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  1. 18 2月, 2015 1 次提交
  3. 10 2月, 2015 8 次提交
  5. 02 2月, 2015 3 次提交
    • P
      rcu: add call_rcu · 26387f86
      由 Paolo Bonzini 提交于 
      Asynchronous callbacks provided by call_rcu are particularly important
for QEMU, because the BQL makes it hard to use synchronize_rcu.

In addition, the current RCU implementation is not particularly friendly
to multiple concurrent synchronize_rcu callers, making call_rcu even
more important.
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      26387f86
    • P
      rcu: add rcu library · 7911747b
      由 Paolo Bonzini 提交于 
      This includes a (mangled) copy of the liburcu code.  The main changes
are: 1) removing dependencies on many other header files in liburcu; 2)
removing for simplicity the tentative busy waiting in synchronize_rcu,
which has limited performance effects; 3) replacing futexes in
synchronize_rcu with QemuEvents for Win32 portability.  The API is
the same as liburcu, so it should be possible in the future to require
liburcu on POSIX systems for example and use our copy only on Windows.

Among the various versions available I chose urcu-mb, which is the
least invasive implementation even though it does not have the
fastest rcu_read_{lock,unlock} implementation.  The urcu flavor can
be changed later, after benchmarking.
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      7911747b
    • P
      qemu-thread: fix qemu_event without futexes · 158ef8cb
      由 Paolo Bonzini 提交于 
      This had a possible deadlock that was visible with rcutorture.

    qemu_event_set                    qemu_event_wait
    ----------------------------------------------------------------
                                      cmpxchg reads FREE, writes BUSY
                                      futex_wait: pthread_mutex_lock
                                      futex_wait: value == BUSY
    xchg reads BUSY, writes SET
    futex_wake: pthread_cond_broadcast
                                      futex_wait: pthread_cond_wait
                                      <deadlock>

The fix is simply to avoid condvar tricks and do the obvious locking
around pthread_cond_broadcast:

    qemu_event_set        qemu_event_wait
    ----------------------------------------------------------------
                                      cmpxchg reads FREE, writes BUSY
                                      futex_wait: pthread_mutex_lock
                                      futex_wait: value == BUSY
    xchg reads BUSY, writes SET
    futex_wake: pthread_mutex_lock
    (blocks)
                                      futex_wait: pthread_cond_wait
    (mutex unlocked)
    futex_wake: pthread_cond_broadcast
    futex_wake: pthread_mutex_unlock
                                      futex_wait: pthread_mutex_unlock

Cc: qemu-stable@nongnu.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      158ef8cb
  7. 13 1月, 2015 1 次提交
    • P
      qemu-thread: add per-thread atexit functions · ef57137f
      由 Paolo Bonzini 提交于 
      Destructors are the main additional feature of pthread TLS compared
to __thread.  If we were using C++ (hint, hint!) we could have used
thread-local objects with a destructor.  Since we are not, instead,
we add a simple Notifier-based API.

Note that the notifier must be per-thread as well.  We can add a
global list as well later, perhaps.

The Win32 implementation has some complications because a) detached
threads used not to have a QemuThreadData; b) the main thread does
not go through win32_start_routine, so we have to use atexit too.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Message-id: 1417518350-6167-3-git-send-email-pbonzini@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
      ef57137f
  9. 13 12月, 2014 1 次提交
  11. 10 12月, 2014 4 次提交
  13. 23 11月, 2014 1 次提交
  15. 17 11月, 2014 1 次提交
  17. 02 11月, 2014 1 次提交
  19. 09 10月, 2014 2 次提交
  21. 03 10月, 2014 1 次提交
    • M
      util: Emancipate id_wellformed() from QemuOpts · f5bebbbb
      由 Markus Armbruster 提交于 
      IDs have long spread beyond QemuOpts: not everything with an ID
necessarily goes through QemuOpts.  Commit 9aebf3b8 is about such a
case: block layer names are meant to be well-formed IDs, but some of
them don't go through QemuOpts, and thus weren't checked.  The commit
fixed that the straightforward way: rename the internal QemuOpts
helper id_wellformed() to qemu_opts_id_wellformed() and give it
external linkage.

Instead of using it directly in block.c, the commit adds wrapper
bdrv_is_valid_name(), probably to hide the connection to QemuOpts.

Go one logical step further: emancipate IDs from QemuOpts.  Rename the
function back to id_wellformed(), and put it in another file.  While
there, clean up its value to bool.  Peel off the bdrv_is_valid_name()
wrapper.

