Commit Graph

77 Commits

Author SHA1 Message Date
Stefan Hajnoczi
1404226804 scsi: don't lock AioContext in I/O code path
blk_aio_*() doesn't require the AioContext lock and the SCSI subsystem's
internal state also does not anymore.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231204164259.1515217-4-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-12-21 22:49:27 +01:00
Paolo Bonzini
9bd634b2f5 scsi-generic: fix buffer overflow on block limits inquiry
Using linux 6.x guest, at boot time, an inquiry on a scsi-generic
device makes qemu crash.  This is caused by a buffer overflow when
scsi-generic patches the block limits VPD page.

Do the operations on a temporary on-stack buffer that is guaranteed
to be large enough.

Reported-by: Théo Maillart <tmaillart@freebox.fr>
Analyzed-by: Théo Maillart <tmaillart@freebox.fr>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-18 08:53:51 +02:00
Stefan Hajnoczi
7b7fc3d010 scsi: protect req->aiocb with AioContext lock
If requests are being processed in the IOThread when a SCSIDevice is
unplugged, scsi_device_purge_requests() -> scsi_req_cancel_async() races
with I/O completion callbacks. Both threads load and store req->aiocb.
This can lead to assert(r->req.aiocb == NULL) failures and undefined
behavior.

Protect r->req.aiocb with the AioContext lock to prevent the race.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20230221212218.1378734-2-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-23 19:49:35 +01:00
John Millikin
fe9d8927e2 scsi: Add buf_len parameter to scsi_req_new()
When a SCSI command is received from the guest, the CDB length implied
by the first byte might exceed the number of bytes the guest sent. In
this case scsi_req_new() will read uninitialized data, causing
unpredictable behavior.

Adds the buf_len parameter to scsi_req_new() and plumbs it through the
call stack.

Signed-off-by: John Millikin <john@john-millikin.com>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1127
Message-Id: <20220817053458.698416-1-john@john-millikin.com>
[Fill in correct length for adapters other than ESP. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-09-01 07:42:37 +02:00
Kevin Wolf
51e15194b0 scsi-generic: Fix emulated block limits VPD page
Commits 01ef8185b8 amd 24b36e9813 updated the way that the maximum
transfer length is calculated for patching block limits VPD page in an
INQUIRY response.

The same updates also need to be made for the case where the host device
does not support the block limits VPD page at all and we emulate the
whole page.

Without this fix, on host block devices a maximum transfer length of
(INT_MAX - sector_size) bytes is advertised to the guest, resulting in
I/O errors when a request that exceeds the host limits is made by the
guest. (Prior to commit 24b36e9813, this code path would use the
max_transfer value from the host instead of INT_MAX, but still miss the
fix from 01ef8185b8 where max_transfer is also capped to max_iov
host pages, so it would be less wrong, but still wrong.)

Cc: qemu-stable@nongnu.org
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2096251
Fixes: 01ef8185b8
Fixes: 24b36e9813
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20220822125320.48257-1-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-08-23 16:01:13 +02:00
Stefan Hajnoczi
1ab5096b3a block: get rid of blk->guest_block_size
Commit 1b7fd72955 ("block: rename buffer_alignment to
guest_block_size") noted:

  At this point, the field is set by the device emulation, but completely
  ignored by the block layer.

The last time the value of buffer_alignment/guest_block_size was
actually used was before commit 339064d506 ("block: Don't use guest
sector size for qemu_blockalign()").

This value has not been used since 2013. Get rid of it.

Cc: Xie Yongji <xieyongji@bytedance.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20220518130945.2657905-1-stefanha@redhat.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Faria <afaria@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-06-24 17:07:06 +02:00
Marc-André Lureau
8e3b0cbb72 Replace qemu_real_host_page variables with inlined functions
Replace the global variables with inlined helper functions. getpagesize() is very
likely annotated with a "const" function attribute (at least with glibc), and thus
optimization should apply even better.

