diff options
| author | Peter Maydell | 2016-10-24 16:03:09 +0200 |
|---|---|---|
| committer | Peter Maydell | 2016-10-24 16:03:09 +0200 |
| commit | a3ae21ec3fe036f536dc94cad735931777143103 (patch) | |
| tree | b8110b4ad3a2a21f68f9273acfb704c2c49ceb19 /util/qemu-thread-posix.c | |
| parent | Merge remote-tracking branch 'remotes/sstabellini/tags/xen-20161021-tag' into... (diff) | |
| parent | exec.c: workaround regression caused by alignment change in d2f39ad (diff) | |
| download | qemu-a3ae21ec3fe036f536dc94cad735931777143103.tar.gz qemu-a3ae21ec3fe036f536dc94cad735931777143103.tar.xz qemu-a3ae21ec3fe036f536dc94cad735931777143103.zip | |
Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging
* KVM run_on_cpu fix (Alex)
* atomic usage fixes (Emilio, me)
* hugetlbfs alignment fix (Haozhong)
* CharBackend refactoring (Marc-André)
* test-i386 fixes (me)
* MemoryListener optimizations (me)
* Miscellaneous bugfixes (me)
* iSER support (Roy)
* --version formatting (Thomas)
# gpg: Signature made Mon 24 Oct 2016 14:46:19 BST
# gpg: using RSA key 0xBFFBD25F78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>"
# gpg: aka "Paolo Bonzini <pbonzini@redhat.com>"
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4 E2F7 7E15 100C CD36 69B1
# Subkey fingerprint: F133 3857 4B66 2389 866C 7682 BFFB D25F 78C7 AE83
* remotes/bonzini/tags/for-upstream: (50 commits)
exec.c: workaround regression caused by alignment change in d2f39ad
char: remove explicit_be_open from CharDriverState
char: use common error path in qmp_chardev_add
char: replace avail_connections
char: remove unused qemu_chr_fe_event
char: use an enum for CHR_EVENT
char: remove unused CHR_EVENT_FOCUS
char: move fe_open in CharBackend
char: remove explicit_fe_open, use a set_handlers argument
char: rename chr_close/chr_free
char: move front end handlers in CharBackend
tests: start chardev unit tests
char: make some qemu_chr_fe skip if no driver
char: replace qemu_chr_claim/release with qemu_chr_fe_init/deinit
vhost-user: only initialize queue 0 CharBackend
char: fold qemu_chr_set_handlers in qemu_chr_fe_set_handlers
char: use qemu_chr_fe* functions with CharBackend argument
colo: claim in find_and_check_chardev
char: rename some frontend functions
char: remaining switch to CharBackend in frontend
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'util/qemu-thread-posix.c')
| -rw-r--r-- | util/qemu-thread-posix.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c index 74a3023f3e..ce51b37c1d 100644 --- a/util/qemu-thread-posix.c +++ b/util/qemu-thread-posix.c @@ -360,7 +360,11 @@ void qemu_event_destroy(QemuEvent *ev) void qemu_event_set(QemuEvent *ev) { - if (atomic_mb_read(&ev->value) != EV_SET) { + /* qemu_event_set has release semantics, but because it *loads* + * ev->value we need a full memory barrier here. + */ + smp_mb(); + if (atomic_read(&ev->value) != EV_SET) { if (atomic_xchg(&ev->value, EV_SET) == EV_BUSY) { /* There were waiters, wake them up. */ futex_wake(ev, INT_MAX); @@ -370,7 +374,11 @@ void qemu_event_set(QemuEvent *ev) void qemu_event_reset(QemuEvent *ev) { - if (atomic_mb_read(&ev->value) == EV_SET) { + unsigned value; + + value = atomic_read(&ev->value); + smp_mb_acquire(); + if (value == EV_SET) { /* * If there was a concurrent reset (or even reset+wait), * do nothing. Otherwise change EV_SET->EV_FREE. @@ -383,7 +391,8 @@ void qemu_event_wait(QemuEvent *ev) { unsigned value; - value = atomic_mb_read(&ev->value); + value = atomic_read(&ev->value); + smp_mb_acquire(); if (value != EV_SET) { if (value == EV_FREE) { /* |