Commit 49cc0340 authored by Felipe Franciosi's avatar Felipe Franciosi Committed by Paolo Bonzini
Browse files

vhost-user-scsi: Introduce a vhost-user-scsi sample application 

This commit introduces a vhost-user-scsi backend sample application. It
must be linked with libiscsi and libvhost-user.

To use it, compile with:
  $ make vhost-user-scsi

And run as follows:
  $ ./vhost-user-scsi -u vus.sock -i iscsi://uri_to_target/


  $ qemu-system-x86_64 --enable-kvm -m 512 \
      -object memory-backend-file,id=mem,size=512m,share=on,mem-path=guestmem \
      -numa node,memdev=mem \
      -chardev socket,id=vhost-user-scsi,path=vus.sock \
      -device vhost-user-scsi-pci,chardev=vhost-user-scsi \

The application is currently limited at one LUN only and it processes
requests synchronously (therefore only achieving QD1). The purpose of
the code is to show how a backend can be implemented and to test the
vhost-user-scsi Qemu implementation.

If a different instance of this vhost-user-scsi application is executed
at a remote host, a VM can be live migrated to such a host.

Signed-off-by: default avatarFelipe Franciosi <felipe@nutanix.com>
Message-Id: <1488479153-21203-5-git-send-email-felipe@nutanix.com>
parent f12c1ebd

Makefile

+3 −0
Original line number Diff line number Diff line
@@ -269,6 +269,7 @@ dummy := $(call unnest-vars,, \ 
                ivshmem-client-obj-y \

                ivshmem-server-obj-y \

                libvhost-user-obj-y \

                vhost-user-scsi-obj-y \

                qga-vss-dll-obj-y \

                block-obj-y \

                block-obj-m \
@@ -473,6 +474,8 @@ ivshmem-client$(EXESUF): $(ivshmem-client-obj-y) $(COMMON_LDADDS) 
	$(call LINK, $^)

ivshmem-server$(EXESUF): $(ivshmem-server-obj-y) $(COMMON_LDADDS)

	$(call LINK, $^)

vhost-user-scsi$(EXESUF): $(vhost-user-scsi-obj-y)

	$(call LINK, $^)



module_block.h: $(SRC_PATH)/scripts/modules/module_block.py config-host.mak

	$(call quiet-command,$(PYTHON) $< $@ \

Makefile.objs

+4 −0
Original line number Diff line number Diff line
@@ -110,6 +110,10 @@ qga-vss-dll-obj-y = qga/ 
ivshmem-client-obj-y = contrib/ivshmem-client/

ivshmem-server-obj-y = contrib/ivshmem-server/

libvhost-user-obj-y = contrib/libvhost-user/

vhost-user-scsi.o-cflags := $(LIBISCSI_CFLAGS)

vhost-user-scsi.o-libs := $(LIBISCSI_LIBS)

vhost-user-scsi-obj-y = contrib/vhost-user-scsi/

vhost-user-scsi-obj-y += contrib/libvhost-user/libvhost-user.o



######################################################################

trace-events-subdirs =

contrib/libvhost-user/libvhost-user.h

+6 −5
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <stdint.h>

#include <stdbool.h>

#include <stddef.h>

#include <sys/poll.h>

#include <linux/vhost.h>

#include "standard-headers/linux/virtio_ring.h"
@@ -192,11 +193,11 @@ typedef struct VuVirtq { 
} VuVirtq;



enum VuWatchCondtion {

    VU_WATCH_IN = 1 << 0,

    VU_WATCH_OUT = 1 << 1,

    VU_WATCH_PRI = 1 << 2,

    VU_WATCH_ERR = 1 << 3,

    VU_WATCH_HUP = 1 << 4,

    VU_WATCH_IN = POLLIN,

    VU_WATCH_OUT = POLLOUT,

    VU_WATCH_PRI = POLLPRI,

    VU_WATCH_ERR = POLLERR,

    VU_WATCH_HUP = POLLHUP,

};



typedef void (*vu_panic_cb) (VuDev *dev, const char *err);

contrib/vhost-user-scsi/Makefile.objs

0 → 100644
+1 −0
Original line number Diff line number Diff line 
vhost-user-scsi-obj-y = vhost-user-scsi.o

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

0 → 100644
+886 −0
Original line number Diff line number Diff line 
/*

 * 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 "contrib/libvhost-user/libvhost-user.h"