This avoids the need for a constructor initialization too.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-12-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-06 10:50:38 +02:00
Paolo Bonzini
cc07162953 block: introduce max_hw_iov for use in scsi-generic
Linux limits the size of iovecs to 1024 (UIO_MAXIOV in the kernel
sources, IOV_MAX in POSIX).  Because of this, on some host adapters
requests with many iovecs are rejected with -EINVAL by the
io_submit() or readv()/writev() system calls.

In fact, the same limit applies to SG_IO as well.  To fix both the
EINVAL and the possible performance issues from using fewer iovecs
than allowed by Linux (some HBAs have max_segments as low as 128),
introduce a separate entry in BlockLimits to hold the max_segments
value from sysfs.  This new limit is used only for SG_IO and clamped
to bs->bl.max_iov anyway, just like max_hw_transfer is clamped to
bs->bl.max_transfer.

Reported-by: Halil Pasic <pasic@linux.ibm.com>
Cc: Hanna Reitz <hreitz@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: qemu-block@nongnu.org
Cc: qemu-stable@nongnu.org
Fixes: 18473467d5 ("file-posix: try BLKSECTGET on block devices too, do not round to power of 2", 2021-06-25)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210923130436.1187591-1-pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-10-06 10:25:55 +02:00
Paolo Bonzini
24b36e9813 block: add max_hw_transfer to BlockLimits
For block host devices, I/O can happen through either the kernel file
descriptor I/O system calls (preadv/pwritev, io_submit, io_uring)
or the SCSI passthrough ioctl SG_IO.

In the latter case, the size of each transfer can be limited by the
HBA, while for file descriptor I/O the kernel is able to split and
merge I/O in smaller pieces as needed.  Applying the HBA limits to
file descriptor I/O results in more system calls and suboptimal
performance, so this patch splits the max_transfer limit in two:
max_transfer remains valid and is used in general, while max_hw_transfer
is limited to the maximum hardware size.  max_hw_transfer can then be
included by the scsi-generic driver in the block limits page, to ensure
that the stricter hardware limit is used.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-25 10:54:13 +02:00
Paolo Bonzini
01ef8185b8 scsi-generic: pass max_segments via max_iov field in BlockLimits
I/O to a disk via read/write is not limited by the number of segments allowed
by the host adapter; the kernel can split requests if needed, and the limit
imposed by the host adapter can be very low (256k or so) to avoid that SG_IO
returns EINVAL if memory is heavily fragmented.

Since this value is only interesting for SG_IO-based I/O, do not include
it in the max_transfer and only take it into account when patching the
block limits VPD page in the scsi-generic device.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2021-06-25 10:54:12 +02:00
Maxim Levitsky
06b80795ee block/scsi: correctly emulate the VPD block limits page
When the device doesn't support the VPD block limits page, we emulate it even
for SCSI passthrough.

As a part of the emulation we need to add it to the 'Supported VPD Pages'

The code that does this adds it to the page, but it doesn't increase the length
of the data to be copied to the guest, thus the guest never sees the VPD block
limits page as supported.

Bump the transfer size by 1 in this case.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20201217165612.942849-6-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-15 17:17:09 +02:00
Hannes Reinecke
f3126d65b3 scsi: move host_status handling into SCSI drivers
Some SCSI drivers like virtio have an internal mapping for the
host_status. This patch moves the host_status translation into
the SCSI drivers to allow those drivers to set up the correct
values.

Signed-off-by: Hannes Reinecke <hare@suse.de>.
[Added default handling to avoid touching all drivers. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-06 11:42:57 +01:00
Hannes Reinecke
a108557bbf scsi: inline sg_io_sense_from_errno() into the callers.
Currently sg_io_sense_from_errno() converts the two input parameters
'errno' and 'io_hdr' into sense code and SCSI status. Having
split the function off into scsi_sense_from_errno() and
scsi_sense_from_host_status(), both of which are available generically,
we now inline the logic in the callers so that scsi-disk and
scsi-generic will be able to pass host_status to the HBA.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Message-Id: <20201116184041.60465-7-hare@suse.de>
[Put together from "scsi-disk: Add sg_io callback to evaluate status"
 and what remains of "scsi: split sg_io_sense_from_errno() in two functions",
 with many other fixes. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-06 11:42:56 +01:00
Paolo Bonzini
9738c65720 scsi-generic: do not snoop the output of failed commands
If a READ CAPACITY command would fail, for example s->qdev.blocksize would be
set to zero and cause a division by zero on the next use.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-06 11:42:56 +01:00
Zihao Chang
166854f7cd scsi: allow user to set werror as report
'enospc' is the default for -drive, but qemu allows user to set
drive option werror. If werror of scsi-generic is set to 'report'
by user, qemu will not allow vm to start.

