tests/qtest/vhost-user-blk-test.c

/*
 * QTest testcase for Vhost-user Block Device
 *
 * Based on tests/qtest//virtio-blk-test.c

 * Copyright (c) 2014 SUSE LINUX Products GmbH
 * Copyright (c) 2014 Marc Marí
 * Copyright (c) 2020 Coiby Xu
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 */

#include "qemu/osdep.h"
#include "libqtest-single.h"
#include "qemu/bswap.h"
#include "qemu/module.h"
#include "standard-headers/linux/virtio_blk.h"
#include "standard-headers/linux/virtio_pci.h"
#include "libqos/qgraph.h"
#include "libqos/vhost-user-blk.h"
#include "libqos/libqos-pc.h"

#define TEST_IMAGE_SIZE         (64 * 1024 * 1024)
#define QVIRTIO_BLK_TIMEOUT_US  (30 * 1000 * 1000)
#define PCI_SLOT_HP             0x06

typedef struct {
    pid_t pid;
} QemuStorageDaemonState;

typedef struct QVirtioBlkReq {
    uint32_t type;
    uint32_t ioprio;
    uint64_t sector;
    char *data;
    uint8_t status;
} QVirtioBlkReq;

#if HOST_BIG_ENDIAN
static const bool host_is_big_endian = true;
#else
static const bool host_is_big_endian; /* false */
#endif

static inline void virtio_blk_fix_request(QVirtioDevice *d, QVirtioBlkReq *req)
{
    if (qvirtio_is_big_endian(d) != host_is_big_endian) {
        req->type = bswap32(req->type);
        req->ioprio = bswap32(req->ioprio);
        req->sector = bswap64(req->sector);
    }
}

static inline void virtio_blk_fix_dwz_hdr(QVirtioDevice *d,
    struct virtio_blk_discard_write_zeroes *dwz_hdr)
{
    if (qvirtio_is_big_endian(d) != host_is_big_endian) {
        dwz_hdr->sector = bswap64(dwz_hdr->sector);
        dwz_hdr->num_sectors = bswap32(dwz_hdr->num_sectors);
        dwz_hdr->flags = bswap32(dwz_hdr->flags);
    }
}

static uint64_t virtio_blk_request(QGuestAllocator *alloc, QVirtioDevice *d,
                                   QVirtioBlkReq *req, uint64_t data_size)
{
    uint64_t addr;
    uint8_t status = 0xFF;
    QTestState *qts = global_qtest;

    switch (req->type) {
    case VIRTIO_BLK_T_IN:
    case VIRTIO_BLK_T_OUT:
        g_assert_cmpuint(data_size % 512, ==, 0);
        break;
    case VIRTIO_BLK_T_DISCARD:
    case VIRTIO_BLK_T_WRITE_ZEROES:
        g_assert_cmpuint(data_size %
                         sizeof(struct virtio_blk_discard_write_zeroes), ==, 0);
        break;
    default:
        g_assert_cmpuint(data_size, ==, 0);
    }

    addr = guest_alloc(alloc, sizeof(*req) + data_size);

    virtio_blk_fix_request(d, req);

    qtest_memwrite(qts, addr, req, 16);
    qtest_memwrite(qts, addr + 16, req->data, data_size);
    qtest_memwrite(qts, addr + 16 + data_size, &status, sizeof(status));

    return addr;
}

static void test_invalid_discard_write_zeroes(QVirtioDevice *dev,
                                              QGuestAllocator *alloc,
                                              QTestState *qts,
                                              QVirtQueue *vq,
                                              uint32_t type)
{
    QVirtioBlkReq req;
    struct virtio_blk_discard_write_zeroes dwz_hdr;
    struct virtio_blk_discard_write_zeroes dwz_hdr2[2];
    uint64_t req_addr;
    uint32_t free_head;
    uint8_t status;

    /* More than one dwz is not supported */
    req.type = type;
    req.data = (char *) dwz_hdr2;
    dwz_hdr2[0].sector = 0;
    dwz_hdr2[0].num_sectors = 1;
    dwz_hdr2[0].flags = 0;
    dwz_hdr2[1].sector = 1;
    dwz_hdr2[1].num_sectors = 1;
    dwz_hdr2[1].flags = 0;

    virtio_blk_fix_dwz_hdr(dev, &dwz_hdr2[0]);
    virtio_blk_fix_dwz_hdr(dev, &dwz_hdr2[1]);

    req_addr = virtio_blk_request(alloc, dev, &req, sizeof(dwz_hdr2));

    free_head = qvirtqueue_add(qts, vq, req_addr, 16, false, true);
    qvirtqueue_add(qts, vq, req_addr + 16, sizeof(dwz_hdr2), false, true);
    qvirtqueue_add(qts, vq, req_addr + 16 + sizeof(dwz_hdr2), 1, true,
                   false);

    qvirtqueue_kick(qts, dev, vq, free_head);

    qvirtio_wait_used_elem(qts, dev, vq, free_head, NULL,
                           QVIRTIO_BLK_TIMEOUT_US);
    status = readb(req_addr + 16 + sizeof(dwz_hdr2));
    g_assert_cmpint(status, ==, VIRTIO_BLK_S_UNSUPP);

    guest_free(alloc, req_addr);

