diff options
Diffstat (limited to 'contrib/vhost-user-scsi/vhost-user-scsi.c')
| -rw-r--r-- | contrib/vhost-user-scsi/vhost-user-scsi.c | 436 |
1 files changed, 436 insertions, 0 deletions
diff --git a/contrib/vhost-user-scsi/vhost-user-scsi.c b/contrib/vhost-user-scsi/vhost-user-scsi.c new file mode 100644 index 000000000..4f6e3e2a2 --- /dev/null +++ b/contrib/vhost-user-scsi/vhost-user-scsi.c @@ -0,0 +1,436 @@ +/* + * vhost-user-scsi sample application + * + * Copyright (c) 2016 Nutanix Inc. All rights reserved. + * + * Author: + * Felipe Franciosi <felipe@nutanix.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 <iscsi/iscsi.h> +#define inline __attribute__((gnu_inline)) /* required for libiscsi v1.9.0 */ +#include <iscsi/scsi-lowlevel.h> +#undef inline +#include "libvhost-user-glib.h" +#include "standard-headers/linux/virtio_scsi.h" + + +#define VUS_ISCSI_INITIATOR "iqn.2016-11.com.nutanix:vhost-user-scsi" + +enum { + VHOST_USER_SCSI_MAX_QUEUES = 8, +}; + +typedef struct VusIscsiLun { + struct iscsi_context *iscsi_ctx; + int iscsi_lun; +} VusIscsiLun; + +typedef struct VusDev { + VugDev parent; + + VusIscsiLun lun; + GMainLoop *loop; +} VusDev; + +/** libiscsi integration **/ + +typedef struct virtio_scsi_cmd_req VirtIOSCSICmdReq; +typedef struct virtio_scsi_cmd_resp VirtIOSCSICmdResp; + +static int vus_iscsi_add_lun(VusIscsiLun *lun, char *iscsi_uri) +{ + struct iscsi_url *iscsi_url; + struct iscsi_context *iscsi_ctx; + int ret = 0; + + assert(lun); + assert(iscsi_uri); + assert(!lun->iscsi_ctx); + + iscsi_ctx = iscsi_create_context(VUS_ISCSI_INITIATOR); + if (!iscsi_ctx) { + g_warning("Unable to create iSCSI context"); + return -1; + } + + iscsi_url = iscsi_parse_full_url(iscsi_ctx, iscsi_uri); + if (!iscsi_url) { + g_warning("Unable to parse iSCSI URL: %s", iscsi_get_error(iscsi_ctx)); + goto fail; + } + + iscsi_set_session_type(iscsi_ctx, ISCSI_SESSION_NORMAL); + iscsi_set_header_digest(iscsi_ctx, ISCSI_HEADER_DIGEST_NONE_CRC32C); + if (iscsi_full_connect_sync(iscsi_ctx, iscsi_url->portal, iscsi_url->lun)) { + g_warning("Unable to login to iSCSI portal: %s", + iscsi_get_error(iscsi_ctx)); + goto fail; + } + + lun->iscsi_ctx = iscsi_ctx; + lun->iscsi_lun = iscsi_url->lun; + + g_debug("Context %p created for lun 0: %s", iscsi_ctx, iscsi_uri); + +out: + if (iscsi_url) { + iscsi_destroy_url(iscsi_url); + } + return ret; + +fail: + (void)iscsi_destroy_context(iscsi_ctx); + ret = -1; + goto out; +} + +static struct scsi_task *scsi_task_new(int cdb_len, uint8_t *cdb, int dir, + int xfer_len) +{ + struct scsi_task *task; + + assert(cdb_len > 0); + assert(cdb); + + task = g_new0(struct scsi_task, 1); + memcpy(task->cdb, cdb, cdb_len); + task->cdb_size = cdb_len; + task->xfer_dir = dir; + task->expxferlen = xfer_len; + + return task; +} + +static int get_cdb_len(uint8_t *cdb) +{ + assert(cdb); + + switch (cdb[0] >> 5) { + case 0: return 6; + case 1: /* fall through */ + case 2: return 10; + case 4: return 16; + case 5: return 12; + } + g_warning("Unable to determine cdb len (0x%02hhX)", (uint8_t)(cdb[0] >> 5)); + return -1; +} + +static int handle_cmd_sync(struct iscsi_context *ctx, + VirtIOSCSICmdReq *req, + struct iovec *out, unsigned int out_len, + VirtIOSCSICmdResp *rsp, + struct iovec *in, unsigned int in_len) +{ + struct scsi_task *task; + uint32_t dir; + uint32_t len; + int cdb_len; + int i; + + assert(ctx); + assert(req); + assert(rsp); + + if (!