg ? read_msg : vu_message_read_default;
dev->set_watch = set_watch;
dev->remove_watch = remove_watch;
dev->iface = iface;
@ -2349,7 +2349,7 @@ static void _vu_queue_notify(VuDev *dev, VuVirtq *vq, bool sync)
vu_message_write(dev, dev->slave_fd, &vmsg);
if (ack) {
vu_message_read(dev, dev->slave_fd, &vmsg);
vu_message_read_default(dev, dev->slave_fd, &vmsg);
}
return;
}

View file

@ -36,6 +36,8 @@
*/
#define VHOST_USER_MAX_RAM_SLOTS 32
#define VHOST_USER_HDR_SIZE offsetof(VhostUserMsg, payload.u64)
typedef enum VhostSetConfigType {
VHOST_SET_CONFIG_TYPE_MASTER = 0,
VHOST_SET_CONFIG_TYPE_MIGRATION = 1,
@ -221,6 +223,7 @@ typedef uint64_t (*vu_get_features_cb) (VuDev *dev);
typedef void (*vu_set_features_cb) (VuDev *dev, uint64_t features);
typedef int (*vu_process_msg_cb) (VuDev *dev, VhostUserMsg *vmsg,
int *do_reply);
typedef bool (*vu_read_msg_cb) (VuDev *dev, int sock, VhostUserMsg *vmsg);
typedef void (*vu_queue_set_started_cb) (VuDev *dev, int qidx, bool started);
typedef bool (*vu_queue_is_processed_in_order_cb) (VuDev *dev, int qidx);
typedef int (*vu_get_config_cb) (VuDev *dev, uint8_t *config, uint32_t len);
@ -389,6 +392,23 @@ struct VuDev {
bool broken;
uint16_t max_queues;
/* @read_msg: custom method to read vhost-user message
*
* Read data from vhost_user socket fd and fill up
* the passed VhostUserMsg *vmsg struct.
*
* If reading fails, it should close the received set of file
* descriptors as socket message's auxiliary data.
*
* For the details, please refer to vu_message_read in libvhost-user.c
* which will be used by default if not custom method is provided when
* calling vu_init
*
* Returns: true if vhost-user message successfully received,
* otherwise return false.
*
*/
vu_read_msg_cb read_msg;
/* @set_watch: add or update the given fd to the watch set,
* call cb when condition is met */
vu_set_watch_cb set_watch;
@ -432,6 +452,7 @@ bool vu_init(VuDev *dev,
uint16_t max_queues,
int socket,
vu_panic_cb panic,
vu_read_msg_cb read_msg,
vu_set_watch_cb set_watch,
vu_remove_watch_cb remove_watch,
const VuDevIface *iface);

View file

@ -520,6 +520,7 @@ vubr_accept_cb(int sock, void *ctx)
VHOST_USER_BRIDGE_MAX_QUEUES,
conn_fd,
vubr_panic,
NULL,
vubr_set_watch,
vubr_remove_watch,
&vuiface)) {
@ -573,6 +574,7 @@ vubr_new(const char *path, bool client)
VHOST_USER_BRIDGE_MAX_QUEUES,
dev->sock,
vubr_panic,
NULL,
vubr_set_watch,
vubr_remove_watch,
&vuiface)) {

View file

@ -1013,8 +1013,8 @@ int virtio_session_mount(struct fuse_session *se)
se->vu_socketfd = data_sock;
se->virtio_dev->se = se;
pthread_rwlock_init(&se->virtio_dev->vu_dispatch_rwlock, NULL);
vu_init(&se->virtio_dev->dev, 2, se->vu_socketfd, fv_panic, fv_set_watch,
fv_remove_watch, &fv_iface);
vu_init(&se->virtio_dev->dev, 2, se->vu_socketfd, fv_panic, NULL,
fv_set_watch, fv_remove_watch, &fv_iface);
return 0;
}