546 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			546 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
/*
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 * vhost-user-blk sample application
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 *
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 * Copyright (c) 2017 Intel Corporation. All rights reserved.
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 *
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 * Author:
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 *  Changpeng Liu <changpeng.liu@intel.com>
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 *
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 * This work is based on the "vhost-user-scsi" sample and "virtio-blk" driver
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 * implementation by:
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 *  Felipe Franciosi <felipe@nutanix.com>
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 *  Anthony Liguori <aliguori@us.ibm.com>
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 *
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 * This work is licensed under the terms of the GNU GPL, version 2 only.
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 * See the COPYING file in the top-level directory.
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 */
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#include "qemu/osdep.h"
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#include "standard-headers/linux/virtio_blk.h"
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#include "contrib/libvhost-user/libvhost-user-glib.h"
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#include "contrib/libvhost-user/libvhost-user.h"
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#include <glib.h>
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struct virtio_blk_inhdr {
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    unsigned char status;
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};
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/* vhost user block device */
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typedef struct VubDev {
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    VugDev parent;
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    int blk_fd;
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    struct virtio_blk_config blkcfg;
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    char *blk_name;
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    GMainLoop *loop;
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} VubDev;
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typedef struct VubReq {
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    VuVirtqElement *elem;
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    int64_t sector_num;
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    size_t size;
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    struct virtio_blk_inhdr *in;
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    struct virtio_blk_outhdr *out;
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    VubDev *vdev_blk;
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    struct VuVirtq *vq;
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} VubReq;
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/* refer util/iov.c */
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static size_t vub_iov_size(const struct iovec *iov,
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                              const unsigned int iov_cnt)
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{
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    size_t len;
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    unsigned int i;
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    len = 0;
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    for (i = 0; i < iov_cnt; i++) {
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        len += iov[i].iov_len;
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    }
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    return len;
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}
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static void vub_panic_cb(VuDev *vu_dev, const char *buf)
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{
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    VugDev *gdev;
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    VubDev *vdev_blk;
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    assert(vu_dev);
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    gdev = container_of(vu_dev, VugDev, parent);
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    vdev_blk = container_of(gdev, VubDev, parent);
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    if (buf) {
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        g_warning("vu_panic: %s", buf);
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    }
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    g_main_loop_quit(vdev_blk->loop);
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}
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static void vub_req_complete(VubReq *req)
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{
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    VugDev *gdev = &req->vdev_blk->parent;
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    VuDev *vu_dev = &gdev->parent;
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    /* IO size with 1 extra status byte */
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    vu_queue_push(vu_dev, req->vq, req->elem,
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                  req->size + 1);
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    vu_queue_notify(vu_dev, req->vq);
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    if (req->elem) {
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        free(req->elem);
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    }
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    g_free(req);
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}
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static int vub_open(const char *file_name, bool wce)
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{
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    int fd;
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    int flags = O_RDWR;
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    if (!wce) {
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        flags |= O_DIRECT;
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    }
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    fd = open(file_name, flags);
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    if (fd < 0) {
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        fprintf(stderr, "Cannot open file %s, %s\n", file_name,
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                strerror(errno));
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        return -1;
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    }
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    return fd;
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}
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static ssize_t
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vub_readv(VubReq *req, struct iovec *iov, uint32_t iovcnt)
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{
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    VubDev *vdev_blk = req->vdev_blk;
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    ssize_t rc;
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    if (!iovcnt) {
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        fprintf(stderr, "Invalid Read IOV count\n");
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        return -1;
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    }
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    req->size = vub_iov_size(iov, iovcnt);
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    rc = preadv(vdev_blk->blk_fd, iov, iovcnt, req->sector_num * 512);
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    if (rc < 0) {
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        fprintf(stderr, "%s, Sector %"PRIu64", Size %lu failed with %s\n",
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                vdev_blk->blk_name, req->sector_num, req->size,
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                strerror(errno));
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        return -1;
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    }
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    return rc;
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}
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static ssize_t
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vub_writev(VubReq *req, struct iovec *iov, uint32_t iovcnt)
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{
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    VubDev *vdev_blk = req->vdev_blk;
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    ssize_t rc;
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    if (!iovcnt) {
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        fprintf(stderr, "Invalid Write IOV count\n");
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        return -1;
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    }
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    req->size = vub_iov_size(iov, iovcnt);
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    rc = pwritev(vdev_blk->blk_fd, iov, iovcnt, req->sector_num * 512);
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    if (rc < 0) {
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        fprintf(stderr, "%s, Sector %"PRIu64", Size %lu failed with %s\n",
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                vdev_blk->blk_name, req->sector_num, req->size,