(!req->lun[1] && req->lun[2] == 0x40 && !req->lun[3])) { + /* Ignore anything different than target=0, lun=0 */ + g_debug("Ignoring unconnected lun (0x%hhX, 0x%hhX)", + req->lun[1], req->lun[3]); + rsp->status = SCSI_STATUS_CHECK_CONDITION; + memset(rsp->sense, 0, sizeof(rsp->sense)); + rsp->sense_len = 18; + rsp->sense[0] = 0x70; + rsp->sense[2] = SCSI_SENSE_ILLEGAL_REQUEST; + rsp->sense[7] = 10; + rsp->sense[12] = 0x24; + + return 0; + } + + cdb_len = get_cdb_len(req->cdb); + if (cdb_len == -1) { + return -1; + } + + len = 0; + if (!out_len && !in_len) { + dir = SCSI_XFER_NONE; + } else if (out_len) { + dir = SCSI_XFER_WRITE; + for (i = 0; i < out_len; i++) { + len += out[i].iov_len; + } + } else { + dir = SCSI_XFER_READ; + for (i = 0; i < in_len; i++) { + len += in[i].iov_len; + } + } + + task = scsi_task_new(cdb_len, req->cdb, dir, len); + + if (dir == SCSI_XFER_WRITE) { + task->iovector_out.iov = (struct scsi_iovec *)out; + task->iovector_out.niov = out_len; + } else if (dir == SCSI_XFER_READ) { + task->iovector_in.iov = (struct scsi_iovec *)in; + task->iovector_in.niov = in_len; + } + + g_debug("Sending iscsi cmd (cdb_len=%d, dir=%d, task=%p)", + cdb_len, dir, task); + if (!iscsi_scsi_command_sync(ctx, 0, task, NULL)) { + g_warning("Error serving SCSI command"); + g_free(task); + return -1; + } + + memset(rsp, 0, sizeof(*rsp)); + + rsp->status = task->status; + rsp->resid = task->residual; + + if (task->status == SCSI_STATUS_CHECK_CONDITION) { + rsp->response = VIRTIO_SCSI_S_FAILURE; + rsp->sense_len = task->datain.size - 2; + memcpy(rsp->sense, &task->datain.data[2], rsp->sense_len); + } + + g_free(task); + + g_debug("Filled in rsp: status=%hhX, resid=%u, response=%hhX, sense_len=%u", + rsp->status, rsp->resid, rsp->response, rsp->sense_len); + + return 0; +} + +/** libvhost-user callbacks **/ + +static void vus_panic_cb(VuDev *vu_dev, const char *buf) +{ + VugDev *gdev; + VusDev *vdev_scsi; + + assert(vu_dev); + + gdev = container_of(vu_dev, VugDev, parent); + vdev_scsi = container_of(gdev, VusDev, parent); + if (buf) { + g_warning("vu_panic: %s", buf); + } + + g_main_loop_quit(vdev_scsi->loop); +} + +static void vus_proc_req(VuDev *vu_dev, int idx) +{ + VugDev *gdev; + VusDev *vdev_scsi; + VuVirtq *vq; + VuVirtqElement *elem = NULL; + + assert(vu_dev); + + gdev = container_of(vu_dev, VugDev, parent); + vdev_scsi = container_of(gdev, VusDev, parent); + + vq = vu_get_queue(vu_dev, idx); + if (!vq) { + g_warning("Error fetching VQ (dev=%p, idx=%d)", vu_dev, idx); + vus_panic_cb(vu_dev, NULL); + return; + } + + g_debug("Got kicked on vq[%d]@%p", idx, vq); + + while (1) { + VirtIOSCSICmdReq *req; + VirtIOSCSICmdResp *rsp; + + elem = vu_queue_pop(vu_dev, vq, sizeof(VuVirtqElement)); + if (!elem) { + g_debug("No more elements pending on vq[%d]@%p", idx, vq); + break; + } + g_debug("Popped elem@%p", elem); + + assert(!