    /* num_sectors must be less than config->max_write_zeroes_sectors */
    req.type = type;
    req.data = (char *) &dwz_hdr;
    dwz_hdr.sector = 0;
    dwz_hdr.num_sectors = 0xffffffff;
    dwz_hdr.flags = 0;

    virtio_blk_fix_dwz_hdr(dev, &dwz_hdr);

    req_addr = virtio_blk_request(alloc, dev, &req, sizeof(dwz_hdr));

    free_head = qvirtqueue_add(qts, vq, req_addr, 16, false, true);
    qvirtqueue_add(qts, vq, req_addr + 16, sizeof(dwz_hdr), false, true);
    qvirtqueue_add(qts, vq, req_addr + 16 + sizeof(dwz_hdr), 1, true,
                   false);

    qvirtqueue_kick(qts, dev, vq, free_head);

    qvirtio_wait_used_elem(qts, dev, vq, free_head, NULL,
                           QVIRTIO_BLK_TIMEOUT_US);
    status = readb(req_addr + 16 + sizeof(dwz_hdr));
    g_assert_cmpint(status, ==, VIRTIO_BLK_S_IOERR);

    guest_free(alloc, req_addr);

    /* sector must be less than the device capacity */
    req.type = type;
    req.data = (char *) &dwz_hdr;
    dwz_hdr.sector = TEST_IMAGE_SIZE / 512 + 1;
    dwz_hdr.num_sectors = 1;
    dwz_hdr.flags = 0;

    virtio_blk_fix_dwz_hdr(dev, &dwz_hdr);

    req_addr = virtio_blk_request(alloc, dev, &req, sizeof(dwz_hdr));

    free_head = qvirtqueue_add(qts, vq, req_addr, 16, false, true);
    qvirtqueue_add(qts, vq, req_addr + 16, sizeof(dwz_hdr), false, true);
    qvirtqueue_add(qts, vq, req_addr + 16 + sizeof(dwz_hdr), 1, true,
                   false);

    qvirtqueue_kick(qts, dev, vq, free_head);

    qvirtio_wait_used_elem(qts, dev, vq, free_head, NULL,
                           QVIRTIO_BLK_TIMEOUT_US);
    status = readb(req_addr + 16 + sizeof(dwz_hdr));
    g_assert_cmpint(status, ==, VIRTIO_BLK_S_IOERR);

    guest_free(alloc, req_addr);

    /* reserved flag bits must be zero */
    req.type = type;
    req.data = (char *) &dwz_hdr;
    dwz_hdr.sector = 0;
    dwz_hdr.num_sectors = 1;
    dwz_hdr.flags = ~VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP;

    virtio_blk_fix_dwz_hdr(dev, &dwz_hdr);

    req_addr = virtio_blk_request(alloc, dev, &req, sizeof(dwz_hdr));

    free_head = qvirtqueue_add(qts, vq, req_addr, 16, false, true);
    qvirtqueue_add(qts, vq, req_addr + 16, sizeof(dwz_hdr), false, true);
    qvirtqueue_add(qts, vq, req_addr + 16 + sizeof(dwz_hdr), 1, true,
                   false);

    qvirtqueue_kick(qts, dev, vq, free_head);

    qvirtio_wait_used_elem(qts, dev, vq, free_head, NULL,
                           QVIRTIO_BLK_TIMEOUT_US);
    status = readb(req_addr + 16 + sizeof(dwz_hdr));
    g_assert_cmpint(status, ==, VIRTIO_BLK_S_UNSUPP);

    guest_free(alloc, req_addr);
}

/* Returns the request virtqueue so the caller can perform further tests */
static QVirtQueue *test_basic(QVirtioDevice *dev, QGuestAllocator *alloc)
{
    QVirtioBlkReq req;
    uint64_t req_addr;
    uint64_t capacity;
    uint64_t features;
    uint32_t free_head;
    uint8_t status;
    char *data;
    QTestState *qts = global_qtest;
    QVirtQueue *vq;

    features = qvirtio_get_features(dev);
    features = features & ~(QVIRTIO_F_BAD_FEATURE |
                    (1u << VIRTIO_RING_F_INDIRECT_DESC) |
                    (1u << VIRTIO_RING_F_EVENT_IDX) |
                    (1u << VIRTIO_BLK_F_SCSI));
    qvirtio_set_features(dev, features);

    capacity = qvirtio_config_readq(dev, 0);
    g_assert_cmpint(capacity, ==, TEST_IMAGE_SIZE / 512);

    vq = qvirtqueue_setup(dev, alloc, 0);

    qvirtio_set_driver_ok(dev);

