Commit Graph

20036 Commits

Author SHA1 Message Date
Anthony Liguori
caa3d6d37b Merge remote-tracking branch 'spice/spice.v55' into staging
* spice/spice.v55:
  qxl: set size of PCI IO BAR correctly (16) for revision 2
2012-05-14 10:07:06 -05:00
Anthony Liguori
82ac96a72b Merge remote-tracking branch 'sweil/for-1.1' into staging
* sweil/for-1.1:
  qemu-doc: Use QEMU instead of qemu for product name
  qemu-doc: Fix executable name in examples
  qemu-doc: Add missing parameter in description of -D option
  configure: Use QEMU instead of Qemu
  fix some common typos
  qemu-timer: Fix wrong error message
2012-05-14 10:06:50 -05:00
Paolo Bonzini
90ca64a970 qdev: fix -device foo,?
Since most property types do not have a parse property now, this was
broken.  Fix it by looking at the setter instead.

Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Acked-by: Andreas F=E4rber <afaerber@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-14 10:06:21 -05:00
Anthony Liguori
77f4c9a68a Merge remote-tracking branch 'origin/master' into staging
* origin/master:
  sun4u: implement interrupt clearing registers
  sun4u: initialize OBIO interrupt mappings
  fix block loads broken in commit 30038fd818
  Implement address masking for SPARC v9 CPUs
  vga: disable default VGA if appropriate -device is used
  cputlb: fix watchpoints handling
2012-05-14 08:44:32 -05:00
Uri Lublin
3f6297b922 qxl: set size of PCI IO BAR correctly (16) for revision 2
Also move it up into switch(qxl->revision) block

Signed-off-by: Uri Lublin <uril@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2012-05-14 10:22:18 +02:00
Stefan Weil
b65ee4fa29 qemu-doc: Use QEMU instead of qemu for product name
When 'qemu' was used as a product name or as a generic process name,
it is now replaced by the official upper case 'QEMU'.

v2:
Added missing period (hint from Andreas Färber).

Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
2012-05-14 07:27:24 +02:00
Stefan Weil
3804da9dbe qemu-doc: Fix executable name in examples
The executable name qemu was replaced some time ago by qemu-system-i386.
Fix all examples accordingly.

Some examples will only work with qemu-system-i386 or qemu-system-x86_64
for obvious reasons ("dos.img").

To keep things simple, I did not vary the executable name.
Place holders like qemu-system-TARGET were also only used once
in the enhanced description for QEMU launches using Wine.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
2012-05-14 07:27:24 +02:00
Stefan Weil
8bd383b41a qemu-doc: Add missing parameter in description of -D option
'logfile' is a place holder for a non optional parameter.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
2012-05-14 07:27:24 +02:00
Stefan Weil
2ae4748f4c configure: Use QEMU instead of Qemu
This new 'Qemu' was recently added.
Replace it by the official all upper case 'QEMU'.

Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
2012-05-14 07:27:24 +02:00
Jim Meyering
a31f053129 fix some common typos
These were identified using: http://github.com/lyda/misspell-check
and run like this to create a bourne shell script using GNU sed's
-i option:

git ls-files|grep -vF .bin | misspellings -f - |grep -v '^ERROR:' |perl \
-pe 's/^(.*?)\[(\d+)\]: (\w+) -> "(.*?)"$/sed -i '\''${2}s!$3!$4!'\'' $1/'

Manually eliding the FP, "rela->real" and resolving "addres" to
address (not "adders") we get this:

  sed -i '450s!thru!through!' Changelog
  sed -i '260s!neccessary!necessary!' coroutine-sigaltstack.c
  sed -i '54s!miniscule!minuscule!' disas.c
  sed -i '1094s!thru!through!' hw/usb/hcd-ehci.c
  sed -i '1095s!thru!through!' hw/usb/hcd-ehci.c
  sed -i '21s!unecessary!unnecessary!' qapi-schema-guest.json
  sed -i '307s!explictly!explicitly!' qemu-ga.c
  sed -i '490s!preceeding!preceding!' qga/commands-posix.c
  sed -i '792s!addres!address!' qga/commands-posix.c
  sed -i '6s!beeing!being!' tests/tcg/test-mmap.c