(elem->out_num > 1 && elem->in_num > 1)); + assert(elem->out_num > 0 && elem->in_num > 0); + + if (elem->out_sg[0].iov_len < sizeof(VirtIOSCSICmdReq)) { + g_warning("Invalid virtio-scsi req header"); + vus_panic_cb(vu_dev, NULL); + break; + } + req = (VirtIOSCSICmdReq *)elem->out_sg[0].iov_base; + + if (elem->in_sg[0].iov_len < sizeof(VirtIOSCSICmdResp)) { + g_warning("Invalid virtio-scsi rsp header"); + vus_panic_cb(vu_dev, NULL); + break; + } + rsp = (VirtIOSCSICmdResp *)elem->in_sg[0].iov_base; + + if (handle_cmd_sync(vdev_scsi->lun.iscsi_ctx, + req, &elem->out_sg[1], elem->out_num - 1, + rsp, &elem->in_sg[1], elem->in_num - 1) != 0) { + vus_panic_cb(vu_dev, NULL); + break; + } + + vu_queue_push(vu_dev, vq, elem, 0); + vu_queue_notify(vu_dev, vq); + + free(elem); + } + free(elem); +} + +static void vus_queue_set_started(VuDev *vu_dev, int idx, bool started) +{ + VuVirtq *vq; + + assert(vu_dev); + + vq = vu_get_queue(vu_dev, idx); + + if (idx == 0 || idx == 1) { + g_debug("queue %d unimplemented", idx); + } else { + vu_set_queue_handler(vu_dev, vq, started ? vus_proc_req : NULL); + } +} + +static const VuDevIface vus_iface = { + .queue_set_started = vus_queue_set_started, +}; + +/** misc helpers **/ + +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; +} + +/** vhost-user-scsi **/ + +int main(int argc, char **argv) +{ + VusDev *vdev_scsi = NULL; + char *unix_fn = NULL; + char *iscsi_uri = NULL; + int lsock = -1, csock = -1, opt, err = EXIT_SUCCESS; + + while ((opt = getopt(argc, argv, "u:i:")) != -1) { + switch (opt) { + case 'h': + goto help; + case 'u': + unix_fn = g_strdup(optarg); + break; + case 'i': + iscsi_uri = g_strdup(optarg); + break; + default: + goto help; + } + } + if (!unix_fn || !iscsi_uri) { + goto help; + } + + lsock = unix_sock_new(unix_fn); + if (lsock < 0) { + goto err; + } + + csock = accept(lsock, NULL, NULL); + if (csock < 0) { + perror("accept"); + goto err; + } + + vdev_scsi = g_new0(VusDev, 1); + vdev_scsi->loop = g_main_loop_new(NULL, FALSE); + + if (vus_iscsi_add_lun(&vdev_scsi->lun, iscsi_uri) != 0) { + goto err; + } + + if (!vug_init(&vdev_scsi->parent, VHOST_USER_SCSI_MAX_QUEUES, csock, + vus_panic_cb, &vus_iface)) { + g_printerr("Failed to initialize libvhost-user-glib\n"); + goto err; + } + + g_main_loop_run(vdev_scsi->loop); + + vug_deinit(&vdev_scsi->parent); + +out: + if (vdev_scsi) { + g_main_loop_unref(vdev_scsi->loop); + g_free(vdev_scsi); + unlink(unix_fn); + } + if (csock >= 0) { + close(csock); + } + if (lsock >= 0) { + close(lsock); + } + g_free(unix_fn); + g_free(iscsi_uri); + + return err; + +err: + err = EXIT_FAILURE; + goto out; + +help: + fprintf(stderr, "Usage: %s [ -u unix_sock_path -i iscsi_uri ] | [ -h ]\n", + argv[0]); + fprintf(stderr, " -u path to unix socket\n"); + fprintf(stderr, " -i iscsi uri for lun 0\n"); + fprintf(stderr, " -h print help and quit\n"); + + goto err; +} |