This patch allow user to set werror as 'report' for scsi-generic.

Signed-off-by: Zihao Chang <changzihao1@huawei.com>
Reviewed-by: Fam Zheng <fam@euphon.net>
Message-Id: <20201103061240.1364-1-changzihao1@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-25 14:14:32 +01:00
Hannes Reinecke
b2d50a3343 scsi: add tracing for SG_IO commands
Add tracepoints for SG_IO commands to allow for debugging
of SG_IO commands.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Message-Id: <20201116183114.55703-4-hare@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-25 14:14:32 +01:00
Hannes Reinecke
c9b6609b69 scsi: make io_timeout configurable
The current code sets an infinite timeout on SG_IO requests,
causing the guest to stall if the host experiences a frame
loss.
This patch adds an 'io_timeout' parameter for SCSIDevice to
make the SG_IO timeout configurable, and also shortens the
default timeout to 30 seconds to avoid infinite stalls.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Message-Id: <20201116183114.55703-3-hare@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-25 14:14:32 +01:00
Kevin Wolf
86b1cf3227 block: Separate blk_is_writable() and blk_supports_write_perm()
Currently, blk_is_read_only() tells whether a given BlockBackend can
only be used in read-only mode because its root node is read-only. Some
callers actually try to answer a slightly different question: Is the
BlockBackend configured to be writable, by taking write permissions on
the root node?

This can differ, for example, for CD-ROM devices which don't take write
permissions, but may be backed by a writable image file. scsi-cd allows
write requests to the drive if blk_is_read_only() returns false.
However, the write request will immediately run into an assertion
failure because the write permission is missing.

This patch introduces separate functions for both questions.
blk_supports_write_perm() answers the question whether the block
node/image file can support writable devices, whereas blk_is_writable()
tells whether the BlockBackend is currently configured to be writable.

All calls of blk_is_read_only() are converted to one of the two new
functions.

Fixes: https://bugs.launchpad.net/bugs/1906693
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210118123448.307825-2-kwolf@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-01-27 20:45:20 +01:00
Eduardo Habkost
ce35e2295e qdev: Move softmmu properties to qdev-properties-system.h
Move the property types and property macros implemented in
qdev-properties-system.c to a new qdev-properties-system.h
header.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20201211220529.2290218-16-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-12-18 15:20:17 -05:00
Dmitry Fomichev
afff2db61f scsi-generic: Fix HM-zoned device scan
Several important steps during device scan depend on SCSI type of the
device. For example, max_transfer property is only determined and
assigned if the device has the type of TYPE_DISK.

Host-managed ZBC disks retain most of the properties of regular SCSI
drives, but they have their own SCSI device type, 0x14. This prevents
the proper assignment of max_transfer property for HM-zoned devices in
scsi-generic driver leading to I/O errors if the maximum i/o size
calculated at the guest exceeds the host value.

To fix this, define TYPE_ZBC to have the standard value from SCSI ZBC
standard spec. Several scan steps that were previously done only for
TYPE_DISK devices, are now performed for the SCSI devices having
TYPE_ZBC too.

Reported-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Message-Id: <20200811225122.17342-3-dmitry.fomichev@wdc.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-30 19:09:20 +02:00
Marc-André Lureau
4f67d30b5e qdev: set properties with device_class_set_props()
The following patch will need to handle properties registration during
class_init time. Let's use a device_class_set_props() setter.

spatch --macro-file scripts/cocci-macro-file.h  --sp-file
./scripts/coccinelle/qdev-set-props.cocci --keep-comments --in-place
--dir .

