In a container environment if the vhost-user backend restarts, there's
no way for it to reconnect to virtio-user. To address this, support for
server mode is added. In this mode the socket file is created by virtio-
user, which the backend then connects to. This means that if the backend
restarts, it can reconnect to virtio-user and continue communications.
With current implementation, LSC is enabled at virtio-user side to
support to accept the coming connection.
Server mode virtio-user only supports to work with vhost-user.
Release note is updated in this patch.
Signed-off-by: Zhiyong Yang <zhiyong.y...@intel.com>
---
Cc: maxime.coque...@redhat.com
Cc: jianfeng....@intel.com
Cc: tiwei....@intel.com
Cc: zhihong.w...@intel.com
Cc: dong1.w...@intel.com
Cc: tho...@monjalon.net
Changes in V7:
1. avoid misusing vhost-kernel in server mode virtio-user.
2. move the funciton definition is_vhost_user_by_type before
virtio_user_start_device in order that it can be called.
3. add comments in the code to state feature negotiation limit.
Changes in V6:
1. fix report wrong link stauts in server mode.
2. fix some code style issues.
Changes in V5:
1. Support server mode virtio-user startup in non-blocking mode.
2. rebase on top of dpdk-next-virtio.
Changes in V4:
1. Don't create new pthread any more and use librte_eal interrupt thread
instead.
Changes in V3:
1. use EAL epoll mechanism instead of vhost events. Cancel to export vhost
event APIs.
2. rebase the code on top of dpdk-next-virtio
Changes in V2:
1. split two patches 1/5 and 2/5 from v1 patchset to fix some existing issues
which is not strongly related to support for server mode
2. move fdset related functions to librte_eal from librte_vhost exposed as
new APIs.
3. release note is added in the patch 5/5.
4. squash data structure change patch into 4/5 according to Maxime's suggestion.
doc/guides/rel_notes/release_18_05.rst | 6 ++
drivers/net/virtio/virtio_user/vhost_user.c | 45 ++++++++--
drivers/net/virtio/virtio_user/virtio_user_dev.c | 101 ++++++++++++++++-------
drivers/net/virtio/virtio_user/virtio_user_dev.h | 3 +
drivers/net/virtio/virtio_user_ethdev.c | 101 ++++++++++++++++++++---
5 files changed, 209 insertions(+), 47 deletions(-)
diff --git a/doc/guides/rel_notes/release_18_05.rst
b/doc/guides/rel_notes/release_18_05.rst
index 9cc77f893..f8897b2e9 100644
--- a/doc/guides/rel_notes/release_18_05.rst
+++ b/doc/guides/rel_notes/release_18_05.rst
@@ -58,6 +58,12 @@ New Features
* Added support for NVGRE, VXLAN and GENEVE filters in flow API.
* Added support for DROP action in flow API.
+* **Added support for virtio-user server mode.**
+ In a container environment if the vhost-user backend restarts, there's no way
+ for it to reconnect to virtio-user. To address this, support for server mode
+ is added. In this mode the socket file is created by virtio-user, which the
+ backend connects to. This means that if the backend restarts, it can
reconnect
+ to virtio-user and continue communications.
API Changes
-----------
diff --git a/drivers/net/virtio/virtio_user/vhost_user.c
b/drivers/net/virtio/virtio_user/vhost_user.c
index 91c6449bb..a6df97a00 100644
--- a/drivers/net/virtio/virtio_user/vhost_user.c
+++ b/drivers/net/virtio/virtio_user/vhost_user.c
@@ -378,6 +378,30 @@ vhost_user_sock(struct virtio_user_dev *dev,
return 0;
}
+#define MAX_VIRTIO_USER_BACKLOG 1
+static int
+virtio_user_start_server(struct virtio_user_dev *dev, struct sockaddr_un *un)
+{
+ int ret;
+ int flag;
+ int fd = dev->listenfd;
+
+ ret = bind(fd, (struct sockaddr *)un, sizeof(*un));
+ if (ret < 0) {
+ PMD_DRV_LOG(ERR, "failed to bind to %s: %s; remove it and try
again\n",
+ dev->path, strerror(errno));
+ return -1;
+ }
+ ret = listen(fd, MAX_VIRTIO_USER_BACKLOG);
+ if (ret < 0)
+ return -1;
+
+ flag = fcntl(fd, F_GETFL);
+ fcntl(fd, F_SETFL, flag | O_NONBLOCK);
+
+ return 0;
+}
+
/**
* Set up environment to talk with a vhost user backend.