#include "hw/virtio/virtio-scsi.h"

#include "iscsi/iscsi.h"



#include <glib.h>



/* Small compat shim from glib 2.32 */

#ifndef G_SOURCE_CONTINUE

#define G_SOURCE_CONTINUE TRUE

#endif

#ifndef G_SOURCE_REMOVE

#define G_SOURCE_REMOVE FALSE

#endif



/* #define VUS_DEBUG 1 */



/** Log helpers **/



#define PPRE                                                          \

    struct timespec ts;                                               \

    char   timebuf[64];                                               \

    struct tm tm;                                                     \

    (void)clock_gettime(CLOCK_REALTIME, &ts);                         \

    (void)strftime(timebuf, 64, "%Y%m%d %T", gmtime_r(&ts.tv_sec, &tm))



#define PEXT(lvl, msg, ...) do {                                      \

    PPRE;                                                             \

    fprintf(stderr, "%s.%06ld " lvl ": %s:%s():%d: " msg "\n",        \

            timebuf, ts.tv_nsec / 1000,                               \

            __FILE__, __func__, __LINE__, ## __VA_ARGS__);            \

} while (0)



#define PNOR(lvl, msg, ...) do {                                      \

    PPRE;                                                             \

    fprintf(stderr, "%s.%06ld " lvl ": " msg "\n",                    \

            timebuf, ts.tv_nsec / 1000, ## __VA_ARGS__);              \

} while (0)



#ifdef VUS_DEBUG

#define PDBG(msg, ...) PEXT("DBG", msg, ## __VA_ARGS__)

#define PERR(msg, ...) PEXT("ERR", msg, ## __VA_ARGS__)

#define PLOG(msg, ...) PEXT("LOG", msg, ## __VA_ARGS__)

#else

#define PDBG(msg, ...) { }

#define PERR(msg, ...) PNOR("ERR", msg, ## __VA_ARGS__)

#define PLOG(msg, ...) PNOR("LOG", msg, ## __VA_ARGS__)

#endif



/** vhost-user-scsi specific definitions **/



 /* Only 1 LUN and device supported today */

#define VUS_MAX_LUNS 1

#define VUS_MAX_DEVS 1



#define VUS_ISCSI_INITIATOR "iqn.2016-11.com.nutanix:vhost-user-scsi"



typedef struct iscsi_lun {

    struct iscsi_context *iscsi_ctx;

    int iscsi_lun;

} iscsi_lun_t;



typedef struct vhost_scsi_dev {

    VuDev vu_dev;

    int server_sock;

    GMainLoop *loop;

    GTree *fdmap;   /* fd -> gsource context id */

    iscsi_lun_t luns[VUS_MAX_LUNS];

} vhost_scsi_dev_t;



static vhost_scsi_dev_t *vhost_scsi_devs[VUS_MAX_DEVS];



/** glib event loop integration for libvhost-user and misc callbacks **/



QEMU_BUILD_BUG_ON((int)G_IO_IN != (int)VU_WATCH_IN);

QEMU_BUILD_BUG_ON((int)G_IO_OUT != (int)VU_WATCH_OUT);

QEMU_BUILD_BUG_ON((int)G_IO_PRI != (int)VU_WATCH_PRI);

QEMU_BUILD_BUG_ON((int)G_IO_ERR != (int)VU_WATCH_ERR);

QEMU_BUILD_BUG_ON((int)G_IO_HUP != (int)VU_WATCH_HUP);



typedef struct vus_gsrc {

    GSource parent;

    vhost_scsi_dev_t *vdev_scsi;

    GPollFD gfd;

    vu_watch_cb vu_cb;

} vus_gsrc_t;



static gint vus_fdmap_compare(gconstpointer a, gconstpointer b)

{

    return (b > a) - (b < a);

}



static gboolean vus_gsrc_prepare(GSource *src, gint *timeout)

{

    assert(timeout);



    *timeout = -1;

    return FALSE;

}



static gboolean vus_gsrc_check(GSource *src)

{

    vus_gsrc_t *vus_src = (vus_gsrc_t *)src;



    assert(vus_src);



    return vus_src->gfd.revents & vus_src->gfd.events;

}



static gboolean vus_gsrc_dispatch(GSource *src, GSourceFunc cb, gpointer data)