@@
typedef DeviceClass;
DeviceClass *d;
expression val;
@@
- d->props = val
+ device_class_set_props(d, val)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-20-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24 20:59:15 +01:00
Markus Armbruster
a27bd6c779 Include hw/qdev-properties.h less
In my "build everything" tree, changing hw/qdev-properties.h triggers
a recompile of some 2700 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).

Many places including hw/qdev-properties.h (directly or via hw/qdev.h)
actually need only hw/qdev-core.h.  Include hw/qdev-core.h there
instead.

hw/qdev.h is actually pointless: all it does is include hw/qdev-core.h
and hw/qdev-properties.h, which in turn includes hw/qdev-core.h.
Replace the remaining uses of hw/qdev.h by hw/qdev-properties.h.

While there, delete a few superfluous inclusions of hw/qdev-core.h.

Touching hw/qdev-properties.h now recompiles some 1200 objects.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20190812052359.30071-22-armbru@redhat.com>
2019-08-16 13:31:53 +02:00
Markus Armbruster
ca77ee28e0 Include migration/qemu-file-types.h a lot less
In my "build everything" tree, changing migration/qemu-file-types.h
triggers a recompile of some 2600 out of 6600 objects (not counting
tests and objects that don't depend on qemu/osdep.h).

The culprit is again hw/hw.h, which supposedly includes it for
convenience.

Include migration/qemu-file-types.h only where it's needed.  Touching
it now recompiles less than 200 objects.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-10-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-08-16 13:31:52 +02:00
Shin'ichiro Kawasaki
1849f297f5 scsi-generic: Check sense key before request snooping and patching
When READ CAPACITY command completes, scsi_read_complete() function
snoops the command result and updates SCSIDevice members blocksize and
max_lba . However, this update is executed even when READ CAPACITY
command indicates an error in sense data. This causes unexpected
blocksize update with zero value for SCSI devices without
READ CAPACITY(10) command support and eventually results in a divide
by zero. An emulated device by TCMU-runner is an example of a device
that doesn't support READ CAPACITY(10) command.

To avoid the unexpected update, add sense key check in
scsi_read_complete() function. The function already checks the sense key
for VPD Block Limits emulation. Do the scsi_parse_sense_buf() call for
all requests rather than just for VPD Block Limits emulation, so that
blocksize and max_lba are only updated if READ CAPACITY returns zero
sense key.

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
[Extend the check to all requests, not just READ CAPACITY]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-19 19:04:49 +02:00
Markus Armbruster
0b8fa32f55 Include qemu/module.h where needed, drop it from qemu-common.h
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-4-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
hw/usb/dev-hub.c hw/misc/exynos4210_rng.c hw/misc/bcm2835_rng.c
hw/misc/aspeed_scu.c hw/display/virtio-vga.c hw/arm/stm32f205_soc.c;
ui/cocoa.m fixed up]
2019-06-12 13:18:33 +02:00
Markus Armbruster
856dfd8a03 qemu-common: Move qemu_isalnum() etc. to qemu/ctype.h
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-3-armbru@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2019-06-11 20:22:09 +02:00
Laurent Vivier
5685349864 scsi-generic: Convert from DPRINTF() macro to trace events
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20181211163105.31834-3-lvivier@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-05 16:50:21 +01:00
Paolo Bonzini
e909ff9369 scsi-generic: avoid possible out-of-bounds access to r->buf
Whenever the allocation length of a SCSI request is shorter than the size of the
VPD page list, page_idx is used blindly to index into r->buf.  Even though
the stores in the insertion sort are protected against overflows, the same is not
true of the reads and the final store of 0xb0.

This basically does the same thing as commit 57dbb58d80 ("scsi-generic: avoid
out-of-bounds access to VPD page list", 2018-11-06), except that here the
allocation length can be chosen by the guest.  Note that according to the SCSI
standard, the contents of the PAGE LENGTH field are not altered based
on the allocation length.

