Regardless of running in UPT or legacy mode, the guest igd
drivers may attempt to use stolen memory, however only legacy
mode has BIOS support for reserving stolen memmory in the
guest VM. We zero out the stolen memory size in all cases,
then guest igd driver won't use stolen memory.
In legacy mode, user could use x-igd-gms option to specify the
amount of stolen memory which will be pre-allocated and reserved
by bios for igd use.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99028https://bugs.freedesktop.org/show_bug.cgi?id=99025
Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Since commit 4bb571d857 ("pci/pcie: don't assume cap id 0 is
reserved") removes the internal use of extended capability ID 0, the
comment here becomes invalid. However, peeling back the onion, the
code is still correct and we still can't seed the capability chain
with ID 0, unless we want to muck with using the version number to
force the header to be non-zero, which is much uglier to deal with.
The comment also now covers some of the subtleties of using cap ID 0,
such as transparently indicating absence of capabilities if none are
added. This doesn't detract from the correctness of the referenced
commit as vfio in the kernel also uses capability ID zero to mask
capabilties. In fact, we should skip zero capabilities precisely
because the kernel might also expose such a capability at the head
position and re-introduce the problem.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Peter Xu <peterx@redhat.com>
Reported-by: Jintack Lim <jintack@cs.columbia.edu>
Tested-by: Jintack Lim <jintack@cs.columbia.edu>
Currently we ignore this error, report it with error_reportf_err()
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
The sheepdog URL is broken twice: First it uses a duplicated
http:// prefix, second the website seems to have moved to
https://sheepdog.github.io/sheepdog/ instead.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
If explicit zeroing out before mirroring is required for the target image,
it moves the block job offset counter to EOF, then offset and len counters
count the image size twice. There is no harm but stats are confusing,
specifically the progress of the operation is always reported as 99% by
management tools.
The patch skips offset increase for the first "technical" pass over the
image. This should not cause any further harm.
Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1486045515-8009-1-git-send-email-den@openvz.org
CC: Jeff Cody <jcody@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
CC: Eric Blake <eblake@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
This adds blockdev-add support for iscsi devices.
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
This was previously only available with -iscsi. Again, after this patch,
the -iscsi option only takes effect if an URL is given. New users are
supposed to use the new driver-specific option.
All -iscsi options have a corresponding driver-specific option for the
iscsi block driver now.
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
This was previously only available with -iscsi. Again, after this patch,
the -iscsi option only takes effect if an URL is given. New users are
supposed to use the new driver-specific option.
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
This was previously only available with -iscsi. Again, after this patch,
the -iscsi option only takes effect if an URL is given. New users are
supposed to use the new driver-specific option.
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
This splits the logic in the old parse_chap() function into a part that
parses the -iscsi options into the new driver-specific options, and
another part that actually applies those options (called apply_chap()
now).
Note that this means that username and password specified with -iscsi
only take effect when a URL is provided. This is intentional, -iscsi is
a legacy interface only supported for compatibility, new users should
use the proper driver-specific options.
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
This introduces a .bdrv_parse_filename handler for iscsi which parses an
URL if given and translates it to individual options.
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
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Merge remote-tracking branch 'remotes/armbru/tags/pull-block-2017-02-21' into staging
Changes to -drive without if= and with if=scsi
# gpg: Signature made Tue 21 Feb 2017 12:22:35 GMT
# gpg: using RSA key 0x3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653
* remotes/armbru/tags/pull-block-2017-02-21:
hw/i386: Deprecate -drive if=scsi with PC machine types
hw: Deprecate -drive if=scsi with non-onboard HBAs
hw/scsi: Concentrate -drive if=scsi auto-create in one place
hw: Drop superfluous special checks for orphaned -drive
blockdev: Make orphaned -drive fatal
blockdev: Improve message for orphaned -drive
hw/arm/highbank: Default -drive to if=ide instead of if=scsi
hw: Default -drive to if=none instead of scsi when scsi cannot work
hw: Default -drive to if=none instead of ide when ide cannot work
hw/arm/cubieboard hw/arm/xlnx-ep108: Fix units_per_default_bus
hw: Default -drive to if=ide explicitly where it works
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The PC machines (pc-q35-* pc-i440fx-* pc-* isapc xenfv) automatically
create lsi53c895a SCSI HBAs and SCSI devices to honor -drive if=scsi.
