Commit Graph

31661 Commits

Author SHA1 Message Date
Andreas Färber
7510454e3e cpu: Turn cpu_handle_mmu_fault() into a CPUClass hook
Note that while such functions may exist both for *-user and softmmu,
only *-user uses the CPUState hook, while softmmu reuses the prototype
for calling it directly.

Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:20:46 +01:00
Peter Maydell
7372c2b926 target-m68k: Remove custom qemu_assert() function
Remove the custom qemu_assert() function defined by target-m68k/translate.c
in favour of either using glib g_assert_not_reached() (for the genuinely
can't-happen cases) or cpu_abort() (for the "this isn't implemented",
in line with other unimplemented cases in the target).

This has the benefit of silencing some clang warnings about
variables used while uninitialized (which are emitted because
clang can't figure out that qemu_assert(0, something) never
returns.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:20:46 +01:00
Andreas Färber
9262685b81 cpu: Factor out cpu_generic_init()
All targets using it gain the ability to set -cpu name,key=value,...
options via the default TYPE_CPU CPUClass::parse_features() implementation.

Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:20:46 +01:00
Andreas Färber
1590bbcb02 cpu: Implement CPUClass::parse_features() for the rest of CPUs
CPUs who do not provide their own implementation of feature parsing
will treat each option as a QOM property and set it to the supplied
value.

Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:20:45 +01:00
Andreas Färber
247bf011f6 target-sparc: Defer SPARCCPU feature inference to QOM realize
Gets it out of cpu_sparc_register() and aligns with target-arm.

Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:20:45 +01:00
Andreas Färber
433ac7a968 target-sparc: Implement CPUClass::parse_features() for SPARCCPU
Factor cpu_model parsing out of cpu_sparc_find_by_name() by passing
cpu_sparc_find_by_name() the name portion only and calling
CPUClass::parse_features() from cpu_sparc_register() afterwards.

Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:20:45 +01:00
Andreas Färber
db5d39f786 target-sparc: Use error_report() for CPU error reporting
Replace non-debug fprintf() with error_report().

Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:20:45 +01:00
Andreas Färber
94a444b295 cpu: Introduce CPUClass::parse_features() hook
Adapt the X86CPU implementation to suit the generic hook.
This involves a cleanup of error handling to cope with NULL errp.

Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:20:45 +01:00
Eduardo Habkost
d940ee9b78 target-i386: X86CPU model subclasses
Register separate QOM types for each x86 CPU model.

This will allow management code to more easily probe what each CPU model
provides, by simply creating objects using the appropriate class name,
without having to restart QEMU.

This also allows us to eliminate the qdev_prop_set_globals_for_type()
hack to set CPU-model-specific global properties.

Instead of creating separate class_init functions for each class, I just
used class_data to store a pointer to the X86CPUDefinition struct for
each CPU model. This should make the patch shorter and easier to review.
Later we can gradually convert each X86CPUDefinition field to lists of
per-class property defaults.

The "host" CPU model is special, as the feature flags depend on KVM
being initialized. So it has its own class_init and instance_init
function, and feature flags are set on instance_init instead of
class_init.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Tested-by: Eduardo Habkost <ehabkost@redhat.com>
[AF: Limit the host CPU type to CONFIG_KVM as build fix]
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:20:07 +01:00
Andreas Färber
500050d1e0 target-i386: Prepare CPUClass::class_by_name for X86CPU
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Tested-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:49 +01:00
Eduardo Habkost
ef02ef5f45 target-i386: Enable x2apic by default on KVM
When on KVM mode, enable x2apic by default on all CPU models.

Normally we try to keep the CPU model definitions as close as the real
CPUs as possible, but x2apic can be emulated by KVM without host CPU
support for x2apic, and it improves performance by reducing APIC access
overhead. x2apic emulation is available on KVM since 2009 (Linux
2.6.32-rc1), there's no reason for not enabling x2apic by default when
running KVM.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:49 +01:00
Eduardo Habkost
8fb4f821e9 target-i386: Introduce x86_cpu_compat_disable_kvm_features()
Instead of the feature-specific disable_kvm_pv_eoi() function, create a
more general function that can be used to disable other feature bits in
machine-type compat code.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:49 +01:00
Eduardo Habkost
5fcca9ff3b target-i386: Make kvm_default_features an array
We will later make the KVM-specific code affect other feature words,
too.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:49 +01:00
Eduardo Habkost
74f54bc4ba target-i386: Don't declare variables in the middle of blocks
Some of my recent changes introduced variable declarations in the middle
of code blocks.

