This is the next step for decoupling block accounting functions from
BlockDriverState.
In a future commit the BlockAcctStats structure will be moved from
BlockDriverState to the device models structures.

Note that bdrv_get_stats was introduced so device models can retrieve the
BlockAcctStats structure of a BlockDriverState without being aware of it's
layout.
This function should go away when BlockAcctStats will be embedded in the device
models structures.

CC: Kevin Wolf <kwolf@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Keith Busch <keith.busch@intel.com>
CC: Anthony Liguori <aliguori@amazon.com>
CC: "Michael S. Tsirkin" <mst@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Eric Blake <eblake@redhat.com>
CC: Peter Maydell <peter.maydell@linaro.org>
CC: Michael Tokarev <mjt@tls.msk.ru>
CC: John Snow <jsnow@redhat.com>
CC: Markus Armbruster <armbru@redhat.com>
CC: Alexander Graf <agraf@suse.de>
CC: Max Reitz <mreitz@redhat.com>
Signed-off-by: NBenoît Canet <benoit.canet@nodalink.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The middle term goal is to move the BlockAcctStats structure in the device models.
(Capturing I/O accounting statistics in the device models is good for billing)
This patch make a small step in this direction by removing a reference to BDRV.

CC: Kevin Wolf <kwolf@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Keith Busch <keith.busch@intel.com>
CC: Anthony Liguori <aliguori@amazon.com>
CC: "Michael S. Tsirkin" <mst@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: John Snow <jsnow@redhat.com>
CC: Richard Henderson <rth@twiddle.net>
CC: Markus Armbruster <armbru@redhat.com>
CC: Alexander Graf <agraf@suse.de>i
Signed-off-by: NBenoît Canet <benoit.canet@nodalink.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This allows us to pass error information to caller.
Reviewed-by: NAndreas Färber <afaerber@suse.de>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

In function virtio_blk_handle_request, it may freed memory pointed by req,
So do not access member of req after calling this function.

Cc: qemu-stable@nongnu.org
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Nzhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Without this correction, only a three descriptor layout is accepted, and
requests with just two descriptors are not completed and no error message is
displayed.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NMarc Marí <marc.mari.barcelo@gmail.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

The block layer fails such reads and writes just fine.  However, they
then get treated like valid operations that fail: the error action
gets executed.  Unwanted; reporting the error to the guest is the only
sensible action.

Reject them before passing them to the block layer.  This bypasses the
error action and I/O accounting.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

When a device model's I/O operation fails, we execute the error
action.  This lets layers above QEMU implement thin provisioning, or
attempt to correct errors before they reach the guest.  But when the
I/O operation fails because it's invalid, reporting the error to the
guest is the only sensible action.

If the guest's read or write asks for an invalid sector range, fail
the request right away, without considering the error action.  No
change with error action BDRV_ACTION_REPORT.

Furthermore, bypass I/O accounting, because we want to track only I/O
that actually reaches the block layer.

The next commit will extend "invalid sector range" to cover attempts
to read/write beyond the end of the medium.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The memory allocation between hw/block/virtio-blk.c,
hw/block/dataplane/virtio-blk.c, and hw/virtio/dataplane/vring.c is
messy.  Structs are allocated in different files than they are freed in.
This is risky and makes memory leaks easier.

Embed VirtQueueElement in VirtIOBlockReq to reduce the amount of memory
allocation we need to juggle.  This also makes vring.c and virtio.c
slightly more similar.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

In commit de6c8042 ("virtio-blk: Avoid
zeroing every request structure") we avoided the 40 KB memset when
allocating VirtIOBlockReq.

The memset was reintroduced in commit
671ec3f0 ("virtio-blk: Convert
VirtIOBlockReq.elem to pointer").

It must be fixed again to avoid a performance regression.

Cc: Fam Zheng <famz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Up until now -device virtio-blk-pci,x-iothread=<id> was used to assign
an IOThread.  This was a temporary solution while we cleaned up QOM link
properties.

This patch switches over to a QOM link property since it is now possible
to restrict the setter to unrealized instances and automatically unref
the IOThread when the virtio-blk-pci device is freed.

Since the "iothread" property is a QOM property and not a qdev property,
we must alias it explicitly for virtio-blk-pci, as well as CCW and
s390-virtio.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

There is no need to make DEFINE_VIRTIO_BLK_PROPERTIES() public.  Inline
it into virtio-blk.c so it cannot be used by mistake from other source
files.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

This function is no longer used since parent objects now use child
aliases to set the VirtIOBlkConf directly.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

Note that st*_raw and ld*_raw are effectively replaced by st*_p and ld*_p.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Reviewed-by: NAnthony Liguori <aliguori@us.ibm.com>
[ pass VirtIODevice * to memory accessors,
  Greg Kurz <gkurz@linux.vnet.ibm.com> ]
Signed-off-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: NAlexander Graf <agraf@suse.de>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

Signed-off-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: NAlexander Graf <agraf@suse.de>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

In order to migrate virtio subsections, they should be streamed after
the device itself. We need the device specific code to be called from
the common migration code to achieve this. This patch introduces load
and save methods for this purpose.
Suggested-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: NAlexander Graf <agraf@suse.de>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

The BH must be called in the AioContext of bs. Currently it is only the
main loop, but with coming changes, it could also be a dataplane
IOThread.
Signed-off-by: NFam Zheng <famz@redhat.com>
Tested-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

So that dataplane can use virtio_blk_handle_request and
virtio_submit_multiwrite.
Signed-off-by: NFam Zheng <famz@redhat.com>
Tested-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

virtio_blk_req_complete will call VirtIOBlock.complete_request() to push
data and notify guest. No functional change.

