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  1. 08 4月, 2015 1 次提交
  3. 04 4月, 2015 1 次提交
  5. 02 4月, 2015 2 次提交
  7. 01 4月, 2015 2 次提交
    • P
      rcu: do not create thread in pthread_atfork callback · a59629fc
      由 Paolo Bonzini 提交于 
      If QEMU forks after the CPU threads have been created, qemu_mutex_lock_iothread
will not be able to do qemu_cpu_kick_thread.  There is no solution other than
assuming that forks after the CPU threads have been created will end up in an
exec.  Forks before the CPU threads have been created (such as -daemonize)
have to call rcu_after_fork manually.

Notably, the oxygen theme for GTK+ forks and shows a "No such process" error
without this patch.

This patch can be reverted once the iothread loses the "kick the TCG thread"
magic.

User-mode emulation does not use the iothread, so it can also call
rcu_after_fork.

Reported by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Tested by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      a59629fc
    • L
      qom: Add can_be_deleted callback to UserCreatableClass · d6edb155
      由 Lin Ma 提交于 
      If backends implement the can_be_deleted and it returns false,
Then the qmp_object_del won't delete the given backends.
Signed-off-by: NLin Ma <lma@suse.com>
Message-Id: <1427704589-7688-2-git-send-email-lma@suse.com>
Reviewed-by: NIgor Mammedov <imammedo@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      d6edb155
  9. 26 3月, 2015 1 次提交
  11. 20 3月, 2015 1 次提交
  13. 19 3月, 2015 3 次提交
    • A
      virtio: serial: expose a 'guest_writable' callback for users · 4add73aa
      由 Amit Shah 提交于 
      Users of virtio-serial may want to know when a port becomes writable.  A
port can stop accepting writes if the guest port is open but not being
read from.  In this case, data gets queued up in the virtqueue, and
after the vq is full, writes to the port do not succeed.

When the guest reads off a vq element, and adds a new one for the host
to put data in, we can tell users the port is available for more writes,
via the new ->guest_writable() callback.
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
      4add73aa
    • S
      elf-loader: Add missing error handling for call of lseek · 23bf2e76
      由 Stefan Weil 提交于 
      This fixes a warning from Coverity.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>
      23bf2e76
    • S
      Fix remaining warnings from Sparse (void return) · e7ae771f
      由 Stefan Weil 提交于 
      Sparse report:

hw/display/vga.c:2000:5: warning: returning void-valued expression
hw/intc/arm_gic.c:707:9: warning: returning void-valued expression
hw/intc/etraxfs_pic.c:138:9: warning: returning void-valued expression
hw/nvram/fw_cfg.c:475:5: warning: returning void-valued expression
hw/timer/a9gtimer.c:124:5: warning: returning void-valued expression
hw/tpm/tpm_tis.c:794:5: warning: returning void-valued expression
hw/usb/hcd-musb.c:558:9: warning: returning void-valued expression
hw/usb/hcd-musb.c:776:13: warning: returning void-valued expression
hw/usb/hcd-musb.c:867:5: warning: returning void-valued expression
hw/usb/hcd-musb.c:932:5: warning: returning void-valued expression
include/qom/cpu.h:584:5: warning: returning void-valued expression
monitor.c:4686:13: warning: returning void-valued expression
monitor.c:4690:13: warning: returning void-valued expression

Cc: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Andreas Färber <afaerber@suse.de>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>
      e7ae771f
  15. 18 3月, 2015 6 次提交
  17. 17 3月, 2015 4 次提交
  19. 16 3月, 2015 3 次提交
  21. 14 3月, 2015 1 次提交
    • R
      tcg: Change translator-side labels to a pointer · 42a268c2
      由 Richard Henderson 提交于 
      This is improved type checking for the translators -- it's no longer
possible to accidentally swap arguments to the branch functions.

Note that the code generating backends still manipulate labels as int.

With notable exceptions, the scope of the change is just a few lines
for each target, so it's not worth building extra machinery to do this
change in per-target increments.

Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Cc: Michael Walle <michael@walle.cc>
Cc: Leon Alrae <leon.alrae@imgtec.com>
Cc: Anthony Green <green@moxielogic.com>
Cc: Jia Liu <proljc@gmail.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Blue Swirl <blauwirbel@gmail.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: NBastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: NRichard Henderson <rth@twiddle.net>
      42a268c2
  23. 13 3月, 2015 1 次提交
    • P
      queue: fix QSLIST_INSERT_HEAD_ATOMIC race · 2120465f
      由 Paolo Bonzini 提交于 
      There is a not-so-subtle race in QSLIST_INSERT_HEAD_ATOMIC.

Because atomic_cmpxchg returns the old value instead of a success flag,
QSLIST_INSERT_HEAD_ATOMIC was checking for success by comparing against
the second argument to atomic_cmpxchg.  Unfortunately, this only works
if the second argument is a local or thread-local variable.

If it is in memory, it can be subject to common subexpression elimination
(and then everything's fine) or reloaded after the atomic_cmpxchg,
depending on the compiler's whims.  If the latter happens, the race can
happen.  A thread can sneak in, doing something on elm->field.sle_next
after the atomic_cmpxchg and before the comparison.  This causes a wrong
failure, and then two threads are using "elm" at the same time.  In the
case discovered by Christian, the sequence was likely something like this:

    thread 1                   | thread 2
    QSLIST_INSERT_HEAD_ATOMIC  |
      atomic_cmpxchg succeeds  |
      elm added to list        |
                               | steal release_pool
                               | QSLIST_REMOVE_HEAD
                               | elm removed from list
                               | ...
                               | QSLIST_INSERT_HEAD_ATOMIC
                               |   (overwrites sle_next)
      spurious failure         |
      atomic_cmpxchg succeeds  |
      elm added to list again  |
                               |
    steal release_pool         |
    QSLIST_REMOVE_HEAD         |
    elm removed again          |

The last three steps could be done by a third thread as well.
A reproducer that failed in a matter of seconds is as follows:

- the guest has 32 VCPUs on a 28 core host (hyperthreading was enabled),
  memory was 16G just to err on the safe side (the host has 64G, but hey
  at least you need no s390)

- the guest has 24 null-aio virtio-blk devices using dataplane
  (-object iothread,id=ioN -drive if=none,id=blkN,driver=null-aio,size=500G
  -device virtio-blk-pci,iothread=ioN,drive=blkN)

- the guest also has a single network interface.  It's only doing loopback
  tests so slirp vs. tap and the model doesn't matter.

- the guest is running fio with the following script:

     [global]
     rw=randread
     blocksize=16k
     ioengine=libaio
     runtime=10m
     buffered=0
     fallocate=none
     time_based
     iodepth=32

     [virtio1a]
     filename=/dev/block/252\:16

     [virtio1b]
     filename=/dev/block/252\:16

     ...

     [virtio24a]
     filename=/dev/block/252\:384

     [virtio24b]
     filename=/dev/block/252\:384

     [listen1]
     protocol=tcp
     ioengine=net
     port=12345
     listen
     rw=read
     bs=4k
     size=1000g

     [connect1]
     protocol=tcp
     hostname=localhost
     ioengine=net
     port=12345
     protocol=tcp
     rw=write
     startdelay=1
     size=1000g

     ...

     [listen8]
     protocol=tcp
     ioengine=net
     port=12352
     listen
     rw=read
     bs=4k
     size=1000g

     [connect8]
     protocol=tcp
     hostname=localhost
     ioengine=net
     port=12352
     rw=write
     startdelay=1
     size=1000g

Moral of the story: I should refrain from writing more clever stuff.
At least it looks like it is not too clever to be undebuggable.
Reported-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Tested-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-id: 1426002357-6889-1-git-send-email-pbonzini@redhat.com
Fixes: c740ad92Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
      2120465f
  25. 12 3月, 2015 14 次提交