[dpdk-dev] [PATCH v4 1/1] net/virtio-user: add support for server mode
Tan, Jianfeng
jianfeng.tan at intel.com
Tue Apr 3 17:16:26 CEST 2018
On 4/3/2018 8:20 PM, zhiyong.yang at intel.com wrote:
> virtio-user adds support for server mode in this patch.
>
> Client mode vhost-user startup firstly, server mode virtio-user startups
> and creates the socket file to exchange vhost messages.
>
> If the connection is broken, client mode vhost-user can support to
> reconnect virtio-user.
>
> Server mode virtio-user supports many times' vhost-user reconnections with
> the same parameter configurations.
>
> Release note is updated in the patch.
With current implementation, we have to enable LSC; or no chance to
accept the coming connection. We shall point this out.
And if possible, split this patch into multiple patches.
>
> Signed-off-by: Zhiyong Yang <zhiyong.yang at intel.com>
> ---
> doc/guides/rel_notes/release_18_05.rst | 6 ++
> drivers/net/virtio/virtio_user/vhost_user.c | 64 ++++++++++++--
> drivers/net/virtio/virtio_user/virtio_user_dev.c | 45 +++++++---
> drivers/net/virtio/virtio_user/virtio_user_dev.h | 4 +
> drivers/net/virtio/virtio_user_ethdev.c | 103 +++++++++++++++++++++--
> 5 files changed, 194 insertions(+), 28 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..1b3401d4f 100644
> --- a/drivers/net/virtio/virtio_user/vhost_user.c
> +++ b/drivers/net/virtio/virtio_user/vhost_user.c
> @@ -378,6 +378,50 @@ vhost_user_sock(struct virtio_user_dev *dev,
> return 0;
> }
>
> +static void
> +virtio_user_set_block(int fd, bool enabled)
This is only used once, no need to abstract it into a function?
> +{
> + int f;
> +
> + f = fcntl(fd, F_GETFL);
> + if (enabled)
> + fcntl(fd, F_SETFL, f & ~O_NONBLOCK);
> + else
> + fcntl(fd, F_SETFL, f | O_NONBLOCK);
> +}
> +
> +#define MAX_VIRTIO_USER_BACKLOG 128
We only allow one connection from vhost-user, so how about just make the
backlog queue length as 1?
> +static int
> +virtio_user_start_server(struct virtio_user_dev *dev, struct sockaddr_un *un)
> +{
> + int ret;
> + int fd = dev->listenfd;
> + int connectfd;
> +
> + 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));
> + goto err;
> + }
> + ret = listen(fd, MAX_VIRTIO_USER_BACKLOG);
> + if (ret < 0)
> + goto err;
> +
> + connectfd = accept(fd, NULL, NULL);
> + if (connectfd >= 0)
> + dev->connected = true;
> + else
> + goto err;
if (connectfd < 0)
goto err;
dev->connected = true;
dev->vhostfd = connectfd;
...
> +
> + dev->vhostfd = connectfd;
> + virtio_user_set_block(connectfd, true);
> + return 0;
> +err:
> + close(dev->listenfd);
> + return -1;
> +}
> +
> /**
> * Set up environment to talk with a vhost user backend.
