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[PULL 21/31] block/export: port virtio-blk discard/write zeroes input va
From: |
Kevin Wolf |
Subject: |
[PULL 21/31] block/export: port virtio-blk discard/write zeroes input validation |
Date: |
Fri, 5 Mar 2021 17:54:44 +0100 |
From: Stefan Hajnoczi <stefanha@redhat.com>
Validate discard/write zeroes the same way we do for virtio-blk. Some of
these checks are mandated by the VIRTIO specification, others are
internal to QEMU.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20210223144653.811468-11-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
block/export/vhost-user-blk-server.c | 116 +++++++++++++++++++++------
1 file changed, 93 insertions(+), 23 deletions(-)
diff --git a/block/export/vhost-user-blk-server.c
b/block/export/vhost-user-blk-server.c
index f74796241c..04044228d4 100644
--- a/block/export/vhost-user-blk-server.c
+++ b/block/export/vhost-user-blk-server.c
@@ -29,6 +29,8 @@
enum {
VHOST_USER_BLK_NUM_QUEUES_DEFAULT = 1,
+ VHOST_USER_BLK_MAX_DISCARD_SECTORS = 32768,
+ VHOST_USER_BLK_MAX_WRITE_ZEROES_SECTORS = 32768,
};
struct virtio_blk_inhdr {
unsigned char status;
@@ -65,30 +67,102 @@ static void vu_blk_req_complete(VuBlkReq *req)
free(req);
}
+static bool vu_blk_sect_range_ok(VuBlkExport *vexp, uint64_t sector,
+ size_t size)
+{
+ uint64_t nb_sectors = size >> BDRV_SECTOR_BITS;
+ uint64_t total_sectors;
+
+ if (nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
+ return false;
+ }
+ if ((sector << VIRTIO_BLK_SECTOR_BITS) % vexp->blk_size) {
+ return false;
+ }
+ blk_get_geometry(vexp->export.blk, &total_sectors);
+ if (sector > total_sectors || nb_sectors > total_sectors - sector) {
+ return false;
+ }
+ return true;
+}
+
static int coroutine_fn
-vu_blk_discard_write_zeroes(BlockBackend *blk, struct iovec *iov,
+vu_blk_discard_write_zeroes(VuBlkExport *vexp, struct iovec *iov,
uint32_t iovcnt, uint32_t type)
{
+ BlockBackend *blk = vexp->export.blk;
struct virtio_blk_discard_write_zeroes desc;
- ssize_t size = iov_to_buf(iov, iovcnt, 0, &desc, sizeof(desc));
+ ssize_t size;
+ uint64_t sector;
+ uint32_t num_sectors;
+ uint32_t max_sectors;
+ uint32_t flags;
+ int bytes;
+
+ /* Only one desc is currently supported */
+ if (unlikely(iov_size(iov, iovcnt) > sizeof(desc))) {
+ return VIRTIO_BLK_S_UNSUPP;
+ }
+
+ size = iov_to_buf(iov, iovcnt, 0, &desc, sizeof(desc));
if (unlikely(size != sizeof(desc))) {
- error_report("Invalid size %zd, expect %zu", size, sizeof(desc));
- return -EINVAL;
+ error_report("Invalid size %zd, expected %zu", size, sizeof(desc));
+ return VIRTIO_BLK_S_IOERR;
}
- uint64_t range[2] = { le64_to_cpu(desc.sector) << 9,
- le32_to_cpu(desc.num_sectors) << 9 };
- if (type == VIRTIO_BLK_T_DISCARD) {
- if (blk_co_pdiscard(blk, range[0], range[1]) == 0) {
- return 0;
+ sector = le64_to_cpu(desc.sector);
+ num_sectors = le32_to_cpu(desc.num_sectors);
+ flags = le32_to_cpu(desc.flags);
+ max_sectors = (type == VIRTIO_BLK_T_WRITE_ZEROES) ?
+ VHOST_USER_BLK_MAX_WRITE_ZEROES_SECTORS :
+ VHOST_USER_BLK_MAX_DISCARD_SECTORS;
+
+ /* This check ensures that 'bytes' fits in an int */
+ if (unlikely(num_sectors > max_sectors)) {
+ return VIRTIO_BLK_S_IOERR;
+ }
+
+ bytes = num_sectors << VIRTIO_BLK_SECTOR_BITS;
+
+ if (unlikely(!vu_blk_sect_range_ok(vexp, sector, bytes))) {
+ return VIRTIO_BLK_S_IOERR;
+ }
+
+ /*
+ * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for discard
+ * and write zeroes commands if any unknown flag is set.
+ */
+ if (unlikely(flags & ~VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) {
+ return VIRTIO_BLK_S_UNSUPP;
+ }
+
+ if (type == VIRTIO_BLK_T_WRITE_ZEROES) {
+ int blk_flags = 0;
+
+ if (flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP) {
+ blk_flags |= BDRV_REQ_MAY_UNMAP;
+ }
+
+ if (blk_co_pwrite_zeroes(blk, sector << VIRTIO_BLK_SECTOR_BITS,
+ bytes, blk_flags) == 0) {
+ return VIRTIO_BLK_S_OK;
}
- } else if (type == VIRTIO_BLK_T_WRITE_ZEROES) {
- if (blk_co_pwrite_zeroes(blk, range[0], range[1], 0) == 0) {
- return 0;
+ } else if (type == VIRTIO_BLK_T_DISCARD) {
+ /*
+ * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for
+ * discard commands if the unmap flag is set.