*
@@ -405,13 +429,24 @@ vhost_user_setup(struct virtio_user_dev *dev)
memset(&un, 0, sizeof(un));
un.sun_family = AF_UNIX;
snprintf(un.sun_path, sizeof(un.sun_path), "%s", dev->path);
- if (connect(fd, (struct sockaddr *)&un, sizeof(un)) < 0) {
- PMD_DRV_LOG(ERR, "connect error, %s", strerror(errno));
- close(fd);
- return -1;
+
+ if (dev->is_server) {
+ dev->listenfd = fd;
+ if (virtio_user_start_server(dev, &un) < 0) {
+ PMD_DRV_LOG(ERR, "virtio-user startup fails in server
mode");
+ close(fd);
+ return -1;
+ }
+ dev->vhostfd = -1;
+ } else {
+ if (connect(fd, (struct sockaddr *)&un, sizeof(un)) < 0) {
+ PMD_DRV_LOG(ERR, "connect error, %s", strerror(errno));
+ close(fd);
+ return -1;
+ }
+ dev->vhostfd = fd;
}
- dev->vhostfd = fd;
return 0;
}
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c
b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index f90fee9e5..38b8bc90d 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -93,12 +93,26 @@ virtio_user_queue_setup(struct virtio_user_dev *dev,
return 0;
}
+int
+is_vhost_user_by_type(const char *path)
+{
+ struct stat sb;
+
+ if (stat(path, &sb) == -1)
+ return 0;
+
+ return S_ISSOCK(sb.st_mode);
+}
+
int
virtio_user_start_device(struct virtio_user_dev *dev)
{
uint64_t features;
int ret;
+ if (is_vhost_user_by_type(dev->path) && dev->vhostfd < 0)
+ return -1;
+
/* Do not check return as already done in init, or reset in stop */
dev->ops->send_request(dev, VHOST_USER_SET_OWNER, NULL);
@@ -174,17 +188,6 @@ parse_mac(struct virtio_user_dev *dev, const char *mac)
}
}
-int
-is_vhost_user_by_type(const char *path)
-{
- struct stat sb;
-
- if (stat(path, &sb) == -1)
- return 0;
-
- return S_ISSOCK(sb.st_mode);
-}
-
static int
virtio_user_dev_init_notify(struct virtio_user_dev *dev)
{
@@ -254,6 +257,8 @@ virtio_user_fill_intr_handle(struct virtio_user_dev *dev)
eth_dev->intr_handle->fd = -1;
if (dev->vhostfd >= 0)
eth_dev->intr_handle->fd = dev->vhostfd;
+ else if (dev->is_server)
+ eth_dev->intr_handle->fd = dev->listenfd;
return 0;
}
@@ -267,21 +272,32 @@ virtio_user_dev_setup(struct virtio_user_dev *dev)
dev->vhostfds = NULL;
dev->tapfds = NULL;
- if (is_vhost_user_by_type(dev->path)) {
- dev->ops = &ops_user;
- } else {
- dev->ops = &ops_kernel;
-
- dev->vhostfds = malloc(dev->max_queue_pairs * sizeof(int));
- dev->tapfds = malloc(dev->max_queue_pairs * sizeof(int));
- if (!dev->vhostfds || !dev->tapfds) {
- PMD_INIT_LOG(ERR, "Failed to malloc");
+ if (dev->is_server) {
+ if (access(dev->path, F_OK) == 0 &&
+ !is_vhost_user_by_type(dev->path)) {
+ PMD_DRV_LOG(ERR, "Server mode doesn't support
vhost-kernel!");
return -1;
}
-
- for (q = 0; q < dev->max_queue_pairs; ++q) {
- dev->vhostfds[q] = -1;