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                strerror(errno));
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        return -1;
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    }
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    return rc;
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}
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static void
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vub_flush(VubReq *req)
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{
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    VubDev *vdev_blk = req->vdev_blk;
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    fdatasync(vdev_blk->blk_fd);
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}
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static int vub_virtio_process_req(VubDev *vdev_blk,
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                                     VuVirtq *vq)
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{
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    VugDev *gdev = &vdev_blk->parent;
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    VuDev *vu_dev = &gdev->parent;
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    VuVirtqElement *elem;
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    uint32_t type;
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    unsigned in_num;
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    unsigned out_num;
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    VubReq *req;
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    elem = vu_queue_pop(vu_dev, vq, sizeof(VuVirtqElement) + sizeof(VubReq));
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    if (!elem) {
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        return -1;
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    }
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    /* refer to hw/block/virtio_blk.c */
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    if (elem->out_num < 1 || elem->in_num < 1) {
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        fprintf(stderr, "virtio-blk request missing headers\n");
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        free(elem);
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        return -1;
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    }
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    req = g_new0(VubReq, 1);
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    req->vdev_blk = vdev_blk;
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    req->vq = vq;
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    req->elem = elem;
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    in_num = elem->in_num;
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    out_num = elem->out_num;
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    /* don't support VIRTIO_F_ANY_LAYOUT and virtio 1.0 only */
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    if (elem->out_sg[0].iov_len < sizeof(struct virtio_blk_outhdr)) {
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        fprintf(stderr, "Invalid outhdr size\n");
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        goto err;
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    }
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    req->out = (struct virtio_blk_outhdr *)elem->out_sg[0].iov_base;
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    out_num--;
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    if (elem->in_sg[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) {
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        fprintf(stderr, "Invalid inhdr size\n");
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        goto err;
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    }
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    req->in = (struct virtio_blk_inhdr *)elem->in_sg[in_num - 1].iov_base;
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    in_num--;
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    type = le32toh(req->out->type);
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    switch (type & ~(VIRTIO_BLK_T_OUT | VIRTIO_BLK_T_BARRIER)) {
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        case VIRTIO_BLK_T_IN: {
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            ssize_t ret = 0;
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            bool is_write = type & VIRTIO_BLK_T_OUT;
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            req->sector_num = le64toh(req->out->sector);
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            if (is_write) {
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                ret  = vub_writev(req, &elem->out_sg[1], out_num);
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            } else {
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                ret = vub_readv(req, &elem->in_sg[0], in_num);
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            }
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            if (ret >= 0) {
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                req->in->status = VIRTIO_BLK_S_OK;
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            } else {
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                req->in->status = VIRTIO_BLK_S_IOERR;
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            }
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            vub_req_complete(req);
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            break;
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        }
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        case VIRTIO_BLK_T_FLUSH: {
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            vub_flush(req);
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            req->in->status = VIRTIO_BLK_S_OK;
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            vub_req_complete(req);
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            break;
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        }
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        case VIRTIO_BLK_T_GET_ID: {
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            size_t size = MIN(vub_iov_size(&elem->in_sg[0], in_num),
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                              VIRTIO_BLK_ID_BYTES);
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            snprintf(elem->in_sg[0].iov_base, size, "%s", "vhost_user_blk");
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            req->in->status = VIRTIO_BLK_S_OK;
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            req->size = elem->in_sg[0].iov_len;
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            vub_req_complete(req);
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            break;
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        }
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        default: {
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            req->in->status = VIRTIO_BLK_S_UNSUPP;
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            vub_req_complete(req);
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            break;
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        }
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    }
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    return 0;
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err:
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    free(elem);
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    g_free(req);
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    return -1;
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}
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static void vub_process_vq(VuDev *vu_dev, int idx)
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{
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    VugDev *gdev;
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    VubDev *vdev_blk;
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    VuVirtq *vq;
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    int ret;
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    if ((idx < 0) || (idx >= VHOST_MAX_NR_VIRTQUEUE)) {
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        fprintf(stderr, "VQ Index out of range: %d\n", idx);
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        vub_panic_cb(vu_dev, NULL);
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        return;
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    }
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    gdev = container_of(vu_dev, VugDev, parent);
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    vdev_blk = container_of(gdev, VubDev, parent);
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    assert(vdev_blk);
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    vq = vu_get_queue(vu_dev, idx);
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    assert(vq);
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    while (1) {
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        ret = vub_virtio_process_req(vdev_blk, vq);
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        if (ret) {
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            break;
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        }
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    }
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}
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static void vub_queue_set_started(VuDev *vu_dev, int idx, bool started)
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{
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    VuVirtq *vq;
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    assert(vu_dev);
