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* [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements
@ 2016-10-10 13:59 Paolo Bonzini
  2016-10-10 13:59 ` [Qemu-devel] [PATCH 1/5] atomic: introduce smp_mb_acquire and smp_mb_release Paolo Bonzini
                   ` (9 more replies)
  0 siblings, 10 replies; 26+ messages in thread
From: Paolo Bonzini @ 2016-10-10 13:59 UTC (permalink / raw)
  To: qemu-devel; +Cc: cota, alex.bennee

See each patch.  My attempt at fixing whatever I did when I obviously
didn't know enough^W about the C11 memory model, and at setting a
better example for future generations...

Paolo Bonzini (5):
  atomic: introduce smp_mb_acquire and smp_mb_release
  cpus: use atomic_read to read seqlock-protected variables
  qemu-thread: use acquire/release to clarify semantics of QemuEvent
  rcu: simplify memory barriers
  atomic: base mb_read/mb_set on load-acquire and store-release

 cpus.c                   |   9 +--
 docs/atomics.txt         |  84 ++++++++++++++++------------
 include/qemu/atomic.h    | 139 ++++++++++++++++++++---------------------------
 util/qemu-thread-posix.c |  15 ++++-
 util/qemu-thread-win32.c |  15 ++++-
 util/rcu.c               |  11 ++--
 6 files changed, 143 insertions(+), 130 deletions(-)

-- 
2.7.4

^ permalink raw reply	[flat|nested] 26+ messages in thread

* [Qemu-devel] [PATCH 1/5] atomic: introduce smp_mb_acquire and smp_mb_release
  2016-10-10 13:59 [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements Paolo Bonzini
@ 2016-10-10 13:59 ` Paolo Bonzini
  2016-10-10 15:29   ` Eric Blake
  2016-10-10 13:59 ` [Qemu-devel] [PATCH 2/5] cpus: use atomic_read to read seqlock-protected variables Paolo Bonzini
                   ` (8 subsequent siblings)
  9 siblings, 1 reply; 26+ messages in thread
From: Paolo Bonzini @ 2016-10-10 13:59 UTC (permalink / raw)
  To: qemu-devel; +Cc: cota, alex.bennee

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 docs/atomics.txt      | 79 ++++++++++++++++++++++++++++++---------------------
 include/qemu/atomic.h | 50 +++++++++++++++++++-------------
 2 files changed, 77 insertions(+), 52 deletions(-)

diff --git a/docs/atomics.txt b/docs/atomics.txt
index c95950b..5cd8e32 100644
--- a/docs/atomics.txt
+++ b/docs/atomics.txt
@@ -15,7 +15,8 @@ Macros defined by qemu/atomic.h fall in three camps:
 - compiler barriers: barrier();
 
 - weak atomic access and manual memory barriers: atomic_read(),
-  atomic_set(), smp_rmb(), smp_wmb(), smp_mb(), smp_read_barrier_depends();
+  atomic_set(), smp_rmb(), smp_wmb(), smp_mb(), smp_mb_acquire(),
+  smp_mb_release(), smp_read_barrier_depends();
 
 - sequentially consistent atomic access: everything else.
 
@@ -111,8 +112,8 @@ consistent primitives.
 
 When using this model, variables are accessed with atomic_read() and
 atomic_set(), and restrictions to the ordering of accesses is enforced
-using the smp_rmb(), smp_wmb(), smp_mb() and smp_read_barrier_depends()
-memory barriers.
+using the memory barrier macros: smp_rmb(), smp_wmb(), smp_mb(),
+smp_mb_acquire(), smp_mb_release(), smp_read_barrier_depends().
 
 atomic_read() and atomic_set() prevents the compiler from using
 optimizations that might otherwise optimize accesses out of existence
@@ -124,7 +125,7 @@ other threads, and which are local to the current thread or protected
 by other, more mundane means.
 
 Memory barriers control the order of references to shared memory.
-They come in four kinds:
+They come in six kinds:
 
 - smp_rmb() guarantees that all the LOAD operations specified before
   the barrier will appear to happen before all the LOAD operations
@@ -142,6 +143,16 @@ They come in four kinds:
   In other words, smp_wmb() puts a partial ordering on stores, but is not
   required to have any effect on loads.
 
+- smp_mb_acquire() guarantees that all the LOAD operations specified before
+  the barrier will appear to happen before all the LOAD or STORE operations
+  specified after the barrier with respect to the other components of
+  the system.
+
+- smp_mb_release() guarantees that all the STORE operations specified *after*
+  the barrier will appear to happen before all the LOAD or STORE operations
+  specified *before* the barrier with respect to the other components of
+  the system.
+
 - smp_mb() guarantees that all the LOAD and STORE operations specified
   before the barrier will appear to happen before all the LOAD and
   STORE operations specified after the barrier with respect to the other
@@ -149,8 +160,9 @@ They come in four kinds:
 
   smp_mb() puts a partial ordering on both loads and stores.  It is
   stronger than both a read and a write memory barrier; it implies both
-  smp_rmb() and smp_wmb(), but it also prevents STOREs coming before the
-  barrier from overtaking LOADs coming after the barrier and vice versa.
+  smp_mb_acquire() and smp_mb_release(), but it also prevents STOREs
+  coming before the barrier from overtaking LOADs coming after the
+  barrier and vice versa.
 
 - smp_read_barrier_depends() is a weaker kind of read barrier.  On
   most processors, whenever two loads are performed such that the
@@ -173,24 +185,21 @@ They come in four kinds:
 This is the set of barriers that is required *between* two atomic_read()
 and atomic_set() operations to achieve sequential consistency:
 
-                    |               2nd operation             |
-                    |-----------------------------------------|
-     1st operation  | (after last) | atomic_read | atomic_set |
-     ---------------+--------------+-------------+------------|
-     (before first) |              | none        | smp_wmb()  |
-     ---------------+--------------+-------------+------------|
-     atomic_read    | smp_rmb()    | smp_rmb()*  | **         |
-     ---------------+--------------+-------------+------------|
-     atomic_set     | none         | smp_mb()*** | smp_wmb()  |
-     ---------------+--------------+-------------+------------|
+                    |               2nd operation                   |
+                    |-----------------------------------------------|
+     1st operation  | (after last)   | atomic_read | atomic_set     |
+     ---------------+----------------+-------------+----------------|
+     (before first) |                | none        | smp_mb_release |
+     ---------------+----------------+-------------+----------------|
+     atomic_read    | smp_mb_acquire | smp_rmb     | **             |
+     ---------------+----------------+-------------+----------------|
+     atomic_set     | none           | smp_mb()*** | smp_wmb()      |
+     ---------------+----------------+-------------+----------------|
 
        * Or smp_read_barrier_depends().
 
-      ** This requires a load-store barrier.  How to achieve this varies
-         depending on the machine, but in practice smp_rmb()+smp_wmb()
-         should have the desired effect.  For example, on PowerPC the
-         lwsync instruction is a combined load-load, load-store and
-         store-store barrier.
+      ** This requires a load-store barrier.  This is achieved by
+         either smp_mb_acquire() or smp_mb_release().
 
      *** This requires a store-load barrier.  On most machines, the only
          way to achieve this is a full barrier.
@@ -199,11 +208,11 @@ and atomic_set() operations to achieve sequential consistency:
 You can see that the two possible definitions of atomic_mb_read()
 and atomic_mb_set() are the following:
 
-    1) atomic_mb_read(p)   = atomic_read(p); smp_rmb()
-       atomic_mb_set(p, v) = smp_wmb(); atomic_set(p, v); smp_mb()
+    1) atomic_mb_read(p)   = atomic_read(p); smp_mb_acquire()
+       atomic_mb_set(p, v) = smp_mb_release(); atomic_set(p, v); smp_mb()
 
-    2) atomic_mb_read(p)   = smp_mb() atomic_read(p); smp_rmb()
-       atomic_mb_set(p, v) = smp_wmb(); atomic_set(p, v);
+    2) atomic_mb_read(p)   = smp_mb() atomic_read(p); smp_mb_acquire()
+       atomic_mb_set(p, v) = smp_mb_release(); atomic_set(p, v);
 
 Usually the former is used, because smp_mb() is expensive and a program
 normally has more reads than writes.  Therefore it makes more sense to
@@ -222,7 +231,7 @@ place barriers instead:
      thread 1                                thread 1
      -------------------------               ------------------------
      (other writes)
-                                             smp_wmb()
+                                             smp_mb_release()
      atomic_mb_set(&a, x)                    atomic_set(&a, x)
                                              smp_wmb()
      atomic_mb_set(&b, y)                    atomic_set(&b, y)
@@ -233,7 +242,13 @@ place barriers instead:
      y = atomic_mb_read(&b)                  y = atomic_read(&b)
                                              smp_rmb()
      x = atomic_mb_read(&a)                  x = atomic_read(&a)
-                                             smp_rmb()
+                                             smp_mb_acquire()
+
+  Note that the barrier between the stores in thread 1, and between
+  the loads in thread 2, has been optimized here to a write or a
+  read memory barrier respectively.  On some architectures, notably
+  ARMv7, smp_mb_acquire and smp_mb_release are just as expensive as
+  smp_mb, but smp_rmb and/or smp_wmb are more efficient.
 
 - sometimes, a thread is accessing many variables that are otherwise
   unrelated to each other (for example because, apart from the current
@@ -246,12 +261,12 @@ place barriers instead:
      n = 0;                                  n = 0;
      for (i = 0; i < 10; i++)          =>    for (i = 0; i < 10; i++)
        n += atomic_mb_read(&a[i]);             n += atomic_read(&a[i]);
-                                             smp_rmb();
+                                             smp_mb_acquire();
 
   Similarly, atomic_mb_set() can be transformed as follows:
   smp_mb():
 
-                                             smp_wmb();
+                                             smp_mb_release();
      for (i = 0; i < 10; i++)          =>    for (i = 0; i < 10; i++)
        atomic_mb_set(&a[i], false);            atomic_set(&a[i], false);
                                              smp_mb();
@@ -261,7 +276,7 @@ The two tricks can be combined.  In this case, splitting a loop in
 two lets you hoist the barriers out of the loops _and_ eliminate the
 expensive smp_mb():
 
-                                             smp_wmb();
+                                             smp_mb_release();
      for (i = 0; i < 10; i++) {        =>    for (i = 0; i < 10; i++)
        atomic_mb_set(&a[i], false);            atomic_set(&a[i], false);
        atomic_mb_set(&b[i], false);          smb_wmb();
@@ -312,8 +327,8 @@ access and for data dependency barriers:
                              smp_read_barrier_depends();
                              z = b[y];
 
-smp_wmb() also pairs with atomic_mb_read(), and smp_rmb() also pairs
-with atomic_mb_set().
+smp_wmb() also pairs with atomic_mb_read() and smp_mb_acquire().
+and smp_rmb() also pairs with atomic_mb_set() and smp_mb_release().
 
 
 COMPARISON WITH LINUX KERNEL MEMORY BARRIERS
diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h
index c4f6950..b108df0 100644
--- a/include/qemu/atomic.h
+++ b/include/qemu/atomic.h
@@ -72,16 +72,16 @@
  * Add one here, and similarly in smp_rmb() and smp_read_barrier_depends().
  */
 
-#define smp_mb()    ({ barrier(); __atomic_thread_fence(__ATOMIC_SEQ_CST); })
-#define smp_wmb()   ({ barrier(); __atomic_thread_fence(__ATOMIC_RELEASE); })
-#define smp_rmb()   ({ barrier(); __atomic_thread_fence(__ATOMIC_ACQUIRE); })
+#define smp_mb()                     ({ barrier(); __atomic_thread_fence(__ATOMIC_SEQ_CST); })
+#define smp_mb_release()             ({ barrier(); __atomic_thread_fence(__ATOMIC_RELEASE); })
+#define smp_mb_acquire()             ({ barrier(); __atomic_thread_fence(__ATOMIC_ACQUIRE); })
 
 /* Most compilers currently treat consume and acquire the same, but really
  * no processors except Alpha need a barrier here.  Leave it in if
  * using Thread Sanitizer to avoid warnings, otherwise optimize it away.
  */
 #if defined(__SANITIZE_THREAD__)
-#define smp_read_barrier_depends() ({ barrier(); __atomic_thread_fence(__ATOMIC_CONSUME); })
+#define smp_read_barrier_depends()   ({ barrier(); __atomic_thread_fence(__ATOMIC_CONSUME); })
 #elif defined(__alpha__)
 #define smp_read_barrier_depends()   asm volatile("mb":::"memory")
 #else
@@ -149,13 +149,13 @@
     QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *));   \
     typeof_strip_qual(*ptr) _val;                       \
      __atomic_load(ptr, &_val, __ATOMIC_RELAXED);       \
-     smp_rmb();                                         \
+     smp_mb_acquire();                                  \
     _val;                                               \
     })
 
 #define atomic_mb_set(ptr, i)  do {                     \
     QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *));   \
-    smp_wmb();                                          \
+    smp_mb_release();                                   \
     __atomic_store_n(ptr, i, __ATOMIC_RELAXED);         \
     smp_mb();                                           \
 } while(0)
@@ -238,8 +238,8 @@
  * here (a compiler barrier only).  QEMU doesn't do accesses to write-combining
  * qemu memory or non-temporal load/stores from C code.
  */
-#define smp_wmb()   barrier()
-#define smp_rmb()   barrier()
+#define smp_mb_release()   barrier()
+#define smp_mb_acquire()   barrier()
 
 /*
  * __sync_lock_test_and_set() is documented to be an acquire barrier only,
@@ -263,13 +263,15 @@
  * smp_mb has the same problem as on x86 for not-very-new GCC
  * (http://patchwork.ozlabs.org/patch/126184/, Nov 2011).
  */
-#define smp_wmb()   ({ asm volatile("eieio" ::: "memory"); (void)0; })
+#define smp_wmb()          ({ asm volatile("eieio" ::: "memory"); (void)0; })
 #if defined(__powerpc64__)
-#define smp_rmb()   ({ asm volatile("lwsync" ::: "memory"); (void)0; })
+#define smp_mb_release()   ({ asm volatile("lwsync" ::: "memory"); (void)0; })
+#define smp_mb_acquire()   ({ asm volatile("lwsync" ::: "memory"); (void)0; })
 #else
-#define smp_rmb()   ({ asm volatile("sync" ::: "memory"); (void)0; })
+#define smp_mb_release()   ({ asm volatile("sync" ::: "memory"); (void)0; })
+#define smp_mb_acquire()   ({ asm volatile("sync" ::: "memory"); (void)0; })
 #endif
-#define smp_mb()    ({ asm volatile("sync" ::: "memory"); (void)0; })
+#define smp_mb()           ({ asm volatile("sync" ::: "memory"); (void)0; })
 
 #endif /* _ARCH_PPC */
 
@@ -277,18 +279,18 @@
  * For (host) platforms we don't have explicit barrier definitions
  * for, we use the gcc __sync_synchronize() primitive to generate a
  * full barrier.  This should be safe on all platforms, though it may
- * be overkill for smp_wmb() and smp_rmb().
+ * be overkill for smp_mb_acquire() and smp_mb_release().
  */
 #ifndef smp_mb
-#define smp_mb()    __sync_synchronize()
+#define smp_mb()           __sync_synchronize()
 #endif
 
-#ifndef smp_wmb
-#define smp_wmb()   __sync_synchronize()
+#ifndef smp_mb_acquire
+#define smp_mb_acquire()   __sync_synchronize()
 #endif
 
-#ifndef smp_rmb
-#define smp_rmb()   __sync_synchronize()
+#ifndef smp_mb_release
+#define smp_mb_release()   __sync_synchronize()
 #endif
 
 #ifndef smp_read_barrier_depends
@@ -365,13 +367,13 @@
  */
 #define atomic_mb_read(ptr)    ({           \
     typeof(*ptr) _val = atomic_read(ptr);   \
-    smp_rmb();                              \
+    smp_mb_acquire();                       \
     _val;                                   \
 })
 
 #ifndef atomic_mb_set
 #define atomic_mb_set(ptr, i)  do {         \
-    smp_wmb();                              \
+    smp_mb_release();                       \
     atomic_set(ptr, i);                     \
     smp_mb();                               \
 } while (0)
@@ -404,4 +406,12 @@
 #define atomic_or(ptr, n)      ((void) __sync_fetch_and_or(ptr, n))
 
 #endif /* __ATOMIC_RELAXED */
+
+#ifndef smp_wmb
+#define smp_wmb()   smp_mb_release()
+#endif
+#ifndef smp_rmb
+#define smp_rmb()   smp_mb_acquire()
+#endif
+
 #endif /* QEMU_ATOMIC_H */
-- 
2.7.4

^ permalink raw reply related	[flat|nested] 26+ messages in thread

* [Qemu-devel] [PATCH 2/5] cpus: use atomic_read to read seqlock-protected variables
  2016-10-10 13:59 [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements Paolo Bonzini
  2016-10-10 13:59 ` [Qemu-devel] [PATCH 1/5] atomic: introduce smp_mb_acquire and smp_mb_release Paolo Bonzini
@ 2016-10-10 13:59 ` Paolo Bonzini
  2016-10-12  8:44   ` Alex Bennée
  2016-10-13 19:20   ` Emilio G. Cota
  2016-10-10 13:59 ` [Qemu-devel] [PATCH 3/5] qemu-thread: use acquire/release to clarify semantics of QemuEvent Paolo Bonzini
                   ` (7 subsequent siblings)
  9 siblings, 2 replies; 26+ messages in thread
From: Paolo Bonzini @ 2016-10-10 13:59 UTC (permalink / raw)
  To: qemu-devel; +Cc: cota, alex.bennee

There is a data race if the variable is written concurrently to the
read.  In C11 this has undefined behavior.  Use atomic_read.  The
write side does not need atomic_set, because it is protected by a
mutex.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 cpus.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/cpus.c b/cpus.c
index b2fbe33..3fc2f6e 100644
--- a/cpus.c
+++ b/cpus.c
@@ -170,7 +170,8 @@ int64_t cpu_get_icount_raw(void)
 static int64_t cpu_get_icount_locked(void)
 {
     int64_t icount = cpu_get_icount_raw();
-    return timers_state.qemu_icount_bias + cpu_icount_to_ns(icount);
+    int64_t ns = cpu_icount_to_ns(icount);
+    return atomic_read(&timers_state.qemu_icount_bias) + ns;
 }
 
 int64_t cpu_get_icount(void)
@@ -206,7 +207,7 @@ int64_t cpu_get_ticks(void)
     }
 
     ticks = timers_state.cpu_ticks_offset;
-    if (timers_state.cpu_ticks_enabled) {
+    if (atomic_read(&timers_state.cpu_ticks_enabled)) {
         ticks += cpu_get_host_ticks();
     }
 
@@ -225,8 +226,8 @@ static int64_t cpu_get_clock_locked(void)
 {
     int64_t time;
 
-    time = timers_state.cpu_clock_offset;
-    if (timers_state.cpu_ticks_enabled) {
+    time = atomic_read(&timers_state.cpu_clock_offset);
+    if (atomic_read(&timers_state.cpu_ticks_enabled)) {
         time += get_clock();
     }
 
-- 
2.7.4

^ permalink raw reply related	[flat|nested] 26+ messages in thread

* [Qemu-devel] [PATCH 3/5] qemu-thread: use acquire/release to clarify semantics of QemuEvent
  2016-10-10 13:59 [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements Paolo Bonzini
  2016-10-10 13:59 ` [Qemu-devel] [PATCH 1/5] atomic: introduce smp_mb_acquire and smp_mb_release Paolo Bonzini
  2016-10-10 13:59 ` [Qemu-devel] [PATCH 2/5] cpus: use atomic_read to read seqlock-protected variables Paolo Bonzini
@ 2016-10-10 13:59 ` Paolo Bonzini
  2016-10-12  9:21   ` Alex Bennée
  2016-10-10 13:59 ` [Qemu-devel] [PATCH 4/5] rcu: simplify memory barriers Paolo Bonzini
                   ` (6 subsequent siblings)
  9 siblings, 1 reply; 26+ messages in thread
From: Paolo Bonzini @ 2016-10-10 13:59 UTC (permalink / raw)
  To: qemu-devel; +Cc: cota, alex.bennee

Do not use the somewhat mysterious atomic_mb_read/atomic_mb_set,
instead make sure that the operations on QemuEvent are annotated
with the desired acquire and release semantics.

