Previously libvhost dispatch events in its own GMainContext. Now vhost-user
client's kick event can be dispatched in block device drive's AioContext
thus IOThread is supported. And also allow vu_message_read and
vu_kick_cb to be replaced so QEMU can run them as coroutines.
Signed-off-by: Coiby Xu <coiby...@gmail.com>
---
contrib/libvhost-user/libvhost-user.c | 54 ++++++++++++++++++++++++---
contrib/libvhost-user/libvhost-user.h | 38 ++++++++++++++++++-
2 files changed, 85 insertions(+), 7 deletions(-)
diff --git a/contrib/libvhost-user/libvhost-user.c
b/contrib/libvhost-user/libvhost-user.c
index b89bf18501..f95664bb22 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -67,8 +67,6 @@
/* 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
@@ -260,7 +258,7 @@ have_userfault(void)
}
static bool
-vu_message_read(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
+vu_message_read_(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
{
char control[CMSG_SPACE(VHOST_MEMORY_MAX_NREGIONS * sizeof(int))] = { };
struct iovec iov = {
@@ -328,6 +326,17 @@ fail:
return false;
}
+static bool vu_message_read(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
+{
+ vu_read_msg_cb read_msg;
+ if (dev->co_iface) {
+ read_msg = dev->co_iface->read_msg;
+ } else {
+ read_msg = vu_message_read_;
+ }
+ return read_msg(dev, conn_fd, vmsg);
+}
+
static bool
vu_message_write(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
{
@@ -1075,9 +1084,14 @@ vu_set_vring_kick_exec(VuDev *dev, VhostUserMsg *vmsg)
}
if (dev->vq[index].kick_fd != -1 && dev->vq[index].handler) {
+ if (dev->set_watch_packed_data) {
+ dev->set_watch_packed_data(dev, dev->vq[index].kick_fd,
VU_WATCH_IN,
+ dev->co_iface->kick_callback,
+ (void *)(long)index);
+ } else {
dev->set_watch(dev, dev->vq[index].kick_fd, VU_WATCH_IN,
vu_kick_cb, (void *)(long)index);
-
+ }
DPRINT("Waiting for kicks on fd: %d for vq: %d\n",
dev->vq[index].kick_fd, index);
}
@@ -1097,8 +1111,14 @@ void vu_set_queue_handler(VuDev *dev, VuVirtq *vq,
vq->handler = handler;
if (vq->kick_fd >= 0) {
if (handler) {
+ if (dev->set_watch_packed_data) {
+ dev->set_watch_packed_data(dev, vq->kick_fd, VU_WATCH_IN,
+ dev->co_iface->kick_callback,
+ (void *)(long)qidx);
+ } else {
dev->set_watch(dev, vq->kick_fd, VU_WATCH_IN,
vu_kick_cb, (void *)(long)qidx);
+ }
} else {
dev->remove_watch(dev, vq->kick_fd);
}
@@ -1627,6 +1647,12 @@ vu_deinit(VuDev *dev)
}
if (vq->kick_fd != -1) {
+ /* remove watch for kick_fd
+ * When client process is running in gdb and
+ * quit command is run in gdb, QEMU will still dispatch the event
+ * which will cause segment fault in the callback function
+ */
+ dev->remove_watch(dev, vq->kick_fd);
close(vq->kick_fd);
vq->kick_fd = -1;
}
@@ -1682,7 +1708,7 @@ vu_init(VuDev *dev,
assert(max_queues > 0);
assert(socket >= 0);
- assert(set_watch);
+ /* assert(set_watch); */
assert(remove_watch);
assert(iface);
assert(panic);
@@ -1715,6 +1741,24 @@ vu_init(VuDev *dev,
return true;
}
+bool
+vu_init_packed_data(VuDev *dev,
+ uint16_t max_queues,
+ int socket,
+ vu_panic_cb panic,
+ vu_set_watch_cb_packed_data set_watch_packed_data,
+ vu_remove_watch_cb remove_watch,
+ const VuDevIface *iface,
+ const CoIface *co_iface)
+{
+ if (vu_init(dev, max_queues, socket, panic, NULL, remove_watch, iface)) {
+ dev->set_watch_packed_data = set_watch_packed_data;
+ dev->co_iface = co_iface;
+ return true;
+ }
+ return false;
+}
+
VuVirtq *
vu_get_queue(VuDev *dev, int qidx)
{
diff --git a/contrib/libvhost-user/libvhost-user.h
b/contrib/libvhost-user/libvhost-user.h
index 5cb7708559..6aadeaa0f2 100644
--- a/contrib/libvhost-user/libvhost-user.h
+++ b/contrib/libvhost-user/libvhost-user.h
@@ -30,6 +30,8 @@
#define VHOST_MEMORY_MAX_NREGIONS 8
+#define VHOST_USER_HDR_SIZE offsetof(VhostUserMsg, payload.u64)
+
typedef enum VhostSetConfigType {
VHOST_SET_CONFIG_TYPE_MASTER = 0,
VHOST_SET_CONFIG_TYPE_MIGRATION = 1,
@@ -201,6 +203,7 @@ 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);
@@ -208,6 +211,20 @@ typedef int (*vu_set_config_cb) (VuDev *dev, const uint8_t
*data,
uint32_t offset, uint32_t size,
uint32_t flags);
+typedef void (*vu_watch_cb_packed_data) (void *packed_data);
+
+typedef void (*vu_set_watch_cb_packed_data) (VuDev *dev, int fd, int condition,
+ vu_watch_cb_packed_data cb,
+ void *data);
+/*
+ * allowing vu_read_msg_cb and kick_callback to be replaced so QEMU
+ * can run them as coroutines
+ */
+typedef struct CoIface {
+ vu_read_msg_cb read_msg;
+ vu_watch_cb_packed_data kick_callback;
+} CoIface;
+
typedef struct VuDevIface {
/* called by VHOST_USER_GET_FEATURES to get the features bitmask */
vu_get_features_cb get_features;
@@ -372,7 +389,8 @@ struct VuDev {
/* @set_watch: add or update the given fd to the watch set,
* call cb when condition is met */
vu_set_watch_cb set_watch;
-
+ /* AIO dispatch will only one data pointer to callback function */
+ vu_set_watch_cb_packed_data set_watch_packed_data;
/* @remove_watch: remove the given fd from the watch set */
vu_remove_watch_cb remove_watch;
@@ -380,7 +398,7 @@ struct VuDev {
* re-initialize */
vu_panic_cb panic;
const VuDevIface *iface;
-
+ const CoIface *co_iface;
/* Postcopy data */
int postcopy_ufd;
bool postcopy_listening;
@@ -417,6 +435,22 @@ bool vu_init(VuDev *dev,
const VuDevIface *iface);
+/**
+ * vu_init_packed_data:
+ * Same as vu_init except for set_watch_packed_data which will pack
+ * two parameters into a struct thus QEMU aio_dispatch can pass the
+ * required data to callback function.
+ *
+ * Returns: true on success, false on failure.
+ **/
+bool vu_init_packed_data(VuDev *dev,
+ uint16_t max_queues,
+ int socket,
+ vu_panic_cb panic,
+ vu_set_watch_cb_packed_data set_watch_packed_data,
+ vu_remove_watch_cb remove_watch,
+ const VuDevIface *iface,
+ const CoIface *co_iface);
/**
* vu_deinit:
* @dev: a VuDev context
--
2.25.0
