The vring.c code currently assumes that guest and host endianness match,
which is not true for a number of cases:

- emulating targets with a different endianness than the host
- bi-endian targets, where the correct endianness depends on the virtio
  device
- upcoming support for the virtio-1 standard mandates little-endian
  accesses even for big-endian targets and hosts

Make sure to use accessors that depend on the virtio device.

Note that dataplane now needs to be built per-target.

Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Fam Zheng <famz@redhat.com>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Tested-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 1422289602-17874-2-git-send-email-cornelia.huck@de.ibm.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

this adds a knob to disable request merging for debugging or benchmarks if dedired.
Signed-off-by: NPeter Lieven <pl@kamp.de>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

this patch finally introduces multiread support to virtio-blk. While
multiwrite support was there for a long time, read support was missing.

The complete merge logic is moved into virtio-blk.c which has
been the only user of request merging ever since. This is required
to be able to merge chunks of requests and immediately invoke callbacks
for those requests. Secondly, this is required to switch to
direct invocation of coroutines which is planned at a later stage.

The following benchmarks show the performance of running fio with
4 worker threads on a local ram disk. The numbers show the average
of 10 test runs after 1 run as warmup phase.

              |        4k        |       64k        |        4k
MB/s          | rd seq | rd rand | rd seq | rd rand | wr seq | wr rand
--------------+--------+---------+--------+---------+--------+--------
master        | 1221   | 1187    | 4178   | 4114    | 1745   | 1213
multiread     | 1829   | 1189    | 4639   | 4110    | 1894   | 1216
Signed-off-by: NPeter Lieven <pl@kamp.de>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

As it was not obvious (at least for me) where the 32 comes from;
add a constant for it.
Signed-off-by: NPeter Lieven <pl@kamp.de>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

In preparation for calling blk_aio_ioctl. Also make the function static
as no other files need it.
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The 'config' field in the VirtIOSerial structure keeps a copy of the virtio
console's config space as visible to the guest, that is to say, in guest
endianness.  This is fiddly to maintain, because on some targets, such as
powerpc, the "guest endianness" can change when a new guest OS boots.

In fact, there's no need to maintain such a guest view of config space -
instead we can reconstruct it from host-format data when it is accessed
with get_config.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAmit Shah <amit.shah@redhat.com>

commit 1773d9ee (virtio-net: cleanup: init and exit function)
removed the definition of virtio_net_init(), but didn't remove its
declaration in the header.  Clean that up.

Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: NGonglei <arei.gonglei@huawei.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

The cdb is not zeroed by virtio_scsi_init_req, so fix the misleading
comment.
Suggested-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

There's no use to constantly trying to enable dataplane if we failed
to set up guest or host notifiers, so fence it off in that case.
We'll try again if the device is reinitialized.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

We need this to protect dataplane thread from race conditions with block
jobs until the latter is made dataplane-safe.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Device models should access their block backends only through the
block-backend.h API.  Convert them, and drop direct includes of
inappropriate headers.

Just four uses of BlockDriverState are left:

* The Xen paravirtual block device backend (xen_disk.c) opens images
  itself when set up via xenbus, bypassing blockdev.c.  I figure it
  should go through qmp_blockdev_add() instead.

* Device model "usb-storage" prompts for keys.  No other device model
  does, and this one probably shouldn't do it, either.

* ide_issue_trim_cb() uses bdrv_aio_discard() instead of
  blk_aio_discard() because it fishes its backend out of a BlockAIOCB,
  which has only the BlockDriverState.

* PC87312State has an unused BlockDriverState[] member.

The next two commits take care of the latter two.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This is consistent with how VirtIOFOOConf variables are named
elsewhere, and makes blk available for BlockBackend variables.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Commit 12c5674b turned it into a pointer to member blk.conf.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NBenoît Canet <benoit.canet@nodalink.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

For VIRTIO_SCSI_T_TMF_ABORT_TASK and VIRTIO_SCSI_T_TMF_ABORT_TASK_SET,
use scsi_req_cancel_async to start the cancellation.

Because each tmf command may cancel multiple requests, we need to use a
counter to track the number of remaining requests we still need to wait
for.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Queue the popped requests while calling
virtio_scsi_handle_cmd_req_prepare(), then submit them after all
prepared.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Mechanical change, in preparation for bdrv_io_plug/bdrv_io_unplug.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Similar to virtio-blk-dataplane, we stop the iothread while migration
starts and restart it when migration finishes.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This implements the core part of dataplane feature of virtio-scsi.

A few fields are added in VirtIOSCSICommon to maintain the dataplane
status. These fields are managed by a new source file:
virtio-scsi-dataplane.c.

Most code in this file will run on an iothread, unless otherwise
commented as in a global mutex context, such as those functions to
start, stop and setting the iothread property.