{

    vhost_scsi_dev_t *vdev_scsi;

    vus_gsrc_t *vus_src = (vus_gsrc_t *)src;



    assert(vus_src);

    assert(!(vus_src->vu_cb && cb));



    vdev_scsi = vus_src->vdev_scsi;



    assert(vdev_scsi);



    if (cb) {

        return cb(data);

    }

    if (vus_src->vu_cb) {

        vus_src->vu_cb(&vdev_scsi->vu_dev, vus_src->gfd.revents, data);

    }

    return G_SOURCE_CONTINUE;

}



static GSourceFuncs vus_gsrc_funcs = {

    vus_gsrc_prepare,

    vus_gsrc_check,

    vus_gsrc_dispatch,

    NULL

};



static int vus_gsrc_new(vhost_scsi_dev_t *vdev_scsi, int fd, GIOCondition cond,

                        vu_watch_cb vu_cb, GSourceFunc gsrc_cb, gpointer data)

{

    GSource *vus_gsrc;

    vus_gsrc_t *vus_src;

    guint id;



    assert(vdev_scsi);

    assert(fd >= 0);

    assert(vu_cb || gsrc_cb);

    assert(!(vu_cb && gsrc_cb));



    vus_gsrc = g_source_new(&vus_gsrc_funcs, sizeof(vus_gsrc_t));

    if (!vus_gsrc) {

        PERR("Error creating GSource for new watch");

        return -1;

    }

    vus_src = (vus_gsrc_t *)vus_gsrc;



    vus_src->vdev_scsi = vdev_scsi;

    vus_src->gfd.fd = fd;

    vus_src->gfd.events = cond;

    vus_src->vu_cb = vu_cb;



    g_source_add_poll(vus_gsrc, &vus_src->gfd);

    g_source_set_callback(vus_gsrc, gsrc_cb, data, NULL);

    id = g_source_attach(vus_gsrc, NULL);

    assert(id);

    g_source_unref(vus_gsrc);



    g_tree_insert(vdev_scsi->fdmap, (gpointer)(uintptr_t)fd,

                                    (gpointer)(uintptr_t)id);



    return 0;

}



/* from libiscsi's scsi-lowlevel.h **

 *

 * nb. We can't directly include scsi-lowlevel.h due to a namespace conflict:

 *     QEMU's scsi.h also defines "SCSI_XFER_NONE".

 */



#define SCSI_CDB_MAX_SIZE           16



struct scsi_iovector {

    struct scsi_iovec *iov;

    int niov;

    int nalloc;

    size_t offset;

    int consumed;

};



struct scsi_allocated_memory {

    struct scsi_allocated_memory *next;

    char buf[0];

};



struct scsi_data {

    int            size;

    unsigned char *data;

};



enum scsi_sense_key {

    SCSI_SENSE_NO_SENSE            = 0x00,

    SCSI_SENSE_RECOVERED_ERROR     = 0x01,

    SCSI_SENSE_NOT_READY           = 0x02,

    SCSI_SENSE_MEDIUM_ERROR        = 0x03,

    SCSI_SENSE_HARDWARE_ERROR      = 0x04,

    SCSI_SENSE_ILLEGAL_REQUEST     = 0x05,

    SCSI_SENSE_UNIT_ATTENTION      = 0x06,

    SCSI_SENSE_DATA_PROTECTION     = 0x07,

    SCSI_SENSE_BLANK_CHECK         = 0x08,

    SCSI_SENSE_VENDOR_SPECIFIC     = 0x09,

    SCSI_SENSE_COPY_ABORTED        = 0x0a,

    SCSI_SENSE_COMMAND_ABORTED     = 0x0b,

    SCSI_SENSE_OBSOLETE_ERROR_CODE = 0x0c,

    SCSI_SENSE_OVERFLOW_COMMAND    = 0x0d,

    SCSI_SENSE_MISCOMPARE          = 0x0e

};



struct scsi_sense {

    unsigned char       error_type;

    enum scsi_sense_key key;

    int                 ascq;

    unsigned            sense_specific:1;

    unsigned            ill_param_in_cdb:1;

    unsigned            bit_pointer_valid:1;

    unsigned char       bit_pointer;

    uint16_t            field_pointer;