+ */
+ if (unlikely(flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) {
+ return VIRTIO_BLK_S_UNSUPP;
+ }
+
+ if (blk_co_pdiscard(blk, sector << VIRTIO_BLK_SECTOR_BITS,
+ bytes) == 0) {
+ return VIRTIO_BLK_S_OK;
}
}
- return -EINVAL;
+ return VIRTIO_BLK_S_IOERR;
}
static void coroutine_fn vu_blk_virtio_process_req(void *opaque)
@@ -177,19 +251,13 @@ static void coroutine_fn vu_blk_virtio_process_req(void
*opaque)
}
case VIRTIO_BLK_T_DISCARD:
case VIRTIO_BLK_T_WRITE_ZEROES: {
- int rc;
-
if (!vexp->writable) {
req->in->status = VIRTIO_BLK_S_IOERR;
break;
}
- rc = vu_blk_discard_write_zeroes(blk, &elem->out_sg[1], out_num, type);
- if (rc == 0) {
- req->in->status = VIRTIO_BLK_S_OK;
- } else {
- req->in->status = VIRTIO_BLK_S_IOERR;
- }
+ req->in->status = vu_blk_discard_write_zeroes(vexp, out_iov, out_num,
+ type);
break;
}
default:
@@ -362,11 +430,13 @@ vu_blk_initialize_config(BlockDriverState *bs,
config->min_io_size = cpu_to_le16(1);
config->opt_io_size = cpu_to_le32(1);
config->num_queues = cpu_to_le16(num_queues);
- config->max_discard_sectors = cpu_to_le32(32768);
+ config->max_discard_sectors =
+ cpu_to_le32(VHOST_USER_BLK_MAX_DISCARD_SECTORS);
config->max_discard_seg = cpu_to_le32(1);
config->discard_sector_alignment =
cpu_to_le32(blk_size >> VIRTIO_BLK_SECTOR_BITS);
- config->max_write_zeroes_sectors = cpu_to_le32(32768);
+ config->max_write_zeroes_sectors
+ = cpu_to_le32(VHOST_USER_BLK_MAX_WRITE_ZEROES_SECTORS);
config->max_write_zeroes_seg = cpu_to_le32(1);
}
--
2.29.2
- [PULL 05/31] iotests: Fix up python style in 300, (continued)
- [PULL 05/31] iotests: Fix up python style in 300, Kevin Wolf, 2021/03/05
- [PULL 09/31] qemu-storage-daemon: add --pidfile option, Kevin Wolf, 2021/03/05
- [PULL 02/31] backup: Remove nodes from job in .clean(), Kevin Wolf, 2021/03/05
- [PULL 26/31] block/parallels: BDRVParallelsState: add cluster_size field, Kevin Wolf, 2021/03/05
- [PULL 11/31] docs: replace insecure /tmp examples in qsd docs, Kevin Wolf, 2021/03/05
- [PULL 19/31] block/export: use VIRTIO_BLK_SECTOR_BITS, Kevin Wolf, 2021/03/05
- [PULL 25/31] parallels.txt: fix bitmap L1 table description, Kevin Wolf, 2021/03/05
- [PULL 10/31] docs: show how to spawn qemu-storage-daemon with fd passing, Kevin Wolf, 2021/03/05
- [PULL 20/31] block/export: fix vhost-user-blk export sector number calculation, Kevin Wolf, 2021/03/05
- [PULL 17/31] tests/qtest: add multi-queue test case to vhost-user-blk-test, Kevin Wolf, 2021/03/05
- [PULL 21/31] block/export: port virtio-blk discard/write zeroes input validation,
Kevin Wolf <=
- [PULL 23/31] block/export: port virtio-blk read/write range check, Kevin Wolf, 2021/03/05
- [PULL 03/31] backup-top: Refuse I/O in inactive state, Kevin Wolf, 2021/03/05
- [PULL 30/31] MAINTAINERS: update parallels block driver, Kevin Wolf, 2021/03/05
- [PULL 31/31] docs: qsd: Explain --export nbd,name=... default, Kevin Wolf, 2021/03/05
- [PULL 28/31] iotests.py: add unarchive_sample_image() helper, Kevin Wolf, 2021/03/05
- [PULL 24/31] qcow2-bitmap: make bytes_covered_by_bitmap_cluster() public, Kevin Wolf, 2021/03/05
- [PULL 07/31] storage-daemon: report unexpected arguments on the fly, Kevin Wolf, 2021/03/05
- [PULL 04/31] iotests/283: Check that finalize drops backup-top, Kevin Wolf, 2021/03/05
- [PULL 27/31] parallels: support bitmap extension for read-only mode, Kevin Wolf, 2021/03/05
- [PULL 18/31] block/export: fix blk_size double byteswap, Kevin Wolf, 2021/03/05