Fix the code so that it compiles without warnings when using
-Wdeclaration-after-statement.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:49 +01:00
Eduardo Habkost
9576de7573 target-i386: Rename x86_def_t to X86CPUDefinition
As the new X86CPU subclass code is going to change lots of the code
invoving x86_def_t, let's rename the struct to match coding style first.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:49 +01:00
Eduardo Habkost
285f025d2c target-i386: Call x86_cpu_load_def() earlier
As we will initialize the X86CPU fields on instance_init eventually,
move the code that initializes the X86CPU data based on the CPU model
name closer to the object_new() call.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:49 +01:00
Eduardo Habkost
c080e30ec8 target-i386: Rename cpu_x86_register() to x86_cpu_load_def()
There isn't any kind of "registration" involved in cpu_x86_register()
anymore: it is simply looking up a CPU model name and loading the model
definition data into the X86CPU object. Rename it to x86_cpu_load_def()
to reflect what it does.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:49 +01:00
Andreas Färber
8c2e1b0093 cpu: Turn cpu_has_work() into a CPUClass hook
Default to false.

Tidy variable naming and inline cast uses while at it.

Tested-by: Jia Liu <proljc@gmail.com> (or32)
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:49 +01:00
Andreas Färber
1cf5ccbca8 target-xtensa: Clean up ENV_GET_CPU() usage
Commits a00817cc4c and
fdfba1a298 added usages of ENV_GET_CPU()
macro in target-specific code.

Use xtensa_env_get_cpu() instead.

Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:49 +01:00
Andreas Färber
62864712b3 target-unicore32: Clean up ENV_GET_CPU() usage
Commit fdfba1a298 added a usage of
ENV_GET_CPU() macro in target-specific code.

Use uc32_env_get_cpu() instead.

Cc: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:49 +01:00
Andreas Färber
2fad1112db target-sparc: Clean up ENV_GET_CPU() usage
Commits fdfba1a298,
2c17449b30 and
f606604f1c added usages of ENV_GET_CPU()
macro in target-specific code.

Use sparc_env_get_cpu() instead and reuse the variables.

Cc: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:49 +01:00
Andreas Färber
2efc6be2ea target-s390x: Clean up ENV_GET_CPU() usage
Commits f606604f1c,
2c17449b30 and
5ce5944dc0 added usages of ENV_GET_CPU()
macro in target-specific code.

Use s390_env_get_cpu() instead.

Cc: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:48 +01:00
Andreas Färber
33276f1b9c target-ppc: Clean up ENV_GET_CPU() usage
Commits fdfba1a298,
ab1da85791,
f606604f1c and
2c17449b30 added usages of ENV_GET_CPU()
macro in target-specific code.

Use ppc_env_get_cpu() instead.

Cc: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:48 +01:00
Andreas Färber
19d6ca16d9 target-i386: Clean up ENV_GET_CPU() usage
Commits fdfba1a298,
f606604f1c and
2c17449b30 added usages of ENV_GET_CPU()
macro in target-specific code.

Use x86_env_get_cpu() or reuse existing X86CPU variable instead.

Cc: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:48 +01:00
Andreas Färber
70d74660e7 target-arm: Clean up ENV_GET_CPU() usage
Commits ab1da85791,
fdfba1a298,
2c17449b30 added usages of ENV_GET_CPU()
macro to target-specific code.

Use arm_env_get_cpu() instead and enforce separating variable
declarations.

Cc: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:48 +01:00
Andreas Färber
d2810ffd34 target-alpha: Clean up ENV_GET_CPU() usage
Commits 2c17449b30,
fdfba1a298,
ab1da85791 and
f606604f1c added usages of ENV_GET_CPU()
macro in target-specific code.

Use alpha_env_get_cpu() instead.

Cc: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:48 +01:00
Edgar E. Iglesias
9d111183d5 cpu: Don't clear cpu->exit_request on reset
cpu->exit_request is part of the execution environment and should
not be cleared when a CPU resets.

Otherwise, we might deadlock QEMU if a CPU resets while there is
I/O going on.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-03-13 19:01:48 +01:00
Peter Maydell
57fac92c2d Block pull request
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Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging

Block pull request

# gpg: Signature made Thu 13 Mar 2014 13:50:49 GMT using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/block-pull-request: (24 commits)
  block/raw-win32: bdrv_parse_filename() for hdev
  block/raw-posix: Strip protocol prefix on creation
  block/raw-posix: bdrv_parse_filename() for cdrom
  block/raw-posix: bdrv_parse_filename() for floppy
  block/raw-posix: bdrv_parse_filename() for hdev
  qemu-io: Fix warnings from static code analysis
  block: Unlink temporary file
  qcow2: Don't write with BDRV_O_INCOMING
  qcow2: Keep option in qcow2_invalidate_cache()
  qmp: add query-iothreads command
  iothread: stash thread ID away
  dataplane: replace internal thread with IOThread
  iothread: add "iothread" qdev property type
  qdev: make get_pointer() handle temporary strings
  iothread: add I/O thread object
  aio: add aio_context_acquire() and aio_context_release()
  rfifolock: add recursive FIFO lock
  object: add object_get_canonical_path_component()
  block: Rewrite the snapshot authorization mechanism for block filters.
  iotests: Test corruption during COW request
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2014-03-13 15:33:04 +00:00
Andreas Färber
41975b269c oslib-posix: Fix build on FreeBSD
Commit 10f5bff622 (util: Split out
exec_dir from os_find_datadir) moved code from os-posix.c to
util/oslib-posix.c but forgot to move a FreeBSD #include alongside,
needed for CTL_KERN among others.