For giggles, try -drive if=scsi,bus=25,media=cdrom --- this makes QEMU
create 25 of them.
lsi53c895a is thoroughly obsolete (PCI Ultra2 SCSI, ca. 2000), and
currently has no maintainer in QEMU. megasas is a better choice,
except with old OSes that lack drivers. virtio-scsi is a much better
choice when you have a driver, but only (newish) Linux comes with one
in the box. There is no good default that works for all guests.
Encourage users to pick a non-obsolete SCSI HBA that works for them by
deprecating -drive if=scsi.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1487161136-9018-4-git-send-email-armbru@redhat.com>
Acked-By: Paolo Bonzini <pbonzini@redhat.com>
Block backends defined with "-drive if=T" with T other than "none" are
meant to be picked up by machine initialization code: a suitable
frontend gets created and wired up automatically.
Drives defined with if=scsi are also picked up by SCSI HBAs added with
-device, unlike other interface types. Deprecate this usage, as follows.
Create the frontends for onboard HBAs in machine initialization code,
exactly like we do for if=ide and other interface types. Change
scsi_legacy_handle_cmdline() to create a frontend only when it's still
missing, and warn that this usage is deprecated.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1487161136-9018-3-git-send-email-armbru@redhat.com>
The logic to create frontends for -drive if=scsi is in SCSI HBAs. For
all other interface types, it's in machine initialization code.
A few machine types create the SCSI HBAs necessary for that. That's
also not done for other interface types.
I'm going to deprecate these SCSI eccentricities. In preparation for
that, create the frontends in main() instead of the SCSI HBAs, by
calling new function scsi_legacy_handle_cmdline() there.
Note that not all SCSI HBAs create frontends. Take care not to change
that.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1487161136-9018-2-git-send-email-armbru@redhat.com>
Acked-By: Paolo Bonzini <pbonzini@redhat.com>
We've traditionally rejected orphans here and there, but not
systematically. For instance, the sun4m machines have an onboard SCSI
HBA (bus=0), and have always rejected bus>0. Other machines with an
onboard SCSI HBA don't.
Commit a66c9dc made all orphans trigger a warning, and the previous
commit turned this into an error. The checks "here and there" are now
redundant. Drop them.
Note that the one in mips_jazz.c was wrong: it rejected bus > MAX_FD,
but MAX_FD is the number of floppy drives per bus.
Error messages change from
$ qemu-system-x86_64 -drive if=ide,bus=2
qemu-system-x86_64: Too many IDE buses defined (3 > 2)
$ qemu-system-mips64 -M magnum,accel=qtest -drive if=floppy,bus=2,id=fd1
qemu: too many floppy drives
$ qemu-system-sparc -M LX -drive if=scsi,bus=1
qemu: too many SCSI bus
to
$ qemu-system-x86_64 -drive if=ide,bus=2
qemu-system-x86_64: -drive if=ide,bus=2: machine type does not support if=ide,bus=2,unit=0
$ qemu-system-mips64 -M magnum,accel=qtest -drive if=floppy,bus=2,id=fd1
qemu-system-mips64: -drive if=floppy,bus=2,id=fd1: machine type does not support if=floppy,bus=2,unit=0
$ qemu-system-sparc -M LX -drive if=scsi,bus=1
qemu-system-sparc: -drive if=scsi,bus=1: machine type does not support if=scsi,bus=1,unit=0
Cc: John Snow <jsnow@redhat.com>
Cc: "Hervé Poussineau" <hpoussin@reactos.org>
Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1487153147-11530-9-git-send-email-armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Block backends defined with "-drive if=T" with T other than "none" are
meant to be picked up by machine initialization code: a suitable
frontend gets created and wired up automatically.
If machine initialization code doesn't comply, the block backend
remains unused. This triggers a warning since commit a66c9dc, v2.2.0.
Drives created by default are exempted; use -nodefaults to get rid of
them.
Turn this warning into an error.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1487153147-11530-8-git-send-email-armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
We warn when a -drive isn't supported by the machine type (commit
a66c9dc):
$ qemu-system-x86_64 -S -display none -drive if=mtd
Warning: Orphaned drive without device: id=mtd0,file=,if=mtd,bus=0,unit=0
Improve this to point to the offending bit of configuration:
qemu-system-x86_64: -drive if=mtd: warning: machine type does not support if=mtd,bus=0,unit=0
Especially nice when it's hidden behind -readconfig foo.cfg:
qemu-system-x86_64:foo.cfg:140: warning: machine type does not support if=mtd,bus=0,unit=0
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1487153147-11530-7-git-send-email-armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
These machines have no onboard SCSI HBA, and no way to plug one.
