From 406d2aa2cc0770526081da00780ed2124cff1654 Mon Sep 17 00:00:00 2001 From: Changpeng Liu Date: Thu, 4 Jan 2018 09:53:34 +0800 Subject: contrib/vhost-user-blk: introduce a vhost-user-blk sample application MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This commit introduces a vhost-user-blk backend device, it uses UNIX domain socket to communicate with QEMU. The vhost-user-blk sample application should be used with QEMU vhost-user-blk-pci device. To use it, complie with: make vhost-user-blk and start like this: vhost-user-blk -b /dev/sdb -s /path/vhost.socket Signed-off-by: Changpeng Liu Reviewed-by: Marc-André Lureau Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- contrib/vhost-user-blk/Makefile.objs | 1 + contrib/vhost-user-blk/vhost-user-blk.c | 545 ++++++++++++++++++++++++++++++++ 2 files changed, 546 insertions(+) create mode 100644 contrib/vhost-user-blk/Makefile.objs create mode 100644 contrib/vhost-user-blk/vhost-user-blk.c (limited to 'contrib') diff --git a/contrib/vhost-user-blk/Makefile.objs b/contrib/vhost-user-blk/Makefile.objs new file mode 100644 index 0000000000..72e2cdc3ad --- /dev/null +++ b/contrib/vhost-user-blk/Makefile.objs @@ -0,0 +1 @@ +vhost-user-blk-obj-y = vhost-user-blk.o diff --git a/contrib/vhost-user-blk/vhost-user-blk.c b/contrib/vhost-user-blk/vhost-user-blk.c new file mode 100644 index 0000000000..67dac8155a --- /dev/null +++ b/contrib/vhost-user-blk/vhost-user-blk.c @@ -0,0 +1,545 @@ +/* + * vhost-user-blk sample application + * + * Copyright (c) 2017 Intel Corporation. All rights reserved. + * + * Author: + * Changpeng Liu + * + * This work is based on the "vhost-user-scsi" sample and "virtio-blk" driver + * implementation by: + * Felipe Franciosi + * Anthony Liguori + * + * This work is licensed under the terms of the GNU GPL, version 2 only. + * See the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "standard-headers/linux/virtio_blk.h" +#include "contrib/libvhost-user/libvhost-user-glib.h" +#include "contrib/libvhost-user/libvhost-user.h" + +#include + +struct virtio_blk_inhdr { + unsigned char status; +}; + +/* vhost user block device */ +typedef struct VubDev { + VugDev parent; + int blk_fd; + struct virtio_blk_config blkcfg; + char *blk_name; + GMainLoop *loop; +} VubDev; + +typedef struct VubReq { + VuVirtqElement *elem; + int64_t sector_num; + size_t size; + struct virtio_blk_inhdr *in; + struct virtio_blk_outhdr *out; + VubDev *vdev_blk; + struct VuVirtq *vq; +} VubReq; + +/* refer util/iov.c */ +static size_t vub_iov_size(const struct iovec *iov, + const unsigned int iov_cnt) +{ + size_t len; + unsigned int i; + + len = 0; + for (i = 0; i < iov_cnt; i++) { + len += iov[i].iov_len; + } + return len; +} + +static void vub_panic_cb(VuDev *vu_dev, const char *buf) +{ + VugDev *gdev; + VubDev *vdev_blk; + + assert(vu_dev); + + gdev = container_of(vu_dev, VugDev, parent); + vdev_blk = container_of(gdev, VubDev, parent); + if (buf) { + g_warning("vu_panic: %s", buf); + } + + g_main_loop_quit(vdev_blk->loop); +} + +static void vub_req_complete(VubReq *req) +{ + VugDev *gdev = &req->vdev_blk->parent; + VuDev *vu_dev = &gdev->parent; + + /* IO size with 1 extra status byte */ + vu_queue_push(vu_dev, req->vq, req->elem, + req->size + 1); + vu_queue_notify(vu_dev, req->vq); + + if (req->elem) { + free(req->elem); + } + + g_free(req); +} + +static int vub_open(const char *file_name, bool wce) +{ + int fd; + int flags = O_RDWR; + + if (!wce) { + flags |= O_DIRECT; + } + + fd = open(file_name, flags); + if (fd < 0) { + fprintf(stderr, "Cannot open file %s, %s\n", file_name, + strerror(errno)); + return -1; + } + + return fd; +} + +static ssize_t +vub_readv(VubReq *req, struct iovec *iov, uint32_t iovcnt) +{ + VubDev *vdev_blk = req->vdev_blk; + ssize_t rc; + + if (!iovcnt) { + fprintf(stderr, "Invalid Read IOV count\n"); + return -1; + } + + req->size = vub_iov_size(iov, iovcnt); + rc = preadv(vdev_blk->blk_fd, iov, iovcnt, req->sector_num * 512); + if (rc < 0) { + fprintf(stderr, "%s, Sector %"PRIu64", Size %lu failed with %s\n", + vdev_blk->blk_name, req->sector_num, req->size, + strerror(errno)); + return -1; + } + + return rc; +} + +static ssize_t +vub_writev(VubReq *req, struct iovec *iov, uint32_t iovcnt) +{ + VubDev *vdev_blk = req->vdev_blk; + ssize_t rc; + + if (!iovcnt) { + fprintf(stderr, "Invalid Write IOV count\n"); + return -1; + } + + req->size = vub_iov_size(iov, iovcnt); + rc = pwritev(vdev_blk->blk_fd, iov, iovcnt, req->sector_num * 512); + if (rc < 0) { + fprintf(stderr, "%s, Sector %"PRIu64", Size %lu failed with %s\n", + vdev_blk->blk_name, req->sector_num, req->size, + strerror(errno)); + return -1; + } + + return rc; +} + +static void +vub_flush(VubReq *req) +{ + VubDev *vdev_blk = req->vdev_blk; + + fdatasync(vdev_blk->blk_fd); +} + +static int vub_virtio_process_req(VubDev *vdev_blk, + VuVirtq *vq) +{ + VugDev *gdev = &vdev_blk->parent; + VuDev *vu_dev = &gdev->parent; + VuVirtqElement *elem; + uint32_t type; + unsigned in_num; + unsigned out_num; + VubReq *req; + + elem = vu_queue_pop(vu_dev, vq, sizeof(VuVirtqElement) + sizeof(VubReq)); + if (!elem) { + return -1; + } + + /* refer to hw/block/virtio_blk.c */ + if (elem->out_num < 1 || elem->in_num < 1) { + fprintf(stderr, "virtio-blk request missing headers\n"); + free(elem); + return -1; + } + + req = g_new0(VubReq, 1); + req->vdev_blk = vdev_blk; + req->vq = vq; + req->elem = elem; + + in_num = elem->in_num; + out_num = elem->out_num; + + /* don't support VIRTIO_F_ANY_LAYOUT and virtio 1.0 only */ + if (elem->out_sg[0].iov_len < sizeof(struct virtio_blk_outhdr)) { + fprintf(stderr, "Invalid outhdr size\n"); + goto err; + } + req->out = (struct virtio_blk_outhdr *)elem->out_sg[0].iov_base; + out_num--; + + if (elem->in_sg[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) { + fprintf(stderr, "Invalid inhdr size\n"); + goto err; + } + req->in = (struct virtio_blk_inhdr *)elem->in_sg[in_num - 1].iov_base; + in_num--; + + type = le32toh(req->out->type); + switch (type & ~(VIRTIO_BLK_T_OUT | VIRTIO_BLK_T_BARRIER)) { + case VIRTIO_BLK_T_IN: { + ssize_t ret = 0; + bool is_write = type & VIRTIO_BLK_T_OUT; + req->sector_num = le64toh(req->out->sector); + if (is_write) { + ret = vub_writev(req, &elem->out_sg[1], out_num); + } else { + ret = vub_readv(req, &elem->in_sg[0], in_num); + } + if (ret >= 0) { + req->in->status = VIRTIO_BLK_S_OK; + } else { + req->in->status = VIRTIO_BLK_S_IOERR; + } + vub_req_complete(req); + break; + } + case VIRTIO_BLK_T_FLUSH: { + vub_flush(req); + req->in->status = VIRTIO_BLK_S_OK; + vub_req_complete(req); + break; + } + case VIRTIO_BLK_T_GET_ID: { + size_t size = MIN(vub_iov_size(&elem->in_sg[0], in_num), + VIRTIO_BLK_ID_BYTES); + snprintf(elem->in_sg[0].iov_base, size, "%s", "vhost_user_blk"); + req->in->status = VIRTIO_BLK_S_OK; + req->size = elem->in_sg[0].iov_len; + vub_req_complete(req); + break; + } + default: { + req->in->status = VIRTIO_BLK_S_UNSUPP; + vub_req_complete(req); + break; + } + } + + return 0; + +err: + free(elem); + g_free(req); + return -1; +} + +static void vub_process_vq(VuDev *vu_dev, int idx) +{ + VugDev *gdev; + VubDev *vdev_blk; + VuVirtq *vq; + int ret; + + if ((idx < 0) || (idx >= VHOST_MAX_NR_VIRTQUEUE)) { + fprintf(stderr, "VQ Index out of range: %d\n", idx); + vub_panic_cb(vu_dev, NULL); + return; + } + + gdev = container_of(vu_dev, VugDev, parent); + vdev_blk = container_of(gdev, VubDev, parent); + assert(vdev_blk); + + vq = vu_get_queue(vu_dev, idx); + assert(vq); + + while (1) { + ret = vub_virtio_process_req(vdev_blk, vq); + if (ret) { + break; + } + } +} + +static void vub_queue_set_started(VuDev *vu_dev, int idx, bool started) +{ + VuVirtq *vq; + + assert(vu_dev); + + vq = vu_get_queue(vu_dev, idx); + vu_set_queue_handler(vu_dev, vq, started ? vub_process_vq : NULL); +} + +static uint64_t +vub_get_features(VuDev *dev) +{ + return 1ull << VIRTIO_BLK_F_SIZE_MAX | + 1ull << VIRTIO_BLK_F_SEG_MAX | + 1ull << VIRTIO_BLK_F_TOPOLOGY | + 1ull << VIRTIO_BLK_F_BLK_SIZE | + 1ull << VIRTIO_BLK_F_FLUSH | + 1ull << VIRTIO_BLK_F_CONFIG_WCE | + 1ull << VIRTIO_F_VERSION_1 | + 1ull << VHOST_USER_F_PROTOCOL_FEATURES; +} + +static int +vub_get_config(VuDev *vu_dev, uint8_t *config, uint32_t len) +{ + VugDev *gdev; + VubDev *vdev_blk; + + gdev = container_of(vu_dev, VugDev, parent); + vdev_blk = container_of(gdev, VubDev, parent); + memcpy(config, &vdev_blk->blkcfg, len); + + return 0; +} + +static int +vub_set_config(VuDev *vu_dev, const uint8_t *data, + uint32_t offset, uint32_t size, uint32_t flags) +{ + VugDev *gdev; + VubDev *vdev_blk; + uint8_t wce; + int fd; + + /* don't support live migration */ + if (flags != VHOST_SET_CONFIG_TYPE_MASTER) { + return -1; + } + + gdev = container_of(vu_dev, VugDev, parent); + vdev_blk = container_of(gdev, VubDev, parent); + + if (offset != offsetof(struct virtio_blk_config, wce) || + size != 1) { + return -1; + } + + wce = *data; + if (wce == vdev_blk->blkcfg.wce) { + /* Do nothing as same with old configuration */ + return 0; + } + + vdev_blk->blkcfg.wce = wce; + fprintf(stdout, "Write Cache Policy Changed\n"); + if (vdev_blk->blk_fd >= 0) { + close(vdev_blk->blk_fd); + vdev_blk->blk_fd = -1; + } + + fd = vub_open(vdev_blk->blk_name, wce); + if (fd < 0) { + fprintf(stderr, "Error to open block device %s\n", vdev_blk->blk_name); + vdev_blk->blk_fd = -1; + return -1; + } + vdev_blk->blk_fd = fd; + + return 0; +} + +static const VuDevIface vub_iface = { + .get_features = vub_get_features, + .queue_set_started = vub_queue_set_started, + .get_config = vub_get_config, + .set_config = vub_set_config, +}; + +static int unix_sock_new(char *unix_fn) +{ + int sock; + struct sockaddr_un un; + size_t len; + + assert(unix_fn); + + sock = socket(AF_UNIX, SOCK_STREAM, 0); + if (sock <= 0) { + perror("socket"); + return -1; + } + + un.sun_family = AF_UNIX; + (void)snprintf(un.sun_path, sizeof(un.sun_path), "%s", unix_fn); + len = sizeof(un.sun_family) + strlen(un.sun_path); + + (void)unlink(unix_fn); + if (bind(sock, (struct sockaddr *)&un, len) < 0) { + perror("bind"); + goto fail; + } + + if (listen(sock, 1) < 0) { + perror("listen"); + goto fail; + } + + return sock; + +fail: + (void)close(sock); + + return -1; +} + +static void vub_free(struct VubDev *vdev_blk) +{ + if (!vdev_blk) { + return; + } + + g_main_loop_unref(vdev_blk->loop); + if (vdev_blk->blk_fd >= 0) { + close(vdev_blk->blk_fd); + } + g_free(vdev_blk); +} + +static uint32_t +vub_get_blocksize(int fd) +{ + uint32_t blocksize = 512; + +#if defined(__linux__) && defined(BLKSSZGET) + if (ioctl(fd, BLKSSZGET, &blocksize) == 0) { + return blocklen; + } +#endif + + return blocksize; +} + +static void +vub_initialize_config(int fd, struct virtio_blk_config *config) +{ + off64_t capacity; + + capacity = lseek64(fd, 0, SEEK_END); + config->capacity = capacity >> 9; + config->blk_size = vub_get_blocksize(fd); + config->size_max = 65536; + config->seg_max = 128 - 2; + config->min_io_size = 1; + config->opt_io_size = 1; + config->num_queues = 1; +} + +static VubDev * +vub_new(char *blk_file) +{ + VubDev *vdev_blk; + + vdev_blk = g_new0(VubDev, 1); + vdev_blk->loop = g_main_loop_new(NULL, FALSE); + vdev_blk->blk_fd = vub_open(blk_file, 0); + if (vdev_blk->blk_fd < 0) { + fprintf(stderr, "Error to open block device %s\n", blk_file); + vub_free(vdev_blk); + return NULL; + } + vdev_blk->blkcfg.wce = 0; + vdev_blk->blk_name = blk_file; + + /* fill virtio_blk_config with block parameters */ + vub_initialize_config(vdev_blk->blk_fd, &vdev_blk->blkcfg); + + return vdev_blk; +} + +int main(int argc, char **argv) +{ + int opt; + char *unix_socket = NULL; + char *blk_file = NULL; + int lsock = -1, csock = -1; + VubDev *vdev_blk = NULL; + + while ((opt = getopt(argc, argv, "b:s:h")) != -1) { + switch (opt) { + case 'b': + blk_file = g_strdup(optarg); + break; + case 's': + unix_socket = g_strdup(optarg); + break; + case 'h': + default: + printf("Usage: %s [-b block device or file, -s UNIX domain socket]" + " | [ -h ]\n", argv[0]); + return 0; + } + } + + if (!unix_socket || !blk_file) { + printf("Usage: %s [-b block device or file, -s UNIX domain socket] |" + " [ -h ]\n", argv[0]); + return -1; + } + + lsock = unix_sock_new(unix_socket); + if (lsock < 0) { + goto err; + } + + csock = accept(lsock, (void *)0, (void *)0); + if (csock < 0) { + fprintf(stderr, "Accept error %s\n", strerror(errno)); + goto err; + } + + vdev_blk = vub_new(blk_file); + if (!vdev_blk) { + goto err; + } + + vug_init(&vdev_blk->parent, csock, vub_panic_cb, &vub_iface); + + g_main_loop_run(vdev_blk->loop); + + vug_deinit(&vdev_blk->parent); + +err: + vub_free(vdev_blk); + if (csock >= 0) { + close(csock); + } + if (lsock >= 0) { + close(lsock); + } + g_free(unix_socket); + g_free(blk_file); + + return 0; +} -- cgit v1.2.3