2 files changed, 680 insertions, 0 deletions

diff --git a/contrib/vhost-user-blk/meson.build b/contrib/vhost-user-blk/meson.build
new file mode 100644
index 000000000..7f47ad1b2
--- /dev/null
+++ b/contrib/vhost-user-blk/meson.build
@@ -0,0 +1,5 @@
+# FIXME: broken on 32-bit architectures
+executable('vhost-user-blk', files('vhost-user-blk.c'),
+           dependencies: [qemuutil, vhost_user],
+           build_by_default: true,
+           install: false)
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 000000000..865bb5773
--- /dev/null
+++ b/contrib/vhost-user-blk/vhost-user-blk.c
@@ -0,0 +1,675 @@
+/*
+ * vhost-user-blk sample application
+ *
+ * Copyright (c) 2017 Intel Corporation. All rights reserved.
+ *
+ * Author:
+ *  Changpeng Liu <changpeng.liu@intel.com>
+ *
+ * This work is based on the "vhost-user-scsi" sample and "virtio-blk" driver
+ * implementation by:
+ *  Felipe Franciosi <felipe@nutanix.com>
+ *  Anthony Liguori <aliguori@us.ibm.com>
+ *
+ * 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 "libvhost-user-glib.h"
+
+#if defined(__linux__)
+#include <linux/fs.h>
+#include <sys/ioctl.h>
+#endif
+
+enum {
+    VHOST_USER_BLK_MAX_QUEUES = 8,
+};
+
+struct virtio_blk_inhdr {
+    unsigned char status;
+};
+
+/* vhost user block device */
+typedef struct VubDev {
+    VugDev parent;
+    int blk_fd;
+    struct virtio_blk_config blkcfg;
+    bool enable_ro;
+    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 size_t vub_iov_to_buf(const struct iovec *iov,
+                             const unsigned int iov_cnt, void *buf)
+{
+    size_t len;
+    unsigned int i;
+
+    len = 0;
+    for (i = 0; i < iov_cnt; i++) {
+        memcpy(buf + len,  iov[i].iov_base, iov[i].iov_len);
+        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 int
+vub_discard_write_zeroes(VubReq *req, struct iovec *iov, uint32_t iovcnt,
+                         uint32_t type)
+{
+    struct virtio_blk_discard_write_zeroes *desc;
+    ssize_t size;
+    void *buf;
+
+    size = vub_iov_size(iov, iovcnt);
+    if (size != sizeof(*desc)) {
+        fprintf(stderr, "Invalid size %ld, expect %ld\n", size, sizeof(*desc));
+        return -1;
+    }
+    buf = g_new0(char, size);
+    vub_iov_to_buf(iov, iovcnt, buf);
+
+    #if defined(__linux__) && defined(BLKDISCARD) && defined(BLKZEROOUT)
+    VubDev *vdev_blk = req->vdev_blk;
+    desc = (struct virtio_blk_discard_write_zeroes *)buf;
+    uint64_t range[2] = { le64toh(desc->sector) << 9,
+                          le32toh(desc->num_sectors) << 9 };
+    if (type == VIRTIO_BLK_T_DISCARD) {
+        if (ioctl(vdev_blk->blk_fd, BLKDISCARD, range) == 0) {
+            g_free(buf);
+            return 0;
+        }
+    } else if (type == VIRTIO_BLK_T_WRITE_ZEROES) {
+        if (ioctl(vdev_blk->blk_fd, BLKZEROOUT, range) == 0) {
+            g_free(buf);
+            return 0;
+        }
+    }
+    #endif
+
+    g_free(buf);
+    return -1;
+}
+
+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_BARRIER) {
+    case VIRTIO_BLK_T_IN:
+    case VIRTIO_BLK_T_OUT: {
+        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;
+    }
+    case VIRTIO_BLK_T_DISCARD:
+    case VIRTIO_BLK_T_WRITE_ZEROES: {
+        int rc;
+        rc = vub_discard_write_zeroes(req, &elem->out_sg[1], out_num, type);
+        if (rc == 0) {
+            req->in->status = VIRTIO_BLK_S_OK;
+        } else {
+            req->in->status = VIRTIO_BLK_S_IOERR;
+        }
+        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;
+
+    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)
+{
+    uint64_t features;
+    VugDev *gdev;
+    VubDev *vdev_blk;
+
+    gdev = container_of(dev, VugDev, parent);
+    vdev_blk = container_of(gdev, VubDev, parent);
+
+    features = 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 |
+               #if defined(__linux__) && defined(BLKDISCARD) && defined(BLKZEROOUT)
+               1ull << VIRTIO_BLK_F_DISCARD |
+               1ull << VIRTIO_BLK_F_WRITE_ZEROES |
+               #endif
+               1ull << VIRTIO_BLK_F_CONFIG_WCE;
+