    /* Write and read with 3 descriptor layout */
    /* Write request */
    req.type = VIRTIO_BLK_T_OUT;
    req.ioprio = 1;
    req.sector = 0;
    req.data = g_malloc0(512);
    strcpy(req.data, "TEST");

    req_addr = virtio_blk_request(alloc, dev, &req, 512);

    g_free(req.data);

    free_head = qvirtqueue_add(qts, vq, req_addr, 16, false, true);
    qvirtqueue_add(qts, vq, req_addr + 16, 512, false, true);
    qvirtqueue_add(qts, vq, req_addr + 528, 1, true, false);

    qvirtqueue_kick(qts, dev, vq, free_head);

    qvirtio_wait_used_elem(qts, dev, vq, free_head, NULL,
                           QVIRTIO_BLK_TIMEOUT_US);
    status = readb(req_addr + 528);
    g_assert_cmpint(status, ==, 0);

    guest_free(alloc, req_addr);

    /* Read request */
    req.type = VIRTIO_BLK_T_IN;
    req.ioprio = 1;
    req.sector = 0;
    req.data = g_malloc0(512);

    req_addr = virtio_blk_request(alloc, dev, &req, 512);

    g_free(req.data);

    free_head = qvirtqueue_add(qts, vq, req_addr, 16, false, true);
    qvirtqueue_add(qts, vq, req_addr + 16, 512, true, true);
    qvirtqueue_add(qts, vq, req_addr + 528, 1, true, false);

    qvirtqueue_kick(qts, dev, vq, free_head);

    qvirtio_wait_used_elem(qts, dev, vq, free_head, NULL,
                           QVIRTIO_BLK_TIMEOUT_US);
    status = readb(req_addr + 528);
    g_assert_cmpint(status, ==, 0);

    data = g_malloc0(512);
    qtest_memread(qts, req_addr + 16, data, 512);
    g_assert_cmpstr(data, ==, "TEST");
    g_free(data);

    guest_free(alloc, req_addr);

    if (features & (1u << VIRTIO_BLK_F_WRITE_ZEROES)) {
        struct virtio_blk_discard_write_zeroes dwz_hdr;
        void *expected;

        /*
         * WRITE_ZEROES request on the same sector of previous test where
         * we wrote "TEST".
         */
        req.type = VIRTIO_BLK_T_WRITE_ZEROES;
        req.data = (char *) &dwz_hdr;
        dwz_hdr.sector = 0;
        dwz_hdr.num_sectors = 1;
        dwz_hdr.flags = 0;

        virtio_blk_fix_dwz_hdr(dev, &dwz_hdr);

        req_addr = virtio_blk_request(alloc, dev, &req, sizeof(dwz_hdr));

        free_head = qvirtqueue_add(qts, vq, req_addr, 16, false, true);
        qvirtqueue_add(qts, vq, req_addr + 16, sizeof(dwz_hdr), false, true);
        qvirtqueue_add(qts, vq, req_addr + 16 + sizeof(dwz_hdr), 1, true,
                       false);

        qvirtqueue_kick(qts, dev, vq, free_head);

        qvirtio_wait_used_elem(qts, dev, vq, free_head, NULL,
                               QVIRTIO_BLK_TIMEOUT_US);
        status = readb(req_addr + 16 + sizeof(dwz_hdr));
        g_assert_cmpint(status, ==, 0);

        guest_free(alloc, req_addr);

        /* Read request to check if the sector contains all zeroes */
        req.type = VIRTIO_BLK_T_IN;
        req.ioprio = 1;
        req.sector = 0;
        req.data = g_malloc0(512);

        req_addr = virtio_blk_request(alloc, dev, &req, 512);

        g_free(req.data);

        free_head = qvirtqueue_add(qts, vq, req_addr, 16, false, true);
        qvirtqueue_add(qts, vq, req_addr + 16, 512, true, true);
        qvirtqueue_add(qts, vq, req_addr + 528, 1, true, false);

        qvirtqueue_kick(qts, dev, vq, free_head);

        qvirtio_wait_used_elem(qts, dev, vq, free_head, NULL,
                               QVIRTIO_BLK_TIMEOUT_US);
        status = readb(req_addr + 528);
        g_assert_cmpint(status, ==, 0);

        data = g_malloc(512);
        expected = g_malloc0(512);
        qtest_memread(qts, req_addr + 16, data, 512);
        g_assert_cmpmem(data, 512, expected, 512);
        g_free(expected);
        g_free(data);

        guest_free(alloc, req_addr);

        test_invalid_discard_write_zeroes(dev, alloc, qts, vq,
                                          VIRTIO_BLK_T_WRITE_ZEROES);
    }

    if (features & (1u << VIRTIO_BLK_F_DISCARD)) {
        struct virtio_blk_discard_write_zeroes dwz_hdr;

        req.type = VIRTIO_BLK_T_DISCARD;
        req.data = (char *) &dwz_hdr;
        dwz_hdr.sector = 0;
        dwz_hdr.num_sectors = 1;
        dwz_hdr.flags = 0;

