RE: [RFC 18/27] vhost: add VDUSE device creation and destruction

["Xia, Chenbo" <chenbo.xia@intel.com>]

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Friday, March 31, 2023 11:43 PM
> To: dev@dpdk.org; david.marchand@redhat.com; Xia, Chenbo
> <chenbo.xia@intel.com>; mkp@redhat.com; fbl@redhat.com;
> jasowang@redhat.com; Liang, Cunming <cunming.liang@intel.com>; Xie, Yongji
> <xieyongji@bytedance.com>; echaudro@redhat.com; eperezma@redhat.com;
> amorenoz@redhat.com
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
> Subject: [RFC 18/27] vhost: add VDUSE device creation and destruction
> 
> This patch adds initial support for VDUSE, which includes
> the device creation and destruction.
> 
> It does not include the virtqueues configuration, so this is
> not functionnal at this point.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  lib/vhost/meson.build |   4 +
>  lib/vhost/socket.c    |  34 +++++---
>  lib/vhost/vduse.c     | 184 ++++++++++++++++++++++++++++++++++++++++++
>  lib/vhost/vduse.h     |  33 ++++++++
>  lib/vhost/vhost.h     |   2 +
>  5 files changed, 245 insertions(+), 12 deletions(-)
>  create mode 100644 lib/vhost/vduse.c
>  create mode 100644 lib/vhost/vduse.h
> 
> diff --git a/lib/vhost/meson.build b/lib/vhost/meson.build
> index cdcd403df3..a57a15937f 100644
> --- a/lib/vhost/meson.build
> +++ b/lib/vhost/meson.build
> @@ -30,6 +30,10 @@ sources = files(
>          'virtio_net.c',
>          'virtio_net_ctrl.c',
>  )
> +if cc.has_header('linux/vduse.h')
> +    sources += files('vduse.c')
> +    cflags += '-DVHOST_HAS_VDUSE'
> +endif
>  headers = files(
>          'rte_vdpa.h',
>          'rte_vhost.h',
> diff --git a/lib/vhost/socket.c b/lib/vhost/socket.c
> index e95c3ffeac..a8a1c4cd2b 100644
> --- a/lib/vhost/socket.c
> +++ b/lib/vhost/socket.c
> @@ -18,6 +18,7 @@
>  #include <rte_log.h>
> 
>  #include "fd_man.h"
> +#include "vduse.h"
>  #include "vhost.h"
>  #include "vhost_user.h"
> 
> @@ -35,6 +36,7 @@ struct vhost_user_socket {
>  	int socket_fd;
>  	struct sockaddr_un un;
>  	bool is_server;
> +	bool is_vduse;
>  	bool reconnect;
>  	bool iommu_support;
>  	bool use_builtin_virtio_net;
> @@ -992,18 +994,21 @@ rte_vhost_driver_register(const char *path, uint64_t
> flags)
>  #endif
>  	}
> 
> -	if ((flags & RTE_VHOST_USER_CLIENT) != 0) {
> -		vsocket->reconnect = !(flags & RTE_VHOST_USER_NO_RECONNECT);
> -		if (vsocket->reconnect && reconn_tid == 0) {
> -			if (vhost_user_reconnect_init() != 0)
> -				goto out_mutex;
> -		}
> +	if (!strncmp("/dev/vduse/", path, strlen("/dev/vduse/"))) {
> +		vsocket->is_vduse = true;
>  	} else {
> -		vsocket->is_server = true;
> -	}
> -	ret = create_unix_socket(vsocket);
> -	if (ret < 0) {
> -		goto out_mutex;
> +		if ((flags & RTE_VHOST_USER_CLIENT) != 0) {
> +			vsocket->reconnect = !(flags &
> RTE_VHOST_USER_NO_RECONNECT);
> +			if (vsocket->reconnect && reconn_tid == 0) {
> +				if (vhost_user_reconnect_init() != 0)
> +					goto out_mutex;
> +			}
> +		} else {
> +			vsocket->is_server = true;
> +		}
> +		ret = create_unix_socket(vsocket);
> +		if (ret < 0)
> +			goto out_mutex;
>  	}
> 
>  	vhost_user.vsockets[vhost_user.vsocket_cnt++] = vsocket;
> @@ -1068,7 +1073,9 @@ rte_vhost_driver_unregister(const char *path)
>  		if (strcmp(vsocket->path, path))
>  			continue;
> 
> -		if (vsocket->is_server) {
> +		if (vsocket->is_vduse) {
> +			vduse_device_destroy(path);
> +		} else if (vsocket->is_server) {
>  			/*
>  			 * If r/wcb is executing, release vhost_user's
>  			 * mutex lock, and try again since the r/wcb
> @@ -1171,6 +1178,9 @@ rte_vhost_driver_start(const char *path)
>  	if (!vsocket)
>  		return -1;
> 
> +	if (vsocket->is_vduse)
> +		return vduse_device_create(path);
> +
>  	if (fdset_tid == 0) {
>  		/**
>  		 * create a pipe which will be waited by poll and notified to
> diff --git a/lib/vhost/vduse.c b/lib/vhost/vduse.c
> new file mode 100644
> index 0000000000..336761c97a
> --- /dev/null
> +++ b/lib/vhost/vduse.c
> @@ -0,0 +1,184 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright (c) 2023 Red Hat, Inc.