Upon start, we set up guest/host event notifiers, in a same way as
virtio-blk does. The handlers then pop request from vring and call into
virtio-scsi.c functions to process it. So we need to make sure make all
those called functions work with iothread, too.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Move VirtIOSCSIReq to header and add one field "vring" as a wrapper
structure of Vring, VirtIOSCSIVring.

This is necessary for coming dataplane code that runs uses vring on
iothread.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Similar to this property in virtio-blk for dataplane, add it as a QOM
link in virtio-scsi and an alias in virtio-scsi-pci and virtio-scsi-ccw,
in order to assign an iothread to the device.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

For better code sharing, add a helper function that handles
reference counting of the virtio backend for virtio proxy devices.

Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: NGonglei <arei.gonglei@huawei.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Compiler warning (w32, w64):

include/hw/virtio/virtio_ring.h:142:26: warning:
 cast from pointer to integer of different size [-Wpointer-to-int-cast]

When sizeof(long) < sizeof(void *), this is not only a warning but a
real program error.

Add also missing blanks in the same statement.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 1411536002-14088-1-git-send-email-sw@weilnetz.de
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Later this will be called by dataplane code.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

To share with dataplane code later.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

To share with datplane code later.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

To share with dataplane code.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This is the "common part" to handle one cmd request. Refactor out for
later usage of dataplane iothread code.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Dataplane doesn't depend on linux-aio any more, so we don't need the
compiling condition now.

Configure options are kept but just print a message.
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-id: 1410329871-28885-4-git-send-email-famz@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This header has no further dependencies. It only has some stable data
types and primitive functions, so we can copy it to include/hw/virtio in
order to allow vring code (and its user virtio-blk dataplane) to be
built unconditionally, even for cross compiling.
Suggested-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-id: 1410329871-28885-2-git-send-email-famz@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

The plan is to add new accounting metrics (latency, invalid requests, failed
requests, queue depth) and block.c is overpopulated so it will be better to work
in a separate module.

Moreover the long term plan is to have statistics in each of the BDS of the graph
for metrology purpose; this means that the device model statistics must move from
the topmost BDS to the device model.

So we need to decouple the statistic code from BlockDriverState.

This is another argument for the extraction of the code in a separate module.

CC: Kevin Wolf <kwolf@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
CC: Eric Blake <eblake@redhat.com>
CC: Benoit Canet <benoit@irqsave.net>
CC: Fam Zheng <famz@redhat.com>
CC: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NBenoît Canet <benoit.canet@nodalink.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

To ensure two virtserialports don't get added to the system with the
same 'name' parameter, we need to access all the ports on all the
devices added, and compare the names.

We currently don't have a list of all VirtIOSerial devices added to the
system.  This commit adds a simple linked list in which devices are put
when they're initialized, and removed when they go away.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>

This fixes a warning from smatch (static code analyser).
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

Right now starting a machine with virtio-scsi and a <= 2.0 machine type
fails with:

    qemu-system-x86_64: -device virtio-scsi-pci: Property .any_layout not found

This is because the any_layout bit was actually never set after
virtio-scsi was changed to support arbitrary layout for virtio buffers.

(This was just a cleanup and a preparation for virtio 1.0; no guest
actually checks the bit, but the new request parsing algorithms are
tested even with old guest).
Reported-by: NDavid Gilbert <dgilbert@redhat.com>
Reviewed-by: NDavid Gilbert <dgilbert@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@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>

VirtQueueElement is allocated in vring_pop() so it seems to make sense
that vring_push() should free it.  Alas, virtio-blk frees
VirtQueueElement itself in virtio_blk_free_request().

This patch solves a double-free assertion in glib's g_slice_free().

Rename vring_free_element() to vring_unmap_element() since it no longer
frees the VirtQueueElement.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Tested-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The two common virtio features can be defined per bus, so move all
into bus class device to make code more clean.

As discussed with cornelia, s390-virtio-blk doesn't support
the two features at all, so keep s390-virtio as it.

Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> #for s390 ccw
Suggested-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NMing Lei <ming.lei@canonical.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

MST: rebase and resolve conflicts

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>

Move the x-data-plane property.  Originally it was outside since not
every transport may wish to support dataplane.  But that makes little
sense when we have a dedicated CONFIG_VIRTIO_BLK_DATA_PLANE ifdef
already.

This move makes it easier to switch to property aliases in the next
patch.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

It becomes unwiedly to duplicate all virtio-blk qdev property
definitions due to an #ifdef.  The C preprocessor syntax makes it a
little hard to resolve this cleanly but we can extract the #ifdef and
call a macro it defines later.

Avoiding duplication is important since it will only get worse when we
move the x-data-plane qdev property here too.  We'd have a combinatorial
explosion since x-data-plane has its own #ifdef.
Suggested-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>