        virtio_blk_fix_dwz_hdr(dev, &dwz_hdr);

        req_addr = virtio_blk_request(alloc, dev, &req, sizeof(dwz_hdr));

        free_head = qvirtqueue_add(qts, vq, req_addr, 16, false, true);
        qvirtqueue_add(qts, vq, req_addr + 16, sizeof(dwz_hdr), false, true);
        qvirtqueue_add(qts, vq, req_addr + 16 + sizeof(dwz_hdr),
                       1, true, false);

        qvirtqueue_kick(qts, dev, vq, free_head);

        qvirtio_wait_used_elem(qts, dev, vq, free_head, NULL,
                               QVIRTIO_BLK_TIMEOUT_US);
        status = readb(req_addr + 16 + sizeof(dwz_hdr));
        g_assert_cmpint(status, ==, 0);

        guest_free(alloc, req_addr);

        test_invalid_discard_write_zeroes(dev, alloc, qts, vq,
                                          VIRTIO_BLK_T_DISCARD);
    }

    if (features & (1u << VIRTIO_F_ANY_LAYOUT)) {
        /* Write and read with 2 descriptor layout */
        /* Write request */
        req.type = VIRTIO_BLK_T_OUT;
        req.ioprio = 1;
        req.sector = 1;
        req.data = g_malloc0(512);
        strcpy(req.data, "TEST");

        req_addr = virtio_blk_request(alloc, dev, &req, 512);

        g_free(req.data);

        free_head = qvirtqueue_add(qts, vq, req_addr, 528, false, true);
        qvirtqueue_add(qts, vq, req_addr + 528, 1, true, false);
        qvirtqueue_kick(qts, dev, vq, free_head);

        qvirtio_wait_used_elem(qts, dev, vq, free_head, NULL,
                               QVIRTIO_BLK_TIMEOUT_US);
        status = readb(req_addr + 528);
        g_assert_cmpint(status, ==, 0);

        guest_free(alloc, req_addr);

        /* Read request */
        req.type = VIRTIO_BLK_T_IN;
        req.ioprio = 1;
        req.sector = 1;
        req.data = g_malloc0(512);

        req_addr = virtio_blk_request(alloc, dev, &req, 512);

        g_free(req.data);

        free_head = qvirtqueue_add(qts, vq, req_addr, 16, false, true);
        qvirtqueue_add(qts, vq, req_addr + 16, 513, true, false);

        qvirtqueue_kick(qts, dev, vq, free_head);

        qvirtio_wait_used_elem(qts, dev, vq, free_head, NULL,
                               QVIRTIO_BLK_TIMEOUT_US);
        status = readb(req_addr + 528);
        g_assert_cmpint(status, ==, 0);

        data = g_malloc0(512);
        qtest_memread(qts, req_addr + 16, data, 512);
        g_assert_cmpstr(data, ==, "TEST");
        g_free(data);

        guest_free(alloc, req_addr);
    }

    return vq;
}

static void basic(void *obj, void *data, QGuestAllocator *t_alloc)
{
    QVhostUserBlk *blk_if = obj;
    QVirtQueue *vq;

    vq = test_basic(blk_if->vdev, t_alloc);
    qvirtqueue_cleanup(blk_if->vdev->bus, vq, t_alloc);

}

static void indirect(void *obj, void *u_data, QGuestAllocator *t_alloc)
{
    QVirtQueue *vq;
    QVhostUserBlk *blk_if = obj;
    QVirtioDevice *dev = blk_if->vdev;
    QVirtioBlkReq req;
    QVRingIndirectDesc *indirect;
    uint64_t req_addr;
    uint64_t capacity;
    uint64_t features;
    uint32_t free_head;
    uint8_t status;
    char *data;
    QTestState *qts = global_qtest;

    features = qvirtio_get_features(dev);
    g_assert_cmphex(features & (1u << VIRTIO_RING_F_INDIRECT_DESC), !=, 0);
    features = features & ~(QVIRTIO_F_BAD_FEATURE |
                            (1u << VIRTIO_RING_F_EVENT_IDX) |
                            (1u << VIRTIO_BLK_F_SCSI));
    qvirtio_set_features(dev, features);

    capacity = qvirtio_config_readq(dev, 0);
    g_assert_cmpint(capacity, ==, TEST_IMAGE_SIZE / 512);

    vq = qvirtqueue_setup(dev, t_alloc, 0);
    qvirtio_set_driver_ok(dev);

    /* Write request */
    req.type = VIRTIO_BLK_T_OUT;
    req.ioprio = 1;
    req.sector = 0;
    req.data = g_malloc0(512);
    strcpy(req.data, "TEST");

    req_addr = virtio_blk_request(t_alloc, dev, &req, 512);

    g_free(req.data);

    indirect = qvring_indirect_desc_setup(qts, dev, t_alloc, 2);
    qvring_indirect_desc_add(dev, qts, indirect, req_addr, 528, false);
    qvring_indirect_desc_add(dev, qts, indirect, req_addr + 528, 1, true);
    free_head = qvirtqueue_add_indirect(qts, vq, indirect);
    qvirtqueue_kick(qts, dev, vq, free_head);

    qvirtio_wait_used_elem(qts, dev, vq, free_head, NULL,
                           QVIRTIO_BLK_TIMEOUT_US);
    status = readb(req_addr + 528);
    g_assert_cmpint(status, ==, 0);

    g_free(indirect);
    guest_free(t_alloc, req_addr);