Cc: Fam Zheng <famz@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andreas Färber <andreas.faerber@web.de>
Message-id: 1394717279-23406-1-git-send-email-andreas.faerber@web.de
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2014-03-13 14:34:16 +00:00
Max Reitz
57ed25b1b0 block/raw-win32: bdrv_parse_filename() for hdev
The "host_device" protocol driver should strip the "host_device:" prefix
from filenames if present.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:42:25 +01:00
Max Reitz
cc28c6aa46 block/raw-posix: Strip protocol prefix on creation
The hdev_create() implementation in block/raw-posix.c is used by the
"host_device", "host_cdrom" and "host_floppy" protocol block drivers
together. Thus, any of the associated prefixes may occur and exactly one
should should be stripped, if it does (thus,
"host_device:host_cdrom:/dev/cdrom" is not shortened to "/dev/cdrom").

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:42:25 +01:00
Max Reitz
18fa1c42a3 block/raw-posix: bdrv_parse_filename() for cdrom
The "host_cdrom" protocol drivers should strip the "host_cdrom:" prefix
from filenames if present.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:42:24 +01:00
Max Reitz
d3f4984583 block/raw-posix: bdrv_parse_filename() for floppy
The "host_floppy" protocol driver should strip the "host_floppy:" prefix
from filenames if present.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:42:24 +01:00
Max Reitz
7af803d4f8 block/raw-posix: bdrv_parse_filename() for hdev
The "host_device" protocol driver should strip the "host_device:" prefix
from filenames if present.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:42:24 +01:00
Stefan Weil
f988388025 qemu-io: Fix warnings from static code analysis
Smatch complains about several global symbols which should be local.

Add the missing 'static' attributes and move the 'extern' declaration
of variable qemuio_misalign to qemu-io.h. This variable also changes
the type from 'int' to 'bool' which better fits documents its use.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:42:24 +01:00
Max Reitz
9562f69cfd block: Unlink temporary file
If the image file cannot be opened and was created as a temporary file,
it should be deleted; thus, in this case, we should jump to the
"unlink_and_fail" label and not just to "fail".

Reported-by: Benoît Canet <benoit@irqsave.net>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:42:24 +01:00
Kevin Wolf
27eb6c097c qcow2: Don't write with BDRV_O_INCOMING
qcow2_open() causes writes when repairing an image with the dirty flag
set and when clearing autoclear flags. It shouldn't do this when another
qemu instance is still actively working on this image file.

One effect of the bug is that images may have a cleared dirty flag while
the migration source host still has it in use with lazy refcounts
enabled, so refcounts are not accurate and the dirty flag must remain
set.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:42:24 +01:00
Kevin Wolf
d475e5acd2 qcow2: Keep option in qcow2_invalidate_cache()
Instead of manually building a list of all options from BDRVQcowState
values just reuse the options that were used to open the image.
qcow2_open() won't fully use all of the options in the QDict, but that's
okay.

This fixes all of the driver-specific options in qcow2, except for
lazy-refcounts, which was special cased before.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:42:24 +01:00
Stefan Hajnoczi
dc3dd0d2be qmp: add query-iothreads command
The "query-iothreads" command returns a list of information about
iothreads.  See the patch for API documentation.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:42:24 +01:00
Stefan Hajnoczi
88eb7c29e4 iothread: stash thread ID away
Keep the thread ID around so we can report it via QMP.

There's only one problem: qemu_get_thread_id() (gettid() wrapper on
Linux) must be called from the thread itself.  There is no way to get
the thread ID outside the thread.

This patch uses a condvar to wait for iothread_run() to populate the
thread_id inside the thread.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:42:24 +01:00
Stefan Hajnoczi
48ff269272 dataplane: replace internal thread with IOThread
Today virtio-blk dataplane uses a 1:1 device-per-thread model.  Now that
IOThreads have been introduced we can generalize this to N:M devices per
threads.

This patch drops thread code from dataplane in favor of running inside
an IOThread AioContext.