The code was introduced by commit 6c219fc8a1 ("scsi-generic: keep VPD
page list sorted", 2018-11-06) but the overflow was already possible before.

Reported-by: Kevin Wolf <kwolf@redhat.com>
Fixes: a71c775b24
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-05 16:50:19 +01:00
Paolo Bonzini
763c56872b scsi-generic: do not do VPD emulation for sense other than ILLEGAL_REQUEST
Pass other sense, such as UNIT_ATTENTION or BUSY, directly to the
guest.

Reported-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-11-06 21:35:06 +01:00
Paolo Bonzini
3d4a8bf0ee scsi-generic: avoid invalid access to struct when emulating block limits
Emulation of the block limits VPD page called back into scsi-disk.c,
which however expected the request to be for a SCSIDiskState and
accessed a scsi-generic device outside the bounds of its struct
(namely to retrieve s->max_unmap_size and s->max_io_size).

To avoid this, move the emulation code to a separate function that
takes a new SCSIBlockLimits struct and marshals it into the VPD
response format.

Reported-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-11-06 21:35:06 +01:00
Paolo Bonzini
57dbb58d80 scsi-generic: avoid out-of-bounds access to VPD page list
A device can report an excessive number of VPD pages when asked for a
list; this can cause an out-of-bounds access to buf in
scsi_generic_set_vpd_bl_emulation.  It should not happen, but
it is technically not incorrect so handle it: do not check any byte
past the allocation length that was sent to the INQUIRY command.

Reported-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-11-06 21:35:05 +01:00
Paolo Bonzini
6c219fc8a1 scsi-generic: keep VPD page list sorted
Block limits emulation is just placing 0xb0 as the final byte of the
VPD pages list.  However, VPD page numbers must be sorted, so change
that to an in-place insert.  Since I couldn't find any disk that triggered
the loop more than once, this was tested by adding manually 0xb1
at the end of the list and checking that 0xb0 was added before.

Reported-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-11-06 21:35:05 +01:00
Daniel Henrique Barboza
a71c775b24 hw/scsi: add VPD Block Limits emulation
The VPD Block Limits Inquiry page is optional, allowing SCSI devices
to not implement it. This is the case for devices like the MegaRAID
SAS 9361-8i and Microsemi PM8069.

In case of SCSI passthrough, the response of this request is used by
the QEMU SCSI layer to set the max_io_sectors that the guest
device will support, based on the value of the max_sectors_kb that
the device has set in the host at that time. Without this response,
the guest kernel is free to assume any value of max_io_sectors
for the SCSI device. If this value is greater than the value from
the host, SCSI Sense errors will occur because the guest will send
read/write requests that are larger than the underlying host device
is configured to support. An example of this behavior can be seen
in [1].

A workaround is to set the max_sectors_kb host value back in the guest
kernel (a process that can be automated using rc.local startup scripts
and the like), but this has several drawbacks:

- it can be troublesome if the guest has many passthrough devices that
needs this tuning;

- if a change in max_sectors_kb is made in the host side, manual change
in the guests will also be required;

- during an OS install it is difficult, and sometimes not possible, to
go to a terminal and change the max_sectors_kb prior to the installation.
This means that the disk can't be used during the install process. The
easiest alternative here is to roll back to scsi-hd, install the guest
and then go back to SCSI passthrough when the installation is done and
max_sectors_kb can be set.

An easier way would be to QEMU handle the absence of the Block Limits
VPD device response, setting max_io_sectors accordingly and allowing
the guest to use the device without the hassle.

This patch adds emulation of the Block Limits VPD response for
SCSI passthrough devices of type TYPE_DISK that doesn't support
it. The following changes were made:

- scsi_handle_inquiry_reply will now check the available VPD
pages from the Inquiry EVPD reply. In case the device does not

- a new function called scsi_generic_set_vpd_bl_emulation,
that is called during device realize,  was created to set a
new flag 'needs_vpd_bl_emulation' of the device. This function
retrieves the Inquiry EVPD response of the device to check for
VPD BL support.