    /* Read request */
    req.type = VIRTIO_BLK_T_IN;
    req.ioprio = 1;
    req.sector = 0;
    req.data = g_malloc0(512);
    strcpy(req.data, "TEST");

    req_addr = virtio_blk_request(t_alloc, dev, &req, 512);

    g_free(req.data);

    indirect = qvring_indirect_desc_setup(qts, dev, t_alloc, 2);
    qvring_indirect_desc_add(dev, qts, indirect, req_addr, 16, false);
    qvring_indirect_desc_add(dev, qts, indirect, req_addr + 16, 513, true);
    free_head = qvirtqueue_add_indirect(qts, vq, indirect);
    qvirtqueue_kick(qts, dev, vq, free_head);

    qvirtio_wait_used_elem(qts, dev, vq, free_head, NULL,
                           QVIRTIO_BLK_TIMEOUT_US);
    status = readb(req_addr + 528);
    g_assert_cmpint(status, ==, 0);

    data = g_malloc0(512);
    qtest_memread(qts, req_addr + 16, data, 512);
    g_assert_cmpstr(data, ==, "TEST");
    g_free(data);

    g_free(indirect);
    guest_free(t_alloc, req_addr);
    qvirtqueue_cleanup(dev->bus, vq, t_alloc);
}

static void idx(void *obj, void *u_data, QGuestAllocator *t_alloc)
{
    QVirtQueue *vq;
    QVhostUserBlkPCI *blk = obj;
    QVirtioPCIDevice *pdev = &blk->pci_vdev;
    QVirtioDevice *dev = &pdev->vdev;
    QVirtioBlkReq req;
    uint64_t req_addr;
    uint64_t capacity;
    uint64_t features;
    uint32_t free_head;
    uint32_t write_head;
    uint32_t desc_idx;
    uint8_t status;
    char *data;
    QOSGraphObject *blk_object = obj;
    QPCIDevice *pci_dev = blk_object->get_driver(blk_object, "pci-device");
    QTestState *qts = global_qtest;

    if (qpci_check_buggy_msi(pci_dev)) {
        return;
    }

    qpci_msix_enable(pdev->pdev);
    qvirtio_pci_set_msix_configuration_vector(pdev, t_alloc, 0);

    features = qvirtio_get_features(dev);
    features = features & ~(QVIRTIO_F_BAD_FEATURE |
                            (1u << VIRTIO_RING_F_INDIRECT_DESC) |
                            (1u << VIRTIO_F_NOTIFY_ON_EMPTY) |
                            (1u << VIRTIO_BLK_F_SCSI));
    qvirtio_set_features(dev, features);

    capacity = qvirtio_config_readq(dev, 0);
    g_assert_cmpint(capacity, ==, TEST_IMAGE_SIZE / 512);

    vq = qvirtqueue_setup(dev, t_alloc, 0);
    qvirtqueue_pci_msix_setup(pdev, (QVirtQueuePCI *)vq, t_alloc, 1);

    qvirtio_set_driver_ok(dev);

    /*
     * libvhost-user signals the call fd in VHOST_USER_SET_VRING_CALL, make
     * sure to wait for the isr here so we don't race and confuse it later on.
     */
    qvirtio_wait_queue_isr(qts, dev, vq, QVIRTIO_BLK_TIMEOUT_US);

    /* Write request */
    req.type = VIRTIO_BLK_T_OUT;
    req.ioprio = 1;
    req.sector = 0;
    req.data = g_malloc0(512);
    strcpy(req.data, "TEST");

    req_addr = virtio_blk_request(t_alloc, dev, &req, 512);

    g_free(req.data);

    free_head = qvirtqueue_add(qts, vq, req_addr, 16, false, true);
    qvirtqueue_add(qts, vq, req_addr + 16, 512, false, true);
    qvirtqueue_add(qts, vq, req_addr + 528, 1, true, false);
    qvirtqueue_kick(qts, dev, vq, free_head);

    qvirtio_wait_used_elem(qts, dev, vq, free_head, NULL,
                           QVIRTIO_BLK_TIMEOUT_US);

    /* Write request */
    req.type = VIRTIO_BLK_T_OUT;
    req.ioprio = 1;
    req.sector = 1;
    req.data = g_malloc0(512);
    strcpy(req.data, "TEST");

    req_addr = virtio_blk_request(t_alloc, dev, &req, 512);

    g_free(req.data);