+    if (vdev_blk->enable_ro) {
+        features |= 1ull << VIRTIO_BLK_F_RO;
+    }
+
+    return features;
+}
+
+static uint64_t
+vub_get_protocol_features(VuDev *dev)
+{
+    return 1ull << VHOST_USER_PROTOCOL_F_CONFIG |
+           1ull << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD;
+}
+
+static int
+vub_get_config(VuDev *vu_dev, uint8_t *config, uint32_t len)
+{
+    VugDev *gdev;
+    VubDev *vdev_blk;
+
+    if (len > sizeof(struct virtio_blk_config)) {
+        return -1;
+    }
+
+    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_protocol_features = vub_get_protocol_features,
+    .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 blocksize;
+    }
+#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;
+    #if defined(__linux__) && defined(BLKDISCARD) && defined(BLKZEROOUT)
+    config->max_discard_sectors = 32768;
+    config->max_discard_seg = 1;
+    config->discard_sector_alignment = config->blk_size >> 9;
+    config->max_write_zeroes_sectors = 32768;
+    config->max_write_zeroes_seg = 1;
+    #endif
+}
+
+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, 1);
+    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->enable_ro = false;
+    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;
+}
+
+static int opt_fdnum = -1;
+static char *opt_socket_path;
+static char *opt_blk_file;
+static gboolean opt_print_caps;
+static gboolean opt_read_only;
+
+static GOptionEntry entries[] = {
+    { "print-capabilities", 'c', 0, G_OPTION_ARG_NONE, &opt_print_caps,
+      "Print capabilities", NULL },
+    { "fd", 'f', 0, G_OPTION_ARG_INT, &opt_fdnum,
+      "Use inherited fd socket", "FDNUM" },
+    { "socket-path", 's', 0, G_OPTION_ARG_FILENAME, &opt_socket_path,
+      "Use UNIX socket path", "PATH" },
+    {"blk-file", 'b', 0, G_OPTION_ARG_FILENAME, &opt_blk_file,
+     "block device or file path", "PATH"},
+    { "read-only", 'r', 0, G_OPTION_ARG_NONE, &opt_read_only,
+      "Enable read-only", NULL }
+};
+
+int main(int argc, char **argv)
+{
+    int lsock = -1, csock = -1;
+    VubDev *vdev_blk = NULL;
+    GError *error = NULL;
+    GOptionContext *context;
+
+    context = g_option_context_new(NULL);
+    g_option_context_add_main_entries(context, entries, NULL);
+    if (!g_option_context_parse(context, &argc, &argv, &error)) {
+        g_printerr("Option parsing failed: %s\n", error->message);
+        exit(EXIT_FAILURE);
+    }
+    if (opt_print_caps) {
+        g_print("{\n");
+        g_print("  \"type\": \"block\",\n");
+        g_print("  \"features\": [\n");
+        g_print("    \"read-only\",\n");
+        g_print("    \"blk-file\"\n");
+        g_print("  ]\n");
+        g_print("}\n");
+        exit(EXIT_SUCCESS);
+    }
+
+    if (!opt_blk_file) {
+        g_print("%s\n", g_option_context_get_help(context, true, NULL));
+        exit(EXIT_FAILURE);
+    }
+
+    if (opt_socket_path) {
+        lsock = unix_sock_new(opt_socket_path);
+        if (lsock < 0) {
+            exit(EXIT_FAILURE);
+        }
+    } else if (opt_fdnum < 0) {
+        g_print("%s\n", g_option_context_get_help(context, true, NULL));
+        exit(EXIT_FAILURE);
+    } else {
+        lsock = opt_fdnum;
+    }
+
+    csock = accept(lsock, NULL, NULL);
+    if (csock < 0) {
+        g_printerr("Accept error %s\n", strerror(errno));
+        exit(EXIT_FAILURE);
+    }
+
+    vdev_blk = vub_new(opt_blk_file);
+    if (!vdev_blk) {
+        exit(EXIT_FAILURE);
+    }
+    if (opt_read_only) {
+        vdev_blk->enable_ro = true;
+    }
+
+    if (!vug_init(&vdev_blk->parent, VHOST_USER_BLK_MAX_QUEUES, csock,
+                  vub_panic_cb, &vub_iface)) {
+        g_printerr("Failed to initialize libvhost-user-glib\n");
+        exit(EXIT_FAILURE);
+    }
+
+    g_main_loop_run(vdev_blk->loop);
+    g_main_loop_unref(vdev_blk->loop);
+    g_option_context_free(context);
+    vug_deinit(&vdev_blk->parent);
+    vub_free(vdev_blk);
+    if (csock >= 0) {
+        close(csock);
+    }
+    if (lsock >= 0) {
+        close(lsock);
+    }
+    g_free(opt_socket_path);
+    g_free(opt_blk_file);
+
+    return 0;
+}