Later, this will allow dataplane to provide it's own (vring_) version.
Signed-off-by: NFam Zheng <famz@redhat.com>
Tested-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

out_sg is checked by iov_to_buf below, so it can be dropped.

Add assert and iov_discard_back around in_sg, as the in_sg is handled in
dataplane code.
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The virtio code currently assumes that the outhdr is in its own iovec.
This is not guaranteed by the spec, so we should relax this assumption.

Convert the VirtIOBlockReq.out field to structrue so that we can use
iov_to_buf and then discard the header from the beginning of iovec.
Suggested-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This will make converging with dataplane code easier.

Add virtio_blk_free_request to handle the freeing of request internal
fields.
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

For later reusing by dataplane code.
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

In order to let event defines use existing types later, instead of
redefine new ones, some old type defines for spice and vnc are changed,
and BlockErrorAction is moved from block.h to qapi schema. Note that
BlockErrorAction is not merged with BlockdevOnError.

At this point, VncInfo is not made a child of VncBasicInfo, because
VncBasicInfo has mandatory fields where VncInfo makes them optional.
Signed-off-by: NWenchao Xia <wenchaoqemu@gmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

The ld_raw and st_raw definitions are only needed in code that
must compile for both user-mode and softmmu emulation.  Device
models can use the equivalent ld_p/st_p which are simple
pointer accessors.
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The common logic to process a scsi request in a VirtQueueElement is
extracted to a function to share with dataplane.

This makes VirtIOBlockReq.scsi unused, so drop it.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Dataplane now uses block layer. Protect bdrv_set_enable_write_cache with
aio_context_acquire and aio_context_release, so we can enable config-wce
to allow guest to modify the write cache online.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

The alignment field is now set to the value that is promised to the
guest, rather than required by the host.  The next patches will make
QEMU aware of the host-provided values, so make this clear.

The alignment is also not about memory buffers, but about the sectors on
the disk, change the documentation of the field.

At this point, the field is set by the device emulation, but completely
ignored by the block layer.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NWenchao Xia <xiawenc@linux.vnet.ibm.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>

Signed-off-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Signed-off-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Rename variable qdev -> dev since that's what realize's argument is called
by convention.
Signed-off-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Return an Error so that it can be propagated later.
Tested-by: NStefan Hajnoczi <stefanha@redhat.com>
Acked-by: NStefan Hajnoczi <stefanha@redhat.com>
[AF: Rebased]
Signed-off-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This ensures hot-unplug is handled properly by the proxy, and avoids
leaking bus_name which is freed by virtio_device_exit.

Cc: qemu-stable@nongnu.org
Acked-by: NAndreas Faerber <afaerber@suse.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Report from valgrind:

==19521== Source and destination overlap in memcpy(0x31d38938, 0x31d38938, 64)
==19521==    at 0x4A0A343: memcpy@@GLIBC_2.14 (in
/usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==19521==    by 0x42774E: virtio_blk_device_init (virtio-blk.c:686)
==19521==    by 0x46EE9E: virtio_device_init (virtio.c:1158)
==19521==    by 0x25405E: device_realize (qdev.c:178)
==19521==    by 0x2559B5: device_set_realized (qdev.c:699)
==19521==    by 0x3A819B: property_set_bool (object.c:1315)
==19521==    by 0x3A6CE0: object_property_set (object.c:803)

Valgrind is right: blk == &s->blks, so it is a memcpy of 64 byte with
source == destination which can be removed.
Reported-by: NDave Airlie <airlied@gmail.com>
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

The following sequence happens:
- the SeaBIOS virtio-blk driver does not support the WCE feature, which
causes QEMU to disable writeback caching

- the Linux virtio-blk driver resets the device, finds WCE is available
but writeback caching is disabled; tells block layer to not send cache
flush commands

- the Linux virtio-blk driver sets the DRIVER_OK bit, which causes
writeback caching to be re-enabled, but the Linux virtio-blk driver does
not know of this side effect and cache flushes remain disabled

The bug is at the third step.  If the guest does know about CONFIG_WCE,
QEMU should ignore the WCE feature's state.  The guest will control the
cache mode solely using configuration space.  This change makes Linux
do flushes correctly, but Linux will keep SeaBIOS's writethrough mode.

Hence, whenever the guest is reset, the cache mode of the disk should
be reset to whatever was specified in the "-drive" option.  With this
change, the Linux virtio-blk driver finds that writeback caching is
enabled, and tells the block layer to send cache flush commands
appropriately.

Reported-by: Rusty Russell <rusty@au1.ibm.com
Cc: qemu-stable@nongnu.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

The category will be used to sort the devices displayed in
the command line help.
Signed-off-by: NMarcel Apfelbaum <marcel.a@redhat.com>
Message-id: 1375107465-25767-4-git-send-email-marcel.a@redhat.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Although the dataplane thread does not cooperate with dirty memory
logging yet it's fairly easy to temporarily disable dataplane during
live migration.  This way virtio-blk can live migrate when
x-data-plane=on.

The dataplane thread will restart after migration is cancelled or if the
guest resuming virtio-blk operation after migration completes.
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This clean the init and the exit functions and rename virtio_common_cleanup
to virtio_cleanup.
Signed-off-by: NKONRAD Frederic <fred.konrad@greensocs.com>
Message-id: 1366791683-5350-7-git-send-email-fred.konrad@greensocs.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

This remove the function pointer in VirtIODevice, and use only
VirtioDeviceClass function pointer.
Signed-off-by: NKONRAD Frederic <fred.konrad@greensocs.com>
Message-id: 1366791683-5350-5-git-send-email-fred.konrad@greensocs.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Minor fixes to documentation and code comments.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>