> + */
> +
> +#include <stdint.h>
> +#include <stdio.h>
> +#include <unistd.h>
> +#include <fcntl.h>
> +
> +
> +#include <linux/vduse.h>
> +#include <linux/virtio_net.h>
> +
> +#include <sys/ioctl.h>
> +#include <sys/mman.h>
> +
> +#include <rte_common.h>
> +
> +#include "vduse.h"
> +#include "vhost.h"
> +
> +#define VHOST_VDUSE_API_VERSION 0
> +#define VDUSE_CTRL_PATH "/dev/vduse/control"
> +
> +#define VDUSE_NET_SUPPORTED_FEATURES ((1ULL << VIRTIO_NET_F_MRG_RXBUF) |
> \
> +				(1ULL << VIRTIO_F_ANY_LAYOUT) | \
> +				(1ULL << VIRTIO_F_VERSION_1)   | \
> +				(1ULL << VIRTIO_RING_F_INDIRECT_DESC) | \
> +				(1ULL << VIRTIO_RING_F_EVENT_IDX) | \
> +				(1ULL << VIRTIO_F_IN_ORDER) | \
> +				(1ULL << VIRTIO_F_IOMMU_PLATFORM))
> +
> +static struct vhost_backend_ops vduse_backend_ops = {
> +};
> +
> +int
> +vduse_device_create(const char *path)
> +{
> +	int control_fd, dev_fd, vid, ret;
> +	uint32_t i;
> +	struct virtio_net *dev;
> +	uint64_t ver = VHOST_VDUSE_API_VERSION;
> +	struct vduse_dev_config *dev_config = NULL;
> +	const char *name = path + strlen("/dev/vduse/");
> +
> +	control_fd = open(VDUSE_CTRL_PATH, O_RDWR);
> +	if (control_fd < 0) {
> +		VHOST_LOG_CONFIG(name, ERR, "Failed to open %s: %s\n",
> +				VDUSE_CTRL_PATH, strerror(errno));
> +		return -1;
> +	}
> +
> +	if (ioctl(control_fd, VDUSE_SET_API_VERSION, &ver)) {
> +		VHOST_LOG_CONFIG(name, ERR, "Failed to set API version: %"
> PRIu64 ": %s\n",
> +				ver, strerror(errno));
> +		ret = -1;
> +		goto out_ctrl_close;
> +	}
> +
> +	dev_config = malloc(offsetof(struct vduse_dev_config, config));
> +	if (!dev_config) {
> +		VHOST_LOG_CONFIG(name, ERR, "Failed to allocate VDUSE
> config\n");
> +		ret = -1;
> +		goto out_ctrl_close;
> +	}
> +
> +	memset(dev_config, 0, sizeof(struct vduse_dev_config));
> +
> +	strncpy(dev_config->name, name, VDUSE_NAME_MAX - 1);
> +	dev_config->device_id = VIRTIO_ID_NET;
> +	dev_config->vendor_id = 0;
> +	dev_config->features = VDUSE_NET_SUPPORTED_FEATURES;
> +	dev_config->vq_num = 2;
> +	dev_config->vq_align = sysconf(_SC_PAGE_SIZE);
> +	dev_config->config_size = 0;
> +
> +	ret = ioctl(control_fd, VDUSE_CREATE_DEV, dev_config);
> +	if (ret < 0) {
> +		VHOST_LOG_CONFIG(name, ERR, "Failed to create VDUSE
> device: %s\n",
> +				strerror(errno));
> +		goto out_free;
> +	}
> +
> +	dev_fd = open(path, O_RDWR);
> +	if (dev_fd < 0) {
> +		VHOST_LOG_CONFIG(name, ERR, "Failed to open device %s: %s\n",
> +				path, strerror(errno));
> +		ret = -1;
> +		goto out_dev_close;
> +	}
> +
> +	vid = vhost_new_device(&vduse_backend_ops);
> +	if (vid < 0) {
> +		VHOST_LOG_CONFIG(name, ERR, "Failed to create new Vhost
> device\n");
> +		ret = -1;
> +		goto out_dev_close;
> +	}
> +
> +	dev = get_device(vid);
> +	if (!dev) {
> +		ret = -1;
> +		goto out_dev_close;
> +	}
> +
> +	strncpy(dev->ifname, path, IF_NAME_SZ - 1);
> +	dev->vduse_ctrl_fd = control_fd;
> +	dev->vduse_dev_fd = dev_fd;
> +	vhost_setup_virtio_net(dev->vid, true, true, true, true);
