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virtio-blk: remove SCSI passthrough functionality

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The legacy SCSI passthrough functionality has never been enabled for
VIRTIO 1.0 and was deprecated more than four years ago.

Get rid of it---almost, because QEMU is advertising it unconditionally
for legacy virtio-blk devices.  Just parse the header and return a
nonzero status.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2024-05-10 15:51:57 +02:00
parent 993e38020f
commit a271b8d7b2
4 changed files with 19 additions and 167 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
docs/about/deprecated.rst
View File

@ -296,16 +296,6 @@ Device options
Emulated device options
'''''''''''''''''''''''
``-device virtio-blk,scsi=on|off`` (since 5.0)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The virtio-blk SCSI passthrough feature is a legacy VIRTIO feature. VIRTIO 1.0
and later do not support it because the virtio-scsi device was introduced for
full SCSI support. Use virtio-scsi instead when SCSI passthrough is required.
Note this also applies to ``-device virtio-blk-pci,scsi=on|off``, which is an
alias.
``-device nvme-ns,eui64-default=on|off`` (since 7.1)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

8
docs/about/removed-features.rst
View File

@ -510,6 +510,14 @@ than zero.
Removed along with the ``compression`` migration capability.
``-device virtio-blk,scsi=on|off`` (since 9.1)
''''''''''''''''''''''''''''''''''''''''''''''
The virtio-blk SCSI passthrough feature is a legacy VIRTIO feature. VIRTIO 1.0
and later do not support it because the virtio-scsi device was introduced for
full SCSI support. Use virtio-scsi instead when SCSI passthrough is required.
User-mode emulator command line arguments
-----------------------------------------