};



enum scsi_residual {

    SCSI_RESIDUAL_NO_RESIDUAL = 0,

    SCSI_RESIDUAL_UNDERFLOW,

    SCSI_RESIDUAL_OVERFLOW

};



struct scsi_task {

    int status;

    int cdb_size;

    int xfer_dir;

    int expxferlen;

    unsigned char cdb[SCSI_CDB_MAX_SIZE];

    enum scsi_residual residual_status;

    size_t residual;

    struct scsi_sense sense;

    struct scsi_data datain;

    struct scsi_allocated_memory *mem;

    void *ptr;



    uint32_t itt;

    uint32_t cmdsn;

    uint32_t lun;



    struct scsi_iovector iovector_in;

    struct scsi_iovector iovector_out;

};



/** libiscsi integration **/



static int iscsi_add_lun(iscsi_lun_t *lun, char *iscsi_uri)

{

    struct iscsi_url *iscsi_url;

    struct iscsi_context *iscsi_ctx;

    int ret = 0;



    assert(lun);

    assert(iscsi_uri);



    iscsi_ctx = iscsi_create_context(VUS_ISCSI_INITIATOR);

    if (!iscsi_ctx) {

        PERR("Unable to create iSCSI context");

        return -1;

    }



    iscsi_url = iscsi_parse_full_url(iscsi_ctx, iscsi_uri);

    if (!iscsi_url) {

        PERR("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)) {

        PERR("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;



    PDBG("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 = calloc(1, sizeof(struct scsi_task));

    if (!task) {

        PERR("Error allocating task: %s", strerror(errno));

        return NULL;

    }



    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;

    }

    PERR("Unable to determine cdb len (0x%02hhX)", 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 */

        PDBG("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_TO_DEV;

        for (i = 0; i < out_len; i++) {

            len += out[i].iov_len;

        }

    } else {

        dir = SCSI_XFER_FROM_DEV;

        for (i = 0; i < in_len; i++) {

            len += in[i].iov_len;

        }

    }



    task = scsi_task_new(cdb_len, req->cdb, dir, len);

    if (!task) {

        PERR("Unable to create iscsi task");

        return -1;

    }



    if (dir == SCSI_XFER_TO_DEV) {

        task->iovector_out.iov = (struct scsi_iovec *)out;

        task->iovector_out.niov = out_len;

    } else if (dir == SCSI_XFER_FROM_DEV) {

        task->iovector_in.iov = (struct scsi_iovec *)in;

        task->iovector_in.niov = in_len;

    }



    PDBG("Sending iscsi cmd (cdb_len=%d, dir=%d, task=%p)",

         cdb_len, dir, task);

    if (!iscsi_scsi_command_sync(ctx, 0, task, NULL)) {

        PERR("Error serving SCSI command");

        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);

    }



    free(task);



    PDBG("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 vhost_scsi_dev_t *vdev_scsi_find_by_vu(VuDev *vu_dev);



static void vus_panic_cb(VuDev *vu_dev, const char *buf)

{

    vhost_scsi_dev_t *vdev_scsi;



    assert(vu_dev);



    vdev_scsi = vdev_scsi_find_by_vu(vu_dev);



    if (buf) {

        PERR("vu_panic: %s", buf);

    }



    if (vdev_scsi) {

        assert(vdev_scsi->loop);

        g_main_loop_quit(vdev_scsi->loop);

    }

}



static void vus_add_watch_cb(VuDev *vu_dev, int fd, int vu_evt, vu_watch_cb cb,

                             void *pvt) {

    vhost_scsi_dev_t *vdev_scsi;

    guint id;



    assert(vu_dev);

    assert(fd >= 0);

    assert(cb);



    vdev_scsi = vdev_scsi_find_by_vu(vu_dev);

    if (!vdev_scsi) {

        vus_panic_cb(vu_dev, NULL);

        return;

    }



    id = (guint)(uintptr_t)g_tree_lookup(vdev_scsi->fdmap,

                                         (gpointer)(uintptr_t)fd);

    if (id) {

        GSource *vus_src = g_main_context_find_source_by_id(NULL, id);

        assert(vus_src);

        g_source_destroy(vus_src);

        (void)g_tree_remove(vdev_scsi->fdmap, (gpointer)(uintptr_t)fd);

    }



    if (vus_gsrc_new(vdev_scsi, fd, vu_evt, cb, NULL, pvt)) {

        vus_panic_cb(vu_dev, NULL);

    }

}



static void vus_del_watch_cb(VuDev *vu_dev, int fd)