- dev->tapfds[q] = -1;
+ dev->ops = &ops_user;
+ } else {
+ if (is_vhost_user_by_type(dev->path)) {
+ dev->ops = &ops_user;
+ } else {
+ dev->ops = &ops_kernel;
+
+ dev->vhostfds = malloc(dev->max_queue_pairs *
+ sizeof(int));
+ dev->tapfds = malloc(dev->max_queue_pairs *
+ sizeof(int));
+ if (!dev->vhostfds || !dev->tapfds) {
+ PMD_INIT_LOG(ERR, "Failed to malloc");
+ return -1;
+ }
+
+ for (q = 0; q < dev->max_queue_pairs; ++q) {
+ dev->vhostfds[q] = -1;
+ dev->tapfds[q] = -1;
+ }
}
}
@@ -337,16 +353,29 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char
*path, int queues,
return -1;
}
- if (dev->ops->send_request(dev, VHOST_USER_SET_OWNER, NULL) < 0) {
- PMD_INIT_LOG(ERR, "set_owner fails: %s", strerror(errno));
- return -1;
- }
+ if (dev->vhostfd >= 0) {
+ if (dev->ops->send_request(dev, VHOST_USER_SET_OWNER,
+ NULL) < 0) {
+ PMD_INIT_LOG(ERR, "set_owner fails: %s",
+ strerror(errno));
+ return -1;
+ }
- if (dev->ops->send_request(dev, VHOST_USER_GET_FEATURES,
- &dev->device_features) < 0) {
- PMD_INIT_LOG(ERR, "get_features failed: %s", strerror(errno));
- return -1;
+ if (dev->ops->send_request(dev, VHOST_USER_GET_FEATURES,
+ &dev->device_features) < 0) {
+ PMD_INIT_LOG(ERR, "get_features failed: %s",
+ strerror(errno));
+ return -1;
+ }
+ } else {
+ /* We just pretend vhost-user can support all these features.
+ * Note that this could be problematic that if some feature is
+ * negotiated but not supported by the vhost-user which comes
+ * later.
+ */
+ dev->device_features = VIRTIO_USER_SUPPORTED_FEATURES;
}
+
if (dev->mac_specified)
dev->device_features |= (1ull << VIRTIO_NET_F_MAC);
@@ -388,6 +417,11 @@ virtio_user_dev_uninit(struct virtio_user_dev *dev)
close(dev->vhostfd);
+ if (dev->is_server && dev->listenfd >= 0) {
+ close(dev->listenfd);
+ dev->listenfd = -1;
+ }
+
if (dev->vhostfds) {
for (i = 0; i < dev->max_queue_pairs; ++i)
close(dev->vhostfds[i]);
@@ -396,6 +430,9 @@ virtio_user_dev_uninit(struct virtio_user_dev *dev)
}
free(dev->ifname);
+
+ if (dev->is_server)
+ unlink(dev->path);
}
static uint8_t
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h
b/drivers/net/virtio/virtio_user/virtio_user_dev.h
index 5f8755771..ade727e46 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
@@ -6,6 +6,7 @@
#define _VIRTIO_USER_DEV_H
#include <limits.h>
+#include <stdbool.h>
#include "../virtio_pci.h"
#include "../virtio_ring.h"
#include "vhost.h"
@@ -13,6 +14,8 @@
struct virtio_user_dev {
/* for vhost_user backend */
int vhostfd;
+ int listenfd; /* listening fd */
+ bool is_server; /* server or client mode */
/* for vhost_kernel backend */
char *ifname;
diff --git a/drivers/net/virtio/virtio_user_ethdev.c