In particular, qemu_event_set wakes up the waiting thread, so it must
be a release from the POV of the waker (compare with qemu_mutex_unlock).
And it actually needs a full barrier, because that's the only thing that
provides something like a "load-release".

Use smp_mb_acquire until we have atomic_load_acquire and
atomic_store_release in atomic.h.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 util/qemu-thread-posix.c | 15 ++++++++++++---
 util/qemu-thread-win32.c | 15 ++++++++++++---
 2 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
index 74a3023..ce51b37 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) {
             /*
diff --git a/util/qemu-thread-win32.c b/util/qemu-thread-win32.c
index 98a5ddf..dcdc014 100644
--- a/util/qemu-thread-win32.c
+++ b/util/qemu-thread-win32.c
@@ -274,7 +274,11 @@ 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.  */
             SetEvent(ev->event);
@@ -284,7 +288,11 @@ 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 (atomic_read(&ev->value) == EV_SET) {
         /* If there was a concurrent reset (or even reset+wait),
          * do nothing.  Otherwise change EV_SET->EV_FREE.
          */
@@ -296,7 +304,8 @@ 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) {
             /* qemu_event_set is not yet going to call SetEvent, but we are
-- 
2.7.4

^ permalink raw reply related	[flat|nested] 26+ messages in thread

* [Qemu-devel] [PATCH 4/5] rcu: simplify memory barriers
  2016-10-10 13:59 [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements Paolo Bonzini
                   ` (2 preceding siblings ...)
  2016-10-10 13:59 ` [Qemu-devel] [PATCH 3/5] qemu-thread: use acquire/release to clarify semantics of QemuEvent Paolo Bonzini
@ 2016-10-10 13:59 ` Paolo Bonzini
  2016-10-10 13:59 ` [Qemu-devel] [PATCH 5/5] atomic: base mb_read/mb_set on load-acquire and store-release Paolo Bonzini
                   ` (5 subsequent siblings)
  9 siblings, 0 replies; 26+ messages in thread
From: Paolo Bonzini @ 2016-10-10 13:59 UTC (permalink / raw)
  To: qemu-devel; +Cc: cota, alex.bennee

Thanks to the acquire semantics of qemu_event_reset and qemu_event_wait,
some memory barriers can be removed.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 util/rcu.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/util/rcu.c b/util/rcu.c
index bceb3e4..9adc5e4 100644
--- a/util/rcu.c
+++ b/util/rcu.c
@@ -82,14 +82,16 @@ static void wait_for_readers(void)
         /* Instead of using atomic_mb_set for index->waiting, and
          * atomic_mb_read for index->ctr, memory barriers are placed
          * manually since writes to different threads are independent.
-         * atomic_mb_set has a smp_wmb before...
+         * qemu_event_reset has acquire semantics, so no memory barrier
+         * is needed here.
          */
-        smp_wmb();
         QLIST_FOREACH(index, &registry, node) {
             atomic_set(&index->waiting, true);
         }
 
-        /* ... and a smp_mb after.  */
+        /* Here, order the stores to index->waiting before the
+         * loads of index->ctr.
+         */
         smp_mb();
 
         QLIST_FOREACH_SAFE(index, &registry, node, tmp) {
@@ -104,9 +106,6 @@ static void wait_for_readers(void)
             }
         }
 
-        /* atomic_mb_read has smp_rmb after.  */
-        smp_rmb();
-
         if (QLIST_EMPTY(&registry)) {
             break;
         }
-- 
2.7.4

^ permalink raw reply related	[flat|nested] 26+ messages in thread

* [Qemu-devel] [PATCH 5/5] atomic: base mb_read/mb_set on load-acquire and store-release
  2016-10-10 13:59 [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements Paolo Bonzini
                   ` (3 preceding siblings ...)
  2016-10-10 13:59 ` [Qemu-devel] [PATCH 4/5] rcu: simplify memory barriers Paolo Bonzini
@ 2016-10-10 13:59 ` Paolo Bonzini
  2016-10-12  9:28   ` Alex Bennée
  2016-10-20 18:36   ` Pranith Kumar
  2016-10-10 16:53 ` [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements no-reply
                   ` (4 subsequent siblings)
  9 siblings, 2 replies; 26+ messages in thread
From: Paolo Bonzini @ 2016-10-10 13:59 UTC (permalink / raw)
  To: qemu-devel; +Cc: cota, alex.bennee

This introduces load-acquire and store-release operations in QEMU.
For now, just use them as an implementation detail of atomic_mb_read
and atomic_mb_set.

Since docs/atomics.txt documents that atomic_mb_read only synchronizes
with an atomic_mb_set of the same variable, we can use the new implementation
everywhere instead of seq-cst loads and stores.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 docs/atomics.txt      |  5 +--
 include/qemu/atomic.h | 93 +++++++++++++++++----------------------------------
 2 files changed, 34 insertions(+), 64 deletions(-)

diff --git a/docs/atomics.txt b/docs/atomics.txt
index 5cd8e32..9a1f8aa 100644
--- a/docs/atomics.txt
+++ b/docs/atomics.txt
@@ -374,8 +374,9 @@ and memory barriers, and the equivalents in QEMU:
   note that smp_store_mb() is a little weaker than atomic_mb_set().
   atomic_mb_read() compiles to the same instructions as Linux's
   smp_load_acquire(), but this should be treated as an implementation
-  detail.  If required, QEMU might later add atomic_load_acquire() and
-  atomic_store_release() macros.
+  detail.  QEMU does have atomic_load_acquire() and atomic_store_release()
+  macros, but for now they are only used within atomic.h.  This may
+  change in the future.
 
 
 SOURCES
diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h
index b108df0..d940e98 100644
--- a/include/qemu/atomic.h
+++ b/include/qemu/atomic.h
@@ -135,44 +135,18 @@
     __atomic_store_n(ptr, i, __ATOMIC_RELEASE);       \
 } while(0)
 
-/* atomic_mb_read/set semantics map Java volatile variables. They are
- * less expensive on some platforms (notably POWER & ARMv7) than fully
- * sequentially consistent operations.
- *
- * As long as they are used as paired operations they are safe to
- * use. See docs/atomic.txt for more discussion.
- */
-
-#if defined(_ARCH_PPC)
-#define atomic_mb_read(ptr)                             \
-    ({                                                  \
-    QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *));   \
-    typeof_strip_qual(*ptr) _val;                       \
-     __atomic_load(ptr, &_val, __ATOMIC_RELAXED);       \
-     smp_mb_acquire();                                  \
-    _val;                                               \
-    })
-
-#define atomic_mb_set(ptr, i)  do {                     \
-    QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *));   \
-    smp_mb_release();                                   \
-    __atomic_store_n(ptr, i, __ATOMIC_RELAXED);         \
-    smp_mb();                                           \
-} while(0)
-#else
-#define atomic_mb_read(ptr)                             \
+#define atomic_load_acquire(ptr)                        \
     ({                                                  \
     QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *));   \
     typeof_strip_qual(*ptr) _val;                       \
-    __atomic_load(ptr, &_val, __ATOMIC_SEQ_CST);        \
+    __atomic_load(ptr, &_val, __ATOMIC_ACQUIRE);        \
     _val;                                               \
     })
 
-#define atomic_mb_set(ptr, i)  do {                     \
+#define atomic_store_release(ptr, i)  do {              \
     QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *));   \
-    __atomic_store_n(ptr, i, __ATOMIC_SEQ_CST);         \
+    __atomic_store_n(ptr, i, __ATOMIC_RELEASE);         \
 } while(0)
-#endif
 
 
 /* All the remaining operations are fully sequentially consistent */
@@ -248,11 +222,6 @@
  */
 #define atomic_xchg(ptr, i)    (barrier(), __sync_lock_test_and_set(ptr, i))
 
-/*
- * Load/store with Java volatile semantics.
- */
-#define atomic_mb_set(ptr, i)  ((void)atomic_xchg(ptr, i))
-
 #elif defined(_ARCH_PPC)
 
 /*
@@ -343,41 +312,16 @@
     atomic_set(ptr, i);                           \
 } while (0)
 
-/* These have the same semantics as Java volatile variables.
- * See http://gee.cs.oswego.edu/dl/jmm/cookbook.html:
- * "1. Issue a StoreStore barrier (wmb) before each volatile store."
- *  2. Issue a StoreLoad barrier after each volatile store.
- *     Note that you could instead issue one before each volatile load, but
- *     this would be slower for typical programs using volatiles in which
- *     reads greatly outnumber writes. Alternatively, if available, you
- *     can implement volatile store as an atomic instruction (for example
- *     XCHG on x86) and omit the barrier. This may be more efficient if
- *     atomic instructions are cheaper than StoreLoad barriers.
- *  3. Issue LoadLoad and LoadStore barriers after each volatile load."
- *
- * If you prefer to think in terms of "pairing" of memory barriers,
- * an atomic_mb_read pairs with an atomic_mb_set.
- *
- * And for the few ia64 lovers that exist, an atomic_mb_read is a ld.acq,
- * while an atomic_mb_set is a st.rel followed by a memory barrier.
- *
- * These are a bit weaker than __atomic_load/store with __ATOMIC_SEQ_CST
- * (see docs/atomics.txt), and I'm not sure that __ATOMIC_ACQ_REL is enough.
- * Just always use the barriers manually by the rules above.
- */
-#define atomic_mb_read(ptr)    ({           \
+#define atomic_load_acquire(ptr)    ({      \
     typeof(*ptr) _val = atomic_read(ptr);   \
     smp_mb_acquire();                       \
     _val;                                   \
 })
 
-#ifndef atomic_mb_set
-#define atomic_mb_set(ptr, i)  do {         \
+#define atomic_store_release(ptr, i)  do {  \
     smp_mb_release();                       \
     atomic_set(ptr, i);                     \
-    smp_mb();                               \
 } while (0)
-#endif
 
 #ifndef atomic_xchg
 #if defined(__clang__)
@@ -414,4 +358,29 @@
 #define smp_rmb()   smp_mb_acquire()
 #endif
 
+/* atomic_mb_read/set semantics map Java volatile variables. They are
+ * less expensive on some platforms (notably POWER) than fully
+ * sequentially consistent operations.
+ *
+ * As long as they are used as paired operations they are safe to
+ * use. See docs/atomic.txt for more discussion.
+ */
+
+/* This is more efficient than a store plus a fence.  */
+#if defined(__i386__) || defined(__x86_64__) || defined(__s390x__)
+#define atomic_mb_set(ptr, i)  ((void)atomic_xchg(ptr, i))
+#endif
+
+#ifndef atomic_mb_read
+#define atomic_mb_read(ptr)                             \
+    atomic_load_acquire(ptr)
+#endif
+
+#ifndef atomic_mb_set
+#define atomic_mb_set(ptr, i)  do {                     \
+    atomic_store_release(ptr, i);                       \
+    smp_mb();                                           \
+} while(0)
+#endif
+
 #endif /* QEMU_ATOMIC_H */
-- 
2.7.4

^ permalink raw reply related	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 1/5] atomic: introduce smp_mb_acquire and smp_mb_release
  2016-10-10 13:59 ` [Qemu-devel] [PATCH 1/5] atomic: introduce smp_mb_acquire and smp_mb_release Paolo Bonzini
@ 2016-10-10 15:29   ` Eric Blake
  2016-10-10 16:38     ` Paolo Bonzini
  0 siblings, 1 reply; 26+ messages in thread
From: Eric Blake @ 2016-10-10 15:29 UTC (permalink / raw)
  To: Paolo Bonzini, qemu-devel; +Cc: cota, alex.bennee

[-- Attachment #1: Type: text/plain, Size: 1298 bytes --]

On 10/10/2016 08:59 AM, Paolo Bonzini wrote:
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  docs/atomics.txt      | 79 ++++++++++++++++++++++++++++++---------------------
>  include/qemu/atomic.h | 50 +++++++++++++++++++-------------
>  2 files changed, 77 insertions(+), 52 deletions(-)
> 

>  
> +- smp_mb_acquire() guarantees that all the LOAD operations specified before
> +  the barrier will appear to happen before all the LOAD or STORE operations
> +  specified after the barrier with respect to the other components of
> +  the system.
> +
> +- smp_mb_release() guarantees that all the STORE operations specified *after*
> +  the barrier will appear to happen before all the LOAD or STORE operations

Sounds impossible.  Should this be 'will appear to happen after all'?

> +  specified *before* the barrier with respect to the other components of
> +  the system.
> +
>  - smp_mb() guarantees that all the LOAD and STORE operations specified
>    before the barrier will appear to happen before all the LOAD and
>    STORE operations specified after the barrier with respect to the other
> @@ -149,8 +160,9 @@ They come in four kinds:


-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 604 bytes --]

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 1/5] atomic: introduce smp_mb_acquire and smp_mb_release
  2016-10-10 15:29   ` Eric Blake
@ 2016-10-10 16:38     ` Paolo Bonzini
  0 siblings, 0 replies; 26+ messages in thread
From: Paolo Bonzini @ 2016-10-10 16:38 UTC (permalink / raw)
  To: Eric Blake, qemu-devel; +Cc: cota, alex.bennee



On 10/10/2016 17:29, Eric Blake wrote:
> On 10/10/2016 08:59 AM, Paolo Bonzini wrote:
>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>> ---
>>  docs/atomics.txt      | 79 ++++++++++++++++++++++++++++++---------------------
>>  include/qemu/atomic.h | 50 +++++++++++++++++++-------------
>>  2 files changed, 77 insertions(+), 52 deletions(-)
>>
> 
>>  
>> +- smp_mb_acquire() guarantees that all the LOAD operations specified before
>> +  the barrier will appear to happen before all the LOAD or STORE operations
>> +  specified after the barrier with respect to the other components of
>> +  the system.
>> +
>> +- smp_mb_release() guarantees that all the STORE operations specified *after*
>> +  the barrier will appear to happen before all the LOAD or STORE operations
> 
> Sounds impossible.  Should this be 'will appear to happen after all'?

Yes, of course.  Damn copy and paste...