Also, manually fix "arithmentic", spotted by Peter Maydell:

  sed -i 's!arithmentic!arithmetic!' coroutine-sigaltstack.c

Signed-off-by: Jim Meyering <meyering@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
2012-05-14 07:27:24 +02:00
Stefan Weil
52ef651f56 qemu-timer: Fix wrong error message
Function timeSetEvent returns 0 when it fails, but it does not set
an error code which can be retrieved by GetLastError.

Therefore calling GetLastError is useless.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
2012-05-14 07:27:24 +02:00
Artyom Tarasenko
94d1991445 sun4u: implement interrupt clearing registers
Implement registers for clearing OBIO and PCI interrupts

Signed-off-by: Artyom Tarasenko <atar4qemu@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-05-12 09:49:19 +00:00
Artyom Tarasenko
d1d80055ba sun4u: initialize OBIO interrupt mappings
Similarly to PCI interrupt mappings, the OBIO ones have to be initialized.

Signed-off-by: Artyom Tarasenko <atar4qemu@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-05-12 09:49:17 +00:00
Artyom Tarasenko
00b2ace509 fix block loads broken in commit 30038fd818
Fix UltraSPARC/JPS1/UA2007 VIS block load instructions broken in
30038fd818.

Signed-off-by: Artyom Tarasenko <atar4qemu@gmail.com>
[blauwirbel@gmail.com: trimmed unwanted part of patch]
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-05-12 09:48:05 +00:00
Artyom Tarasenko
22036a49dd Implement address masking for SPARC v9 CPUs
According to UltraSPARC - IIi User's manual:

14.1.11 Address Masking (Impdep #125)
When PSTATE.AM=1, the CALL, JMPL, and RDPC instructions and all traps
transmit zero in the high-order 32-bits of the PC to their specified
destination registers.

Signed-off-by: Artyom Tarasenko <atar4qemu@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-05-12 09:46:00 +00:00
Paolo Bonzini
7f1b17f297 vga: disable default VGA if appropriate -device is used
This is a partial revert of commits a369da5 (vga: improve VGA logic,
committed 2012-01-22) and c5bd4f3 (vga: fix -nodefaults -device VGA,
2012-01-24) which broke command-line option parsing in different ways.

Since commit a369da5 it has become impossible to specify a VGA device
entirely with QemuOpts-enabled options, i.e. without needing an explicit
"-vga none".

In addition, until commit c5bd4f3 -nodefaults would not disable the device
you specified with the legacy "-vga" option, independent of the order.
Since commit c5bd4f3 QEMU -nodefaults will override a previous -vga
option.

I did not reintroduce machine->no_vga.  Boards can simply ignore the
vga_interface_type variable, and most will indeed do so.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-05-12 09:15:25 +00:00
Max Filippov
56eb21e158 cputlb: fix watchpoints handling
Cleanup commit e554861766 have changed
code_address calculation in the tlb_set_page function in case of access
to a page with a watchpoint. This caused QEMU segfault in the xtensa
test_break unit test. Fix it by moving code_address assignment above
memory_region_section_get_iotlb call.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-05-12 09:14:38 +00:00
Amos Kong
d5c5dacc70 use inet_listen()/inet_connect() to support ipv6 migration
Use help functions in qemu-socket.c for tcp migration,
which already support ipv6 addresses.

Currently errp will be set to UNDEFINED_ERROR when migration fails,
qemu would output "migration failed: ...", and current user can
see a message("An undefined error has occurred") in monitor.

This patch changed tcp_start_outgoing_migration()/inet_connect()
/inet_connect_opts(), socket error would be passed back,
then current user can see a meaningful err message in monitor.

Qemu will exit if listening fails, so output socket error
to qemu stderr.