As a bonus we solve the case where a guest keeps submitting I/O requests
while dataplane is trying to stop.  Previously the dataplane thread
would continue to process requests until the request gave it a break.
Now we can shut down in bounded time thanks to
aio_context_acquire/release.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:42:24 +01:00
Stefan Hajnoczi
6e4a876b43 iothread: add "iothread" qdev property type
Add a "iothread" qdev property type so devices can be hooked up to an
IOThread from the comand-line:

  qemu -object iothread,id=iothread0 \
       -device some-device,x-iothread=iothread0

Note that Paolo Bonzini <pbonzini@redhat.com> has suggested using QOM
links instead.  This way the relationship between the objects is
reflected in QOM.  There are currently shortcomings of
object_property_add_link() which prevent this use case.  I will attempt
to fix them and move to QOM links in a separate series.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:42:24 +01:00
Igor Mammedov
7d1de46448 qdev: make get_pointer() handle temporary strings
get_pointer()'s print() callback might return a heap allocated
string, to avoid adding dedicated get_pointer_foo for this case
convert current print() callbacks to return temporary heap
allocated string and make get_pointer() free it.

Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:42:24 +01:00
Stefan Hajnoczi
be8d853766 iothread: add I/O thread object
This is a stand-in for Michael Roth's QContext.  I expect this to be
replaced once QContext is completed.

The IOThread object is an AioContext event loop thread.  This patch adds
the concept of multiple event loop threads, allowing users to define
them.

When SMP guests run on SMP hosts it makes sense to instantiate multiple
IOThreads.  This spreads event loop processing across multiple cores.
Note that additional patches are required to actually bind a device to
an IOThread.

[Andreas Färber <afaerber@suse.de> pointed out that the embedded parent
object instance should be called "parent_obj" and have a newline
afterwards.  This patch has been changed to reflect this.
-- Stefan]

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:42:24 +01:00
Stefan Hajnoczi
98563fc3ec aio: add aio_context_acquire() and aio_context_release()
It can be useful to run an AioContext from a thread which normally does
not "own" the AioContext.  For example, request draining can be
implemented by acquiring the AioContext and looping aio_poll() until all
requests have been completed.

The following pattern should work:

  /* Event loop thread */
  while (running) {
      aio_context_acquire(ctx);
      aio_poll(ctx, true);
      aio_context_release(ctx);
  }

  /* Another thread */
  aio_context_acquire(ctx);
  bdrv_read(bs, 0x1000, buf, 1);
  aio_context_release(ctx);

This patch implements aio_context_acquire() and aio_context_release().

Note that existing aio_poll() callers do not need to worry about
acquiring and releasing - it is only needed when multiple threads will
call aio_poll() on the same AioContext.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:42:24 +01:00
Stefan Hajnoczi
2da61b671e rfifolock: add recursive FIFO lock
QemuMutex does not guarantee fairness and cannot be acquired
recursively:

Fairness means each locker gets a turn and the scheduler cannot cause
starvation.

Recursive locking is useful for composition, it allows a sequence of
locking operations to be invoked atomically by acquiring the lock around
them.

This patch adds RFifoLock, a recursive lock that guarantees FIFO order.
Its first user is added in the next patch.

RFifoLock has one additional feature: it can be initialized with an
optional contention callback.  The callback is invoked whenever a thread
must wait for the lock.  For example, it can be used to poke the current
owner so that they release the lock soon.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:42:21 +01:00
Stefan Hajnoczi
11f590b1a2 object: add object_get_canonical_path_component()
It is often useful to find an object's child property name.  Also use
this new function to simplify the implementation of
object_get_canonical_path().

Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:23:27 +01:00
Benoît Canet
b5042a3622 block: Rewrite the snapshot authorization mechanism for block filters.
This patch keep the recursive way of doing things but simplify it by giving
two responsabilities to all block filters implementors.

They will need to do two things:

-Set the is_filter field of their block driver to true.

-Implement the bdrv_recurse_is_first_non_filter method of their block driver like
it is done on the Quorum block driver. (block/quorum.c)

[Paolo Bonzini <pbonzini@redhat.com> pointed out that this patch changes
the semantics of blkverify, which now recurses down both bs->file and
s->test_file.
-- Stefan]

Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:23:27 +01:00
Max Reitz
98d39e34fe iotests: Test corruption during COW request
Extend test file 060 by a test case for corruption occuring concurrently
to a COW request. QEMU should not crash but rather return an appropriate
error message.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:23:27 +01:00
Max Reitz
938789ea92 block: bs->drv may be NULL in bdrv_debug_resume()
Currently, bdrv_debug_resume() requires every bs->drv in the BDS stack
to be NULL until a bs->drv with an implementation of bdrv_debug_resume()
is found. For a normal function, this would be fine, but this is a
function for debugging purposes and should therefore allow intermediate
BDS not to have a driver (i.e., be "ejected"). Otherwise, it is hard to
debug such situations.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:23:27 +01:00