Paolo

>> +  specified *before* the barrier with respect to the other components of
>> +  the system.
>> +
>>  - smp_mb() guarantees that all the LOAD and STORE operations specified
>>    before the barrier will appear to happen before all the LOAD and
>>    STORE operations specified after the barrier with respect to the other
>> @@ -149,8 +160,9 @@ They come in four kinds:
> 
> 

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements
  2016-10-10 13:59 [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements Paolo Bonzini
                   ` (4 preceding siblings ...)
  2016-10-10 13:59 ` [Qemu-devel] [PATCH 5/5] atomic: base mb_read/mb_set on load-acquire and store-release Paolo Bonzini
@ 2016-10-10 16:53 ` no-reply
  2016-10-11 19:21 ` no-reply
                   ` (3 subsequent siblings)
  9 siblings, 0 replies; 26+ messages in thread
From: no-reply @ 2016-10-10 16:53 UTC (permalink / raw)
  To: pbonzini; +Cc: famz, qemu-devel, cota, alex.bennee

Hi,

Your series seems to have some coding style problems. See output below for
more information:

Message-id: 1476107947-31430-1-git-send-email-pbonzini@redhat.com
Subject: [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements
Type: series

=== TEST SCRIPT BEGIN ===
#!/bin/bash

BASE=base
n=1
total=$(git log --oneline $BASE.. | wc -l)
failed=0

# Useful git options
git config --local diff.renamelimit 0
git config --local diff.renames True

commits="$(git log --format=%H --reverse $BASE..)"
for c in $commits; do
    echo "Checking PATCH $n/$total: $(git show --no-patch --format=%s $c)..."
    if ! git show $c --format=email | ./scripts/checkpatch.pl --mailback -; then
        failed=1
        echo
    fi
    n=$((n+1))
done

exit $failed
=== TEST SCRIPT END ===

Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
From https://github.com/patchew-project/qemu
 - [tag update]      patchew/1475847779-7336-1-git-send-email-kwolf@redhat.com -> patchew/1475847779-7336-1-git-send-email-kwolf@redhat.com
 - [tag update]      patchew/1476099707-526-1-git-send-email-berrange@redhat.com -> patchew/1476099707-526-1-git-send-email-berrange@redhat.com
 * [new tag]         patchew/1476107947-31430-1-git-send-email-pbonzini@redhat.com -> patchew/1476107947-31430-1-git-send-email-pbonzini@redhat.com
 * [new tag]         patchew/1476113163-24578-1-git-send-email-peter.maydell@linaro.org -> patchew/1476113163-24578-1-git-send-email-peter.maydell@linaro.org
 * [new tag]         patchew/20161010152848.17902-1-rkrcmar@redhat.com -> patchew/20161010152848.17902-1-rkrcmar@redhat.com
 - [tag update]      patchew/cover.1475757437.git.berto@igalia.com -> patchew/cover.1475757437.git.berto@igalia.com
Switched to a new branch 'test'
8e1cfa9 atomic: base mb_read/mb_set on load-acquire and store-release
5cfb494 rcu: simplify memory barriers
5886ce0 qemu-thread: use acquire/release to clarify semantics of QemuEvent
7a5cb66 cpus: use atomic_read to read seqlock-protected variables
e663e45 atomic: introduce smp_mb_acquire and smp_mb_release

=== OUTPUT BEGIN ===
Checking PATCH 1/5: atomic: introduce smp_mb_acquire and smp_mb_release...
ERROR: line over 90 characters
#195: FILE: include/qemu/atomic.h:75:
+#define smp_mb()                     ({ barrier(); __atomic_thread_fence(__ATOMIC_SEQ_CST); })

ERROR: memory barrier without comment
#195: FILE: include/qemu/atomic.h:75:
+#define smp_mb()                     ({ barrier(); __atomic_thread_fence(__ATOMIC_SEQ_CST); })

ERROR: line over 90 characters
#196: FILE: include/qemu/atomic.h:76:
+#define smp_mb_release()             ({ barrier(); __atomic_thread_fence(__ATOMIC_RELEASE); })

ERROR: line over 90 characters
#197: FILE: include/qemu/atomic.h:77:
+#define smp_mb_acquire()             ({ barrier(); __atomic_thread_fence(__ATOMIC_ACQUIRE); })

ERROR: line over 90 characters
#205: FILE: include/qemu/atomic.h:84:
+#define smp_read_barrier_depends()   ({ barrier(); __atomic_thread_fence(__ATOMIC_CONSUME); })

ERROR: memory barrier without comment
#205: FILE: include/qemu/atomic.h:84:
+#define smp_read_barrier_depends()   ({ barrier(); __atomic_thread_fence(__ATOMIC_CONSUME); })

ERROR: spaces required around that ':' (ctx:OxW)
#241: FILE: include/qemu/atomic.h:266:
+#define smp_wmb()          ({ asm volatile("eieio" ::: "memory"); (void)0; })
                                                      ^

ERROR: memory barrier without comment
#241: FILE: include/qemu/atomic.h:266:
+#define smp_wmb()          ({ asm volatile("eieio" ::: "memory"); (void)0; })

ERROR: spaces required around that ':' (ctx:OxW)
#244: FILE: include/qemu/atomic.h:268:
+#define smp_mb_release()   ({ asm volatile("lwsync" ::: "memory"); (void)0; })
                                                       ^

ERROR: spaces required around that ':' (ctx:OxW)
#245: FILE: include/qemu/atomic.h:269:
+#define smp_mb_acquire()   ({ asm volatile("lwsync" ::: "memory"); (void)0; })
                                                       ^

ERROR: spaces required around that ':' (ctx:OxW)
#248: FILE: include/qemu/atomic.h:271:
+#define smp_mb_release()   ({ asm volatile("sync" ::: "memory"); (void)0; })
                                                     ^

ERROR: spaces required around that ':' (ctx:OxW)
#249: FILE: include/qemu/atomic.h:272:
+#define smp_mb_acquire()   ({ asm volatile("sync" ::: "memory"); (void)0; })
                                                     ^

ERROR: spaces required around that ':' (ctx:OxW)
#252: FILE: include/qemu/atomic.h:274:
+#define smp_mb()           ({ asm volatile("sync" ::: "memory"); (void)0; })
                                                     ^

ERROR: memory barrier without comment
#252: FILE: include/qemu/atomic.h:274:
+#define smp_mb()           ({ asm volatile("sync" ::: "memory"); (void)0; })

ERROR: memory barrier without comment
#265: FILE: include/qemu/atomic.h:285:
+#define smp_mb()           __sync_synchronize()

ERROR: memory barrier without comment
#303: FILE: include/qemu/atomic.h:411:
+#define smp_wmb()   smp_mb_release()

ERROR: memory barrier without comment
#306: FILE: include/qemu/atomic.h:414:
+#define smp_rmb()   smp_mb_acquire()

total: 17 errors, 0 warnings, 274 lines checked

Your patch has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.

Checking PATCH 2/5: cpus: use atomic_read to read seqlock-protected variables...
Checking PATCH 3/5: qemu-thread: use acquire/release to clarify semantics of QemuEvent...
Checking PATCH 4/5: rcu: simplify memory barriers...
Checking PATCH 5/5: atomic: base mb_read/mb_set on load-acquire and store-release...
WARNING: architecture specific defines should be avoided
#155: FILE: include/qemu/atomic.h:370:
+#if defined(__i386__) || defined(__x86_64__) || defined(__s390x__)

ERROR: memory barrier without comment
#167: FILE: include/qemu/atomic.h:382:
+    smp_mb();                                           \

ERROR: space required before the open parenthesis '('
#168: FILE: include/qemu/atomic.h:383:
+} while(0)

total: 2 errors, 1 warnings, 142 lines checked

Your patch has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.

=== OUTPUT END ===

Test command exited with code: 1


---
Email generated automatically by Patchew [http://patchew.org/].
Please send your feedback to patchew-devel@freelists.org

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements
  2016-10-10 13:59 [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements Paolo Bonzini
                   ` (5 preceding siblings ...)
  2016-10-10 16:53 ` [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements no-reply
@ 2016-10-11 19:21 ` no-reply
  2016-10-12 11:32 ` Alex Bennée
                   ` (2 subsequent siblings)
  9 siblings, 0 replies; 26+ messages in thread
From: no-reply @ 2016-10-11 19:21 UTC (permalink / raw)
  To: pbonzini; +Cc: famz, qemu-devel, cota, alex.bennee

Hi,

Your series failed automatic build test. Please find the testing commands and
their output below. If you have docker installed, you can probably reproduce it
locally.

Subject: [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements
Message-id: 1476107947-31430-1-git-send-email-pbonzini@redhat.com
Type: series

=== TEST SCRIPT BEGIN ===
#!/bin/bash
set -e
git submodule update --init dtc
# Let docker tests dump environment info
export SHOW_ENV=1
make J=8 docker-test-quick@centos6
make J=8 docker-test-mingw@fedora
=== TEST SCRIPT END ===

Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
Switched to a new branch 'test'
8e1cfa9 atomic: base mb_read/mb_set on load-acquire and store-release
5cfb494 rcu: simplify memory barriers
5886ce0 qemu-thread: use acquire/release to clarify semantics of QemuEvent
7a5cb66 cpus: use atomic_read to read seqlock-protected variables
e663e45 atomic: introduce smp_mb_acquire and smp_mb_release

=== OUTPUT BEGIN ===
Submodule 'dtc' (git://git.qemu-project.org/dtc.git) registered for path 'dtc'
Cloning into 'dtc'...
Submodule path 'dtc': checked out '65cc4d2748a2c2e6f27f1cf39e07a5dbabd80ebf'
  BUILD   centos6
  ARCHIVE qemu.tgz
  ARCHIVE dtc.tgz
  COPY    RUNNER
  RUN     test-quick in centos6
Packages installed:
SDL-devel-1.2.14-7.el6_7.1.x86_64
ccache-3.1.6-2.el6.x86_64
epel-release-6-8.noarch
gcc-4.4.7-17.el6.x86_64
git-1.7.1-4.el6_7.1.x86_64
glib2-devel-2.28.8-5.el6.x86_64
libfdt-devel-1.4.0-1.el6.x86_64
make-3.81-23.el6.x86_64
package g++ is not installed
pixman-devel-0.32.8-1.el6.x86_64
tar-1.23-15.el6_8.x86_64
zlib-devel-1.2.3-29.el6.x86_64

Environment variables:
PACKAGES=libfdt-devel ccache     tar git make gcc g++     zlib-devel glib2-devel SDL-devel pixman-devel     epel-release
HOSTNAME=c4cfd0d39435
TERM=xterm
MAKEFLAGS= -j8
HISTSIZE=1000
J=8
USER=root
CCACHE_DIR=/var/tmp/ccache
EXTRA_CONFIGURE_OPTS=
V=
SHOW_ENV=1
MAIL=/var/spool/mail/root
PATH=/usr/lib/ccache:/usr/lib64/ccache:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
PWD=/
LANG=en_US.UTF-8
TARGET_LIST=
HISTCONTROL=ignoredups
SHLVL=1
HOME=/root
TEST_DIR=/tmp/qemu-test
LOGNAME=root
LESSOPEN=||/usr/bin/lesspipe.sh %s
FEATURES= dtc
DEBUG=
G_BROKEN_FILENAMES=1
CCACHE_HASHDIR=
_=/usr/bin/env