    /* Notify after processing the third request */
    qvirtqueue_set_used_event(qts, vq, 2);
    free_head = qvirtqueue_add(qts, vq, req_addr, 16, false, true);
    qvirtqueue_add(qts, vq, req_addr + 16, 512, false, true);
    qvirtqueue_add(qts, vq, req_addr + 528, 1, true, false);
    qvirtqueue_kick(qts, dev, vq, free_head);
    write_head = free_head;

    /* No notification expected */
    status = qvirtio_wait_status_byte_no_isr(qts, dev,
                                             vq, req_addr + 528,
                                             QVIRTIO_BLK_TIMEOUT_US);
    g_assert_cmpint(status, ==, 0);

    guest_free(t_alloc, req_addr);

    /* Read request */
    req.type = VIRTIO_BLK_T_IN;
    req.ioprio = 1;
    req.sector = 1;
    req.data = g_malloc0(512);

    req_addr = virtio_blk_request(t_alloc, dev, &req, 512);

    g_free(req.data);

    free_head = qvirtqueue_add(qts, vq, req_addr, 16, false, true);
    qvirtqueue_add(qts, vq, req_addr + 16, 512, true, true);
    qvirtqueue_add(qts, vq, req_addr + 528, 1, true, false);

    qvirtqueue_kick(qts, dev, vq, free_head);

    /* We get just one notification for both requests */
    qvirtio_wait_used_elem(qts, dev, vq, write_head, NULL,
                           QVIRTIO_BLK_TIMEOUT_US);
    g_assert(qvirtqueue_get_buf(qts, vq, &desc_idx, NULL));
    g_assert_cmpint(desc_idx, ==, free_head);

    status = readb(req_addr + 528);
    g_assert_cmpint(status, ==, 0);

    data = g_malloc0(512);
    qtest_memread(qts, req_addr + 16, data, 512);
    g_assert_cmpstr(data, ==, "TEST");
    g_free(data);

    guest_free(t_alloc, req_addr);

    /* End test */
    qpci_msix_disable(pdev->pdev);

    qvirtqueue_cleanup(dev->bus, vq, t_alloc);
}

static void pci_hotplug(void *obj, void *data, QGuestAllocator *t_alloc)
{
    QVirtioPCIDevice *dev1 = obj;
    QVirtioPCIDevice *dev;
    QTestState *qts = dev1->pdev->bus->qts;

    if (dev1->pdev->bus->not_hotpluggable) {
        g_test_skip("pci bus does not support hotplug");
        return;
    }

    /* plug secondary disk */
    qtest_qmp_device_add(qts, "vhost-user-blk-pci", "drv1",
                         "{'addr': %s, 'chardev': 'char2'}",
                         stringify(PCI_SLOT_HP) ".0");

    dev = virtio_pci_new(dev1->pdev->bus,
                         &(QPCIAddress) { .devfn = QPCI_DEVFN(PCI_SLOT_HP, 0)
                                        });
    g_assert_nonnull(dev);
    g_assert_cmpint(dev->vdev.device_type, ==, VIRTIO_ID_BLOCK);
    qvirtio_pci_device_disable(dev);
    qos_object_destroy((QOSGraphObject *)dev);

    /* unplug secondary disk */
    qpci_unplug_acpi_device_test(qts, "drv1", PCI_SLOT_HP);
}

static void multiqueue(void *obj, void *data, QGuestAllocator *t_alloc)
{
    QVirtioPCIDevice *pdev1 = obj;
    QVirtioDevice *dev1 = &pdev1->vdev;
    QVirtioPCIDevice *pdev8;
    QVirtioDevice *dev8;
    QTestState *qts = pdev1->pdev->bus->qts;
    uint64_t features;
    uint16_t num_queues;

    if (pdev1->pdev->bus->not_hotpluggable) {
        g_test_skip("bus pci.0 does not support hotplug");
        return;
    }

    /*
     * The primary device has 1 queue and VIRTIO_BLK_F_MQ is not enabled. The
     * VIRTIO specification allows VIRTIO_BLK_F_MQ to be enabled when there is
     * only 1 virtqueue, but --device vhost-user-blk-pci doesn't do this (which
     * is also spec-compliant).
     */
    features = qvirtio_get_features(dev1);
    g_assert_cmpint(features & (1u << VIRTIO_BLK_F_MQ), ==, 0);
    features = features & ~(QVIRTIO_F_BAD_FEATURE |
                            (1u << VIRTIO_RING_F_INDIRECT_DESC) |
                            (1u << VIRTIO_F_NOTIFY_ON_EMPTY) |
                            (1u << VIRTIO_BLK_F_SCSI));
    qvirtio_set_features(dev1, features);