For IPv6 brackets must be mandatory if you require a port.
Referencing to RFC5952, the recommended format is:
  [2312::8274]:5200

test status: Successed
listen side: qemu-kvm .... -incoming tcp:[2312::8274]:5200
client side: qemu-kvm ...
             (qemu) migrate -d tcp:[2312::8274]:5200

Signed-off-by: Amos Kong <akong@redhat.com>
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-10 12:37:57 -05:00
Amos Kong
029409e5a9 sockets: use error class to pass listen error
Add a new argument in inet_listen()/inet_listen_opts()
to pass back listen error.

Change nbd, qemu-char, vnc to use new interface.

Signed-off-by: Amos Kong <akong@redhat.com>
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-10 12:37:57 -05:00
Amos Kong
a6ba35b3be sockets: change inet_connect() to support nonblock socket
Add a bool argument to inet_connect() to assign if set socket
to block/nonblock, and delete original argument 'socktype'
that is unused.
Add a new argument to inet_connect()/inet_connect_opts(),
to pass back connect error by error class.

Retry to connect when -EINTR is got. Connect's successful
for nonblock socket when following errors are got, user
should wait for connecting by select():
  -EINPROGRESS
  -EWOULDBLOCK (win32)
  -WSAEALREADY (win32)

Change nbd, vnc to use new interface.

Signed-off-by: Amos Kong <akong@redhat.com>
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-10 12:37:57 -05:00
Amos Kong
aed3d11df6 qerror: add five qerror strings
Add five new qerror strings, they are about listen/connect socket:
  QERR_SOCKET_CONNECT_IN_PROGRESS
  QERR_SOCKET_CONNECT_FAILED
  QERR_SOCKET_LISTEN_FAILED
  QERR_SOCKET_BIND_FAILED
  QERR_SOCKET_CREATE_FAILED

Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Amos Kong <akong@redhat.com>
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-10 12:37:57 -05:00
Eduardo Habkost
e2d87bff12 move CPU definitions to /usr/share/qemu/cpus-x86_64.conf (v2)
Changes v1 -> v2:
 - userconfig variable is now bool, not int

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-10 12:37:57 -05:00
Eduardo Habkost
f29a56147b implement -no-user-config command-line option (v3)
Changes v2 -> v3:
 - Rebase against latest qemu.git

Changes v1 -> v2:
 - Change 'userconfig' field/variables to bool instead of int
 - Coding style change

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-10 12:37:57 -05:00
Eduardo Habkost
3ed2d9ee1f vl.c: change 'defconfig' variable to bool (v2)
Changes v1 -> v2:
 - Actually change the variable type declaration to 'bool'

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-10 12:37:56 -05:00
Eduardo Habkost
756557de64 move list of default config files to an array
More files will be added to the list, with additional attributes, later.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-10 12:37:56 -05:00
Eduardo Habkost
c8262a4767 eliminate arch_config_name variable
Not needed anymore, as the code that uses the variable is already inside
arch_init.c.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-10 12:37:55 -05:00
Eduardo Habkost
b5a8fe5e8a move code to read default config files to a separate function (v2)
Function added to arch_init.c because it depends on arch-specific
settings.

Changes v1 -> v2:
 - Move qemu_read_default_config_file() prototype to qemu-config.h