> *
> @@ -390,6 +434,7 @@ vhost_user_setup(struct virtio_user_dev *dev)
> {
> int fd;
> int flag;
> + int ret = 0;
> struct sockaddr_un un;
>
> fd = socket(AF_UNIX, SOCK_STREAM, 0);
> @@ -405,14 +450,21 @@ 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;
> + ret = virtio_user_start_server(dev, &un);
> + } else {
> + dev->vhostfd = fd;
> + if (connect(fd, (struct sockaddr *)&un, sizeof(un)) < 0) {
> + PMD_DRV_LOG(ERR, "connect error, %s", strerror(errno));
> + close(fd);
> + return -1;
> + }
> + dev->connected = true;
> }
>
> - dev->vhostfd = fd;
> - return 0;
> + return ret;
> }
>
> static int
> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> index f90fee9e5..dd9fa9bdf 100644
> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> @@ -142,6 +142,9 @@ int virtio_user_stop_device(struct virtio_user_dev *dev)
> {
> uint32_t i;
>
> + if (!dev->connected)
> + return -1;
> +
> for (i = 0; i < dev->max_queue_pairs; ++i)
> dev->ops->enable_qp(dev, i, 0);
>
> @@ -267,21 +270,27 @@ virtio_user_dev_setup(struct virtio_user_dev *dev)
> dev->vhostfds = NULL;
> dev->tapfds = NULL;
Add a check here:
if (dev->is_server && !is_vhost_user_by_type(dev->path))
return error;
>
> - if (is_vhost_user_by_type(dev->path)) {
> - dev->ops = &ops_user;
> + if (dev->is_server) {
> + dev->ops = &ops_user;/* server mode only supports vhost 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;
> + 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;
> + }
> }
> }
>
> @@ -388,6 +397,11 @@ 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;
> + }
> + dev->connected = false;
> if (dev->vhostfds) {
> for (i = 0; i < dev->max_queue_pairs; ++i)
> close(dev->vhostfds[i]);
> @@ -396,6 +410,9 @@ 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 64467b4f9..68056720d 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 +14,9 @@
> struct virtio_user_dev {
> /* for vhost_user backend */
> int vhostfd;
> + int listenfd; /* listening fd */
> + bool connected; /* connection status */
Seems not necessary to add this field; as the connection status can be
deduced from (vhostfd>=0)
> + 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..5b8c8e291 100644
> --- a/drivers/net/virtio/virtio_user_ethdev.c
> +++ b/drivers/net/virtio/virtio_user_ethdev.c
> @@ -24,15 +24,76 @@
> #define virtio_user_get_dev(hw) \
> ((struct virtio_user_dev *)(hw)->virtio_user_dev)
>
> +static void
> +virtio_user_server_reconnection(struct virtio_user_dev *dev)
s/reconnection/reconnect?
> +{
> + int ret;
> + int flag;
> + int connectfd;
> + struct rte_eth_dev *eth_dev = &rte_eth_devices[dev->port_id];
> +
> + if (dev->connected)
> + return;
> +
> + connectfd = accept(dev->listenfd, NULL, NULL);
> + if (connectfd < 0)
> + return;
> +
> + 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;
> +
> + 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;
> + }
> + 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;
> + }
> + }
> + dev->connected = true;
> + PMD_INIT_LOG(NOTICE, "server mode virtio-user reconnection succeeds!");
> +}
> +
> 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
> @@ -65,8 +126,7 @@ virtio_user_read_dev_config(struct virtio_hw *hw, size_t offset,
> r = recv(dev->vhostfd, buf, 128, MSG_PEEK);
As server mode and the connection is not connected, vhostfd is -1 now,
then r < 0 and errno is EBADF, how could it go into server handling in
the "else if" block?
> if (r == 0 || (r < 0 && errno != EAGAIN)) {
> 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
Can you also correct this note as we support server mode now?
> * connection is broken, it can never be up
> * again. Besides, this function could be called
> @@ -74,9 +134,14 @@ virtio_user_read_dev_config(struct virtio_hw *hw, size_t offset,
> * callback cannot be unregistered here, set an
> * alarm to do it.
> */
> - rte_eal_alarm_set(1,
> + if (dev->connected) {
> + dev->connected = false;
> + PMD_DRV_LOG(ERR, "virtio-user port %u is down",
> + hw->port_id);
> + rte_eal_alarm_set(1,
> virtio_user_delayed_handler,
> (void *)hw);
> + }
> } else {
> dev->status |= VIRTIO_NET_S_LINK_UP;
> }
> @@ -85,7 +150,10 @@ 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)
> + virtio_user_server_reconnection(dev);
> +
> *(uint16_t *)dst = dev->status;
> }
>
> @@ -278,12 +346,15 @@ 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,
> @@ -378,10 +449,12 @@ 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;
> int ret = -1;
> + struct virtio_user_dev *vu_dev = NULL;
>
> kvlist = rte_kvargs_parse(rte_vdev_device_args(dev), valid_args);
> if (!kvlist) {
> @@ -445,6 +518,15 @@ 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) {
> @@ -476,6 +558,11 @@ 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");
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