166
hw/block/virtio-blk.c
View File

@ -172,57 +172,6 @@ static void virtio_blk_discard_write_zeroes_complete(void *opaque, int ret)
virtio_blk_free_request(req);
}
#ifdef __linux__
typedef struct {
VirtIOBlockReq *req;
struct sg_io_hdr hdr;
} VirtIOBlockIoctlReq;
static void virtio_blk_ioctl_complete(void *opaque, int status)
{
VirtIOBlockIoctlReq *ioctl_req = opaque;
VirtIOBlockReq *req = ioctl_req->req;
VirtIOBlock *s = req->dev;
VirtIODevice *vdev = VIRTIO_DEVICE(s);
struct virtio_scsi_inhdr *scsi;
struct sg_io_hdr *hdr;
scsi = (void *)req->elem.in_sg[req->elem.in_num - 2].iov_base;
if (status) {
status = VIRTIO_BLK_S_UNSUPP;
virtio_stl_p(vdev, &scsi->errors, 255);
goto out;
}
hdr = &ioctl_req->hdr;
/*
* From SCSI-Generic-HOWTO: "Some lower level drivers (e.g. ide-scsi)
* clear the masked_status field [hence status gets cleared too, see
* block/scsi_ioctl.c] even when a CHECK_CONDITION or COMMAND_TERMINATED
* status has occurred. However they do set DRIVER_SENSE in driver_status
* field. Also a (sb_len_wr > 0) indicates there is a sense buffer.
*/
if (hdr->status == 0 && hdr->sb_len_wr > 0) {
hdr->status = CHECK_CONDITION;
}
virtio_stl_p(vdev, &scsi->errors,
hdr->status | (hdr->msg_status << 8) |
(hdr->host_status << 16) | (hdr->driver_status << 24));
virtio_stl_p(vdev, &scsi->residual, hdr->resid);
virtio_stl_p(vdev, &scsi->sense_len, hdr->sb_len_wr);
virtio_stl_p(vdev, &scsi->data_len, hdr->dxfer_len);
out:
virtio_blk_req_complete(req, status);
virtio_blk_free_request(req);
g_free(ioctl_req);
}
#endif
static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s, VirtQueue *vq)
{
VirtIOBlockReq *req = virtqueue_pop(vq, sizeof(VirtIOBlockReq));
@ -233,20 +182,14 @@ static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s, VirtQueue *vq)
return req;
}
static int virtio_blk_handle_scsi_req(VirtIOBlockReq *req)
static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
{
int status = VIRTIO_BLK_S_OK;
struct virtio_scsi_inhdr *scsi = NULL;
int status;
struct virtio_scsi_inhdr *scsi;
VirtIOBlock *blk = req->dev;
VirtIODevice *vdev = VIRTIO_DEVICE(blk);
VirtQueueElement *elem = &req->elem;
#ifdef __linux__
int i;
VirtIOBlockIoctlReq *ioctl_req;
BlockAIOCB *acb;
#endif
/*
* We require at least one output segment each for the virtio_blk_outhdr
* and the SCSI command block.
@ -262,95 +205,16 @@ static int virtio_blk_handle_scsi_req(VirtIOBlockReq *req)
/*
* The scsi inhdr is placed in the second-to-last input segment, just
* before the regular inhdr.
*
* Just put anything nonzero so that the ioctl fails in the guest.
*/
scsi = (void *)elem->in_sg[elem->in_num - 2].iov_base;
if (!virtio_has_feature(blk->host_features, VIRTIO_BLK_F_SCSI)) {
status = VIRTIO_BLK_S_UNSUPP;
goto fail;
}
/*
* No support for bidirection commands yet.
*/
if (elem->out_num > 2 && elem->in_num > 3) {
status = VIRTIO_BLK_S_UNSUPP;
goto fail;
}
#ifdef __linux__
ioctl_req = g_new0(VirtIOBlockIoctlReq, 1);
ioctl_req->req = req;
ioctl_req->hdr.interface_id = 'S';
ioctl_req->hdr.cmd_len = elem->out_sg[1].iov_len;
ioctl_req->hdr.cmdp = elem->out_sg[1].iov_base;
ioctl_req->hdr.dxfer_len = 0;
if (elem->out_num > 2) {
/*
* If there are more than the minimally required 2 output segments
* there is write payload starting from the third iovec.
*/
ioctl_req->hdr.dxfer_direction = SG_DXFER_TO_DEV;
ioctl_req->hdr.iovec_count = elem->out_num - 2;
for (i = 0; i < ioctl_req->hdr.iovec_count; i++) {
ioctl_req->hdr.dxfer_len += elem->out_sg[i + 2].iov_len;
}
ioctl_req->hdr.dxferp = elem->out_sg + 2;
} else if (elem->in_num > 3) {
/*
* If we have more than 3 input segments the guest wants to actually
* read data.
*/
ioctl_req->hdr.dxfer_direction = SG_DXFER_FROM_DEV;
ioctl_req->hdr.iovec_count = elem->in_num - 3;
for (i = 0; i < ioctl_req->hdr.iovec_count; i++) {
ioctl_req->hdr.dxfer_len += elem->in_sg[i].iov_len;
}
ioctl_req->hdr.dxferp = elem->in_sg;
} else {
/*
* Some SCSI commands don't actually transfer any data.
*/
ioctl_req->hdr.dxfer_direction = SG_DXFER_NONE;
}
ioctl_req->hdr.sbp = elem->in_sg[elem->in_num - 3].iov_base;
ioctl_req->hdr.mx_sb_len = elem->in_sg[elem->in_num - 3].iov_len;
acb = blk_aio_ioctl(blk->blk, SG_IO, &ioctl_req->hdr,
virtio_blk_ioctl_complete, ioctl_req);
if (!acb) {
g_free(ioctl_req);
status = VIRTIO_BLK_S_UNSUPP;
goto fail;
}
return -EINPROGRESS;
#else
abort();
#endif
virtio_stl_p(vdev, &scsi->errors, 255);
status = VIRTIO_BLK_S_UNSUPP;
fail:
/* Just put anything nonzero so that the ioctl fails in the guest. */
if (scsi) {
virtio_stl_p(vdev, &scsi->errors, 255);
}
return status;
}
static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
{
int status;
status = virtio_blk_handle_scsi_req(req);
if (status != -EINPROGRESS) {
virtio_blk_req_complete(req, status);
virtio_blk_free_request(req);
}
virtio_blk_req_complete(req, status);
virtio_blk_free_request(req);
}
static inline void submit_requests(VirtIOBlock *s, MultiReqBuffer *mrb,
@ -1379,13 +1243,9 @@ static uint64_t virtio_blk_get_features(VirtIODevice *vdev, uint64_t features,
virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY);
virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY);
virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE);
if (virtio_has_feature(features, VIRTIO_F_VERSION_1)) {
if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_SCSI)) {
error_setg(errp, "Please set scsi=off for virtio-blk devices in order to use virtio 1.0");
return 0;
}
} else {
if (!virtio_has_feature(features, VIRTIO_F_VERSION_1)) {
virtio_clear_feature(&features, VIRTIO_F_ANY_LAYOUT);
/* Added for historical reasons, removing it could break migration. */
virtio_add_feature(&features, VIRTIO_BLK_F_SCSI);
}
@ -2132,10 +1992,6 @@ static Property virtio_blk_properties[] = {
DEFINE_PROP_STRING("serial", VirtIOBlock, conf.serial),
DEFINE_PROP_BIT64("config-wce", VirtIOBlock, host_features,
VIRTIO_BLK_F_CONFIG_WCE, true),
#ifdef __linux__
DEFINE_PROP_BIT64("scsi", VirtIOBlock, host_features,
VIRTIO_BLK_F_SCSI, false),
#endif
DEFINE_PROP_BIT("request-merging", VirtIOBlock, conf.request_merging, 0,
true),
DEFINE_PROP_UINT16("num-queues", VirtIOBlock, conf.num_queues,

2
hw/core/machine.c
View File

@ -265,8 +265,6 @@ GlobalProperty hw_compat_2_5[] = {
const size_t hw_compat_2_5_len = G_N_ELEMENTS(hw_compat_2_5);
GlobalProperty hw_compat_2_4[] = {
/* Optional because the 'scsi' property is Linux-only */
{ "virtio-blk-device", "scsi", "true", .optional = true },
{ "e1000", "extra_mac_registers", "off" },
{ "virtio-pci", "x-disable-pcie", "on" },
{ "virtio-pci", "migrate-extra", "off" },