- scsi_handle_inquiry_reply will now check the available VPD
pages from the Inquiry EVPD reply in case the device needs
VPD BL emulation, adding the Block Limits page (0xb0) to
the list. This will make the guest kernel aware of the
support that we're now providing by emulation.

- a new function scsi_emulate_block_limits creates the
emulated Block Limits response. This function is called
inside scsi_read_complete in case the device requires
Block Limits VPD emulation and we detected a SCSI Sense
error in the VPD Block Limits reply that was issued
from the guest kernel to the device. This error is
expected: we're reporting support from our side, but
the device isn't aware of it.

With this patch, the guest now queries the Block Limits
page during the device configuration because it is being
advertised in the Supported Pages response. It will either
receive the Block Limits page from the hardware, if it supports
it, or will receive an emulated response from QEMU. At any rate,
the guest now has the information to set the max_sectors_kb
parameter accordingly, sparing the user of SCSI sense errors
that would happen without the emulated response and in the
absence of Block Limits support from the hardware.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1566195

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1566195
Reported-by: Dac Nguyen <dacng@us.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20180627172432.11120-4-danielhb413@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-06-29 13:02:50 +02:00
Daniel Henrique Barboza
a0c7e35b17 hw/scsi: centralize SG_IO calls into single function
For the VPD Block Limits emulation with SCSI passthrough,
we'll issue an Inquiry request with EVPD set to retrieve
the available VPD pages of the device. This would be done in
a way similar of what scsi_generic_read_device_identification
does: create a SCSI command and a reply buffer, fill in the
sg_io_hdr_t structure, call blk_ioctl, check if an error
occurred, process the response.

This same process is done in other 2 functions, get_device_type
and get_stream_blocksize. They differ in the command/reply
buffer and post-processing, everything else is almost a
copy/paste.

Instead of adding a forth copy/pasted-ish code when adding
the passthrough VPD BL emulation, this patch extirpates
this repetition of those 3 functions and put it into
a new one called scsi_SG_IO_FROM_DEV. Any future code that
wants to execute an SG_DXFER_FROM_DEV to the device can
use it, avoiding filling sg_io_hdr_t again and et cetera.

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20180627172432.11120-3-danielhb413@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-06-29 13:02:50 +02:00
Daniel Henrique Barboza
0a96ca2437 hw/scsi: cleanups before VPD BL emulation
To add support for the emulation of Block Limits VPD page
for passthrough devices, a few adjustments in the current code
base is required to avoid repetition and improve clarity.

In scsi-generic.c, detach the Inquiry handling from
scsi_read_complete and put it into a new function called
scsi_handle_inquiry_reply. This change aims to avoid
cluttering of scsi_read_complete when we more logic in the
Inquiry response handling is added in the next patches,
centralizing the changes in the new function.

In scsi-disk.c, take the build of all emulated VPD pages
from scsi_disk_emulate_inquiry and make it available to
other files into a non-static function called
scsi_disk_emulate_vpd_page. Making it public will allow
the future VPD BL emulation code for passthrough devices
to use it from scsi-generic.c, avoiding copy/pasting this
code solely for that purpose. It also has the advantage of
providing emulation of all VPD pages in case we need to
emulate other pages in other scenarios. As a bonus,
scsi_disk_emulate_inquiry got tidier.

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20180627172432.11120-2-danielhb413@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-06-29 13:02:50 +02:00
Philippe Mathieu-Daudé
6dd046a3c4 hw: Do not include "sysemu/blockdev.h" if it is not necessary
Remove those unneeded includes to speed up the compilation
process a little bit.