{

    vhost_scsi_dev_t *vdev_scsi;

    guint id;



    assert(vu_dev);

    assert(fd >= 0);



    vdev_scsi = vdev_scsi_find_by_vu(vu_dev);

    if (!vdev_scsi) {

        vus_panic_cb(vu_dev, NULL);

        return;

    }



    id = (guint)(uintptr_t)g_tree_lookup(vdev_scsi->fdmap,

                                         (gpointer)(uintptr_t)fd);

    if (id) {

        GSource *vus_src = g_main_context_find_source_by_id(NULL, id);

        assert(vus_src);

        g_source_destroy(vus_src);

        (void)g_tree_remove(vdev_scsi->fdmap, (gpointer)(uintptr_t)fd);

    }

}



static void vus_proc_ctl(VuDev *vu_dev, int idx)

{

    /* Control VQ not implemented */

}



static void vus_proc_evt(VuDev *vu_dev, int idx)

{

    /* Event VQ not implemented */

}



static void vus_proc_req(VuDev *vu_dev, int idx)

{

    vhost_scsi_dev_t *vdev_scsi;

    VuVirtq *vq;



    assert(vu_dev);



    vdev_scsi = vdev_scsi_find_by_vu(vu_dev);

    if (!vdev_scsi) {

        vus_panic_cb(vu_dev, NULL);

        return;

    }



    if ((idx < 0) || (idx >= VHOST_MAX_NR_VIRTQUEUE)) {

        PERR("VQ Index out of range: %d", idx);

        vus_panic_cb(vu_dev, NULL);

        return;

    }



    vq = vu_get_queue(vu_dev, idx);

    if (!vq) {

        PERR("Error fetching VQ (dev=%p, idx=%d)", vu_dev, idx);

        vus_panic_cb(vu_dev, NULL);

        return;

    }



    PDBG("Got kicked on vq[%d]@%p", idx, vq);



    while (1) {

        VuVirtqElement *elem;

        VirtIOSCSICmdReq *req;

        VirtIOSCSICmdResp *rsp;



        elem = vu_queue_pop(vu_dev, vq, sizeof(VuVirtqElement));

        if (!elem) {

            PDBG("No more elements pending on vq[%d]@%p", idx, vq);

            break;

        }

        PDBG("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)) {

            PERR("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)) {

            PERR("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->luns[0].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);

    }

}



static void vus_queue_set_started(VuDev *vu_dev, int idx, bool started)

{

    VuVirtq *vq;



    assert(vu_dev);



    if ((idx < 0) || (idx >= VHOST_MAX_NR_VIRTQUEUE)) {

        PERR("VQ Index out of range: %d", idx);

        vus_panic_cb(vu_dev, NULL);

        return;

    }



    vq = vu_get_queue(vu_dev, idx);



    switch (idx) {

    case 0:

        vu_set_queue_handler(vu_dev, vq, started ? vus_proc_ctl : NULL);

        break;

    case 1:

        vu_set_queue_handler(vu_dev, vq, started ? vus_proc_evt : NULL);

        break;

    default:

        vu_set_queue_handler(vu_dev, vq, started ? vus_proc_req : NULL);

    }

}



static const VuDevIface vus_iface = {

    .queue_set_started = vus_queue_set_started,

};



static gboolean vus_vhost_cb(gpointer data)

{

    VuDev *vu_dev = (VuDev *)data;



    assert(vu_dev);



    if (!vu_dispatch(vu_dev) != 0) {

        PERR("Error processing vhost message");

        vus_panic_cb(vu_dev, NULL);

        return G_SOURCE_REMOVE;

    }



    return G_SOURCE_CONTINUE;

}



/** 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 **/



static vhost_scsi_dev_t *vdev_scsi_find_by_vu(VuDev *vu_dev)

{

    int i;



    assert(vu_dev);



    for (i = 0; i < VUS_MAX_DEVS; i++) {

        if (&vhost_scsi_devs[i]->vu_dev == vu_dev) {

            return vhost_scsi_devs[i];

        }

    }



    PERR("Unknown VuDev %p", vu_dev);

    return NULL;

}



static void vdev_scsi_deinit(vhost_scsi_dev_t *vdev_scsi)

{

    if (!vdev_scsi) {

        return;

    }



    if (vdev_scsi->server_sock >= 0) {

        struct sockaddr_storage ss;

        socklen_t sslen = sizeof(ss);



        if (getsockname(vdev_scsi->server_sock, (struct sockaddr *)&ss,

                        &sslen) == 0) {

            struct sockaddr_un *su = (struct sockaddr_un *)&ss;