Configure options:
--enable-werror --target-list=x86_64-softmmu,aarch64-softmmu --prefix=/var/tmp/qemu-build/install
No C++ compiler available; disabling C++ specific optional code
Install prefix    /var/tmp/qemu-build/install
BIOS directory    /var/tmp/qemu-build/install/share/qemu
binary directory  /var/tmp/qemu-build/install/bin
library directory /var/tmp/qemu-build/install/lib
module directory  /var/tmp/qemu-build/install/lib/qemu
libexec directory /var/tmp/qemu-build/install/libexec
include directory /var/tmp/qemu-build/install/include
config directory  /var/tmp/qemu-build/install/etc
local state directory   /var/tmp/qemu-build/install/var
Manual directory  /var/tmp/qemu-build/install/share/man
ELF interp prefix /usr/gnemul/qemu-%M
Source path       /tmp/qemu-test/src
C compiler        cc
Host C compiler   cc
C++ compiler      
Objective-C compiler cc
ARFLAGS           rv
CFLAGS            -O2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -g 
QEMU_CFLAGS       -I/usr/include/pixman-1    -pthread -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include   -fPIE -DPIE -m64 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wall -Wundef -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common -fwrapv  -Wendif-labels -Wmissing-include-dirs -Wempty-body -Wnested-externs -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wold-style-declaration -Wold-style-definition -Wtype-limits -fstack-protector-all
LDFLAGS           -Wl,--warn-common -Wl,-z,relro -Wl,-z,now -pie -m64 -g 
make              make
install           install
python            python -B
smbd              /usr/sbin/smbd
module support    no
host CPU          x86_64
host big endian   no
target list       x86_64-softmmu aarch64-softmmu
tcg debug enabled no
gprof enabled     no
sparse enabled    no
strip binaries    yes
profiler          no
static build      no
pixman            system
SDL support       yes (1.2.14)
GTK support       no 
GTK GL support    no
VTE support       no 
TLS priority      NORMAL
GNUTLS support    no
GNUTLS rnd        no
libgcrypt         no
libgcrypt kdf     no
nettle            no 
nettle kdf        no
libtasn1          no
curses support    no
virgl support     no
curl support      no
mingw32 support   no
Audio drivers     oss
Block whitelist (rw) 
Block whitelist (ro) 
VirtFS support    no
VNC support       yes
VNC SASL support  no
VNC JPEG support  no
VNC PNG support   no
xen support       no
brlapi support    no
bluez  support    no
Documentation     no
PIE               yes
vde support       no
netmap support    no
Linux AIO support no
ATTR/XATTR support yes
Install blobs     yes
KVM support       yes
RDMA support      no
TCG interpreter   no
fdt support       yes
preadv support    yes
fdatasync         yes
madvise           yes
posix_madvise     yes
libcap-ng support no
vhost-net support yes
vhost-scsi support yes
vhost-vsock support yes
Trace backends    log
spice support     no 
rbd support       no
xfsctl support    no
smartcard support no
libusb            no
usb net redir     no
OpenGL support    no
OpenGL dmabufs    no
libiscsi support  no
libnfs support    no
build guest agent yes
QGA VSS support   no
QGA w32 disk info no
QGA MSI support   no
seccomp support   no
coroutine backend ucontext
coroutine pool    yes
debug stack usage no
GlusterFS support no
Archipelago support no
gcov              gcov
gcov enabled      no
TPM support       yes
libssh2 support   no
TPM passthrough   yes
QOM debugging     yes
lzo support       no
snappy support    no
bzip2 support     no
NUMA host support no
tcmalloc support  no
jemalloc support  no
avx2 optimization no
replication support yes
  GEN     x86_64-softmmu/config-devices.mak.tmp
  GEN     aarch64-softmmu/config-devices.mak.tmp
  GEN     config-host.h
  GEN     qemu-options.def
  GEN     qmp-commands.h
  GEN     qapi-types.h
  GEN     qapi-visit.h
  GEN     qapi-event.h
  GEN     x86_64-softmmu/config-devices.mak
  GEN     aarch64-softmmu/config-devices.mak
  GEN     qmp-introspect.h
  GEN     module_block.h
  GEN     tests/test-qapi-types.h
  GEN     tests/test-qapi-visit.h
  GEN     tests/test-qmp-commands.h
  GEN     tests/test-qapi-event.h
  GEN     tests/test-qmp-introspect.h
  GEN     config-all-devices.mak
  GEN     trace/generated-events.h
  GEN     trace/generated-tracers.h
  GEN     trace/generated-tcg-tracers.h
  GEN     trace/generated-helpers-wrappers.h
  GEN     trace/generated-helpers.h
  CC      tests/qemu-iotests/socket_scm_helper.o
  GEN     qga/qapi-generated/qga-qapi-types.h
  GEN     qga/qapi-generated/qga-qapi-visit.h
  GEN     qga/qapi-generated/qga-qmp-commands.h
  GEN     qga/qapi-generated/qga-qapi-types.c
  GEN     qga/qapi-generated/qga-qapi-visit.c
  GEN     qga/qapi-generated/qga-qmp-marshal.c
  GEN     qmp-introspect.c
  GEN     qapi-types.c
  GEN     qapi-visit.c
  GEN     qapi-event.c
  CC      qapi/qapi-visit-core.o
  CC      qapi/qapi-dealloc-visitor.o
  CC      qapi/qmp-input-visitor.o
  CC      qapi/qmp-output-visitor.o
  CC      qapi/qmp-registry.o
  CC      qapi/qmp-dispatch.o
  CC      qapi/string-input-visitor.o
  CC      qapi/string-output-visitor.o
  CC      qapi/opts-visitor.o
  CC      qapi/qapi-clone-visitor.o
  CC      qapi/qmp-event.o
  CC      qapi/qapi-util.o
  CC      qobject/qnull.o
  CC      qobject/qint.o
  CC      qobject/qstring.o
  CC      qobject/qdict.o
  CC      qobject/qlist.o
  CC      qobject/qfloat.o
  CC      qobject/qbool.o
  CC      qobject/qjson.o
  CC      qobject/qobject.o
  CC      qobject/json-lexer.o
  CC      qobject/json-streamer.o
  CC      qobject/json-parser.o
  GEN     trace/generated-events.c
  CC      trace/control.o
  CC      trace/qmp.o
  CC      util/osdep.o
  CC      util/cutils.o
  CC      util/unicode.o
  CC      util/qemu-timer-common.o
  CC      util/bufferiszero.o
  CC      util/compatfd.o
  CC      util/event_notifier-posix.o
  CC      util/mmap-alloc.o
  CC      util/oslib-posix.o
  CC      util/qemu-openpty.o
  CC      util/qemu-thread-posix.o
  CC      util/memfd.o
  CC      util/envlist.o
  CC      util/path.o
  CC      util/module.o
  CC      util/bitmap.o
  CC      util/bitops.o
  CC      util/hbitmap.o
  CC      util/fifo8.o
  CC      util/acl.o
  CC      util/error.o
  CC      util/qemu-error.o
  CC      util/id.o
  CC      util/iov.o
  CC      util/qemu-config.o
  CC      util/qemu-sockets.o
  CC      util/uri.o
  CC      util/notify.o
  CC      util/qemu-option.o
  CC      util/qemu-progress.o
  CC      util/hexdump.o
  CC      util/crc32c.o
  CC      util/uuid.o
  CC      util/throttle.o
  CC      util/getauxval.o
  CC      util/readline.o
  CC      util/rfifolock.o
  CC      util/rcu.o
  CC      util/qemu-coroutine.o
  CC      util/qemu-coroutine-lock.o
  CC      util/qemu-coroutine-io.o
  CC      util/qemu-coroutine-sleep.o
  CC      util/coroutine-ucontext.o
  CC      util/buffer.o
  CC      util/timed-average.o
  CC      util/base64.o
  CC      util/log.o
  CC      util/qdist.o
  CC      util/qht.o
  CC      util/range.o
  CC      crypto/pbkdf-stub.o
  CC      stubs/arch-query-cpu-def.o
  CC      stubs/arch-query-cpu-model-expansion.o
  CC      stubs/arch-query-cpu-model-comparison.o
  CC      stubs/arch-query-cpu-model-baseline.o
  CC      stubs/bdrv-next-monitor-owned.o
  CC      stubs/blk-commit-all.o
  CC      stubs/blockdev-close-all-bdrv-states.o
  CC      stubs/clock-warp.o
  CC      stubs/cpu-get-clock.o
  CC      stubs/cpu-get-icount.o
  CC      stubs/dump.o
  CC      stubs/fdset-add-fd.o
  CC      stubs/fdset-find-fd.o
  CC      stubs/fdset-get-fd.o
  CC      stubs/fdset-remove-fd.o
  CC      stubs/gdbstub.o
  CC      stubs/get-fd.o
  CC      stubs/get-next-serial.o
  CC      stubs/get-vm-name.o
  CC      stubs/iothread-lock.o
  CC      stubs/is-daemonized.o
  CC      stubs/machine-init-done.o
  CC      stubs/migr-blocker.o
  CC      stubs/mon-is-qmp.o
  CC      stubs/mon-printf.o
  CC      stubs/monitor-init.o
  CC      stubs/notify-event.o
  CC      stubs/qtest.o
  CC      stubs/replay.o
  CC      stubs/replay-user.o
  CC      stubs/runstate-check.o
  CC      stubs/reset.o
  CC      stubs/set-fd-handler.o
  CC      stubs/slirp.o
  CC      stubs/sysbus.o
  CC      stubs/trace-control.o
  CC      stubs/uuid.o
  CC      stubs/vm-stop.o
  CC      stubs/vmstate.o
  CC      stubs/cpus.o
  CC      stubs/kvm.o
  CC      stubs/qmp_pc_dimm_device_list.o
  CC      stubs/target-monitor-defs.o
  CC      stubs/target-get-monitor-def.o
  CC      stubs/vhost.o
  CC      stubs/iohandler.o
  CC      stubs/smbios_type_38.o
  CC      stubs/ipmi.o
  CC      stubs/pc_madt_cpu_entry.o
  CC      contrib/ivshmem-client/ivshmem-client.o
  CC      contrib/ivshmem-client/main.o
  CC      contrib/ivshmem-server/ivshmem-server.o
  CC      contrib/ivshmem-server/main.o
  CC      qemu-nbd.o
  CC      async.o
  CC      thread-pool.o
  CC      block.o
  CC      blockjob.o
  CC      main-loop.o
  CC      iohandler.o
  CC      qemu-timer.o
  CC      aio-posix.o
  CC      qemu-io-cmds.o
  CC      replication.o
  CC      block/raw_bsd.o
  CC      block/qcow.o
  CC      block/vdi.o
  CC      block/vmdk.o
  CC      block/cloop.o
  CC      block/bochs.o
  CC      block/vpc.o
  CC      block/vvfat.o
  CC      block/dmg.o
  CC      block/qcow2.o
  CC      block/qcow2-refcount.o
  CC      block/qcow2-cluster.o
  CC      block/qcow2-snapshot.o
  CC      block/qcow2-cache.o
  CC      block/qed.o
  CC      block/qed-gencb.o
  CC      block/qed-l2-cache.o
  CC      block/qed-table.o
  CC      block/qed-cluster.o
  CC      block/qed-check.o
  CC      block/vhdx.o
  CC      block/vhdx-endian.o
  CC      block/vhdx-log.o
  CC      block/quorum.o
  CC      block/parallels.o
  CC      block/blkdebug.o
  CC      block/blkverify.o
  CC      block/blkreplay.o
  CC      block/block-backend.o
  CC      block/snapshot.o
  CC      block/qapi.o
  CC      block/raw-posix.o
  CC      block/null.o
  CC      block/mirror.o
  CC      block/commit.o
  CC      block/io.o
  CC      block/throttle-groups.o
  CC      block/nbd.o
  CC      block/nbd-client.o
  CC      block/sheepdog.o
  CC      block/accounting.o
  CC      block/dirty-bitmap.o
  CC      block/write-threshold.o
  CC      block/backup.o
  CC      block/replication.o
  CC      block/crypto.o
  CC      nbd/server.o
  CC      nbd/client.o
  CC      nbd/common.o
  CC      crypto/init.o
  CC      crypto/hash.o
  CC      crypto/hash-glib.o
  CC      crypto/aes.o
  CC      crypto/desrfb.o
  CC      crypto/cipher.o
  CC      crypto/tlscreds.o
  CC      crypto/tlscredsanon.o
  CC      crypto/tlscredsx509.o
  CC      crypto/tlssession.o
  CC      crypto/secret.o
  CC      crypto/random-platform.o
  CC      crypto/pbkdf.o
  CC      crypto/ivgen.o
  CC      crypto/ivgen-essiv.o
  CC      crypto/ivgen-plain.o
  CC      crypto/ivgen-plain64.o
  CC      crypto/afsplit.o
  CC      crypto/xts.o
  CC      crypto/block.o
  CC      crypto/block-qcow.o
  CC      crypto/block-luks.o
  CC      io/channel.o
  CC      io/channel-command.o
  CC      io/channel-buffer.o
  CC      io/channel-file.o
  CC      io/channel-socket.o
  CC      io/channel-tls.o
  CC      io/channel-watch.o
  CC      io/channel-websock.o
  CC      io/channel-util.o
  CC      io/task.o
  CC      qom/object.o
  CC      qom/container.o
  CC      qom/qom-qobject.o
  CC      qom/object_interfaces.o
  GEN     qemu-img-cmds.h
  CC      qemu-io.o
  CC      qemu-bridge-helper.o
  CC      blockdev.o
  CC      blockdev-nbd.o
  CC      iothread.o
  CC      qdev-monitor.o
  CC      device-hotplug.o
  CC      os-posix.o
  CC      qemu-char.o
  CC      page_cache.o
  CC      accel.o
  CC      bt-host.o
  CC      bt-vhci.o
  CC      dma-helpers.o
  CC      vl.o
  CC      tpm.o
  CC      device_tree.o
  GEN     qmp-marshal.c
  CC      qmp.o
  CC      hmp.o
  CC      tcg-runtime.o
  CC      cpus-common.o
  CC      audio/audio.o
  CC      audio/noaudio.o
  CC      audio/wavaudio.o
  CC      audio/mixeng.o
  CC      audio/sdlaudio.o
  CC      audio/ossaudio.o
  CC      audio/wavcapture.o
  CC      backends/rng.o
  CC      backends/rng-egd.o
  CC      backends/rng-random.o
  CC      backends/msmouse.o
  CC      backends/testdev.o
  CC      backends/tpm.o
  CC      backends/hostmem.o
  CC      backends/hostmem-ram.o
  CC      backends/hostmem-file.o
  CC      block/stream.o
  CC      disas/arm.o
  CC      disas/i386.o
  CC      fsdev/qemu-fsdev-dummy.o
  CC      fsdev/qemu-fsdev-opts.o
  CC      hw/acpi/core.o
  CC      hw/acpi/piix4.o
  CC      hw/acpi/pcihp.o
  CC      hw/acpi/ich9.o
  CC      hw/acpi/tco.o
  CC      hw/acpi/cpu_hotplug.o
  CC      hw/acpi/memory_hotplug.o
  CC      hw/acpi/memory_hotplug_acpi_table.o
  CC      hw/acpi/cpu.o
  CC      hw/acpi/acpi_interface.o
  CC      hw/acpi/bios-linker-loader.o
  CC      hw/acpi/aml-build.o
  CC      hw/acpi/ipmi.o
  CC      hw/audio/sb16.o
  CC      hw/audio/es1370.o
  CC      hw/audio/ac97.o
  CC      hw/audio/fmopl.o
  CC      hw/audio/adlib.o
  CC      hw/audio/gus.o
  CC      hw/audio/gusemu_hal.o
  CC      hw/audio/gusemu_mixer.o
  CC      hw/audio/cs4231a.o
  CC      hw/audio/intel-hda.o
  CC      hw/audio/hda-codec.o
  CC      hw/audio/pcspk.o
  CC      hw/audio/wm8750.o
  CC      hw/audio/pl041.o
  CC      hw/audio/lm4549.o
  CC      hw/audio/marvell_88w8618.o
  CC      hw/block/block.o
  CC      hw/block/cdrom.o
  CC      hw/block/hd-geometry.o
  CC      hw/block/fdc.o
  CC      hw/block/m25p80.o
  CC      hw/block/nand.o
  CC      hw/block/pflash_cfi01.o
  CC      hw/block/pflash_cfi02.o
  CC      hw/block/ecc.o
  CC      hw/block/onenand.o
  CC      hw/block/nvme.o
  CC      hw/bt/core.o
  CC      hw/bt/l2cap.o
  CC      hw/bt/sdp.o
  CC      hw/bt/hci.o
  CC      hw/bt/hid.o
  CC      hw/bt/hci-csr.o
  CC      hw/char/ipoctal232.o
  CC      hw/char/parallel.o
  CC      hw/char/pl011.o
  CC      hw/char/serial.o
  CC      hw/char/serial-isa.o
  CC      hw/char/serial-pci.o
  CC      hw/char/virtio-console.o
  CC      hw/char/cadence_uart.o
  CC      hw/char/debugcon.o
  CC      hw/char/imx_serial.o
  CC      hw/core/qdev.o
  CC      hw/core/qdev-properties.o
  CC      hw/core/bus.o
  CC      hw/core/fw-path-provider.o
  CC      hw/core/irq.o
  CC      hw/core/hotplug.o
  CC      hw/core/ptimer.o
  CC      hw/core/sysbus.o
  CC      hw/core/machine.o
  CC      hw/core/null-machine.o
  CC      hw/core/loader.o
  CC      hw/core/qdev-properties-system.o
  CC      hw/core/register.o
  CC      hw/core/or-irq.o
  CC      hw/core/platform-bus.o
  CC      hw/display/ads7846.o
  CC      hw/display/cirrus_vga.o
  CC      hw/display/pl110.o
  CC      hw/display/ssd0303.o
  CC      hw/display/ssd0323.o
  CC      hw/display/vga-pci.o
  CC      hw/display/vga-isa.o
  CC      hw/display/vmware_vga.o
  CC      hw/display/blizzard.o
  CC      hw/display/exynos4210_fimd.o
  CC      hw/display/framebuffer.o
  CC      hw/display/tc6393xb.o
  CC      hw/dma/pl080.o
  CC      hw/dma/pl330.o
  CC      hw/dma/i8257.o
  CC      hw/dma/xlnx-zynq-devcfg.o
  CC      hw/gpio/max7310.o
  CC      hw/gpio/pl061.o
  CC      hw/gpio/zaurus.o
  CC      hw/gpio/gpio_key.o
  CC      hw/i2c/core.o
  CC      hw/i2c/smbus.o
  CC      hw/i2c/smbus_eeprom.o
  CC      hw/i2c/i2c-ddc.o
  CC      hw/i2c/versatile_i2c.o
  CC      hw/i2c/smbus_ich9.o
  CC      hw/i2c/pm_smbus.o
  CC      hw/i2c/bitbang_i2c.o
  CC      hw/i2c/exynos4210_i2c.o
  CC      hw/i2c/imx_i2c.o
  CC      hw/i2c/aspeed_i2c.o
  CC      hw/ide/core.o
  CC      hw/ide/atapi.o
  CC      hw/ide/qdev.o
  CC      hw/ide/pci.o
  CC      hw/ide/isa.o
  CC      hw/ide/piix.o
  CC      hw/ide/microdrive.o
  CC      hw/ide/ahci.o
  CC      hw/ide/ich.o
  CC      hw/input/hid.o
  CC      hw/input/lm832x.o
  CC      hw/input/pckbd.o
  CC      hw/input/pl050.o
  CC      hw/input/ps2.o
  CC      hw/input/stellaris_input.o
  CC      hw/input/tsc2005.o
  CC      hw/input/vmmouse.o
  CC      hw/input/virtio-input.o
  CC      hw/input/virtio-input-hid.o
  CC      hw/input/virtio-input-host.o
  CC      hw/intc/i8259_common.o
  CC      hw/intc/i8259.o
  CC      hw/intc/pl190.o
  CC      hw/intc/imx_avic.o
  CC      hw/intc/realview_gic.o
  CC      hw/intc/ioapic_common.o
  CC      hw/intc/arm_gic_common.o
  CC      hw/intc/arm_gic.o
  CC      hw/intc/arm_gicv2m.o
  CC      hw/intc/arm_gicv3_common.o
  CC      hw/intc/arm_gicv3.o
  CC      hw/intc/arm_gicv3_dist.o
  CC      hw/intc/arm_gicv3_redist.o
  CC      hw/intc/arm_gicv3_its_common.o
  CC      hw/intc/intc.o
  CC      hw/ipack/ipack.o
  CC      hw/ipack/tpci200.o
  CC      hw/ipmi/ipmi.o
  CC      hw/ipmi/ipmi_bmc_sim.o
  CC      hw/ipmi/ipmi_bmc_extern.o
  CC      hw/ipmi/isa_ipmi_kcs.o
  CC      hw/ipmi/isa_ipmi_bt.o
  CC      hw/isa/isa-bus.o
  CC      hw/isa/apm.o
  CC      hw/mem/pc-dimm.o
  CC      hw/mem/nvdimm.o
  CC      hw/misc/applesmc.o
  CC      hw/misc/max111x.o
  CC      hw/misc/tmp105.o
  CC      hw/misc/debugexit.o
  CC      hw/misc/sga.o
  CC      hw/misc/pc-testdev.o
  CC      hw/misc/pci-testdev.o
  CC      hw/misc/arm_l2x0.o
  CC      hw/misc/arm_integrator_debug.o
  CC      hw/misc/a9scu.o
  CC      hw/misc/arm11scu.o
  CC      hw/net/ne2000.o
  CC      hw/net/pcnet-pci.o
  CC      hw/net/eepro100.o
  CC      hw/net/pcnet.o
  CC      hw/net/e1000.o
  CC      hw/net/e1000x_common.o
  CC      hw/net/net_tx_pkt.o
  CC      hw/net/net_rx_pkt.o
  CC      hw/net/e1000e.o
  CC      hw/net/e1000e_core.o
  CC      hw/net/rtl8139.o
  CC      hw/net/vmxnet3.o
  CC      hw/net/smc91c111.o
  CC      hw/net/lan9118.o
  CC      hw/net/ne2000-isa.o
  CC      hw/net/xgmac.o
  CC      hw/net/allwinner_emac.o
  CC      hw/net/imx_fec.o
  CC      hw/net/cadence_gem.o
  CC      hw/net/stellaris_enet.o
  CC      hw/net/rocker/rocker_fp.o
  CC      hw/net/rocker/rocker.o
  CC      hw/net/rocker/rocker_desc.o
  CC      hw/net/rocker/rocker_world.o
  CC      hw/net/rocker/rocker_of_dpa.o
  CC      hw/nvram/eeprom93xx.o
  CC      hw/nvram/fw_cfg.o
  CC      hw/pci-bridge/pci_bridge_dev.o
  CC      hw/pci-bridge/pci_expander_bridge.o
  CC      hw/pci-bridge/xio3130_upstream.o
  CC      hw/pci-bridge/xio3130_downstream.o
  CC      hw/pci-bridge/ioh3420.o
  CC      hw/pci-bridge/i82801b11.o
  CC      hw/pci-host/pam.o
/tmp/qemu-test/src/hw/nvram/fw_cfg.c: In function ‘fw_cfg_dma_transfer’:
/tmp/qemu-test/src/hw/nvram/fw_cfg.c:330: warning: ‘read’ may be used uninitialized in this function
  CC      hw/pci-host/versatile.o
  CC      hw/pci-host/piix.o
  CC      hw/pci-host/q35.o
  CC      hw/pci-host/gpex.o
  CC      hw/pci/pci.o
  CC      hw/pci/pci_bridge.o
  CC      hw/pci/msix.o
  CC      hw/pci/msi.o
  CC      hw/pci/shpc.o
  CC      hw/pci/slotid_cap.o
  CC      hw/pci/pci_host.o
  CC      hw/pci/pcie_host.o
  CC      hw/pci/pcie.o
  CC      hw/pci/pcie_aer.o
  CC      hw/pci/pcie_port.o
  CC      hw/pci/pci-stub.o
  CC      hw/pcmcia/pcmcia.o
  CC      hw/scsi/scsi-disk.o
  CC      hw/scsi/scsi-generic.o
  CC      hw/scsi/scsi-bus.o
  CC      hw/scsi/lsi53c895a.o
  CC      hw/scsi/mptsas.o
  CC      hw/scsi/mptconfig.o
  CC      hw/scsi/mptendian.o
  CC      hw/scsi/megasas.o
  CC      hw/scsi/vmw_pvscsi.o
  CC      hw/scsi/esp.o
  CC      hw/scsi/esp-pci.o
  CC      hw/sd/pl181.o
  CC      hw/sd/ssi-sd.o
  CC      hw/sd/sd.o
  CC      hw/sd/core.o
  CC      hw/sd/sdhci.o
  CC      hw/smbios/smbios.o
  CC      hw/smbios/smbios_type_38.o
  CC      hw/ssi/pl022.o
  CC      hw/ssi/ssi.o
  CC      hw/ssi/xilinx_spips.o
  CC      hw/ssi/aspeed_smc.o
  CC      hw/ssi/stm32f2xx_spi.o
  CC      hw/timer/arm_timer.o
  CC      hw/timer/arm_mptimer.o
  CC      hw/timer/a9gtimer.o
  CC      hw/timer/cadence_ttc.o
  CC      hw/timer/ds1338.o
  CC      hw/timer/hpet.o
  CC      hw/timer/i8254_common.o
  CC      hw/timer/i8254.o
  CC      hw/timer/pl031.o
  CC      hw/timer/twl92230.o
  CC      hw/timer/imx_epit.o
  CC      hw/timer/imx_gpt.o
  CC      hw/timer/stm32f2xx_timer.o
  CC      hw/timer/aspeed_timer.o
  CC      hw/tpm/tpm_tis.o
  CC      hw/tpm/tpm_passthrough.o
  CC      hw/tpm/tpm_util.o
  CC      hw/usb/core.o
  CC      hw/usb/combined-packet.o
  CC      hw/usb/bus.o
  CC      hw/usb/libhw.o
  CC      hw/usb/desc.o
  CC      hw/usb/desc-msos.o
  CC      hw/usb/hcd-uhci.o
  CC      hw/usb/hcd-ohci.o
  CC      hw/usb/hcd-ehci.o
  CC      hw/usb/hcd-ehci-pci.o
  CC      hw/usb/hcd-ehci-sysbus.o
  CC      hw/usb/hcd-xhci.o
  CC      hw/usb/hcd-musb.o
  CC      hw/usb/dev-hub.o
  CC      hw/usb/dev-hid.o
  CC      hw/usb/dev-wacom.o
  CC      hw/usb/dev-storage.o
  CC      hw/usb/dev-uas.o
  CC      hw/usb/dev-audio.o
  CC      hw/usb/dev-serial.o
  CC      hw/usb/dev-network.o
  CC      hw/usb/dev-bluetooth.o
  CC      hw/usb/dev-smartcard-reader.o
  CC      hw/usb/dev-mtp.o
  CC      hw/usb/host-stub.o
  CC      hw/virtio/virtio-rng.o
  CC      hw/virtio/virtio-pci.o
  CC      hw/virtio/virtio-bus.o
  CC      hw/virtio/virtio-mmio.o
  CC      hw/watchdog/watchdog.o
  CC      hw/watchdog/wdt_i6300esb.o
  CC      hw/watchdog/wdt_ib700.o
  CC      migration/migration.o
  CC      migration/socket.o
  CC      migration/fd.o
  CC      migration/exec.o
  CC      migration/tls.o
  CC      migration/vmstate.o
  CC      migration/qemu-file.o
  CC      migration/qemu-file-channel.o
  CC      migration/xbzrle.o
  CC      migration/postcopy-ram.o
  CC      migration/qjson.o
  CC      migration/block.o
  CC      net/net.o
  CC      net/queue.o
  CC      net/checksum.o
  CC      net/util.o
  CC      net/hub.o
  CC      net/socket.o
  CC      net/dump.o
  CC      net/eth.o
  CC      net/l2tpv3.o
  CC      net/tap.o
  CC      net/vhost-user.o
  CC      net/tap-linux.o
  CC      net/slirp.o
  CC      net/filter.o
  CC      net/filter-buffer.o
  CC      net/filter-mirror.o
  CC      net/colo-compare.o
  CC      net/colo.o
  CC      net/filter-rewriter.o
  CC      qom/cpu.o
  CC      replay/replay.o
  CC      replay/replay-internal.o
  CC      replay/replay-events.o
  CC      replay/replay-time.o
  CC      replay/replay-input.o
/tmp/qemu-test/src/replay/replay-internal.c: In function ‘replay_put_array’:
/tmp/qemu-test/src/replay/replay-internal.c:65: warning: ignoring return value of ‘fwrite’, declared with attribute warn_unused_result
  CC      replay/replay-char.o
  CC      replay/replay-snapshot.o
  CC      slirp/cksum.o
  CC      slirp/if.o
  CC      slirp/ip_icmp.o
  CC      slirp/ip6_icmp.o
  CC      slirp/ip6_input.o
  CC      slirp/ip6_output.o
  CC      slirp/ip_input.o
  CC      slirp/ip_output.o
  CC      slirp/dnssearch.o
  CC      slirp/dhcpv6.o
  CC      slirp/slirp.o
  CC      slirp/mbuf.o
  CC      slirp/misc.o
  CC      slirp/sbuf.o
  CC      slirp/socket.o
  CC      slirp/tcp_input.o
  CC      slirp/tcp_output.o
  CC      slirp/tcp_subr.o
  CC      slirp/tcp_timer.o
  CC      slirp/udp.o
  CC      slirp/udp6.o
  CC      slirp/bootp.o
  CC      slirp/tftp.o
/tmp/qemu-test/src/slirp/tcp_input.c: In function ‘tcp_input’:
/tmp/qemu-test/src/slirp/tcp_input.c:219: warning: ‘save_ip.ip_p’ may be used uninitialized in this function
/tmp/qemu-test/src/slirp/tcp_input.c:219: warning: ‘save_ip.ip_len’ may be used uninitialized in this function
/tmp/qemu-test/src/slirp/tcp_input.c:219: warning: ‘save_ip.ip_tos’ may be used uninitialized in this function
/tmp/qemu-test/src/slirp/tcp_input.c:219: warning: ‘save_ip.ip_id’ may be used uninitialized in this function
/tmp/qemu-test/src/slirp/tcp_input.c:219: warning: ‘save_ip.ip_off’ may be used uninitialized in this function
/tmp/qemu-test/src/slirp/tcp_input.c:219: warning: ‘save_ip.ip_ttl’ may be used uninitialized in this function
/tmp/qemu-test/src/slirp/tcp_input.c:219: warning: ‘save_ip.ip_sum’ may be used uninitialized in this function
/tmp/qemu-test/src/slirp/tcp_input.c:219: warning: ‘save_ip.ip_src.s_addr’ may be used uninitialized in this function
/tmp/qemu-test/src/slirp/tcp_input.c:219: warning: ‘save_ip.ip_dst.s_addr’ may be used uninitialized in this function
/tmp/qemu-test/src/slirp/tcp_input.c:220: warning: ‘save_ip6.ip_nh’ may be used uninitialized in this function
  CC      slirp/arp_table.o
  CC      slirp/ndp_table.o
  CC      ui/keymaps.o
  CC      ui/console.o
  CC      ui/cursor.o
  CC      ui/qemu-pixman.o
  CC      ui/input.o
  CC      ui/input-keymap.o
  CC      ui/input-legacy.o
  CC      ui/input-linux.o
  CC      ui/sdl.o
  CC      ui/sdl_zoom.o
  CC      ui/x_keymap.o
  CC      ui/vnc.o
  CC      ui/vnc-enc-zlib.o
  CC      ui/vnc-enc-hextile.o
  CC      ui/vnc-enc-tight.o
  CC      ui/vnc-palette.o
  CC      ui/vnc-enc-zrle.o
  CC      ui/vnc-auth-vencrypt.o
  CC      ui/vnc-ws.o
  CC      ui/vnc-jobs.o
  LINK    tests/qemu-iotests/socket_scm_helper
  CC      qga/commands.o
  CC      qga/guest-agent-command-state.o
  CC      qga/main.o
  CC      qga/commands-posix.o
  CC      qga/channel-posix.o
  AS      optionrom/multiboot.o
  AS      optionrom/linuxboot.o
  CC      optionrom/linuxboot_dma.o
cc: unrecognized option '-no-integrated-as'
cc: unrecognized option '-no-integrated-as'
  AS      optionrom/kvmvapic.o
  CC      qga/qapi-generated/qga-qapi-types.o
  BUILD   optionrom/linuxboot_dma.img
  CC      qga/qapi-generated/qga-qapi-visit.o
  BUILD   optionrom/multiboot.img
  BUILD   optionrom/linuxboot.img
  BUILD   optionrom/linuxboot_dma.raw
  BUILD   optionrom/kvmvapic.img
  CC      qga/qapi-generated/qga-qmp-marshal.o
  CC      qmp-introspect.o
  BUILD   optionrom/multiboot.raw
  BUILD   optionrom/linuxboot.raw
  SIGN    optionrom/linuxboot_dma.bin
  BUILD   optionrom/kvmvapic.raw
  CC      qapi-types.o
  CC      qapi-visit.o
  SIGN    optionrom/multiboot.bin
  SIGN    optionrom/linuxboot.bin
  CC      qapi-event.o
  SIGN    optionrom/kvmvapic.bin
  AR      libqemustub.a
  CC      qemu-img.o
  CC      qmp-marshal.o
  CC      trace/generated-events.o
  AR      libqemuutil.a
  LINK    qemu-ga
  LINK    ivshmem-client
  LINK    ivshmem-server
  LINK    qemu-nbd
  LINK    qemu-img
  LINK    qemu-io
  LINK    qemu-bridge-helper
  GEN     aarch64-softmmu/hmp-commands-info.h
  GEN     aarch64-softmmu/config-target.h
  GEN     aarch64-softmmu/hmp-commands.h
  CC      aarch64-softmmu/exec.o
  CC      aarch64-softmmu/translate-all.o
  CC      aarch64-softmmu/cpu-exec.o
  CC      aarch64-softmmu/translate-common.o
  CC      aarch64-softmmu/cpu-exec-common.o
  CC      aarch64-softmmu/tcg/tcg.o
  CC      aarch64-softmmu/tcg/tcg-op.o
  GEN     x86_64-softmmu/hmp-commands.h
  GEN     x86_64-softmmu/hmp-commands-info.h
  CC      aarch64-softmmu/tcg/optimize.o
  GEN     x86_64-softmmu/config-target.h
  CC      aarch64-softmmu/tcg/tcg-common.o
  CC      aarch64-softmmu/fpu/softfloat.o
  CC      aarch64-softmmu/disas.o
  GEN     aarch64-softmmu/gdbstub-xml.c
  CC      aarch64-softmmu/arch_init.o
  CC      aarch64-softmmu/kvm-stub.o
  CC      aarch64-softmmu/cpus.o
  CC      x86_64-softmmu/exec.o
  CC      aarch64-softmmu/monitor.o
  CC      x86_64-softmmu/translate-all.o
  CC      aarch64-softmmu/gdbstub.o
  CC      x86_64-softmmu/cpu-exec.o
  CC      aarch64-softmmu/balloon.o
  CC      aarch64-softmmu/ioport.o
  CC      x86_64-softmmu/translate-common.o
  CC      aarch64-softmmu/numa.o
  CC      aarch64-softmmu/qtest.o
  CC      aarch64-softmmu/bootdevice.o
  CC      aarch64-softmmu/memory.o
  CC      x86_64-softmmu/cpu-exec-common.o
  CC      x86_64-softmmu/tcg/tcg.o
  CC      aarch64-softmmu/cputlb.o
  CC      aarch64-softmmu/memory_mapping.o
  CC      aarch64-softmmu/dump.o
  CC      aarch64-softmmu/migration/ram.o
  CC      x86_64-softmmu/tcg/tcg-op.o
  CC      aarch64-softmmu/migration/savevm.o
  CC      aarch64-softmmu/xen-common-stub.o
  CC      aarch64-softmmu/xen-hvm-stub.o
  CC      x86_64-softmmu/tcg/optimize.o
  CC      x86_64-softmmu/tcg/tcg-common.o
  CC      aarch64-softmmu/hw/adc/stm32f2xx_adc.o
  CC      aarch64-softmmu/hw/block/virtio-blk.o
  CC      aarch64-softmmu/hw/block/dataplane/virtio-blk.o
  CC      aarch64-softmmu/hw/char/exynos4210_uart.o
  CC      aarch64-softmmu/hw/char/omap_uart.o
  CC      aarch64-softmmu/hw/char/digic-uart.o
  CC      x86_64-softmmu/fpu/softfloat.o
  CC      aarch64-softmmu/hw/char/stm32f2xx_usart.o
  CC      x86_64-softmmu/disas.o
  CC      x86_64-softmmu/arch_init.o
  CC      aarch64-softmmu/hw/char/bcm2835_aux.o
  CC      x86_64-softmmu/cpus.o
  CC      aarch64-softmmu/hw/char/virtio-serial-bus.o
  CC      aarch64-softmmu/hw/core/nmi.o
  CC      aarch64-softmmu/hw/core/generic-loader.o
  CC      aarch64-softmmu/hw/cpu/arm11mpcore.o
  CC      aarch64-softmmu/hw/cpu/realview_mpcore.o
  CC      x86_64-softmmu/monitor.o
  CC      aarch64-softmmu/hw/cpu/a9mpcore.o
  CC      aarch64-softmmu/hw/cpu/a15mpcore.o
  CC      x86_64-softmmu/gdbstub.o
  CC      aarch64-softmmu/hw/cpu/core.o
  CC      x86_64-softmmu/balloon.o
  CC      aarch64-softmmu/hw/display/omap_dss.o
  CC      aarch64-softmmu/hw/display/omap_lcdc.o
  CC      x86_64-softmmu/ioport.o
  CC      x86_64-softmmu/numa.o
  CC      x86_64-softmmu/qtest.o
  CC      x86_64-softmmu/bootdevice.o
  CC      x86_64-softmmu/kvm-all.o
  CC      x86_64-softmmu/memory.o
  CC      aarch64-softmmu/hw/display/pxa2xx_lcd.o
  CC      x86_64-softmmu/cputlb.o
  CC      x86_64-softmmu/memory_mapping.o
  CC      x86_64-softmmu/dump.o
  CC      x86_64-softmmu/migration/ram.o
  CC      x86_64-softmmu/migration/savevm.o
  CC      aarch64-softmmu/hw/display/bcm2835_fb.o
  CC      aarch64-softmmu/hw/display/vga.o
  CC      aarch64-softmmu/hw/display/virtio-gpu.o
  CC      x86_64-softmmu/xen-common-stub.o
  CC      aarch64-softmmu/hw/display/virtio-gpu-3d.o
  CC      x86_64-softmmu/xen-hvm-stub.o
  CC      x86_64-softmmu/hw/acpi/nvdimm.o
  CC      x86_64-softmmu/hw/block/virtio-blk.o
  CC      aarch64-softmmu/hw/display/virtio-gpu-pci.o
  CC      x86_64-softmmu/hw/block/dataplane/virtio-blk.o
  CC      aarch64-softmmu/hw/display/dpcd.o
  CC      x86_64-softmmu/hw/char/virtio-serial-bus.o
  CC      aarch64-softmmu/hw/display/xlnx_dp.o
  CC      x86_64-softmmu/hw/core/nmi.o
  CC      aarch64-softmmu/hw/dma/xlnx_dpdma.o
  CC      x86_64-softmmu/hw/core/generic-loader.o
  CC      aarch64-softmmu/hw/dma/omap_dma.o
  CC      aarch64-softmmu/hw/dma/soc_dma.o
  CC      x86_64-softmmu/hw/cpu/core.o
  CC      x86_64-softmmu/hw/display/vga.o
  CC      x86_64-softmmu/hw/display/virtio-gpu.o
  CC      aarch64-softmmu/hw/dma/pxa2xx_dma.o
  CC      aarch64-softmmu/hw/dma/bcm2835_dma.o
  CC      x86_64-softmmu/hw/display/virtio-gpu-3d.o
  CC      x86_64-softmmu/hw/display/virtio-gpu-pci.o
  CC      aarch64-softmmu/hw/gpio/omap_gpio.o
  CC      x86_64-softmmu/hw/display/virtio-vga.o
  CC      aarch64-softmmu/hw/gpio/imx_gpio.o
  CC      x86_64-softmmu/hw/intc/apic.o
  CC      aarch64-softmmu/hw/i2c/omap_i2c.o
  CC      x86_64-softmmu/hw/intc/apic_common.o
  CC      aarch64-softmmu/hw/input/pxa2xx_keypad.o
  CC      aarch64-softmmu/hw/input/tsc210x.o
  CC      aarch64-softmmu/hw/intc/armv7m_nvic.o
  CC      aarch64-softmmu/hw/intc/exynos4210_gic.o