-drive if=scsi therefore cannot work. They do have an onboard IDE
controller (sysbus-ahci), but fail to honor if=ide.
Change their default to if=ide, and add a TODO comment on what needs
to be done to actually honor -drive if=ide.
Cc: Rob Herring <robh@kernel.org>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-arm@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1487153147-11530-6-git-send-email-armbru@redhat.com>
Block backends defined with -drive if=scsi are meant to be picked up
by machine initialization code: a suitable frontend gets created and
wired up automatically.
if=scsi drives not picked up that way can still be used with -device
as if they had if=none, but that's unclean and best avoided. Unused
ones produce an "Orphaned drive without device" warning.
A few machine types default to if=scsi, even though they don't
actually have a SCSI HBA. This makes no sense. Change their default
to if=none. Affected machines:
* aarch64/arm: realview-pbx-a9 vexpress-a9 vexpress-a15 xilinx-zynq-a9
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>
Cc: Alistair Francis <alistair.francis@xilinx.com>
Cc: qemu-arm@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@xilinx.com>
Message-Id: <1487153147-11530-5-git-send-email-armbru@redhat.com>
Block backends defined with -drive if=ide are meant to be picked up by
machine initialization code: a suitable frontend gets created and
wired up automatically.
if=ide drives not picked up that way can still be used with -device as
if they had if=none, but that's unclean and best avoided. Unused ones
produce an "Orphaned drive without device" warning.
-drive parameter "if" is optional, and the default depends on the
machine type. If a machine type doesn't specify a default, the
default is "ide".
Many machine types implicitly default to if=ide that way, even though
they don't actually have an IDE controller. This makes no sense.
Change the implicit default to if=none. Affected machines:
* all targets: none
* aarch64/arm: akita ast2500 canon cheetah collie connex imx25
integratorcp kzm lm3s6965evb lm3s811evb mainstone musicpal n800 n810
netduino2 nuri palmetto realview romulus sabrelite smdkc210 sx1 sx1
verdex z2
* cris: axis-dev88
* i386/x86_64: xenpv
* lm32: lm32-evr lm32-uclinux milkymist
* m68k: an5206 dummy mcf5208evb
* microblaze/microblazeel: petalogix-ml605 petalogix-s3adsp1800
* mips/mips64/mips64el/mipsel: mipssim
* moxie: moxiesim
* or32: or32-sim
* ppc/ppc64/ppcemb: bamboo ref405ep taihu virtex-ml507
* ppc/ppc64: mpc8544ds ppce500
* sh4/sh4eb: shix
* sparc: leon3_generic
* sparc64: niagara
* tricore: tricore_testboard
* unicore32: puv3
* xtensa/xtensaeb: kc705 lx200 lx60 ml605 sim
None of these machines have an IDE controller, let alone code to
honor if=ide.
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-arm@nongnu.org
Cc: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: xen-devel@lists.xensource.com
Cc: Michael Walle <michael@walle.cc>
Cc: Laurent Vivier <laurent@vivier.eu>
Cc: Anthony Green <green@moxielogic.com>
Cc: Jia Liu <proljc@gmail.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: qemu-ppc@nongnu.org
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Fabien Chouteau <chouteau@adacore.com>
Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Cc: Artyom Tarasenko <atar4qemu@gmail.com>
Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-By: Artyom Tarasenko <atar4qemu@gmail.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1487153147-11530-4-git-send-email-armbru@redhat.com>
Machine types cubieboard, xlnx-ep108, xlnx-zcu102 have an onboard AHCI
controller, but neglect to set their MachineClass member
units_per_default_bus = 1. This permits -drive if=ide,unit=1, which
makes no sense for AHCI. It also screws up index=N for odd N, because
it gets desugared to unit=1,bus=N/2
Doesn't really matter, because these machine types fail to honor
-drive if=ide. Add the missing units_per_default_bus = 1 anyway,
along with a TODO comment on what needs to be done for -drive if=ide.
Also set block_default_type = IF_IDE explicitly. It's currently the
default, but the next commit will change it to something more
sensible, and we want to keep the IF_IDE default for these three
machines. See also the previous commit.
Cc: Beniamino Galvani <b.galvani@gmail.com>
Cc: Alistair Francis <alistair.francis@xilinx.com>
Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-arm@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Alistair Francis <alistair.francis@xilinx.com>
Message-Id: <1487153147-11530-3-git-send-email-armbru@redhat.com>
Block backends defined with -drive if=ide are meant to be picked up by
machine initialization code: a suitable frontend gets created and
wired up automatically.
if=ide drives not picked up that way can still be used with -device as
if they had if=none, but that's unclean and best avoided. Unused ones
produce an "Orphaned drive without device" warning.