> +
> +	for (i = 0; i < 2; i++) {
> +		struct vduse_vq_config vq_cfg = { 0 };
> +
> +		ret = alloc_vring_queue(dev, i);
> +		if (ret) {
> +			VHOST_LOG_CONFIG(name, ERR, "Failed to alloc vring %d
> metadata\n", i);
> +			goto out_dev_destroy;
> +		}
> +
> +		vq_cfg.index = i;
> +		vq_cfg.max_size = 1024;
> +
> +		ret = ioctl(dev->vduse_dev_fd, VDUSE_VQ_SETUP, &vq_cfg);
> +		if (ret) {
> +			VHOST_LOG_CONFIG(name, ERR, "Failed to set-up VQ %d\n",
> i);
> +			goto out_dev_destroy;
> +		}
> +	}
> +
> +	free(dev_config);
> +
> +	return 0;
> +
> +out_dev_destroy:
> +	vhost_destroy_device(vid);
> +out_dev_close:
> +	if (dev_fd >= 0)
> +		close(dev_fd);
> +	ioctl(control_fd, VDUSE_DESTROY_DEV, name);
> +out_free:
> +	free(dev_config);
> +out_ctrl_close:
> +	close(control_fd);
> +
> +	return ret;
> +}
> +
> +int
> +vduse_device_destroy(const char *path)
> +{
> +	const char *name = path + strlen("/dev/vduse/");
> +	struct virtio_net *dev;
> +	int vid, ret;
> +
> +	for (vid = 0; vid < RTE_MAX_VHOST_DEVICE; vid++) {
> +		dev = vhost_devices[vid];
> +
> +		if (dev == NULL)
> +			continue;
> +
> +		if (!strcmp(path, dev->ifname))
> +			break;
> +	}
> +
> +	if (vid == RTE_MAX_VHOST_DEVICE)
> +		return -1;
> +
> +	if (dev->vduse_dev_fd >= 0) {
> +		close(dev->vduse_dev_fd);
> +		dev->vduse_dev_fd = -1;
> +	}
> +
> +	if (dev->vduse_ctrl_fd >= 0) {
> +		ret = ioctl(dev->vduse_ctrl_fd, VDUSE_DESTROY_DEV, name);
> +		if (ret)
> +			VHOST_LOG_CONFIG(name, ERR, "Failed to destroy VDUSE
> device: %s\n",
> +					strerror(errno));
> +		close(dev->vduse_ctrl_fd);
> +		dev->vduse_ctrl_fd = -1;
> +	}
> +
> +	vhost_destroy_device(vid);
> +
> +	return 0;
> +}
> diff --git a/lib/vhost/vduse.h b/lib/vhost/vduse.h
> new file mode 100644
> index 0000000000..a15e5d4c16
> --- /dev/null
> +++ b/lib/vhost/vduse.h
> @@ -0,0 +1,33 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright (c) 2023 Red Hat, Inc.
> + */
> +
> +#ifndef _VDUSE_H
> +#define _VDUSE_H
> +
> +#include "vhost.h"
> +
> +#ifdef VHOST_HAS_VDUSE
> +
> +int vduse_device_create(const char *path);
> +int vduse_device_destroy(const char *path);
> +
> +#else
> +
> +static inline int
> +vduse_device_create(const char *path)
> +{
> +	VHOST_LOG_CONFIG(path, ERR, "VDUSE support disabled at build
> time\n");
> +	return -1;
> +}
> +
> +static inline int
> +vduse_device_destroy(const char *path)
> +{
> +	VHOST_LOG_CONFIG(path, ERR, "VDUSE support disabled at build
> time\n");
> +	return -1;
> +}
> +
> +#endif /* VHOST_HAS_VDUSE */
> +
> +#endif /* _VDUSE_H */
> diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
> index 76663aed24..c8f2a0d43a 100644
> --- a/lib/vhost/vhost.h
> +++ b/lib/vhost/vhost.h
> @@ -524,6 +524,8 @@ struct virtio_net {
> 
>  	int			postcopy_ufd;
>  	int			postcopy_listening;
> +	int			vduse_ctrl_fd;
> +	int			vduse_dev_fd;
> 
>  	struct vhost_virtqueue	*cvq;
> 
> --
> 2.39.2

Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>