Code change produced with:

    $ git grep '#include "sysemu/blockdev.h"' | \
      cut -d: -f-1 | \
      xargs egrep -L "(BlockInterfaceType|DriveInfo|drive_get|blk_legacy_dinfo|blockdev_mark_auto_del)" | \
      xargs sed -i.bak '/#include "sysemu\/blockdev.h"/d'

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20180528232719.4721-15-f4bug@amsat.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-06-01 14:15:10 +02:00
Daniel Henrique Barboza
29e560f00e hw/scsi: support SCSI-2 passthrough without PI
QEMU SCSI code makes assumptions about how the PROTECT and BYTCHK
works in the protocol, denying support for PI (Protection
Information) in case the guest OS requests it. However, in SCSI versions 2
and older, there is no PI concept in the protocol.

This means that when dealing with such devices:

- there is no PROTECT bit in byte 5 of the standard INQUIRY response. The
whole byte is marked as "Reserved";

- there is no RDPROTECT in byte 2 of READ. We have 'Logical Unit Number'
in this field instead;

- there is no VRPROTECT in byte 2 of VERIFY. We have 'Logical Unit Number'
in this field instead. This also means that the BYTCHK bit in this case
is not related to PI.

Since QEMU does not consider these changes, a SCSI passthrough using
a SCSI-2 device will not work. It will mistake these fields with
PI information and return Illegal Request SCSI SENSE thinking
that the driver is asking for PI support.

This patch fixes it by adding a new attribute called 'scsi_version'
that is read from the standard INQUIRY response of passthrough
devices. This allows for a version verification before applying
conditions related to PI that doesn't apply for older versions.

Reported-by: Dac Nguyen <dacng@us.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
Message-Id: <20180327211451.14647-1-danielhb@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-04-09 16:36:39 +02:00
Paolo Bonzini
2343be0d7e scsi-disk: allow customizing the SCSI version
We would like to have different behavior for passthrough devices
depending on the SCSI version they expose.  To prepare for that,
allow the user of emulated devices to specify the desired SCSI
level, and adjust the emulation according to the property value.
The next patch will set the level for scsi-block and scsi-generic
devices.

Based on a patch by Daniel Henrique Barboza
<danielhb@linux.vnet.ibm.com>.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-04-09 16:36:39 +02:00
Paolo Bonzini
09c2c6ffda scsi: turn "is this a SCSI device?" into a conditional hint
If the user does not have permissions to send ioctls to the device (due to
SELinux or cgroups, for example), the output can look like

qemu-kvm: -device scsi-block,drive=disk: cannot get SG_IO version number:
  Operation not permitted.  Is this a SCSI device?

but this is confusing because the ioctl was blocked _before_ the device
even received the SG_GET_VERSION_NUM ioctl.  Therefore, for EPERM errors
the suggestion should be eliminated.  To make that simpler, change the
code to use error_append_hint.

Reported-by: Ala Hino <ahino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-03-26 14:37:15 +02:00
Fam Zheng
c6caae553c scsi-generic: Simplify error handling code
Coverity doesn't like the ignored return value introduced in
9d3b155186 (hw/block: Fix the return type), and other callers are
converted already in ceff3e1f01.

This one was added lately in d9bcd6f7f2 and missed the train. Do it
now.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20180118025245.13042-1-famz@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-02-05 13:54:39 +01:00
Fam Zheng
d9bcd6f7f2 scsi-generic: Add share-rw option
Add the property to the device model, then parse it by calling
blkconf_apply_backend_options().

In addition to blk_set_perm(), the called function also handles error
options and wce. For error options we've already checked that the
default values are used, for wce we don't have the option either so it
is always the default (true). In other words there is no change of
behavior in these regards.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20171205151553.7834-1-famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-01-12 09:54:12 +01:00
Paolo Bonzini
08e2c9f19c scsi: move block/scsi.h to include/scsi/constants.h
Complete the transition by renaming this header, which was
shared by block/iscsi.c and the SCSI emulation code.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-09-19 14:09:31 +02:00
Paolo Bonzini
1ead6b4e24 scsi: introduce sg_io_sense_from_errno
Move more knowledge of SG_IO out of hw/scsi/scsi-generic.c, for
reusability.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-09-19 14:09:11 +02:00
Paolo Bonzini
e5b5728cd3 scsi: move non-emulation specific code to scsi/
util/scsi.c includes some SCSI code that is shared by block/iscsi.c and
hw/scsi, but the introduction of the persistent reservation helper
will add many more instances of this.  There is also include/block/scsi.h,
which actually is not part of the core block layer.

