Пример #1
0
static int coroutine_fn raw_co_writev(BlockDriverState *bs, int64_t sector_num,
                                      int nb_sectors, QEMUIOVector *qiov)
{
    void *buf = NULL;
    BlockDriver *drv;
    QEMUIOVector local_qiov;
    int ret;

    if (bs->probed && sector_num == 0) {
        /* As long as these conditions are true, we can't get partial writes to
         * the probe buffer and can just directly check the request. */
        QEMU_BUILD_BUG_ON(BLOCK_PROBE_BUF_SIZE != 512);
        QEMU_BUILD_BUG_ON(BDRV_SECTOR_SIZE != 512);

        if (nb_sectors == 0) {
            /* qemu_iovec_to_buf() would fail, but we want to return success
             * instead of -EINVAL in this case. */
            return 0;
        }

        buf = qemu_try_blockalign(bs->file, 512);
        if (!buf) {
            ret = -ENOMEM;
            goto fail;
        }

        ret = qemu_iovec_to_buf(qiov, 0, buf, 512);
        if (ret != 512) {
            ret = -EINVAL;
            goto fail;
        }

        drv = bdrv_probe_all(buf, 512, NULL);
        if (drv != bs->drv) {
            ret = -EPERM;
            goto fail;
        }

        /* Use the checked buffer, a malicious guest might be overwriting its
         * original buffer in the background. */
        qemu_iovec_init(&local_qiov, qiov->niov + 1);
        qemu_iovec_add(&local_qiov, buf, 512);
        qemu_iovec_concat(&local_qiov, qiov, 512, qiov->size - 512);
        qiov = &local_qiov;
    }

    BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
    ret = bdrv_co_writev(bs->file, sector_num, nb_sectors, qiov);

fail:
    if (qiov == &local_qiov) {
        qemu_iovec_destroy(&local_qiov);
    }
    qemu_vfree(buf);
    return ret;
}
Пример #2
0
static int coroutine_fn raw_co_writev(BlockDriverState *bs, int64_t sector_num,
                                      int nb_sectors, QEMUIOVector *qiov)
{
    return bdrv_co_writev(bs->file, sector_num, nb_sectors, qiov);
}
Пример #3
0
static int coroutine_fn raw_co_writev(BlockDriverState *bs, int64_t sector_num,
                                      int nb_sectors, QEMUIOVector *qiov)
{
    BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
    return bdrv_co_writev(bs->file, sector_num, nb_sectors, qiov);
}
Пример #4
0
static coroutine_fn int
block_crypto_co_writev(BlockDriverState *bs, int64_t sector_num,
                       int remaining_sectors, QEMUIOVector *qiov)
{
    BlockCrypto *crypto = bs->opaque;
    int cur_nr_sectors; /* number of sectors in current iteration */
    uint64_t bytes_done = 0;
    uint8_t *cipher_data = NULL;
    QEMUIOVector hd_qiov;
    int ret = 0;
    size_t payload_offset =
        qcrypto_block_get_payload_offset(crypto->block) / 512;

    qemu_iovec_init(&hd_qiov, qiov->niov);

    /* Bounce buffer so we have a linear mem region for
     * entire sector. XXX optimize so we avoid bounce
     * buffer in case that qiov->niov == 1
     */
    cipher_data =
        qemu_try_blockalign(bs->file->bs, MIN(BLOCK_CRYPTO_MAX_SECTORS * 512,
                                              qiov->size));
    if (cipher_data == NULL) {
        ret = -ENOMEM;
        goto cleanup;
    }

    while (remaining_sectors) {
        cur_nr_sectors = remaining_sectors;

        if (cur_nr_sectors > BLOCK_CRYPTO_MAX_SECTORS) {
            cur_nr_sectors = BLOCK_CRYPTO_MAX_SECTORS;
        }

        qemu_iovec_to_buf(qiov, bytes_done,
                          cipher_data, cur_nr_sectors * 512);

        if (qcrypto_block_encrypt(crypto->block,
                                  sector_num,
                                  cipher_data, cur_nr_sectors * 512,
                                  NULL) < 0) {
            ret = -EIO;
            goto cleanup;
        }

        qemu_iovec_reset(&hd_qiov);
        qemu_iovec_add(&hd_qiov, cipher_data, cur_nr_sectors * 512);

        ret = bdrv_co_writev(bs->file,
                             payload_offset + sector_num,
                             cur_nr_sectors, &hd_qiov);
        if (ret < 0) {
            goto cleanup;
        }

        remaining_sectors -= cur_nr_sectors;
        sector_num += cur_nr_sectors;
        bytes_done += cur_nr_sectors * 512;
    }

 cleanup:
    qemu_iovec_destroy(&hd_qiov);
    qemu_vfree(cipher_data);

    return ret;
}