b/drivers/net/virtio/virtio_user_ethdev.c
index 263649006..4e7b3c34f 100644
--- a/drivers/net/virtio/virtio_user_ethdev.c
+++ b/drivers/net/virtio/virtio_user_ethdev.c
@@ -24,15 +24,73 @@
#define virtio_user_get_dev(hw) \
((struct virtio_user_dev *)(hw)->virtio_user_dev)
+static int
+virtio_user_server_reconnect(struct virtio_user_dev *dev)
+{
+ int ret;
+ int flag;
+ int connectfd;
+ struct rte_eth_dev *eth_dev = &rte_eth_devices[dev->port_id];
+
+ connectfd = accept(dev->listenfd, NULL, NULL);
+ if (connectfd < 0)
+ return -1;
+
+ dev->vhostfd = connectfd;
+ flag = fcntl(connectfd, F_GETFD);
+ fcntl(connectfd, F_SETFL, flag | O_NONBLOCK);
+
+ ret = virtio_user_start_device(dev);
+ if (ret < 0)
+ return -1;
+
+ if (eth_dev->data->dev_flags & RTE_ETH_DEV_INTR_LSC) {
+ if (rte_intr_disable(eth_dev->intr_handle) < 0) {
+ PMD_DRV_LOG(ERR, "interrupt disable failed");
+ return -1;
+ }
+ rte_intr_callback_unregister(eth_dev->intr_handle,
+ virtio_interrupt_handler,
+ eth_dev);
+ eth_dev->intr_handle->fd = connectfd;
+ rte_intr_callback_register(eth_dev->intr_handle,
+ virtio_interrupt_handler, eth_dev);
+
+ if (rte_intr_enable(eth_dev->intr_handle) < 0) {
+ PMD_DRV_LOG(ERR, "interrupt enable failed");
+ return -1;
+ }
+ }
+ PMD_INIT_LOG(NOTICE, "server mode virtio-user reconnection succeeds!");
+ return 0;
+}
+
static void
virtio_user_delayed_handler(void *param)
{
struct virtio_hw *hw = (struct virtio_hw *)param;
- struct rte_eth_dev *dev = &rte_eth_devices[hw->port_id];
+ struct rte_eth_dev *eth_dev = &rte_eth_devices[hw->port_id];
+ struct virtio_user_dev *dev = virtio_user_get_dev(hw);
- rte_intr_callback_unregister(dev->intr_handle,
- virtio_interrupt_handler,
- dev);
+ if (rte_intr_disable(eth_dev->intr_handle) < 0) {
+ PMD_DRV_LOG(ERR, "interrupt disable failed");
+ return;
+ }
+ rte_intr_callback_unregister(eth_dev->intr_handle,
+ virtio_interrupt_handler, eth_dev);
+ if (dev->is_server) {
+ if (dev->vhostfd >= 0) {
+ close(dev->vhostfd);
+ dev->vhostfd = -1;
+ }
+ eth_dev->intr_handle->fd = dev->listenfd;
+ rte_intr_callback_register(eth_dev->intr_handle,
+ virtio_interrupt_handler, eth_dev);
+ if (rte_intr_enable(eth_dev->intr_handle) < 0) {
+ PMD_DRV_LOG(ERR, "interrupt enable failed");
+ return;
+ }
+ }
}
static void
@@ -67,12 +125,10 @@ virtio_user_read_dev_config(struct virtio_hw *hw, size_t
offset,
dev->status &= (~VIRTIO_NET_S_LINK_UP);
PMD_DRV_LOG(ERR, "virtio-user port %u is down",
hw->port_id);
- /* Only client mode is available now. Once the
- * connection is broken, it can never be up
- * again. Besides, this function could be called
- * in the process of interrupt handling,
- * callback cannot be unregistered here, set an
- * alarm to do it.
