virtio/scsi: Fix and simplify command-line

Fix and simplify the command-line parameter for virtio-scsi. Currently
passing a "scsi:xxxx" parameter without the second "tpgt" argument
causes kvmtool to

virtio/scsi: Fix and simplify command-line

Fix and simplify the command-line parameter for virtio-scsi. Currently
passing a "scsi:xxxx" parameter without the second "tpgt" argument
causes kvmtool to segfault. But only the "wwpn" parameter is necessary.

The tpgt parameter is ignored and was never used upstream. See
linux/vhost_types.h:

* ABI Rev 0: July 2012 version starting point for v3.6-rc merge candidate +
* RFC-v2 vhost-scsi userspace. Add GET_ABI_VERSION ioctl usage
* ABI Rev 1: January 2013. Ignore vhost_tpgt field in struct vhost_scsi_target.
* All the targets under vhost_wwpn can be seen and used by guset.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20230606130426.978945-7-jean-philippe@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>

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virtio/blk: Implement VIRTIO_F_ANY_LAYOUT feature

The current virtio-block implementation assumes that buffers have a
specific layout (5.2.6.4 "Legacy Interface: Framing Requirements").
Modern virti

virtio/blk: Implement VIRTIO_F_ANY_LAYOUT feature

The current virtio-block implementation assumes that buffers have a
specific layout (5.2.6.4 "Legacy Interface: Framing Requirements").
Modern virtio removes this layout constraint, so we have to be careful
when reading buffers. Note that since the Linux driver uses the same
layout as the legacy transport, arbitrary layouts were not actually
tested.

Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Link: https://lore.kernel.org/r/20220607170239.120084-16-jean-philippe.brucker@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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disk/aio: Add wait() disk operation

Add a call into the disk layer to synchronize the AIO queue. Wait for all
pending requests to complete. This will be necessary when resetting a
virtqueue.

The wa

disk/aio: Add wait() disk operation

Add a call into the disk layer to synchronize the AIO queue. Wait for all
pending requests to complete. This will be necessary when resetting a
virtqueue.

The wait() operation isn't the same as flush(). A VIRTIO_BLK_T_FLUSH
request ensures that any write request *that completed before the FLUSH is
sent* is committed to permanent storage (e.g. written back from a write
cache). But it doesn't do anything for requests that are still pending
when the FLUSH is sent.

Avoid introducing a mutex on the io_submit() and io_getevents() paths,
because it can lead to 30% throughput drop on heavy FIO jobs. Instead
manage an inflight counter using compare-and-swap operations, which is
simple enough as the caller doesn't submit new requests while it waits for
the AIO queue to drain. The __sync_fetch_and_* operations are a bit rough
since they use full barriers, but that didn't seem to introduce a
performance regression.

Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

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disk/aio: Cancel AIO thread on cleanup

If the AIO thread is still calling io_getevents() while the exit path
calls io_destroy(), it will segfault. Wait for the thread to finish before
destroying the

disk/aio: Cancel AIO thread on cleanup

If the AIO thread is still calling io_getevents() while the exit path
calls io_destroy(), it will segfault. Wait for the thread to finish before
destroying the context.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

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disk/aio: Fix use of disk->async

Add an 'async' attribute to disk_image_operations, that describes if they
can submit async I/O or not. disk_image->async is now set iff
CONFIG_HAS_AIO and the ops do

disk/aio: Fix use of disk->async

Add an 'async' attribute to disk_image_operations, that describes if they
can submit async I/O or not. disk_image->async is now set iff
CONFIG_HAS_AIO and the ops do use AIO.