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    vq = vu_get_queue(vu_dev, idx);
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    vu_set_queue_handler(vu_dev, vq, started ? vub_process_vq : NULL);
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}
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static uint64_t
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vub_get_features(VuDev *dev)
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{
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    return 1ull << VIRTIO_BLK_F_SIZE_MAX |
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           1ull << VIRTIO_BLK_F_SEG_MAX |
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           1ull << VIRTIO_BLK_F_TOPOLOGY |
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           1ull << VIRTIO_BLK_F_BLK_SIZE |
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           1ull << VIRTIO_BLK_F_FLUSH |
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           1ull << VIRTIO_BLK_F_CONFIG_WCE |
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           1ull << VIRTIO_F_VERSION_1 |
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           1ull << VHOST_USER_F_PROTOCOL_FEATURES;
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}
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static int
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vub_get_config(VuDev *vu_dev, uint8_t *config, uint32_t len)
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{
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    VugDev *gdev;
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    VubDev *vdev_blk;
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    gdev = container_of(vu_dev, VugDev, parent);
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    vdev_blk = container_of(gdev, VubDev, parent);
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    memcpy(config, &vdev_blk->blkcfg, len);
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    return 0;
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}
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static int
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vub_set_config(VuDev *vu_dev, const uint8_t *data,
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               uint32_t offset, uint32_t size, uint32_t flags)
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{
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    VugDev *gdev;
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    VubDev *vdev_blk;
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    uint8_t wce;
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    int fd;
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    /* don't support live migration */
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    if (flags != VHOST_SET_CONFIG_TYPE_MASTER) {
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        return -1;
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    }
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    gdev = container_of(vu_dev, VugDev, parent);
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    vdev_blk = container_of(gdev, VubDev, parent);
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    if (offset != offsetof(struct virtio_blk_config, wce) ||
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        size != 1) {
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        return -1;
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    }
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    wce = *data;
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    if (wce == vdev_blk->blkcfg.wce) {
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        /* Do nothing as same with old configuration */
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        return 0;
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    }
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    vdev_blk->blkcfg.wce = wce;
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    fprintf(stdout, "Write Cache Policy Changed\n");
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    if (vdev_blk->blk_fd >= 0) {
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        close(vdev_blk->blk_fd);
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        vdev_blk->blk_fd = -1;
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    }
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    fd = vub_open(vdev_blk->blk_name, wce);
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    if (fd < 0) {
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        fprintf(stderr, "Error to open block device %s\n", vdev_blk->blk_name);
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        vdev_blk->blk_fd = -1;
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        return -1;
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    }
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    vdev_blk->blk_fd = fd;
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    return 0;
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}
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static const VuDevIface vub_iface = {
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    .get_features = vub_get_features,
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    .queue_set_started = vub_queue_set_started,
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    .get_config = vub_get_config,
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    .set_config = vub_set_config,
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};
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static int unix_sock_new(char *unix_fn)
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{
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    int sock;
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    struct sockaddr_un un;
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    size_t len;
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    assert(unix_fn);
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    sock = socket(AF_UNIX, SOCK_STREAM, 0);
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    if (sock <= 0) {
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        perror("socket");
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        return -1;
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    }
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    un.sun_family = AF_UNIX;
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    (void)snprintf(un.sun_path, sizeof(un.sun_path), "%s", unix_fn);
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    len = sizeof(un.sun_family) + strlen(un.sun_path);
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    (void)unlink(unix_fn);
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    if (bind(sock, (struct sockaddr *)&un, len) < 0) {
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        perror("bind");
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        goto fail;
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    }
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    if (listen(sock, 1) < 0) {
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        perror("listen");
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        goto fail;
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    }
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    return sock;
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fail:
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    (void)close(sock);
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    return -1;
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}
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static void vub_free(struct VubDev *vdev_blk)
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{
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    if (!vdev_blk) {
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        return;
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    }
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    g_main_loop_unref(vdev_blk->loop);
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    if (vdev_blk->blk_fd >= 0) {
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        close(vdev_blk->blk_fd);
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    }
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    g_free(vdev_blk);
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}
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static uint32_t
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vub_get_blocksize(int fd)
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{
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    uint32_t blocksize = 512;
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#if defined(__linux__) && defined(BLKSSZGET)
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    if (ioctl(fd, BLKSSZGET, &blocksize) == 0) {
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        return blocklen;
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    }
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#endif
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    return blocksize;
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}
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static void
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vub_initialize_config(int fd, struct virtio_blk_config *config)
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{
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    off64_t capacity;
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    capacity = lseek64(fd, 0, SEEK_END);
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    config->capacity = capacity >> 9;
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    config->blk_size = vub_get_blocksize(fd);
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    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;
 | 
						|
}
 |