+
+ /* This function could be called in the process
+ * of interrupt handling, callback cannot be
+ * unregistered here, set an alarm to do it.
*/
rte_eal_alarm_set(1,
virtio_user_delayed_handler,
@@ -85,7 +141,12 @@ virtio_user_read_dev_config(struct virtio_hw *hw, size_t
offset,
PMD_DRV_LOG(ERR, "error clearing O_NONBLOCK
flag");
return;
}
+ } else if (dev->is_server) {
+ dev->status &= (~VIRTIO_NET_S_LINK_UP);
+ if (virtio_user_server_reconnect(dev) >= 0)
+ dev->status |= VIRTIO_NET_S_LINK_UP;
}
+
*(uint16_t *)dst = dev->status;
}
@@ -278,12 +339,15 @@ static const char *valid_args[] = {
VIRTIO_USER_ARG_QUEUE_SIZE,
#define VIRTIO_USER_ARG_INTERFACE_NAME "iface"
VIRTIO_USER_ARG_INTERFACE_NAME,
+#define VIRTIO_USER_ARG_SERVER_MODE "server"
+ VIRTIO_USER_ARG_SERVER_MODE,
NULL
};
#define VIRTIO_USER_DEF_CQ_EN 0
#define VIRTIO_USER_DEF_Q_NUM 1
#define VIRTIO_USER_DEF_Q_SZ 256
+#define VIRTIO_USER_DEF_SERVER_MODE 0
static int
get_string_arg(const char *key __rte_unused,
@@ -378,6 +442,7 @@ virtio_user_pmd_probe(struct rte_vdev_device *dev)
uint64_t queues = VIRTIO_USER_DEF_Q_NUM;
uint64_t cq = VIRTIO_USER_DEF_CQ_EN;
uint64_t queue_size = VIRTIO_USER_DEF_Q_SZ;
+ uint64_t server_mode = VIRTIO_USER_DEF_SERVER_MODE;
char *path = NULL;
char *ifname = NULL;
char *mac_addr = NULL;
@@ -445,6 +510,15 @@ virtio_user_pmd_probe(struct rte_vdev_device *dev)
}
}
+ if (rte_kvargs_count(kvlist, VIRTIO_USER_ARG_SERVER_MODE) == 1) {
+ if (rte_kvargs_process(kvlist, VIRTIO_USER_ARG_SERVER_MODE,
+ &get_integer_arg, &server_mode) < 0) {
+ PMD_INIT_LOG(ERR, "error to parse %s",
+ VIRTIO_USER_ARG_SERVER_MODE);
+ goto end;
+ }
+ }
+
if (rte_kvargs_count(kvlist, VIRTIO_USER_ARG_CQ_NUM) == 1) {
if (rte_kvargs_process(kvlist, VIRTIO_USER_ARG_CQ_NUM,
&get_integer_arg, &cq) < 0) {
@@ -469,6 +543,8 @@ virtio_user_pmd_probe(struct rte_vdev_device *dev)
}
if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
+ struct virtio_user_dev *vu_dev;
+
eth_dev = virtio_user_eth_dev_alloc(dev);
if (!eth_dev) {
PMD_INIT_LOG(ERR, "virtio_user fails to alloc device");
@@ -476,6 +552,11 @@ virtio_user_pmd_probe(struct rte_vdev_device *dev)
}
hw = eth_dev->data->dev_private;
+ vu_dev = virtio_user_get_dev(hw);
+ if (server_mode == 1)
+ vu_dev->is_server = true;
+ else
+ vu_dev->is_server = false;
if (virtio_user_dev_init(hw->virtio_user_dev, path, queues, cq,
queue_size, mac_addr, &ifname) < 0) {
PMD_INIT_LOG(ERR, "virtio_user_dev_init fails");
--
2.14.3