-drive parameter "if" is optional, and the default depends on the
machine type. If a machine type doesn't specify a default, the
default is "ide".
Many machine types default to if=ide, even though they don't actually
have an IDE controller. A future patch will change these defaults to
something more sensible. To prepare for it, this patch makes default
"ide" explicit for the machines that actually pick up if=ide drives:
* alpha: clipper
* arm/aarch64: spitz borzoi terrier tosa
* i386/x86_64: generic-pc-machine (with concrete subtypes pc-q35-*
pc-i440fx-* pc-* isapc xenfv)
* mips64el: fulong2e
* mips/mipsel/mips64el: malta mips
* ppc/ppc64: mac99 g3beige prep
* sh4/sh4eb: r2d
* sparc64: sun4u sun4v
Note that ppc64 machine powernv already sets an "ide" default
explicitly. Its IDE controller isn't implemented, yet.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1487153147-11530-2-git-send-email-armbru@redhat.com>
v2:
* Rebased to resolve scsi conflicts
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Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging
Pull request
v2:
* Rebased to resolve scsi conflicts
# gpg: Signature made Tue 21 Feb 2017 11:56:24 GMT
# gpg: using RSA key 0x9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg: aka "Stefan Hajnoczi <stefanha@gmail.com>"
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35 775A 9CA4 ABB3 81AB 73C8
* remotes/stefanha/tags/block-pull-request: (24 commits)
coroutine-lock: make CoRwlock thread-safe and fair
coroutine-lock: add mutex argument to CoQueue APIs
coroutine-lock: place CoMutex before CoQueue in header
test-aio-multithread: add performance comparison with thread-based mutexes
coroutine-lock: add limited spinning to CoMutex
coroutine-lock: make CoMutex thread-safe
block: document fields protected by AioContext lock
async: remove unnecessary inc/dec pairs
aio-posix: partially inline aio_dispatch into aio_poll
block: explicitly acquire aiocontext in aio callbacks that need it
block: explicitly acquire aiocontext in bottom halves that need it
block: explicitly acquire aiocontext in callbacks that need it
block: explicitly acquire aiocontext in timers that need it
aio: push aio_context_acquire/release down to dispatching
qed: introduce qed_aio_start_io and qed_aio_next_io_cb
blkdebug: reschedule coroutine on the AioContext it is running on
coroutine-lock: reschedule coroutine on the AioContext it was running on
nbd: convert to use qio_channel_yield
io: make qio_channel_yield aware of AioContexts
io: add methods to set I/O handlers on AioContext
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This adds a CoMutex around the existing CoQueue. Because the write-side
can just take CoMutex, the old "writer" field is not necessary anymore.
Instead of removing it altogether, count the number of pending writers
during a read-side critical section and forbid further readers from
entering.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213181244.16297-7-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
All that CoQueue needs in order to become thread-safe is help
from an external mutex. Add this to the API.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213181244.16297-6-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This will avoid forward references in the next patch. It is also
more logical because CoQueue is not anymore the basic primitive.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213181244.16297-5-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Add two implementations of the same benchmark as the previous patch,
but using pthreads. One uses a normal QemuMutex, the other is Linux
only and implements a fair mutex based on MCS locks and futexes.
This shows that the slower performance of the 5-thread case is due to
the fairness of CoMutex, rather than to coroutines. If fairness does
not matter, as is the case with two threads, CoMutex can actually be
faster than pthreads.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213181244.16297-4-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Running a very small critical section on pthread_mutex_t and CoMutex
shows that pthread_mutex_t is much faster because it doesn't actually
go to sleep. What happens is that the critical section is shorter
than the latency of entering the kernel and thus FUTEX_WAIT always
fails. With CoMutex there is no such latency but you still want to
avoid wait and wakeup. So introduce it artificially.
This only works with one waiters; because CoMutex is fair, it will
always have more waits and wakeups than a pthread_mutex_t.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213181244.16297-3-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This uses the lock-free mutex described in the paper '"Blocking without
Locking", or LFTHREADS: A lock-free thread library' by Gidenstam and
Papatriantafilou. The same technique is used in OSv, and in fact
the code is essentially a conversion to C of OSv's code.
[Added missing coroutine_fn in tests/test-aio-multithread.c.