This fixes qcow1, which used to set async = 1 even though the qcow
operations don't use AIO. The disk core would perform the read/write
operation without pushing the completion onto the virtio queue, and the
guest would be stuck waiting.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

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disk/aio: Refactor AIO code

Move all AIO code to a separate file, disk/aio.c, to remove as much
#ifdefs as possible. Split the raw read/write disk ops into async and
sync, and choose which ones to u

disk/aio: Refactor AIO code

Move all AIO code to a separate file, disk/aio.c, to remove as much
#ifdefs as possible. Split the raw read/write disk ops into async and
sync, and choose which ones to use depending on CONFIG_HAS_AIO. Note that
we fix raw_image__close() which incorrectly checked CONFIG_HAS_VIRTIO
instead of CONFIG_HAS_AIO, and closed an unitialized disk->evt. A
subsequent commit will complete this refactoring by fixing use of the
'async' disk attribute.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

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virtio/blk: Set VIRTIO_BLK_F_RO when the disk is read-only

Since we don't currently tell the guest when the disk backend is
read-only, it will report any inconsistent read after write as an error.
A

virtio/blk: Set VIRTIO_BLK_F_RO when the disk is read-only

Since we don't currently tell the guest when the disk backend is
read-only, it will report any inconsistent read after write as an error.
An image may be read-only either because user requested it on the
command-line, or because write support isn't implemented. Pass the
read-only attribute using the VIRTIO_BLK_F_RO feature.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

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kvm tools: disk image related cleanup

Move io debug delay into kvm_config, the parser out of builtin-run into the disk code
and make the init/exit functions match the rest of the code in style.

Sig

kvm tools: disk image related cleanup

Move io debug delay into kvm_config, the parser out of builtin-run into the disk code
and make the init/exit functions match the rest of the code in style.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

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kvm tools: Add initial virtio-scsi support

This patch brings virito-scsi support to kvm tool.

With the introduce of tcm_vhost (vhost-scsi)

tcm_vhost: Initial merge for vhost level target fabric

kvm tools: Add initial virtio-scsi support

This patch brings virito-scsi support to kvm tool.

With the introduce of tcm_vhost (vhost-scsi)

tcm_vhost: Initial merge for vhost level target fabric driver

we can implement virito-scsi by simply having vhost-scsi to handle the
SCSI command.

Howto use:
1) Setup the tcm_vhost target through /sys/kernel/config

[Stefan Hajnoczi, Thanks for the script to setup tcm_vhost]

** Setup wwpn and tpgt
$ wwpn="naa.0"
$ tpgt=/sys/kernel/config/target/vhost/$wwpn/tpgt_0
$ nexus=$tpgt/nexus
$ mkdir -p $tpgt
$ echo -n $wwpn > $nexus

** Setup lun using /dev/ram
$ n=0
$ lun=$tpgt/lun/lun_${n}
$ data=/sys/kernel/config/target/core/iblock_0/data_${n}
$ ram=/dev/ram${n}
$ mkdir -p $lun
$ mkdir -p $data
$ echo -n udev_path=${ram} > $data/control
$ echo -n 1 > $data/enable
$ ln -s $data $lun

2) Run kvm tool with the new disk option '-d scsi:$wwpn:$tpgt', e.g
$ lkvm run -k /boot/bzImage -d ~/img/sid.img -d scsi:naa.0:0

Signed-off-by: Asias He <asias.hejun@gmail.com>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

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kvm tools: Enable O_DIRECT support

With Direct I/O, file reads and writes go directly from the applications
to the storage device, bypassing the operating system read and write
caches. This is usefu

kvm tools: Enable O_DIRECT support

With Direct I/O, file reads and writes go directly from the applications
to the storage device, bypassing the operating system read and write
caches. This is useful for applications that manage their own caches.

Open a disk image with O_DIRECT:
$ lkvm run -d ~/img/test.img,direct

The original readonly flag is still supported.
Open a disk image with O_DIRECT and readonly:
$ lkvm run -d ~/img/test.img,direct,ro

Signed-off-by: Asias He <asias.hejun@gmail.com>
Acked-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

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kvm tools: Introduce struct disk_image_params

Introduce struct disk_image_params to contain all the disk image parameters.
This is useful for adding more disk image parameters, e.g. disk image
cache

kvm tools: Introduce struct disk_image_params

Introduce struct disk_image_params to contain all the disk image parameters.
This is useful for adding more disk image parameters, e.g. disk image
cache mode.