[Replaced stray return 0 with return false to match bool returns used
elsewhere in id_wellformed().
--Stefan]
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
      f5bebbbb
  23. 27 9月, 2014 1 次提交
  25. 25 9月, 2014 1 次提交
    • K
      block: Validate node-name · 9aebf3b8
      由 Kevin Wolf 提交于 
      The device_name of a BlockDriverState is currently checked because it is
always used as a QemuOpts ID and qemu_opts_create() checks whether such
IDs are wellformed.

node-name is supposed to share the same namespace, but it isn't checked
currently. This patch adds explicit checks both for device_name and
node-name so that the same rules will still apply even if QemuOpts won't
be used any more at some point.

qemu-img used to use names with spaces in them, which isn't allowed any
more. Replace them with underscores.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
      9aebf3b8
  27. 17 9月, 2014 1 次提交
    • P
      util/qemu-sockets.c: Support specifying IPv4 or IPv6 in socket_dgram() · 8287fea3
      由 Peter Maydell 提交于 
      Currently you can specify whether you want a UDP chardev backend
to be IPv4 or IPv6 using the ipv4 or ipv6 options if you use the
QemuOpts parsing code in inet_dgram_opts(). However the QMP struct
parsing code in socket_dgram() doesn't provide this flexibility
(which in turn prevents us from converting the UDP backend handling
to the new style QAPI framework).

Use the existing inet_addr_to_opts() function to convert the
remote->inet address to option strings; this handles ipv4 and
ipv6 flags as well as host and port. (It will also convert any
'to' specification, which is harmless as it is ignored in this
context.)
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 1409653457-27863-3-git-send-email-peter.maydell@linaro.org
      8287fea3
  29. 09 9月, 2014 2 次提交
  31. 24 8月, 2014 1 次提交
  33. 15 8月, 2014 2 次提交
  35. 18 7月, 2014 2 次提交
  37. 14 7月, 2014 1 次提交
    • K
      dma-helpers: Fix too long qiov · 58f423fb
      由 Kevin Wolf 提交于 
      If the size of the scatter/gather list isn't a multiple of 512, the
number of sectors for the block layer request is rounded down, resulting
in a qiov that doesn't match the request length. Truncate the qiov to the
new length of the request.

This fixes the IDE qtest case /x86_64/ide/bmdma/short_prdt.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
      58f423fb
  39. 10 7月, 2014 1 次提交
  41. 26 6月, 2014 1 次提交
    • M
      qemu_opts_append: Play nicely with QemuOptsList's head · a7607150
      由 Michal Privoznik 提交于 
      When running a libvirt test suite I've noticed the qemu-img is
crashing occasionally. Tracing the problem down led me to the
following valgrind output:

qemu.git $ valgrind -q ./qemu-img create -f qed -obacking_file=/dev/null,backing_fmt=raw qed
==14881== Invalid write of size 8
==14881==    at 0x1D263F: qemu_opts_create (qemu-option.c:692)
==14881==    by 0x130782: bdrv_img_create (block.c:5531)
==14881==    by 0x118DE0: img_create (qemu-img.c:462)
==14881==    by 0x11E7E4: main (qemu-img.c:2830)
==14881==  Address 0x11fedd38 is 24 bytes inside a block of size 232 free'd
==14881==    at 0x4C2CA5E: realloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==14881==    by 0x592D35E: g_realloc (in /usr/lib64/libglib-2.0.so.0.3800.2)
==14881==    by 0x1D38D8: qemu_opts_append (qemu-option.c:1129)
==14881==    by 0x13075E: bdrv_img_create (block.c:5528)
==14881==    by 0x118DE0: img_create (qemu-img.c:462)
==14881==    by 0x11E7E4: main (qemu-img.c:2830)
==14881==
Formatting 'qed', fmt=qed size=0 backing_file='/dev/null' backing_fmt='raw' cluster_size=65536
==14881== Invalid write of size 8
==14881==    at 0x1D28BE: qemu_opts_del (qemu-option.c:750)
==14881==    by 0x130BF3: bdrv_img_create (block.c:5638)
==14881==    by 0x118DE0: img_create (qemu-img.c:462)
==14881==    by 0x11E7E4: main (qemu-img.c:2830)
==14881==  Address 0x11fedd38 is 24 bytes inside a block of size 232 free'd
==14881==    at 0x4C2CA5E: realloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==14881==    by 0x592D35E: g_realloc (in /usr/lib64/libglib-2.0.so.0.3800.2)
==14881==    by 0x1D38D8: qemu_opts_append (qemu-option.c:1129)
==14881==    by 0x13075E: bdrv_img_create (block.c:5528)
==14881==    by 0x118DE0: img_create (qemu-img.c:462)
==14881==    by 0x11E7E4: main (qemu-img.c:2830)
==14881==

The problem is apparently in the qemu_opts_append(). Well, if it
gets called twice or more. On the first call, when @dst is NULL
some initialization is done during which @dst->head list gets
initialized. The list is initialized in a way, so that the list
tail points at the list head. However, the next time
qemu_opts_append() is called for new options to be added,
g_realloc() may move @dst to a new address making the old list tail
point at an invalid address. If that's the case, we must update the
list pointers.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      a7607150
  43. 23 6月, 2014 3 次提交