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-10 12:37:55 -05:00
Anthony Liguori
04120e3bb0 block: fix warning introduced in efcc7a23
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-10 09:10:42 -05:00
Jan Kiszka
a7aae221b0 Switch SIG_IPI to SIGUSR1
Use SIGUSR1 unconditionally as SIG_IPI. First, ucontext coroutines tend
to corrupt RT signal masks due to a 32-on-64-bit Linux kernel bug. And,
second, there appears to be no advantage in using RT signals for VCPU
kicking.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-10 08:33:34 -05:00
Anthony Liguori
2e1201d09b Merge remote-tracking branch 'pmaydell/target-arm.for-upstream' into staging
* pmaydell/target-arm.for-upstream:
  target-arm/cpu.h: Make cpu_init("nonexistent cpu") return NULL
  target-arm: When setting FPSCR.QC, don't clear other FPSCR bits
2012-05-10 08:30:55 -05:00
Anthony Liguori
b3d6ca770d Merge remote-tracking branch 'kwolf/for-anthony' into staging
* kwolf/for-anthony: (30 commits)
  declare ECANCELED on all machines
  tests/Makefile: Add missing $(EXESUF)
  stream: do not copy unallocated sectors from the base
  stream: fix ratelimiting corner case
  stream: fix HMP block_job_set_speed
  stream: pass new base image format to bdrv_change_backing_file
  stream: add testcase for partial streaming
  stream: fix sectors not allocated test
  qemu-io: fix the alloc command
  qemu-io: correctly print non-integer values as decimals
  qemu-img: make "info" backing file output correct and easier to use
  block: move field reset from bdrv_open_common to bdrv_close
  block: protect path_has_protocol from filenames with colons
  block: simplify path_is_absolute
  block: wait for job callback in block_job_cancel_sync
  block: add block_job_sleep_ns
  block: fully delete bs->file when closing
  block: do not reuse the backing file across bdrv_close/bdrv_open
  block: another bdrv_append fix
  block: fix snapshot on QED
  ...
2012-05-10 08:30:34 -05:00
Anthony Liguori
b3def7f5ff Merge remote-tracking branch 'qemu-kvm/uq/master' into staging
* qemu-kvm/uq/master:
  kvm: Fix dirty tracking with large kernel page size
2012-05-10 08:08:31 -05:00
Peter Maydell
ad37ad5b25 target-arm/cpu.h: Make cpu_init("nonexistent cpu") return NULL
The macro definition of cpu_init meant that if cpu_arm_init()
returned NULL this wouldn't result in cpu_init() itself returning
NULL. This had the effect that "-cpu foo" for some unknown CPU
name 'foo' would cause ARM targets to segfault rather than
generating a useful error message. Fix this by making cpu_init
a simple inline function.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Andreas Färber <afaerber@suse.de>
2012-05-10 12:56:09 +00:00
Matt Craighead
7e598de023 target-arm: When setting FPSCR.QC, don't clear other FPSCR bits
This patch fixes a bug affecting a variety of Neon instructions, such as
VQADD.

Signed-off-by: Matt Craighead <mjcraighead@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2012-05-10 12:56:08 +00:00
David Gibson
3145fcb605 kvm: Fix dirty tracking with large kernel page size
If the kernel page size is larger than TARGET_PAGE_SIZE, which
happens for example on ppc64 with kernels compiled for 64K pages,
the dirty tracking doesn't work.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-05-10 12:40:08 +03:00
Paolo Bonzini
2084a8e330 declare ECANCELED on all machines
This is needed in particular on Win32.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 11:01:59 +02:00
Kevin Wolf
6c806637fa tests/Makefile: Add missing $(EXESUF)
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 11:01:59 +02:00
Paolo Bonzini
efcc7a2324 stream: do not copy unallocated sectors from the base
Unallocated sectors should really never be accessed by the guest,
so there's no need to copy them during the streaming process.
If they are read by the guest during streaming, guest-initiated
copy-on-read will copy them (we're in the base == NULL case, which
enables copy on read).  If they are read after we disconnect the
image from the base, they will read as zeroes anyway.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 11:01:59 +02:00
Paolo Bonzini
b21d677ee9 stream: fix ratelimiting corner case
This fixes inability to make progress in streaming if the quota is set
to less than the amount of data that an I/O operation has to write.

In this case, limit->dispatched + n will always be above the quota and,
due to the "goto retry" to recheck cancellation and allocation, streaming
will livelock.

