Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* core support for MemoryRegionCache from myself
* rules.mak speedup and cleanups from myself and Marc-Adnré
* multiboot command line fix from Vlad
* SCSI fixes from myself
* small qemu-timer speedup from myself
* x86 debugging improvements from Doug
* configurable Q35 devices from  Chao
* x86 5-level paging support from Kirill
* x86 SHA_NI support for KVM from Yi Sun
* improved kvmclock migration logic from Marcelo
* bugfixes and doc fixes from others

# gpg: Signature made Thu 22 Dec 2016 15:01:13 GMT
# 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: (25 commits)
  x86: implement la57 paging mode
  target-i386: Fix eflags.TF/#DB handling of syscall/sysret insns
  kvmclock: reduce kvmclock difference on migration
  kvm: sync linux headers
  scsi-disk: fix VERIFY for scsi-block
  hw/block/pflash_cfi*.c: fix confusing assert fail message
  multiboot: copy the cmdline verbatim, unescape module strings
  x86: Fix x86_64 'g' packet response to gdb from 32-bit mode.
  pc: make pit configurable
  pc: make sata configurable
  pc: make smbus configurable
  target-i386: Add Intel SHA_NI instruction support.
  block: drop remaining legacy aio functions in comment
  main-loop: update comment for qemu_mutex_lock/unlock_iothread
  timer: fix misleading comment in timer.h
  qemu-timer: check active_timers outside lock/event
  virtio-scsi: introduce virtio_scsi_acquire/release
  build-sys: remove libtool left-over
  rules.mak: add more rules to avoid chaining
  rules.mak: speedup save-vars load-vars
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 16 insertions, 4 deletions

diff --git a/qemu-timer.c b/qemu-timer.c
index 9299cdc..ff620ec 100644
--- a/qemu-timer.c
+++ b/qemu-timer.c
@@ -174,7 +174,7 @@ void qemu_clock_enable(QEMUClockType type, bool enabled)
 
 bool timerlist_has_timers(QEMUTimerList *timer_list)
 {
-    return !!timer_list->active_timers;
+    return !!atomic_read(&timer_list->active_timers);
 }
 
 bool qemu_clock_has_timers(QEMUClockType type)
@@ -187,6 +187,10 @@ bool timerlist_expired(QEMUTimerList *timer_list)
 {
     int64_t expire_time;
 
+    if (!atomic_read(&timer_list->active_timers)) {
+        return false;
+    }
+
     qemu_mutex_lock(&timer_list->active_timers_lock);
     if (!timer_list->active_timers) {
         qemu_mutex_unlock(&timer_list->active_timers_lock);
@@ -214,6 +218,10 @@ int64_t timerlist_deadline_ns(QEMUTimerList *timer_list)
     int64_t delta;
     int64_t expire_time;
 
+    if (!atomic_read(&timer_list->active_timers)) {
+        return -1;
+    }
+
     if (!timer_list->clock->enabled) {
         return -1;
     }
@@ -363,7 +371,7 @@ static void timer_del_locked(QEMUTimerList *timer_list, QEMUTimer *ts)
         if (!t)
             break;
         if (t == ts) {
-            *pt = t->next;
+            atomic_set(pt, t->next);
             break;
         }
         pt = &t->next;
@@ -386,7 +394,7 @@ static bool timer_mod_ns_locked(QEMUTimerList *timer_list,
     }
     ts->expire_time = MAX(expire_time, 0);
     ts->next = *pt;
-    *pt = ts;
+    atomic_set(pt, ts);
 
     return pt == &timer_list->active_timers;
 }
@@ -481,8 +489,12 @@ bool timerlist_run_timers(QEMUTimerList *timer_list)
     QEMUTimerCB *cb;
     void *opaque;
 
+    if (!atomic_read(&timer_list->active_timers)) {
+        return false;
+    }
+
     qemu_event_reset(&timer_list->timers_done_ev);
-    if (!timer_list->clock->enabled || !timer_list->active_timers) {
+    if (!timer_list->clock->enabled) {
         goto out;
     }