  CC      aarch64-softmmu/hw/intc/exynos4210_combiner.o
  CC      aarch64-softmmu/hw/intc/omap_intc.o
  CC      x86_64-softmmu/hw/intc/ioapic.o
  CC      x86_64-softmmu/hw/isa/lpc_ich9.o
  CC      aarch64-softmmu/hw/intc/bcm2835_ic.o
  CC      x86_64-softmmu/hw/misc/vmport.o
  CC      x86_64-softmmu/hw/misc/ivshmem.o
  CC      x86_64-softmmu/hw/misc/pvpanic.o
  CC      x86_64-softmmu/hw/misc/edu.o
  CC      aarch64-softmmu/hw/intc/bcm2836_control.o
  CC      aarch64-softmmu/hw/intc/allwinner-a10-pic.o
  CC      aarch64-softmmu/hw/intc/aspeed_vic.o
  CC      aarch64-softmmu/hw/intc/arm_gicv3_cpuif.o
  CC      aarch64-softmmu/hw/misc/ivshmem.o
  CC      x86_64-softmmu/hw/misc/hyperv_testdev.o
  CC      x86_64-softmmu/hw/net/virtio-net.o
  CC      x86_64-softmmu/hw/net/vhost_net.o
  CC      x86_64-softmmu/hw/scsi/virtio-scsi.o
  CC      x86_64-softmmu/hw/scsi/virtio-scsi-dataplane.o
  CC      aarch64-softmmu/hw/misc/arm_sysctl.o
  CC      x86_64-softmmu/hw/scsi/vhost-scsi.o
  CC      x86_64-softmmu/hw/timer/mc146818rtc.o
  CC      aarch64-softmmu/hw/misc/cbus.o
  CC      x86_64-softmmu/hw/vfio/common.o
  CC      x86_64-softmmu/hw/vfio/pci.o
  CC      x86_64-softmmu/hw/vfio/pci-quirks.o
  CC      aarch64-softmmu/hw/misc/exynos4210_pmu.o
  CC      aarch64-softmmu/hw/misc/imx_ccm.o
  CC      aarch64-softmmu/hw/misc/imx31_ccm.o
  CC      x86_64-softmmu/hw/vfio/platform.o
  CC      x86_64-softmmu/hw/vfio/calxeda-xgmac.o
  CC      aarch64-softmmu/hw/misc/imx25_ccm.o
  CC      aarch64-softmmu/hw/misc/imx6_ccm.o
  CC      aarch64-softmmu/hw/misc/imx6_src.o
  CC      aarch64-softmmu/hw/misc/mst_fpga.o
  CC      x86_64-softmmu/hw/vfio/amd-xgbe.o
  CC      x86_64-softmmu/hw/vfio/spapr.o
  CC      x86_64-softmmu/hw/virtio/virtio.o
  CC      aarch64-softmmu/hw/misc/omap_clk.o
  CC      aarch64-softmmu/hw/misc/omap_gpmc.o
  CC      aarch64-softmmu/hw/misc/omap_l4.o
  CC      x86_64-softmmu/hw/virtio/virtio-balloon.o
  CC      aarch64-softmmu/hw/misc/omap_sdrc.o
  CC      x86_64-softmmu/hw/virtio/vhost.o
  CC      aarch64-softmmu/hw/misc/omap_tap.o
  CC      x86_64-softmmu/hw/virtio/vhost-backend.o
  CC      x86_64-softmmu/hw/virtio/vhost-user.o
  CC      aarch64-softmmu/hw/misc/bcm2835_mbox.o
  CC      aarch64-softmmu/hw/misc/bcm2835_property.o
  CC      x86_64-softmmu/hw/virtio/vhost-vsock.o
  CC      x86_64-softmmu/hw/i386/multiboot.o
  CC      x86_64-softmmu/hw/i386/pc.o
  CC      x86_64-softmmu/hw/i386/pc_piix.o
  CC      x86_64-softmmu/hw/i386/pc_q35.o
  CC      x86_64-softmmu/hw/i386/pc_sysfw.o
  CC      aarch64-softmmu/hw/misc/zynq_slcr.o
  CC      aarch64-softmmu/hw/misc/zynq-xadc.o
  CC      x86_64-softmmu/hw/i386/x86-iommu.o
  CC      x86_64-softmmu/hw/i386/intel_iommu.o
  CC      x86_64-softmmu/hw/i386/amd_iommu.o
/tmp/qemu-test/src/hw/i386/pc_piix.c: In function ‘igd_passthrough_isa_bridge_create’:
/tmp/qemu-test/src/hw/i386/pc_piix.c:1046: warning: ‘pch_rev_id’ may be used uninitialized in this function
  CC      x86_64-softmmu/hw/i386/kvmvapic.o
  CC      x86_64-softmmu/hw/i386/acpi-build.o
  CC      aarch64-softmmu/hw/misc/stm32f2xx_syscfg.o
  CC      x86_64-softmmu/hw/i386/pci-assign-load-rom.o
  CC      x86_64-softmmu/hw/i386/kvm/clock.o
  CC      x86_64-softmmu/hw/i386/kvm/apic.o
  CC      aarch64-softmmu/hw/misc/edu.o
  CC      aarch64-softmmu/hw/misc/auxbus.o
  CC      x86_64-softmmu/hw/i386/kvm/i8259.o
/tmp/qemu-test/src/hw/i386/acpi-build.c: In function ‘build_append_pci_bus_devices’:
/tmp/qemu-test/src/hw/i386/acpi-build.c:472: warning: ‘notify_method’ may be used uninitialized in this function
  CC      x86_64-softmmu/hw/i386/kvm/ioapic.o
  CC      x86_64-softmmu/hw/i386/kvm/i8254.o
  CC      x86_64-softmmu/hw/i386/kvm/pci-assign.o
  CC      x86_64-softmmu/target-i386/translate.o
  CC      aarch64-softmmu/hw/misc/aspeed_scu.o
  CC      x86_64-softmmu/target-i386/helper.o
  CC      x86_64-softmmu/target-i386/cpu.o
  CC      aarch64-softmmu/hw/misc/aspeed_sdmc.o
  CC      x86_64-softmmu/target-i386/bpt_helper.o
  CC      x86_64-softmmu/target-i386/excp_helper.o
  CC      aarch64-softmmu/hw/net/virtio-net.o
  CC      x86_64-softmmu/target-i386/fpu_helper.o
  CC      x86_64-softmmu/target-i386/cc_helper.o
  CC      aarch64-softmmu/hw/net/vhost_net.o
  CC      aarch64-softmmu/hw/pcmcia/pxa2xx.o
  CC      aarch64-softmmu/hw/scsi/virtio-scsi.o
  CC      aarch64-softmmu/hw/scsi/vhost-scsi.o
  CC      aarch64-softmmu/hw/scsi/virtio-scsi-dataplane.o
  CC      aarch64-softmmu/hw/sd/omap_mmc.o
  CC      aarch64-softmmu/hw/sd/pxa2xx_mmci.o
  CC      aarch64-softmmu/hw/ssi/omap_spi.o
  CC      x86_64-softmmu/target-i386/int_helper.o
  CC      aarch64-softmmu/hw/ssi/imx_spi.o
  CC      x86_64-softmmu/target-i386/svm_helper.o
  CC      x86_64-softmmu/target-i386/smm_helper.o
  CC      aarch64-softmmu/hw/timer/exynos4210_mct.o
  CC      aarch64-softmmu/hw/timer/exynos4210_pwm.o
  CC      aarch64-softmmu/hw/timer/exynos4210_rtc.o
  CC      aarch64-softmmu/hw/timer/omap_gptimer.o
  CC      x86_64-softmmu/target-i386/misc_helper.o
  CC      aarch64-softmmu/hw/timer/omap_synctimer.o
  CC      aarch64-softmmu/hw/timer/pxa2xx_timer.o
  CC      aarch64-softmmu/hw/timer/digic-timer.o
  CC      x86_64-softmmu/target-i386/mem_helper.o
  CC      aarch64-softmmu/hw/timer/allwinner-a10-pit.o
  CC      aarch64-softmmu/hw/usb/tusb6010.o
  CC      x86_64-softmmu/target-i386/seg_helper.o
  CC      aarch64-softmmu/hw/vfio/common.o
  CC      aarch64-softmmu/hw/vfio/pci.o
  CC      x86_64-softmmu/target-i386/mpx_helper.o
  CC      x86_64-softmmu/target-i386/gdbstub.o
  CC      x86_64-softmmu/target-i386/machine.o
  CC      x86_64-softmmu/target-i386/arch_memory_mapping.o
  CC      x86_64-softmmu/target-i386/arch_dump.o
  CC      aarch64-softmmu/hw/vfio/pci-quirks.o
  CC      x86_64-softmmu/target-i386/monitor.o
  CC      x86_64-softmmu/target-i386/kvm.o
  CC      x86_64-softmmu/target-i386/hyperv.o
  CC      aarch64-softmmu/hw/vfio/platform.o
  CC      aarch64-softmmu/hw/vfio/calxeda-xgmac.o
  GEN     trace/generated-helpers.c
  CC      x86_64-softmmu/trace/control-target.o
  CC      aarch64-softmmu/hw/vfio/amd-xgbe.o
  CC      aarch64-softmmu/hw/vfio/spapr.o
  CC      aarch64-softmmu/hw/virtio/virtio.o
  CC      aarch64-softmmu/hw/virtio/virtio-balloon.o
  CC      aarch64-softmmu/hw/virtio/vhost.o
  CC      x86_64-softmmu/trace/generated-helpers.o
  CC      aarch64-softmmu/hw/virtio/vhost-backend.o
  CC      aarch64-softmmu/hw/virtio/vhost-user.o
  CC      aarch64-softmmu/hw/virtio/vhost-vsock.o
  CC      aarch64-softmmu/hw/arm/boot.o
  CC      aarch64-softmmu/hw/arm/collie.o
  CC      aarch64-softmmu/hw/arm/exynos4_boards.o
  CC      aarch64-softmmu/hw/arm/gumstix.o
  CC      aarch64-softmmu/hw/arm/highbank.o
  CC      aarch64-softmmu/hw/arm/digic_boards.o
  CC      aarch64-softmmu/hw/arm/integratorcp.o
  CC      aarch64-softmmu/hw/arm/mainstone.o
  LINK    x86_64-softmmu/qemu-system-x86_64
  CC      aarch64-softmmu/hw/arm/musicpal.o
  CC      aarch64-softmmu/hw/arm/nseries.o
  CC      aarch64-softmmu/hw/arm/omap_sx1.o
  CC      aarch64-softmmu/hw/arm/palm.o
  CC      aarch64-softmmu/hw/arm/realview.o
  CC      aarch64-softmmu/hw/arm/spitz.o
  CC      aarch64-softmmu/hw/arm/stellaris.o
  CC      aarch64-softmmu/hw/arm/tosa.o
  CC      aarch64-softmmu/hw/arm/versatilepb.o
  CC      aarch64-softmmu/hw/arm/vexpress.o
  CC      aarch64-softmmu/hw/arm/virt.o
  CC      aarch64-softmmu/hw/arm/xilinx_zynq.o
  CC      aarch64-softmmu/hw/arm/z2.o
  CC      aarch64-softmmu/hw/arm/virt-acpi-build.o
  CC      aarch64-softmmu/hw/arm/netduino2.o
  CC      aarch64-softmmu/hw/arm/sysbus-fdt.o
  CC      aarch64-softmmu/hw/arm/armv7m.o
  CC      aarch64-softmmu/hw/arm/exynos4210.o
  CC      aarch64-softmmu/hw/arm/pxa2xx.o
  CC      aarch64-softmmu/hw/arm/pxa2xx_gpio.o
  CC      aarch64-softmmu/hw/arm/pxa2xx_pic.o
  CC      aarch64-softmmu/hw/arm/digic.o
  CC      aarch64-softmmu/hw/arm/omap1.o
  CC      aarch64-softmmu/hw/arm/omap2.o
  CC      aarch64-softmmu/hw/arm/strongarm.o
  CC      aarch64-softmmu/hw/arm/allwinner-a10.o
  CC      aarch64-softmmu/hw/arm/cubieboard.o
  CC      aarch64-softmmu/hw/arm/bcm2835_peripherals.o
  CC      aarch64-softmmu/hw/arm/bcm2836.o
  CC      aarch64-softmmu/hw/arm/raspi.o
  CC      aarch64-softmmu/hw/arm/stm32f205_soc.o
  CC      aarch64-softmmu/hw/arm/xlnx-zynqmp.o
  CC      aarch64-softmmu/hw/arm/xlnx-ep108.o
  CC      aarch64-softmmu/hw/arm/fsl-imx25.o
  CC      aarch64-softmmu/hw/arm/imx25_pdk.o
  CC      aarch64-softmmu/hw/arm/fsl-imx31.o
  CC      aarch64-softmmu/hw/arm/kzm.o
  CC      aarch64-softmmu/hw/arm/fsl-imx6.o
  CC      aarch64-softmmu/hw/arm/sabrelite.o
  CC      aarch64-softmmu/hw/arm/aspeed_soc.o
  CC      aarch64-softmmu/hw/arm/aspeed.o
  CC      aarch64-softmmu/target-arm/arm-semi.o
  CC      aarch64-softmmu/target-arm/machine.o
  CC      aarch64-softmmu/target-arm/psci.o
  CC      aarch64-softmmu/target-arm/arch_dump.o
  CC      aarch64-softmmu/target-arm/monitor.o
  CC      aarch64-softmmu/target-arm/kvm-stub.o
  CC      aarch64-softmmu/target-arm/translate.o
  CC      aarch64-softmmu/target-arm/op_helper.o
  CC      aarch64-softmmu/target-arm/helper.o
  CC      aarch64-softmmu/target-arm/cpu.o
  CC      aarch64-softmmu/target-arm/neon_helper.o
  CC      aarch64-softmmu/target-arm/iwmmxt_helper.o
  CC      aarch64-softmmu/target-arm/gdbstub.o
  CC      aarch64-softmmu/target-arm/cpu64.o
  CC      aarch64-softmmu/target-arm/translate-a64.o
  CC      aarch64-softmmu/target-arm/helper-a64.o
  CC      aarch64-softmmu/target-arm/gdbstub64.o
  CC      aarch64-softmmu/target-arm/crypto_helper.o
  CC      aarch64-softmmu/target-arm/arm-powerctl.o
  GEN     trace/generated-helpers.c
  CC      aarch64-softmmu/trace/control-target.o
/tmp/qemu-test/src/target-arm/translate-a64.c: In function ‘handle_shri_with_rndacc’:
/tmp/qemu-test/src/target-arm/translate-a64.c:6333: warning: ‘tcg_src_hi’ may be used uninitialized in this function
/tmp/qemu-test/src/target-arm/translate-a64.c: In function ‘disas_simd_scalar_two_reg_misc’:
/tmp/qemu-test/src/target-arm/translate-a64.c:8060: warning: ‘rmode’ may be used uninitialized in this function
  CC      aarch64-softmmu/gdbstub-xml.o
  CC      aarch64-softmmu/trace/generated-helpers.o
  LINK    aarch64-softmmu/qemu-system-aarch64
  TEST    tests/qapi-schema/alternate-any.out
  TEST    tests/qapi-schema/alternate-array.out
  TEST    tests/qapi-schema/alternate-base.out
  TEST    tests/qapi-schema/alternate-clash.out
  TEST    tests/qapi-schema/alternate-conflict-dict.out
  TEST    tests/qapi-schema/alternate-conflict-string.out
  TEST    tests/qapi-schema/alternate-empty.out
  TEST    tests/qapi-schema/alternate-nested.out
  TEST    tests/qapi-schema/alternate-unknown.out
  TEST    tests/qapi-schema/args-alternate.out
  TEST    tests/qapi-schema/args-any.out
  TEST    tests/qapi-schema/args-array-empty.out
  TEST    tests/qapi-schema/args-array-unknown.out
  TEST    tests/qapi-schema/args-bad-boxed.out
  TEST    tests/qapi-schema/args-boxed-anon.out
  TEST    tests/qapi-schema/args-boxed-empty.out
  TEST    tests/qapi-schema/args-boxed-string.out
  TEST    tests/qapi-schema/args-int.out
  TEST    tests/qapi-schema/args-invalid.out
  TEST    tests/qapi-schema/args-member-array-bad.out
  TEST    tests/qapi-schema/args-member-case.out
  TEST    tests/qapi-schema/args-member-unknown.out
  TEST    tests/qapi-schema/args-name-clash.out
  TEST    tests/qapi-schema/args-union.out
  TEST    tests/qapi-schema/args-unknown.out
  TEST    tests/qapi-schema/bad-base.out
  TEST    tests/qapi-schema/bad-data.out
  TEST    tests/qapi-schema/bad-ident.out
  TEST    tests/qapi-schema/bad-type-bool.out
  TEST    tests/qapi-schema/bad-type-dict.out
  TEST    tests/qapi-schema/bad-type-int.out
  TEST    tests/qapi-schema/base-cycle-direct.out
  TEST    tests/qapi-schema/base-cycle-indirect.out
  TEST    tests/qapi-schema/command-int.out
  TEST    tests/qapi-schema/comments.out
  TEST    tests/qapi-schema/double-type.out
  TEST    tests/qapi-schema/double-data.out
  TEST    tests/qapi-schema/duplicate-key.out
  TEST    tests/qapi-schema/empty.out
  TEST    tests/qapi-schema/enum-bad-name.out
  TEST    tests/qapi-schema/enum-bad-prefix.out
  TEST    tests/qapi-schema/enum-clash-member.out
  TEST    tests/qapi-schema/enum-dict-member.out
  TEST    tests/qapi-schema/enum-int-member.out
  TEST    tests/qapi-schema/enum-member-case.out
  TEST    tests/qapi-schema/enum-missing-data.out
  TEST    tests/qapi-schema/enum-wrong-data.out
  TEST    tests/qapi-schema/escape-outside-string.out
  TEST    tests/qapi-schema/escape-too-big.out
  TEST    tests/qapi-schema/escape-too-short.out
  TEST    tests/qapi-schema/event-boxed-empty.out
  TEST    tests/qapi-schema/event-case.out
  TEST    tests/qapi-schema/event-nest-struct.out
  TEST    tests/qapi-schema/flat-union-array-branch.out
  TEST    tests/qapi-schema/flat-union-bad-base.out
  TEST    tests/qapi-schema/flat-union-bad-discriminator.out
  TEST    tests/qapi-schema/flat-union-base-any.out
  TEST    tests/qapi-schema/flat-union-base-union.out
  TEST    tests/qapi-schema/flat-union-clash-member.out
  TEST    tests/qapi-schema/flat-union-empty.out
  TEST    tests/qapi-schema/flat-union-incomplete-branch.out
  TEST    tests/qapi-schema/flat-union-inline.out
  TEST    tests/qapi-schema/flat-union-int-branch.out
  TEST    tests/qapi-schema/flat-union-invalid-branch-key.out
  TEST    tests/qapi-schema/flat-union-invalid-discriminator.out
  TEST    tests/qapi-schema/flat-union-no-base.out
  TEST    tests/qapi-schema/flat-union-optional-discriminator.out
  TEST    tests/qapi-schema/flat-union-string-discriminator.out
  TEST    tests/qapi-schema/funny-char.out
  TEST    tests/qapi-schema/ident-with-escape.out
  TEST    tests/qapi-schema/include-before-err.out
  TEST    tests/qapi-schema/include-cycle.out
  TEST    tests/qapi-schema/include-format-err.out
  TEST    tests/qapi-schema/include-nested-err.out
  TEST    tests/qapi-schema/include-no-file.out
  TEST    tests/qapi-schema/include-non-file.out
  TEST    tests/qapi-schema/include-relpath.out
  TEST    tests/qapi-schema/include-repetition.out
  TEST    tests/qapi-schema/include-self-cycle.out
  TEST    tests/qapi-schema/include-simple.out
  TEST    tests/qapi-schema/indented-expr.out
  TEST    tests/qapi-schema/leading-comma-list.out
  TEST    tests/qapi-schema/leading-comma-object.out
  TEST    tests/qapi-schema/missing-colon.out
  TEST    tests/qapi-schema/missing-comma-list.out
  TEST    tests/qapi-schema/missing-comma-object.out
  TEST    tests/qapi-schema/missing-type.out
  TEST    tests/qapi-schema/nested-struct-data.out
  TEST    tests/qapi-schema/non-objects.out
  TEST    tests/qapi-schema/qapi-schema-test.out
  TEST    tests/qapi-schema/quoted-structural-chars.out
  TEST    tests/qapi-schema/redefined-builtin.out
  TEST    tests/qapi-schema/redefined-command.out
  TEST    tests/qapi-schema/redefined-event.out
  TEST    tests/qapi-schema/redefined-type.out
  TEST    tests/qapi-schema/reserved-command-q.out
  TEST    tests/qapi-schema/reserved-enum-q.out
  TEST    tests/qapi-schema/reserved-member-has.out
  TEST    tests/qapi-schema/reserved-member-q.out
  TEST    tests/qapi-schema/reserved-member-u.out
  TEST    tests/qapi-schema/reserved-member-underscore.out
  TEST    tests/qapi-schema/reserved-type-kind.out
  TEST    tests/qapi-schema/reserved-type-list.out
  TEST    tests/qapi-schema/returns-alternate.out
  TEST    tests/qapi-schema/returns-array-bad.out
  TEST    tests/qapi-schema/returns-dict.out
  TEST    tests/qapi-schema/returns-unknown.out
  TEST    tests/qapi-schema/returns-whitelist.out
  TEST    tests/qapi-schema/struct-base-clash-deep.out
  TEST    tests/qapi-schema/struct-base-clash.out
  TEST    tests/qapi-schema/struct-data-invalid.out
  TEST    tests/qapi-schema/struct-member-invalid.out
  TEST    tests/qapi-schema/trailing-comma-list.out
  TEST    tests/qapi-schema/trailing-comma-object.out
  TEST    tests/qapi-schema/type-bypass-bad-gen.out
  TEST    tests/qapi-schema/unclosed-list.out
  TEST    tests/qapi-schema/unclosed-object.out
  TEST    tests/qapi-schema/unclosed-string.out
  TEST    tests/qapi-schema/unicode-str.out
  TEST    tests/qapi-schema/union-base-no-discriminator.out
  TEST    tests/qapi-schema/union-branch-case.out
  TEST    tests/qapi-schema/union-clash-branches.out
  TEST    tests/qapi-schema/union-empty.out
  TEST    tests/qapi-schema/union-invalid-base.out
  TEST    tests/qapi-schema/union-optional-branch.out
  TEST    tests/qapi-schema/union-unknown.out
  TEST    tests/qapi-schema/unknown-escape.out
  TEST    tests/qapi-schema/unknown-expr-key.out
  CC      tests/check-qdict.o
  CC      tests/check-qfloat.o
  CC      tests/check-qint.o
  CC      tests/check-qstring.o
  CC      tests/check-qlist.o
  CC      tests/check-qnull.o
  CC      tests/check-qjson.o
  CC      tests/test-qmp-output-visitor.o
  GEN     tests/test-qapi-visit.c
  GEN     tests/test-qapi-types.c
  GEN     tests/test-qapi-event.c
  GEN     tests/test-qmp-introspect.c
  CC      tests/test-clone-visitor.o
  CC      tests/test-qmp-input-visitor.o
  CC      tests/test-qmp-input-strict.o
  CC      tests/test-qmp-commands.o
  GEN     tests/test-qmp-marshal.c
  CC      tests/test-string-input-visitor.o
  CC      tests/test-string-output-visitor.o
  CC      tests/test-qmp-event.o
  CC      tests/test-opts-visitor.o
  CC      tests/test-coroutine.o
  CC      tests/test-visitor-serialization.o
  CC      tests/test-iov.o
  CC      tests/test-aio.o
  CC      tests/test-rfifolock.o
  CC      tests/test-throttle.o
  CC      tests/test-thread-pool.o
  CC      tests/test-hbitmap.o
  CC      tests/test-blockjob.o
  CC      tests/test-blockjob-txn.o
  CC      tests/test-x86-cpuid.o
  CC      tests/test-xbzrle.o
  CC      tests/test-vmstate.o
  CC      tests/test-cutils.o
  CC      tests/test-mul64.o
  CC      tests/test-int128.o
  CC      tests/rcutorture.o
  CC      tests/test-rcu-list.o
  CC      tests/test-qdist.o
/tmp/qemu-test/src/tests/test-int128.c:180: warning: ‘__noclone__’ attribute directive ignored
  CC      tests/test-qht.o
  CC      tests/test-qht-par.o
  CC      tests/qht-bench.o
  CC      tests/test-bitops.o
  CC      tests/check-qom-interface.o
  CC      tests/check-qom-proplist.o
  CC      tests/test-qemu-opts.o
  CC      tests/test-write-threshold.o
  CC      tests/test-crypto-hash.o
  CC      tests/test-crypto-cipher.o
  CC      tests/test-crypto-secret.o
  CC      tests/test-qga.o
  CC      tests/libqtest.o
  CC      tests/test-timed-average.o
  CC      tests/test-io-task.o
  CC      tests/test-io-channel-socket.o
  CC      tests/io-channel-helpers.o
  CC      tests/test-io-channel-file.o
  CC      tests/test-io-channel-command.o
  CC      tests/test-io-channel-buffer.o
  CC      tests/test-base64.o
  CC      tests/test-crypto-ivgen.o
  CC      tests/test-crypto-afsplit.o
  CC      tests/test-crypto-xts.o
  CC      tests/test-crypto-block.o
  CC      tests/test-logging.o
  CC      tests/test-replication.o
  CC      tests/test-bufferiszero.o
  CC      tests/test-uuid.o
  CC      tests/vhost-user-test.o
  CC      tests/libqos/pci.o
  CC      tests/libqos/fw_cfg.o
  CC      tests/libqos/malloc.o
  CC      tests/libqos/i2c.o
  CC      tests/libqos/libqos.o
  CC      tests/libqos/pci-pc.o
  CC      tests/libqos/malloc-pc.o
  CC      tests/libqos/libqos-pc.o
  CC      tests/libqos/ahci.o
  CC      tests/libqos/virtio.o
  CC      tests/libqos/virtio-pci.o
  CC      tests/libqos/virtio-mmio.o
  CC      tests/libqos/malloc-generic.o
  CC      tests/endianness-test.o
  CC      tests/fdc-test.o
  CC      tests/ide-test.o
  CC      tests/ahci-test.o
  CC      tests/hd-geo-test.o
  CC      tests/boot-order-test.o
  CC      tests/bios-tables-test.o
  CC      tests/boot-sector.o
  CC      tests/boot-serial-test.o
  CC      tests/pxe-test.o
/tmp/qemu-test/src/tests/ide-test.c: In function ‘cdrom_pio_impl’:
/tmp/qemu-test/src/tests/ide-test.c:739: warning: ignoring return value of ‘fwrite’, declared with attribute warn_unused_result
/tmp/qemu-test/src/tests/ide-test.c: In function ‘test_cdrom_dma’:
/tmp/qemu-test/src/tests/ide-test.c:832: warning: ignoring return value of ‘fwrite’, declared with attribute warn_unused_result
  CC      tests/rtc-test.o
  CC      tests/ipmi-kcs-test.o
  CC      tests/ipmi-bt-test.o
  CC      tests/i440fx-test.o
/tmp/qemu-test/src/tests/boot-sector.c: In function ‘boot_sector_init’:
/tmp/qemu-test/src/tests/boot-sector.c:89: warning: ignoring return value of ‘fwrite’, declared with attribute warn_unused_result
  CC      tests/fw_cfg-test.o
  CC      tests/drive_del-test.o
  CC      tests/wdt_ib700-test.o
  CC      tests/tco-test.o
  CC      tests/e1000-test.o
  CC      tests/e1000e-test.o
  CC      tests/rtl8139-test.o
  CC      tests/pcnet-test.o
  CC      tests/eepro100-test.o
  CC      tests/ne2000-test.o
  CC      tests/nvme-test.o
  CC      tests/ac97-test.o
  CC      tests/es1370-test.o
  CC      tests/virtio-net-test.o
  CC      tests/virtio-balloon-test.o
  CC      tests/virtio-blk-test.o
  CC      tests/virtio-rng-test.o
  CC      tests/virtio-scsi-test.o
  CC      tests/virtio-serial-test.o
  CC      tests/virtio-console-test.o
  CC      tests/tpci200-test.o
  CC      tests/ipoctal232-test.o
  CC      tests/display-vga-test.o
  CC      tests/intel-hda-test.o
  CC      tests/ivshmem-test.o
  CC      tests/vmxnet3-test.o
  CC      tests/pvpanic-test.o
  CC      tests/i82801b11-test.o
  CC      tests/ioh3420-test.o
  CC      tests/usb-hcd-ohci-test.o
  CC      tests/libqos/malloc-spapr.o
  CC      tests/libqos/libqos-spapr.o
  CC      tests/libqos/rtas.o
  CC      tests/libqos/pci-spapr.o
  CC      tests/libqos/usb.o
  CC      tests/usb-hcd-uhci-test.o
  CC      tests/usb-hcd-ehci-test.o
  CC      tests/usb-hcd-xhci-test.o
  CC      tests/pc-cpu-test.o
  CC      tests/q35-test.o
  CC      tests/test-netfilter.o
  CC      tests/test-filter-mirror.o
  CC      tests/test-filter-redirector.o
  CC      tests/postcopy-test.o
  CC      tests/test-x86-cpuid-compat.o
  CC      tests/device-introspect-test.o
  CC      tests/qom-test.o
  CC      tests/ptimer-test.o
  CC      tests/ptimer-test-stubs.o
  LINK    tests/check-qdict
  LINK    tests/check-qfloat
  LINK    tests/check-qint
  LINK    tests/check-qstring
  LINK    tests/check-qlist
  LINK    tests/check-qnull
  LINK    tests/check-qjson
  CC      tests/test-qapi-visit.o
  CC      tests/test-qapi-types.o
  CC      tests/test-qapi-event.o
  CC      tests/test-qmp-introspect.o
  CC      tests/test-qmp-marshal.o
  LINK    tests/test-coroutine
  LINK    tests/test-iov
  LINK    tests/test-aio
  LINK    tests/test-rfifolock
  LINK    tests/test-throttle
  LINK    tests/test-thread-pool
  LINK    tests/test-hbitmap
  LINK    tests/test-blockjob
  LINK    tests/test-blockjob-txn
  LINK    tests/test-x86-cpuid
  LINK    tests/test-xbzrle
  LINK    tests/test-vmstate
  LINK    tests/test-cutils
  LINK    tests/test-mul64
  LINK    tests/test-int128
  LINK    tests/rcutorture
  LINK    tests/test-rcu-list
  LINK    tests/test-qdist
  LINK    tests/test-qht
  LINK    tests/qht-bench
  LINK    tests/test-bitops
  LINK    tests/check-qom-interface
  LINK    tests/check-qom-proplist
  LINK    tests/test-qemu-opts
  LINK    tests/test-write-threshold
  LINK    tests/test-crypto-hash
  LINK    tests/test-crypto-cipher
  LINK    tests/test-crypto-secret
  LINK    tests/test-qga
  LINK    tests/test-timed-average
  LINK    tests/test-io-task
  LINK    tests/test-io-channel-socket
  LINK    tests/test-io-channel-file
  LINK    tests/test-io-channel-command
  LINK    tests/test-io-channel-buffer
  LINK    tests/test-base64
  LINK    tests/test-crypto-ivgen
  LINK    tests/test-crypto-afsplit
  LINK    tests/test-crypto-xts
  LINK    tests/test-crypto-block
  LINK    tests/test-logging
  LINK    tests/test-replication
  LINK    tests/test-bufferiszero
  LINK    tests/test-uuid
  LINK    tests/vhost-user-test
  LINK    tests/endianness-test
  LINK    tests/fdc-test
  LINK    tests/ide-test
  LINK    tests/ahci-test
  LINK    tests/hd-geo-test
  LINK    tests/boot-order-test
  LINK    tests/bios-tables-test
  LINK    tests/boot-serial-test
  LINK    tests/pxe-test
  LINK    tests/rtc-test
  LINK    tests/ipmi-kcs-test
  LINK    tests/ipmi-bt-test
  LINK    tests/i440fx-test
  LINK    tests/fw_cfg-test
  LINK    tests/drive_del-test
  LINK    tests/wdt_ib700-test
  LINK    tests/tco-test
  LINK    tests/e1000-test
  LINK    tests/e1000e-test
  LINK    tests/rtl8139-test
  LINK    tests/pcnet-test
  LINK    tests/eepro100-test
  LINK    tests/ne2000-test
  LINK    tests/nvme-test
  LINK    tests/ac97-test
  LINK    tests/es1370-test
  LINK    tests/virtio-net-test
  LINK    tests/virtio-balloon-test
  LINK    tests/virtio-blk-test
  LINK    tests/virtio-rng-test
  LINK    tests/virtio-scsi-test
  LINK    tests/virtio-serial-test
  LINK    tests/virtio-console-test
  LINK    tests/tpci200-test
  LINK    tests/ipoctal232-test
  LINK    tests/display-vga-test
  LINK    tests/intel-hda-test
  LINK    tests/ivshmem-test
  LINK    tests/vmxnet3-test
  LINK    tests/pvpanic-test
  LINK    tests/i82801b11-test
  LINK    tests/ioh3420-test
  LINK    tests/usb-hcd-ohci-test
  LINK    tests/usb-hcd-uhci-test
  LINK    tests/usb-hcd-ehci-test
  LINK    tests/usb-hcd-xhci-test
  LINK    tests/pc-cpu-test
  LINK    tests/q35-test
  LINK    tests/test-netfilter
  LINK    tests/test-filter-mirror
  LINK    tests/test-filter-redirector
  LINK    tests/postcopy-test
  LINK    tests/test-x86-cpuid-compat
  LINK    tests/device-introspect-test
  LINK    tests/qom-test
  LINK    tests/ptimer-test
  GTESTER tests/check-qfloat
  GTESTER tests/check-qdict
  GTESTER tests/check-qint
  GTESTER tests/check-qstring
  GTESTER tests/check-qlist
  GTESTER tests/check-qnull
  GTESTER tests/check-qjson
  LINK    tests/test-qmp-output-visitor
  LINK    tests/test-clone-visitor
  LINK    tests/test-qmp-input-visitor
  LINK    tests/test-qmp-input-strict
  LINK    tests/test-qmp-commands
  LINK    tests/test-string-input-visitor
  LINK    tests/test-string-output-visitor
  LINK    tests/test-qmp-event
  LINK    tests/test-opts-visitor
  GTESTER tests/test-coroutine
  LINK    tests/test-visitor-serialization
  GTESTER tests/test-iov
  GTESTER tests/test-aio
  GTESTER tests/test-rfifolock
  GTESTER tests/test-throttle
  GTESTER tests/test-thread-pool
  GTESTER tests/test-hbitmap
  GTESTER tests/test-blockjob
  GTESTER tests/test-blockjob-txn
  GTESTER tests/test-x86-cpuid
  GTESTER tests/test-xbzrle
  GTESTER tests/test-vmstate
  GTESTER tests/test-cutils
  GTESTER tests/test-mul64
  GTESTER tests/test-int128
  GTESTER tests/rcutorture
  GTESTER tests/test-rcu-list
  GTESTER tests/test-qdist
  GTESTER tests/test-qht
  LINK    tests/test-qht-par
  GTESTER tests/test-bitops
  GTESTER tests/check-qom-interface
  GTESTER tests/check-qom-proplist
  GTESTER tests/test-qemu-opts
  GTESTER tests/test-write-threshold
  GTESTER tests/test-crypto-hash
  GTESTER tests/test-crypto-cipher
  GTESTER tests/test-crypto-secret
  GTESTER tests/test-qga
  GTESTER tests/test-timed-average
  GTESTER tests/test-io-task
  GTESTER tests/test-io-channel-socket
  GTESTER tests/test-io-channel-file
  GTESTER tests/test-io-channel-command
  GTESTER tests/test-io-channel-buffer
  GTESTER tests/test-base64
  GTESTER tests/test-crypto-ivgen
  GTESTER tests/test-crypto-afsplit
  GTESTER tests/test-crypto-xts
  GTESTER tests/test-crypto-block
  GTESTER tests/test-logging
  GTESTER tests/test-replication
  GTESTER tests/test-bufferiszero
  GTESTER tests/test-uuid
  GTESTER check-qtest-x86_64
  GTESTER check-qtest-aarch64
  GTESTER tests/test-qmp-output-visitor
  GTESTER tests/test-clone-visitor
  GTESTER tests/test-qmp-input-visitor
  GTESTER tests/test-qmp-input-strict
  GTESTER tests/test-qmp-commands
  GTESTER tests/test-string-input-visitor
  GTESTER tests/test-string-output-visitor
  GTESTER tests/test-qmp-event
  GTESTER tests/test-opts-visitor
  GTESTER tests/test-visitor-serialization
  GTESTER tests/test-qht-par
Could not access KVM kernel module: No such file or directory
failed to initialize KVM: No such file or directory
Back to tcg accelerator.
Could not access KVM kernel module: No such file or directory
failed to initialize KVM: No such file or directory
Back to tcg accelerator.
Could not access KVM kernel module: No such file or directory
failed to initialize KVM: No such file or directory
Back to tcg accelerator.
Could not access KVM kernel module: No such file or directory
failed to initialize KVM: No such file or directory
Back to tcg accelerator.
Could not access KVM kernel module: No such file or directory
failed to initialize KVM: No such file or directory
Back to tcg accelerator.
Could not access KVM kernel module: No such file or directory
failed to initialize KVM: No such file or directory
Back to tcg accelerator.
Could not access KVM kernel module: No such file or directory
failed to initialize KVM: No such file or directory
Back to tcg accelerator.
Could not access KVM kernel module: No such file or directory
failed to initialize KVM: No such file or directory
Back to tcg accelerator.
  BUILD   fedora
  ARCHIVE qemu.tgz
  ARCHIVE dtc.tgz
  COPY    RUNNER
  RUN     test-mingw in fedora
Packages installed:
PyYAML-3.11-12.fc24.x86_64
SDL-devel-1.2.15-21.fc24.x86_64
bc-1.06.95-16.fc24.x86_64
bison-3.0.4-4.fc24.x86_64
ccache-3.3.1-1.fc24.x86_64
clang-3.8.0-2.fc24.x86_64
findutils-4.6.0-7.fc24.x86_64
flex-2.6.0-2.fc24.x86_64
gcc-6.1.1-3.fc24.x86_64
gcc-c++-6.1.1-3.fc24.x86_64
git-2.7.4-2.fc24.x86_64
glib2-devel-2.48.2-1.fc24.x86_64
libfdt-devel-1.4.2-1.fc24.x86_64
make-4.1-5.fc24.x86_64
mingw32-SDL-1.2.15-7.fc24.noarch
mingw32-bzip2-1.0.6-7.fc24.noarch
mingw32-curl-7.47.0-1.fc24.noarch
mingw32-glib2-2.48.2-1.fc24.noarch
mingw32-gmp-6.1.0-1.fc24.noarch
mingw32-gnutls-3.4.14-1.fc24.noarch
mingw32-gtk2-2.24.30-1.fc24.noarch
mingw32-gtk3-3.20.9-1.fc24.noarch
mingw32-libjpeg-turbo-1.4.2-1.fc24.noarch
mingw32-libpng-1.6.23-1.fc24.noarch
mingw32-libssh2-1.4.3-5.fc24.noarch
mingw32-libtasn1-4.5-2.fc24.noarch
mingw32-nettle-3.2-1.fc24.noarch
mingw32-pixman-0.34.0-1.fc24.noarch
mingw32-pkg-config-0.28-6.fc24.x86_64
mingw64-SDL-1.2.15-7.fc24.noarch
mingw64-bzip2-1.0.6-7.fc24.noarch
mingw64-curl-7.47.0-1.fc24.noarch
mingw64-glib2-2.48.2-1.fc24.noarch
mingw64-gmp-6.1.0-1.fc24.noarch
mingw64-gnutls-3.4.14-1.fc24.noarch
mingw64-gtk2-2.24.30-1.fc24.noarch
mingw64-gtk3-3.20.9-1.fc24.noarch
mingw64-libjpeg-turbo-1.4.2-1.fc24.noarch
mingw64-libpng-1.6.23-1.fc24.noarch
mingw64-libssh2-1.4.3-5.fc24.noarch
mingw64-libtasn1-4.5-2.fc24.noarch
mingw64-nettle-3.2-1.fc24.noarch
mingw64-pixman-0.34.0-1.fc24.noarch
mingw64-pkg-config-0.28-6.fc24.x86_64
perl-5.22.2-362.fc24.x86_64
pixman-devel-0.34.0-2.fc24.x86_64
sparse-0.5.0-7.fc24.x86_64
tar-1.28-7.fc24.x86_64
which-2.20-13.fc24.x86_64
zlib-devel-1.2.8-10.fc24.x86_64