            (void)unlink(su->sun_path);

        }



        (void)close(vdev_scsi->server_sock);

        vdev_scsi->server_sock = -1;

    }



    if (vdev_scsi->loop) {

        g_main_loop_unref(vdev_scsi->loop);

        vdev_scsi->loop = NULL;

    }

}



static vhost_scsi_dev_t *vdev_scsi_new(char *unix_fn)

{

    vhost_scsi_dev_t *vdev_scsi = NULL;



    assert(unix_fn);



    vdev_scsi = calloc(1, sizeof(vhost_scsi_dev_t));

    if (!vdev_scsi) {

        PERR("calloc: %s", strerror(errno));

        return NULL;

    }



    vdev_scsi->server_sock = unix_sock_new(unix_fn);

    if (vdev_scsi->server_sock < 0) {

        goto err;

    }



    vdev_scsi->loop = g_main_loop_new(NULL, FALSE);

    if (!vdev_scsi->loop) {

        PERR("Error creating glib event loop");

        goto err;

    }



    vdev_scsi->fdmap = g_tree_new(vus_fdmap_compare);

    if (!vdev_scsi->fdmap) {

        PERR("Error creating glib tree for fdmap");

        goto err;

    }



    return vdev_scsi;



err:

    vdev_scsi_deinit(vdev_scsi);

    free(vdev_scsi);



    return NULL;

}



static int vdev_scsi_add_iscsi_lun(vhost_scsi_dev_t *vdev_scsi,

                                   char *iscsi_uri, uint32_t lun) {

    assert(vdev_scsi);

    assert(iscsi_uri);

    assert(lun < VUS_MAX_LUNS);



    if (vdev_scsi->luns[lun].iscsi_ctx) {

        PERR("Lun %d already configured", lun);

        return -1;

    }



    if (iscsi_add_lun(&vdev_scsi->luns[lun], iscsi_uri) != 0) {

        return -1;

    }



    return 0;

}



static int vdev_scsi_run(vhost_scsi_dev_t *vdev_scsi)

{

    int cli_sock;

    int ret = 0;



    assert(vdev_scsi);

    assert(vdev_scsi->server_sock >= 0);

    assert(vdev_scsi->loop);



    cli_sock = accept(vdev_scsi->server_sock, (void *)0, (void *)0);

    if (cli_sock < 0) {

        perror("accept");

        return -1;

    }



    vu_init(&vdev_scsi->vu_dev,

            cli_sock,

            vus_panic_cb,

            vus_add_watch_cb,

            vus_del_watch_cb,

            &vus_iface);



    if (vus_gsrc_new(vdev_scsi, cli_sock, G_IO_IN, NULL, vus_vhost_cb,

                     &vdev_scsi->vu_dev)) {

        goto fail;

    }



    g_main_loop_run(vdev_scsi->loop);



out:

    vu_deinit(&vdev_scsi->vu_dev);



    return ret;



fail:

    ret = -1;

    goto out;

}



int main(int argc, char **argv)

{

    vhost_scsi_dev_t *vdev_scsi = NULL;

    char *unix_fn = NULL;

    char *iscsi_uri = NULL;

    int opt, err = EXIT_SUCCESS;



    while ((opt = getopt(argc, argv, "u:i:")) != -1) {

        switch (opt) {

        case 'h':

            goto help;

        case 'u':

            unix_fn = strdup(optarg);

            break;

        case 'i':

            iscsi_uri = strdup(optarg);

            break;

        default:

            goto help;

        }

    }

    if (!unix_fn || !iscsi_uri) {

        goto help;

    }



    vdev_scsi = vdev_scsi_new(unix_fn);

    if (!vdev_scsi) {

        goto err;

    }

    vhost_scsi_devs[0] = vdev_scsi;



    if (vdev_scsi_add_iscsi_lun(vdev_scsi, iscsi_uri, 0) != 0) {

        goto err;

    }



    if (vdev_scsi_run(vdev_scsi) != 0) {

        goto err;

    }



out:

    if (vdev_scsi) {

        vdev_scsi_deinit(vdev_scsi);

        free(vdev_scsi);

    }

    if (unix_fn) {

        free(unix_fn);

    }

    if (iscsi_uri) {

        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;

}