    /* Hotplug a secondary device with 8 queues */
    qtest_qmp_device_add(qts, "vhost-user-blk-pci", "drv1",
                         "{'addr': %s, 'chardev': 'char2', 'num-queues': 8}",
                         stringify(PCI_SLOT_HP) ".0");

    pdev8 = virtio_pci_new(pdev1->pdev->bus,
                           &(QPCIAddress) {
                               .devfn = QPCI_DEVFN(PCI_SLOT_HP, 0)
                           });
    g_assert_nonnull(pdev8);
    g_assert_cmpint(pdev8->vdev.device_type, ==, VIRTIO_ID_BLOCK);

    qos_object_start_hw(&pdev8->obj);

    dev8 = &pdev8->vdev;
    features = qvirtio_get_features(dev8);
    g_assert_cmpint(features & (1u << VIRTIO_BLK_F_MQ),
                    ==,
                    (1u << VIRTIO_BLK_F_MQ));
    features = features & ~(QVIRTIO_F_BAD_FEATURE |
                            (1u << VIRTIO_RING_F_INDIRECT_DESC) |
                            (1u << VIRTIO_F_NOTIFY_ON_EMPTY) |
                            (1u << VIRTIO_BLK_F_SCSI) |
                            (1u << VIRTIO_BLK_F_MQ));
    qvirtio_set_features(dev8, features);

    num_queues = qvirtio_config_readw(dev8,
            offsetof(struct virtio_blk_config, num_queues));
    g_assert_cmpint(num_queues, ==, 8);

    qvirtio_pci_device_disable(pdev8);
    qos_object_destroy(&pdev8->obj);

    /* unplug secondary disk */
    qpci_unplug_acpi_device_test(qts, "drv1", PCI_SLOT_HP);
}

/*
 * Check that setting the vring addr on a non-existent virtqueue does
 * not crash.
 */
static void test_nonexistent_virtqueue(void *obj, void *data,
                                       QGuestAllocator *t_alloc)
{
    QVhostUserBlkPCI *blk = obj;
    QVirtioPCIDevice *pdev = &blk->pci_vdev;
    QPCIBar bar0;
    QPCIDevice *dev;

    dev = qpci_device_find(pdev->pdev->bus, QPCI_DEVFN(4, 0));
    g_assert(dev != NULL);
    qpci_device_enable(dev);

    bar0 = qpci_iomap(dev, 0, NULL);

    qpci_io_writeb(dev, bar0, VIRTIO_PCI_QUEUE_SEL, 2);
    qpci_io_writel(dev, bar0, VIRTIO_PCI_QUEUE_PFN, 1);

    g_free(dev);
}

static const char *qtest_qemu_storage_daemon_binary(void)
{
    const char *qemu_storage_daemon_bin;

    qemu_storage_daemon_bin = getenv("QTEST_QEMU_STORAGE_DAEMON_BINARY");
    if (!qemu_storage_daemon_bin) {
        fprintf(stderr, "Environment variable "
                        "QTEST_QEMU_STORAGE_DAEMON_BINARY required\n");
        exit(0);
    }

    /* If we've got a path to the binary, check whether we can access it */
    if (strchr(qemu_storage_daemon_bin, '/') &&
        access(qemu_storage_daemon_bin, X_OK) != 0) {
        fprintf(stderr, "ERROR: '%s' is not accessible\n",
                qemu_storage_daemon_bin);
        exit(1);
    }

    return qemu_storage_daemon_bin;
}

/* g_test_queue_destroy() cleanup function for files */
static void destroy_file(void *path)
{
    unlink(path);
    g_free(path);
    qos_invalidate_command_line();
}

static char *drive_create(void)
{
    int fd, ret;
    /** vhost-user-blk won't recognize drive located in /tmp */
    char *t_path = g_strdup("qtest.XXXXXX");

    /** Create a temporary raw image */
    fd = mkstemp(t_path);
    g_assert_cmpint(fd, >=, 0);
    ret = ftruncate(fd, TEST_IMAGE_SIZE);
    g_assert_cmpint(ret, ==, 0);
    close(fd);

    g_test_queue_destroy(destroy_file, t_path);
    return t_path;
}

static char *create_listen_socket(int *fd)
{
    int tmp_fd;
    char *path;

    /* No race because our pid makes the path unique */
    path = g_strdup_printf("%s/qtest-%d-sock.XXXXXX",
                           g_get_tmp_dir(), getpid());
    tmp_fd = mkstemp(path);
    g_assert_cmpint(tmp_fd, >=, 0);
    close(tmp_fd);
    unlink(path);

    *fd = qtest_socket_server(path);
    g_test_queue_destroy(destroy_file, path);
    return path;
}

/*
 * g_test_queue_destroy() and qtest_add_abrt_handler() cleanup function for
 * qemu-storage-daemon.
 */
static void quit_storage_daemon(void *data)
{
    QemuStorageDaemonState *qsd = data;
    int wstatus;
    pid_t pid;

    /*
     * If we were invoked as a g_test_queue_destroy() cleanup function we need
     * to remove the abrt handler to avoid being called again if the code below
     * aborts. Also, we must not leave the abrt handler installed after
     * cleanup.
     */
    qtest_remove_abrt_handler(data);