Environment variables:
PACKAGES=ccache git tar PyYAML sparse flex bison     glib2-devel pixman-devel zlib-devel SDL-devel libfdt-devel     gcc gcc-c++ clang make perl which bc findutils     mingw32-pixman mingw32-glib2 mingw32-gmp mingw32-SDL mingw32-pkg-config     mingw32-gtk2 mingw32-gtk3 mingw32-gnutls mingw32-nettle mingw32-libtasn1     mingw32-libjpeg-turbo mingw32-libpng mingw32-curl mingw32-libssh2     mingw32-bzip2     mingw64-pixman mingw64-glib2 mingw64-gmp mingw64-SDL mingw64-pkg-config     mingw64-gtk2 mingw64-gtk3 mingw64-gnutls mingw64-nettle mingw64-libtasn1     mingw64-libjpeg-turbo mingw64-libpng mingw64-curl mingw64-libssh2     mingw64-bzip2
HOSTNAME=
TERM=xterm
MAKEFLAGS= -j8
HISTSIZE=1000
J=8
USER=root
CCACHE_DIR=/var/tmp/ccache
EXTRA_CONFIGURE_OPTS=
V=
SHOW_ENV=1
MAIL=/var/spool/mail/root
PATH=/usr/lib/ccache:/usr/lib64/ccache:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
PWD=/
TARGET_LIST=
HISTCONTROL=ignoredups
SHLVL=1
HOME=/root
TEST_DIR=/tmp/qemu-test
LOGNAME=root
LESSOPEN=||/usr/bin/lesspipe.sh %s
FEATURES=mingw clang pyyaml dtc
DEBUG=
_=/usr/bin/env