The persistent reservation manager will also need a home.  A scsi/
directory provides one for both the aforementioned shared code and
the PR manager code.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-09-19 14:09:11 +02:00
Peter Maydell
95a5befc2f Use qemu_tolower() and qemu_toupper(), not tolower() and toupper()
On NetBSD, where tolower() and toupper() are implemented using an
array lookup, the compiler warns if you pass a plain 'char'
to these functions:

gdbstub.c:914:13: warning: array subscript has type 'char'

This reflects the fact that toupper() and tolower() give
undefined behaviour if they are passed a value that isn't
a valid 'unsigned char' or EOF.

We have qemu_tolower() and qemu_toupper() to avoid this problem;
use them.

(The use in scsi-generic.c does not trigger the warning because
it passes a uint8_t; we switch it anyway, for consistency.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> for the s390 part.
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Message-id: 1500568290-7966-1-git-send-email-peter.maydell@linaro.org
2017-07-21 10:32:41 +01:00
Fam Zheng
bed58b4443 scsi-generic: Fill in opt_xfer_len in INQUIRY reply if it is zero
When opt_xfer_len is zero, Linux ignores max_xfer_len erroneously.

While that obviously should be fixed, we do older guests a favor to
always filling in a value.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170327142625.1249-1-famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-27 17:02:07 +02:00
Paolo Bonzini
b9e413dd37 block: explicitly acquire aiocontext in aio callbacks that need it
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170213135235.12274-16-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21 11:39:39 +00:00
Eric Farman
2e144aa779 hw/scsi: Fix debug message of cdb structure in scsi-generic
When running with debug enabled, the scsi-generic cdb that is
dumped skips byte 0 of the command, which is the opcode.  This
makes identifying which command is being issued/completed a
little difficult.  Example:

  0x00 0x00 0x01 0x00 0x00
  scsi-generic: scsi_read_data 0x0
  scsi-generic: Data ready tag=0x0 len=164
  scsi-generic: scsi_read_data 0x0
  scsi-generic: Command complete 0x0x10a42c60 tag=0x0 status=0

Improve this by adding a message prior to the loop, similar to
what exists for scsi-disk.  Clean up a few other messages to be
more explicit of what is being represented.  Example:

  scsi-generic: Command: data=0x12 0x00 0x00 0x01 0x00 0x00
  scsi-generic: scsi_read_data tag=0x0
  scsi-generic: Data ready tag=0x0 len=164
  scsi-generic: scsi_read_data tag=0x0
  scsi-generic: Command complete 0x0x10a452d0 tag=0x0 status=0

Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Message-Id: <20170120162527.66075-2-farman@linux.vnet.ibm.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-01-27 18:07:31 +01:00
Eric Blake
5def6b80e1 block: Switch transfer length bounds to byte-based
Sector-based limits are awkward to think about; in our on-going
quest to move to byte-based interfaces, convert max_transfer_length
and opt_transfer_length.  Rename them (dropping the _length suffix)
so that the compiler will help us catch the change in semantics
across any rebased code, and improve the documentation.  Use unsigned
values, so that we don't have to worry about negative values and
so that bit-twiddling is easier; however, we are still constrained
by 2^31 of signed int in most APIs.

When a value comes from an external source (iscsi and raw-posix),
sanitize the results to ensure that opt_transfer is a power of 2.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05 16:46:25 +02:00
Eric Blake
24ce9a2026 block: Give nonzero result to blk_get_max_transfer_length()
Making all callers special-case 0 as unlimited is awkward,
and we DO have a hard maximum of BDRV_REQUEST_MAX_SECTORS given
our current block layer API limits.

In the case of scsi, this means that we now always advertise a
limit to the guest, even in cases where the underlying layers
previously use 0 for no inherent limit beyond the block layer.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05 16:46:25 +02:00