    /* Before quitting storage-daemon, quit qemu to avoid dubious messages */
    qtest_kill_qemu(global_qtest);

    kill(qsd->pid, SIGTERM);
    pid = waitpid(qsd->pid, &wstatus, 0);
    g_assert_cmpint(pid, ==, qsd->pid);
    if (!WIFEXITED(wstatus)) {
        fprintf(stderr, "%s: expected qemu-storage-daemon to exit\n",
                __func__);
        abort();
    }
    if (WEXITSTATUS(wstatus) != 0) {
        fprintf(stderr, "%s: expected qemu-storage-daemon to exit "
                "successfully, got %d\n",
                __func__, WEXITSTATUS(wstatus));
        abort();
    }

    g_free(data);
}

static void start_vhost_user_blk(GString *cmd_line, int vus_instances,
                                 int num_queues)
{
    const char *vhost_user_blk_bin = qtest_qemu_storage_daemon_binary();
    int i;
    gchar *img_path;
    GString *storage_daemon_command = g_string_new(NULL);
    QemuStorageDaemonState *qsd;

    g_string_append_printf(storage_daemon_command,
                           "exec %s ",
                           vhost_user_blk_bin);

    g_string_append_printf(cmd_line,
            " -object memory-backend-shm,id=mem,size=256M "
            " -M memory-backend=mem -m 256M ");

    for (i = 0; i < vus_instances; i++) {
        int fd;
        char *sock_path = create_listen_socket(&fd);

        /* create image file */
        img_path = drive_create();
        g_string_append_printf(storage_daemon_command,
            "--blockdev driver=file,node-name=disk%d,filename=%s "
            "--export type=vhost-user-blk,id=disk%d,addr.type=fd,addr.str=%d,"
            "node-name=disk%i,writable=on,num-queues=%d ",
            i, img_path, i, fd, i, num_queues);

        g_string_append_printf(cmd_line, "-chardev socket,id=char%d,path=%s ",
                               i + 1, sock_path);
    }

    g_test_message("starting vhost-user backend: %s",
                   storage_daemon_command->str);
    pid_t pid = fork();
    if (pid == 0) {
        /*
         * Close standard file descriptors so tap-driver.pl pipe detects when
         * our parent terminates.
         */
        close(0);
        close(1);
        open("/dev/null", O_RDONLY);
        open("/dev/null", O_WRONLY);

        execlp("/bin/sh", "sh", "-c", storage_daemon_command->str, NULL);
        exit(1);
    }
    g_string_free(storage_daemon_command, true);

    qsd = g_new(QemuStorageDaemonState, 1);
    qsd->pid = pid;

    /* Make sure qemu-storage-daemon is stopped */
    qtest_add_abrt_handler(quit_storage_daemon, qsd);
    g_test_queue_destroy(quit_storage_daemon, qsd);
}

static void *vhost_user_blk_test_setup(GString *cmd_line, void *arg)
{
    start_vhost_user_blk(cmd_line, 1, 1);
    return arg;
}

/*
 * Setup for hotplug.
 *
 * Since vhost-user server only serves one vhost-user client one time,
 * another export
 *
 */
static void *vhost_user_blk_hotplug_test_setup(GString *cmd_line, void *arg)
{
    /* "-chardev socket,id=char2" is used for pci_hotplug*/
    start_vhost_user_blk(cmd_line, 2, 1);
    return arg;
}

static void *vhost_user_blk_multiqueue_test_setup(GString *cmd_line, void *arg)
{
    start_vhost_user_blk(cmd_line, 2, 8);
    return arg;
}

static void register_vhost_user_blk_test(void)
{
    QOSGraphTestOptions opts = {
        .before = vhost_user_blk_test_setup,
    };

    if (!getenv("QTEST_QEMU_STORAGE_DAEMON_BINARY")) {
        g_test_message("QTEST_QEMU_STORAGE_DAEMON_BINARY not defined, "
                       "skipping vhost-user-blk-test");
        return;
    }

    /*
     * tests for vhost-user-blk and vhost-user-blk-pci
     * The tests are borrowed from tests/virtio-blk-test.c. But some tests
     * regarding block_resize don't work for vhost-user-blk.
     * vhost-user-blk device doesn't have -drive, so tests containing
     * block_resize are also abandoned,
     *  - config
     *  - resize
     */
    qos_add_test("basic", "vhost-user-blk", basic, &opts);
    qos_add_test("indirect", "vhost-user-blk", indirect, &opts);
    qos_add_test("idx", "vhost-user-blk-pci", idx, &opts);
    qos_add_test("nxvirtq", "vhost-user-blk-pci",
                 test_nonexistent_virtqueue, &opts);

    opts.before = vhost_user_blk_hotplug_test_setup;
    qos_add_test("hotplug", "vhost-user-blk-pci", pci_hotplug, &opts);

    opts.before = vhost_user_blk_multiqueue_test_setup;
    qos_add_test("multiqueue", "vhost-user-blk-pci", multiqueue, &opts);
}

libqos_init(register_vhost_user_blk_test);