Configure options:
--enable-werror --target-list=x86_64-softmmu,aarch64-softmmu --prefix=/var/tmp/qemu-build/install --cross-prefix=x86_64-w64-mingw32- --enable-trace-backends=simple --enable-debug --enable-gnutls --enable-nettle --enable-curl --enable-vnc --enable-bzip2 --enable-guest-agent --with-sdlabi=1.2 --with-gtkabi=2.0
Install prefix    /var/tmp/qemu-build/install
BIOS directory    /var/tmp/qemu-build/install
binary directory  /var/tmp/qemu-build/install
library directory /var/tmp/qemu-build/install/lib
module directory  /var/tmp/qemu-build/install/lib
libexec directory /var/tmp/qemu-build/install/libexec
include directory /var/tmp/qemu-build/install/include
config directory  /var/tmp/qemu-build/install
local state directory   queried at runtime
Windows SDK       no
Source path       /tmp/qemu-test/src
C compiler        x86_64-w64-mingw32-gcc
Host C compiler   cc
C++ compiler      x86_64-w64-mingw32-g++
Objective-C compiler clang
ARFLAGS           rv
CFLAGS            -g 
QEMU_CFLAGS       -I/usr/x86_64-w64-mingw32/sys-root/mingw/include/pixman-1  -I$(SRC_PATH)/dtc/libfdt -Werror -mms-bitfields -I/usr/x86_64-w64-mingw32/sys-root/mingw/include/glib-2.0 -I/usr/x86_64-w64-mingw32/sys-root/mingw/lib/glib-2.0/include -I/usr/x86_64-w64-mingw32/sys-root/mingw/include  -m64 -mthreads -D__USE_MINGW_ANSI_STDIO=1 -DWIN32_LEAN_AND_MEAN -DWINVER=0x501 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wall -Wundef -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common -fwrapv  -Wendif-labels -Wno-shift-negative-value -Wmissing-include-dirs -Wempty-body -Wnested-externs -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wold-style-declaration -Wold-style-definition -Wtype-limits -fstack-protector-strong -I/usr/x86_64-w64-mingw32/sys-root/mingw/include -I/usr/x86_64-w64-mingw32/sys-root/mingw/include/p11-kit-1 -I/usr/x86_64-w64-mingw32/sys-root/mingw/include  -I/usr/x86_64-w64-mingw32/sys-root/mingw/include   -I/usr/x86_64-w64-mingw32/sys-root/mingw/include/libpng16 
LDFLAGS           -Wl,--nxcompat -Wl,--no-seh -Wl,--dynamicbase -Wl,--warn-common -m64 -g 
make              make
install           install
python            python -B
smbd              /usr/sbin/smbd
module support    no
host CPU          x86_64
host big endian   no
target list       x86_64-softmmu aarch64-softmmu
tcg debug enabled yes
gprof enabled     no
sparse enabled    no
strip binaries    no
profiler          no
static build      no
pixman            system
SDL support       yes (1.2.15)
GTK support       yes (2.24.30)
GTK GL support    no
VTE support       no 
TLS priority      NORMAL
GNUTLS support    yes
GNUTLS rnd        yes
libgcrypt         no
libgcrypt kdf     no
nettle            yes (3.2)
nettle kdf        yes
libtasn1          yes
curses support    no
virgl support     no
curl support      yes
mingw32 support   yes
Audio drivers     dsound
Block whitelist (rw) 
Block whitelist (ro) 
VirtFS support    no
VNC support       yes
VNC SASL support  no
VNC JPEG support  yes
VNC PNG support   yes
xen support       no
brlapi support    no
bluez  support    no
Documentation     no
PIE               no
vde support       no
netmap support    no
Linux AIO support no
ATTR/XATTR support no
Install blobs     yes
KVM support       no
RDMA support      no
TCG interpreter   no
fdt support       yes
preadv support    no
fdatasync         no
madvise           no
posix_madvise     no
libcap-ng support no
vhost-net support no
vhost-scsi support no
vhost-vsock support no
Trace backends    simple
Trace output file trace-<pid>
spice support     no 
rbd support       no
xfsctl support    no
smartcard support no
libusb            no
usb net redir     no
OpenGL support    no
OpenGL dmabufs    no
libiscsi support  no
libnfs support    no
build guest agent yes
QGA VSS support   no
QGA w32 disk info yes
QGA MSI support   no
seccomp support   no
coroutine backend win32
coroutine pool    yes
debug stack usage no
GlusterFS support no
Archipelago support no
gcov              gcov
gcov enabled      no
TPM support       yes
libssh2 support   yes
TPM passthrough   no
QOM debugging     yes
lzo support       no
snappy support    no
bzip2 support     yes
NUMA host support no
tcmalloc support  no
jemalloc support  no
avx2 optimization yes
replication support yes
mkdir -p dtc/libfdt
  GEN     x86_64-softmmu/config-devices.mak.tmp
mkdir -p dtc/tests
  GEN     aarch64-softmmu/config-devices.mak.tmp
  GEN     config-host.h
  GEN     qemu-options.def
  GEN     qmp-commands.h
  GEN     qapi-types.h
  GEN     qapi-visit.h
  GEN     qapi-event.h
  GEN     x86_64-softmmu/config-devices.mak
  GEN     aarch64-softmmu/config-devices.mak
  GEN     qmp-introspect.h
  GEN     module_block.h
  GEN     tests/test-qapi-types.h
  GEN     tests/test-qapi-visit.h
  GEN     tests/test-qmp-commands.h
  GEN     tests/test-qapi-event.h
  GEN     tests/test-qmp-introspect.h
  GEN     config-all-devices.mak
	 DEP /tmp/qemu-test/src/dtc/tests/dumptrees.c
	 DEP /tmp/qemu-test/src/dtc/tests/trees.S
	 DEP /tmp/qemu-test/src/dtc/tests/testutils.c
	 DEP /tmp/qemu-test/src/dtc/tests/value-labels.c
  GEN     trace/generated-events.h
  GEN     trace/generated-tracers.h
	 DEP /tmp/qemu-test/src/dtc/tests/asm_tree_dump.c
	 DEP /tmp/qemu-test/src/dtc/tests/truncated_property.c
  GEN     trace/generated-tcg-tracers.h
	 DEP /tmp/qemu-test/src/dtc/tests/subnode_iterate.c
	 DEP /tmp/qemu-test/src/dtc/tests/integer-expressions.c
	 DEP /tmp/qemu-test/src/dtc/tests/utilfdt_test.c
  GEN     trace/generated-helpers-wrappers.h
	 DEP /tmp/qemu-test/src/dtc/tests/path_offset_aliases.c
	 DEP /tmp/qemu-test/src/dtc/tests/add_subnode_with_nops.c
	 DEP /tmp/qemu-test/src/dtc/tests/dtbs_equal_unordered.c
	 DEP /tmp/qemu-test/src/dtc/tests/dtb_reverse.c
  GEN     trace/generated-helpers.h
	 DEP /tmp/qemu-test/src/dtc/tests/dtbs_equal_ordered.c
	 DEP /tmp/qemu-test/src/dtc/tests/extra-terminating-null.c
	 DEP /tmp/qemu-test/src/dtc/tests/incbin.c
	 DEP /tmp/qemu-test/src/dtc/tests/boot-cpuid.c
	 DEP /tmp/qemu-test/src/dtc/tests/phandle_format.c
	 DEP /tmp/qemu-test/src/dtc/tests/path-references.c
	 DEP /tmp/qemu-test/src/dtc/tests/references.c
	 DEP /tmp/qemu-test/src/dtc/tests/string_escapes.c
	 DEP /tmp/qemu-test/src/dtc/tests/propname_escapes.c
	 DEP /tmp/qemu-test/src/dtc/tests/appendprop2.c
	 DEP /tmp/qemu-test/src/dtc/tests/appendprop1.c
	 DEP /tmp/qemu-test/src/dtc/tests/del_node.c
	 DEP /tmp/qemu-test/src/dtc/tests/del_property.c
	 DEP /tmp/qemu-test/src/dtc/tests/setprop.c
	 DEP /tmp/qemu-test/src/dtc/tests/set_name.c
	 DEP /tmp/qemu-test/src/dtc/tests/rw_tree1.c
	 DEP /tmp/qemu-test/src/dtc/tests/open_pack.c
	 DEP /tmp/qemu-test/src/dtc/tests/nopulate.c
	 DEP /tmp/qemu-test/src/dtc/tests/mangle-layout.c
	 DEP /tmp/qemu-test/src/dtc/tests/move_and_save.c
	 DEP /tmp/qemu-test/src/dtc/tests/sw_tree1.c
	 DEP /tmp/qemu-test/src/dtc/tests/nop_node.c
	 DEP /tmp/qemu-test/src/dtc/tests/nop_property.c
	 DEP /tmp/qemu-test/src/dtc/tests/setprop_inplace.c
	 DEP /tmp/qemu-test/src/dtc/tests/notfound.c
	 DEP /tmp/qemu-test/src/dtc/tests/char_literal.c
	 DEP /tmp/qemu-test/src/dtc/tests/sized_cells.c
	 DEP /tmp/qemu-test/src/dtc/tests/get_alias.c
	 DEP /tmp/qemu-test/src/dtc/tests/node_offset_by_compatible.c
	 DEP /tmp/qemu-test/src/dtc/tests/node_check_compatible.c
	 DEP /tmp/qemu-test/src/dtc/tests/node_offset_by_phandle.c
	 DEP /tmp/qemu-test/src/dtc/tests/node_offset_by_prop_value.c
	 DEP /tmp/qemu-test/src/dtc/tests/parent_offset.c
	 DEP /tmp/qemu-test/src/dtc/tests/supernode_atdepth_offset.c
	 DEP /tmp/qemu-test/src/dtc/tests/get_path.c
	 DEP /tmp/qemu-test/src/dtc/tests/get_phandle.c
	 DEP /tmp/qemu-test/src/dtc/tests/getprop.c
	 DEP /tmp/qemu-test/src/dtc/tests/get_name.c
	 DEP /tmp/qemu-test/src/dtc/tests/path_offset.c
	 DEP /tmp/qemu-test/src/dtc/tests/subnode_offset.c
	 DEP /tmp/qemu-test/src/dtc/tests/find_property.c
	 DEP /tmp/qemu-test/src/dtc/tests/root_node.c
	 DEP /tmp/qemu-test/src/dtc/tests/get_mem_rsv.c
	 DEP /tmp/qemu-test/src/dtc/libfdt/fdt_empty_tree.c
	 DEP /tmp/qemu-test/src/dtc/libfdt/fdt_strerror.c
	 DEP /tmp/qemu-test/src/dtc/libfdt/fdt_rw.c
	 DEP /tmp/qemu-test/src/dtc/libfdt/fdt_sw.c
	 DEP /tmp/qemu-test/src/dtc/libfdt/fdt_wip.c
	 DEP /tmp/qemu-test/src/dtc/libfdt/fdt_ro.c
	 DEP /tmp/qemu-test/src/dtc/libfdt/fdt.c
	 DEP /tmp/qemu-test/src/dtc/util.c
	 DEP /tmp/qemu-test/src/dtc/fdtput.c
	 DEP /tmp/qemu-test/src/dtc/fdtget.c
	 DEP /tmp/qemu-test/src/dtc/fdtdump.c
	 LEX convert-dtsv0-lexer.lex.c
	 DEP /tmp/qemu-test/src/dtc/srcpos.c
	 BISON dtc-parser.tab.c
	 LEX dtc-lexer.lex.c
	 DEP /tmp/qemu-test/src/dtc/treesource.c
	 DEP /tmp/qemu-test/src/dtc/livetree.c
	 DEP /tmp/qemu-test/src/dtc/fstree.c
	 DEP /tmp/qemu-test/src/dtc/flattree.c
	 DEP /tmp/qemu-test/src/dtc/dtc.c
	 DEP /tmp/qemu-test/src/dtc/data.c
	 DEP /tmp/qemu-test/src/dtc/checks.c
	 DEP convert-dtsv0-lexer.lex.c
	 DEP dtc-parser.tab.c
	 DEP dtc-lexer.lex.c
	CHK version_gen.h
	UPD version_gen.h
	 DEP /tmp/qemu-test/src/dtc/util.c
	 CC libfdt/fdt.o
	 CC libfdt/fdt_ro.o
	 CC libfdt/fdt_wip.o
	 CC libfdt/fdt_sw.o
	 CC libfdt/fdt_strerror.o
	 CC libfdt/fdt_rw.o
	 CC libfdt/fdt_empty_tree.o
	 AR libfdt/libfdt.a
x86_64-w64-mingw32-ar: creating libfdt/libfdt.a
a - libfdt/fdt.o
a - libfdt/fdt_ro.o
a - libfdt/fdt_wip.o
a - libfdt/fdt_sw.o
a - libfdt/fdt_rw.o
a - libfdt/fdt_strerror.o
a - libfdt/fdt_empty_tree.o
  RC      version.lo
  RC      version.o
  GEN     qga/qapi-generated/qga-qapi-types.h
  GEN     qga/qapi-generated/qga-qapi-visit.h
  GEN     qga/qapi-generated/qga-qmp-commands.h
  GEN     qga/qapi-generated/qga-qapi-types.c
  GEN     qga/qapi-generated/qga-qapi-visit.c
  GEN     qga/qapi-generated/qga-qmp-marshal.c
  GEN     qmp-introspect.c
  GEN     qapi-types.c
  GEN     qapi-visit.c
  GEN     qapi-event.c
  CC      qapi/qapi-visit-core.o
  CC      qapi/qapi-dealloc-visitor.o
  CC      qapi/qmp-input-visitor.o
  CC      qapi/qmp-output-visitor.o
  CC      qapi/qmp-registry.o
  CC      qapi/qmp-dispatch.o
  CC      qapi/string-input-visitor.o
  CC      qapi/string-output-visitor.o
  CC      qapi/opts-visitor.o
  CC      qapi/qapi-clone-visitor.o
  CC      qapi/qmp-event.o
  CC      qapi/qapi-util.o
  CC      qobject/qnull.o
  CC      qobject/qint.o
  CC      qobject/qstring.o
  CC      qobject/qdict.o
  CC      qobject/qlist.o
  CC      qobject/qfloat.o
  CC      qobject/qbool.o
  CC      qobject/qjson.o
  CC      qobject/qobject.o
  CC      qobject/json-lexer.o
  CC      qobject/json-streamer.o
  CC      qobject/json-parser.o
  GEN     trace/generated-events.c
  CC      trace/simple.o
  GEN     trace/generated-tracers.c
  CC      trace/control.o
  CC      trace/qmp.o
  CC      util/osdep.o
  CC      util/cutils.o
  CC      util/unicode.o
  CC      util/qemu-timer-common.o
  CC      util/bufferiszero.o
  CC      util/event_notifier-win32.o
  CC      util/oslib-win32.o
  CC      util/qemu-thread-win32.o
  CC      util/envlist.o
  CC      util/path.o
  CC      util/module.o
  CC      util/bitmap.o
  CC      util/bitops.o
  CC      util/hbitmap.o
  CC      util/fifo8.o
  CC      util/acl.o
  CC      util/error.o
  CC      util/qemu-error.o
  CC      util/id.o
/tmp/qemu-test/src/util/qemu-thread-win32.c: In function 'qemu_event_reset':
/tmp/qemu-test/src/util/qemu-thread-win32.c:291:14: error: variable 'value' set but not used [-Werror=unused-but-set-variable]
     unsigned value;
              ^~~~~
cc1: all warnings being treated as errors
/tmp/qemu-test/src/rules.mak:60: recipe for target 'util/qemu-thread-win32.o' failed
make: *** [util/qemu-thread-win32.o] Error 1
make: *** Waiting for unfinished jobs....
tests/docker/Makefile.include:107: recipe for target 'docker-run-test-mingw@fedora' failed
make: *** [docker-run-test-mingw@fedora] Error 2
=== OUTPUT END ===

