> -----Original Message-----
> From: Yang, Zhiyong
> Sent: Friday, April 6, 2018 5:26 PM
> To: dev@dpdk.org
> Cc: Yang, Zhiyong; maxime.coque...@redhat.com; Tan, Jianfeng; Bie, Tiwei;
> Wang, Zhihong; Wang, Dong1; tho...@monjalon.net
> Subject: [PATCH v7] net/virtio-user: add support for 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 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>
Reviewed-by: Jianfeng Tan <jianfeng....@intel.com>
Thanks for the great work!
> ---
>
> 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