Signed-off-by: Asias He <asias.hejun@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

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kvm tools: Simplify disk read write function name

We read and write in sectors by default. It makes little sense to add
the extra _sector string for read and write ops/function name.

Signed-off-by:

kvm tools: Simplify disk read write function name

We read and write in sectors by default. It makes little sense to add
the extra _sector string for read and write ops/function name.

Signed-off-by: Asias He <asias.hejun@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

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kvm tools: Fixes for disk image module

Fixes include:
- Error handling
- Cleanup
- Standard init/uninit

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>

kvm tools: Use native vectored AIO in virtio-blk

This patch hooks AIO support into virtio-blk, allowing for faster IO.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
[ penberg@kernel.org: wra

kvm tools: Use native vectored AIO in virtio-blk

This patch hooks AIO support into virtio-blk, allowing for faster IO.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
[ penberg@kernel.org: wrap libaio include with CONFIG_HAS_AIO ]
Signed-off-by: Pekka Enberg <penberg@kernel.org>

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kvm tools: Split io request from completion

This patch splits IO request processing from completion notification.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <p

kvm tools: Split io request from completion

This patch splits IO request processing from completion notification.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

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kvm tools: Add optional callback on disk op completion

This patch adds an optional callback to be called when a disk op completes.

Currently theres not much use for it, but it is the infrastructure

kvm tools: Add optional callback on disk op completion

This patch adds an optional callback to be called when a disk op completes.

Currently theres not much use for it, but it is the infrastructure for adding
aio support.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

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kvm tools: Remove the non-iov interface from disk image ops

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

kvm tools: Switch to using an enum for disk image types

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

kvm tools: Implement VIRTIO_BLK_T_GET_ID

Return device id when requested by virtio-blk.
Device id is currently based on the device information and the inode
number of the underlying disk image.

Sig

kvm tools: Implement VIRTIO_BLK_T_GET_ID

Return device id when requested by virtio-blk.
Device id is currently based on the device information and the inode
number of the underlying disk image.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

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kvm tools: Close the disk images after the guest shuts down

Signed-off-by: Prasad Joshi <prasadjoshi124@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

kvm tools: Add a wrapper function to open disk images

The patch was suggested by Ingo to move the disk image subsystem code
from the kvm-run.c file. The code to open all of the specified disk
images

kvm tools: Add a wrapper function to open disk images

The patch was suggested by Ingo to move the disk image subsystem code
from the kvm-run.c file. The code to open all of the specified disk
images is now moved to a wrapper function in disk/core.c.

Signed-off-by: Prasad Joshi <prasadjoshi124@gmail.com>
Suggested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

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kvm tools: Do not use 'inline' for disk_image__flush

Signed-off-by: Asias He <asias.hejun@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

kvm tools: Rename struct disk_image_operations ops name for raw image

This patch renames:

raw_image__read_sector_ro_mmap to raw_image__read_sector
raw_image__write_sector_ro_mmap to raw_image__writ

kvm tools: Rename struct disk_image_operations ops name for raw image

This patch renames:

raw_image__read_sector_ro_mmap to raw_image__read_sector
raw_image__write_sector_ro_mmap to raw_image__write_sector
raw_image__close_ro_mmap to raw_image__close

Signed-off-by: Asias He <asias.hejun@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

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kvm tools: Tune up ops in 'struct disk_image_operations'

Make read/write ops in 'struct disk_image_operations'
always return the number of bytes read/written and close/flush
ops return int.

Signed-

kvm tools: Tune up ops in 'struct disk_image_operations'

Make read/write ops in 'struct disk_image_operations'
always return the number of bytes read/written and close/flush
ops return int.

Signed-off-by: Asias He <asias.hejun@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

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kvm tools: Split blk device code from raw.c to blk.c

Signed-off-by: Asias He <asias.hejun@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>