qemu/contrib/vhost-user-scsi/vhost-user-scsi.c

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/*
* 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"
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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;
}
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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;
}