This can be reproduced with "block_job_set_speed ide0-hd0 1b".  Of course,
with this patch the requested limit will not be obeyed.  That could be
done with another patch that caps is_allocated's n argument by the slice
quota.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 11:01:59 +02:00
Paolo Bonzini
c6db23958b stream: fix HMP block_job_set_speed
The change of the argument name from value to speed was not propagated there.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 11:01:59 +02:00
Paolo Bonzini
f6133def92 stream: pass new base image format to bdrv_change_backing_file
When an image is modified to point to the new backing file, the backing
file format is set to NULL, which means auto-probe.  This is wrong, in
fact it is a small security problem.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 11:01:59 +02:00
Paolo Bonzini
6e34360973 stream: add testcase for partial streaming
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 11:01:58 +02:00
Paolo Bonzini
863a5d042f stream: fix sectors not allocated test
The test on sectors not allocated can fail if the L1/L2 tables are
not on disk yet.  Allow tests to shutdown the VM early.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:13 +02:00
Paolo Bonzini
cc785c349d qemu-io: fix the alloc command
Because sector_num is not updated, the loop would either go on
forever or return garbage.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:13 +02:00
Paolo Bonzini
8655d2de0a qemu-io: correctly print non-integer values as decimals
qemu-io's cvtstr function sometimes will incorrectly omit the
decimal part of the number, and sometimes will incorrectly include
it.  This patch fixes both.  The former is more serious, and can
be seen in the patches to 027.out and 033.out.

The changes to all other files were scripted with sed, so there were
no "surprises" beyond 027.out and 033.out.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:12 +02:00
Paolo Bonzini
dc5a137125 qemu-img: make "info" backing file output correct and easier to use
qemu-img info should use the same logic as qemu when printing the
backing file path, or debugging becomes quite tricky.  We can also
simplify the output in case the backing file has an absolute path
or a protocol.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:12 +02:00
Paolo Bonzini
6405875cdd block: move field reset from bdrv_open_common to bdrv_close
bdrv_close should leave fields in the same state as bdrv_new.  It is
not up to bdrv_open_common to fix the mess.

Also, backing_format was not being re-initialized.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:12 +02:00
Paolo Bonzini
947995c09e block: protect path_has_protocol from filenames with colons
path_has_protocol will erroneously return "true" if the colon is part
of a filename.  These names are common with stable device names produced
by udev.  We cannot fully protect against this in case the filename
does not have a path component (e.g. if the current directory is
/dev/disk/by-path), but in the common case there will be a slash before
and path_has_protocol can easily detect that and return false.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:12 +02:00
Paolo Bonzini
f53f4da9c6 block: simplify path_is_absolute
On Windows, all the logic is already in is_windows_drive and
is_windows_drive_prefix.  On POSIX, there is no need to look
out for colons.

The win32 code changes the behaviour in some cases, we could have
something like "d:foo.img". The old code would treat it as relative
path, the new one as absolute. Now the path is absolute, because to
go from c:/program files/blah to d:foo.img you cannot say c:/program
files/blah/d:foo.img.  You have to say d:foo.img.  But you could also
say it's relative because (I think, at least it was like that in DOS
15 years ago) d:foo.img is relative to the current path of drive D.
Considering how path_is_absolute is used by path_combine, I think it's
better to treat it as absolute.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:12 +02:00
Paolo Bonzini
fa4478d5c8 block: wait for job callback in block_job_cancel_sync
The limitation on not having I/O after cancellation cannot really be
kept.  Even streaming has a very small race window where you could
cancel a job and have it report completion.  If this window is hit,
bdrv_change_backing_file() will yield and possibly cause accesses to
dangling pointers etc.

So, let's just assume that we cannot know exactly what will happen
after the coroutine has set busy to false.  We can set a very lax
condition:

- if we cancel the job, the coroutine won't set it to false again
(and hence will not call co_sleep_ns again).

- block_job_cancel_sync will wait for the coroutine to exit, which
pretty much ensures no race.

Instead, we track the coroutine that executes the job and put very
strict conditions on what to do while it is quiescent (busy = false).
First of all, the coroutine must never set busy = false while the job
has been cancelled.  Second, the coroutine can be reentered arbitrarily
while it is quiescent, so you cannot really do anything but co_sleep_ns at
that time.  This condition is obeyed by the block_job_sleep_ns function.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:12 +02:00