--Stefan]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213181244.16297-2-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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: 20170213135235.12274-19-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Pull the increment/decrement pair out of aio_bh_poll and into the
callers.
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: 20170213135235.12274-18-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This patch prepares for the removal of unnecessary lockcnt inc/dec pairs.
Extract the dispatching loop for file descriptor handlers into a new
function aio_dispatch_handlers, and then inline aio_dispatch into
aio_poll.
aio_dispatch can now become void.
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: 20170213135235.12274-17-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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>
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: 20170213135235.12274-15-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This covers both file descriptor callbacks and polling callbacks,
since they execute related code.
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: 20170213135235.12274-14-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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: 20170213135235.12274-13-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The AioContext data structures are now protected by list_lock and/or
they are walked with FOREACH_RCU primitives. There is no need anymore
to acquire the AioContext for the entire duration of aio_dispatch.
Instead, just acquire it before and after invoking the callbacks.
The next step is then to push it further down.
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: 20170213135235.12274-12-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
qed_aio_start_io and qed_aio_next_io will not have to acquire/release
the AioContext, while qed_aio_next_io_cb will. Split the functionality
and gain a little type-safety in the process.
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: 20170213135235.12274-11-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Keep the coroutine on the same AioContext. Without this change,
there would be a race between yielding the coroutine and reentering it.
While the race cannot happen now, because the code only runs from a single
AioContext, this will change with multiqueue support in the block layer.
While doing the change, replace custom bottom half with aio_co_schedule.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170213135235.12274-10-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
As a small step towards the introduction of multiqueue, we want
coroutines to remain on the same AioContext that started them,
unless they are moved explicitly with e.g. aio_co_schedule. This patch
avoids that coroutines switch AioContext when they use a CoMutex.
For now it does not make much of a difference, because the CoMutex
is not thread-safe and the AioContext itself is used to protect the
CoMutex from concurrent access. However, this is going to change.
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: 20170213135235.12274-9-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
In the client, read the reply headers from a coroutine, switching the
read side between the "read header" coroutine and the I/O coroutine that
reads the body of the reply.
In the server, if the server can read more requests it will create a new
"read request" coroutine as soon as a request has been read. Otherwise,
the new coroutine is created in nbd_request_put.
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: 20170213135235.12274-8-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Support separate coroutines for reading and writing, and place the
read/write handlers on the AioContext that the QIOChannel is registered
with.
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213135235.12274-7-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This is in preparation for making qio_channel_yield work on
AioContexts other than the main one.
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213135235.12274-6-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Once the thread pool starts using aio_co_wake, it will also need
qemu_get_current_aio_context(). Make test-thread-pool create
an AioContext with qemu_init_main_loop, so that stubs/iothread.c
and tests/iothread.c can provide the rest.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213135235.12274-5-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
qcow2_create2 calls this. Do not run a nested event loop, as that
breaks when aio_co_wake tries to queue the coroutine on the co_queue_wakeup
list of the currently running one.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213135235.12274-4-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
aio_co_wake provides the infrastructure to start a coroutine on a "home"
AioContext. It will be used by CoMutex and CoQueue, so that coroutines
don't jump from one context to another when they go to sleep on a
mutex or waitqueue. However, it can also be used as a more efficient
alternative to one-shot bottom halves, and saves the effort of tracking
which AioContext a coroutine is running on.
aio_co_schedule is the part of aio_co_wake that starts a coroutine
on a remove AioContext, but it is also useful to implement e.g.
bdrv_set_aio_context callbacks.
The implementation of aio_co_schedule is based on a lock-free
multiple-producer, single-consumer queue. The multiple producers use
cmpxchg to add to a LIFO stack. The consumer (a per-AioContext bottom
half) grabs all items added so far, inverts the list to make it FIFO,
and goes through it one item at a time until it's empty. The data
structure was inspired by OSv, which uses it in the very code we'll
"port" to QEMU for the thread-safe CoMutex.
Most of the new code is really tests.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213135235.12274-3-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
AioContext is fairly self contained, the only dependency is QEMUTimer but
that in turn doesn't need anything else. So move them out of block-obj-y
to avoid introducing a dependency from io/ to block-obj-y.
main-loop and its dependency iohandler also need to be moved, because
later in this series io/ will call iohandler_get_aio_context.
[Changed copyright "the QEMU team" to "other QEMU contributors" as
suggested by Daniel Berrange and agreed by Paolo.
--Stefan]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213135235.12274-2-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