Test command exited with code: 2


---
Email generated automatically by Patchew [http://patchew.org/].
Please send your feedback to patchew-devel@freelists.org

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 2/5] cpus: use atomic_read to read seqlock-protected variables
  2016-10-10 13:59 ` [Qemu-devel] [PATCH 2/5] cpus: use atomic_read to read seqlock-protected variables Paolo Bonzini
@ 2016-10-12  8:44   ` Alex Bennée
  2016-10-13 19:20   ` Emilio G. Cota
  1 sibling, 0 replies; 26+ messages in thread
From: Alex Bennée @ 2016-10-12  8:44 UTC (permalink / raw)
  To: Paolo Bonzini; +Cc: qemu-devel, cota


Paolo Bonzini <pbonzini@redhat.com> writes:

> There is a data race if the variable is written concurrently to the
> read.  In C11 this has undefined behavior.  Use atomic_read.  The
> write side does not need atomic_set, because it is protected by a
> mutex.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

> ---
>  cpus.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/cpus.c b/cpus.c
> index b2fbe33..3fc2f6e 100644
> --- a/cpus.c
> +++ b/cpus.c
> @@ -170,7 +170,8 @@ int64_t cpu_get_icount_raw(void)
>  static int64_t cpu_get_icount_locked(void)
>  {
>      int64_t icount = cpu_get_icount_raw();
> -    return timers_state.qemu_icount_bias + cpu_icount_to_ns(icount);
> +    int64_t ns = cpu_icount_to_ns(icount);
> +    return atomic_read(&timers_state.qemu_icount_bias) + ns;
>  }
>
>  int64_t cpu_get_icount(void)
> @@ -206,7 +207,7 @@ int64_t cpu_get_ticks(void)
>      }
>
>      ticks = timers_state.cpu_ticks_offset;
> -    if (timers_state.cpu_ticks_enabled) {
> +    if (atomic_read(&timers_state.cpu_ticks_enabled)) {
>          ticks += cpu_get_host_ticks();
>      }
>
> @@ -225,8 +226,8 @@ static int64_t cpu_get_clock_locked(void)
>  {
>      int64_t time;
>
> -    time = timers_state.cpu_clock_offset;
> -    if (timers_state.cpu_ticks_enabled) {
> +    time = atomic_read(&timers_state.cpu_clock_offset);
> +    if (atomic_read(&timers_state.cpu_ticks_enabled)) {
>          time += get_clock();
>      }


--
Alex Bennée

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 3/5] qemu-thread: use acquire/release to clarify semantics of QemuEvent
  2016-10-10 13:59 ` [Qemu-devel] [PATCH 3/5] qemu-thread: use acquire/release to clarify semantics of QemuEvent Paolo Bonzini
@ 2016-10-12  9:21   ` Alex Bennée
  2016-10-12  9:31     ` Paolo Bonzini
  0 siblings, 1 reply; 26+ messages in thread
From: Alex Bennée @ 2016-10-12  9:21 UTC (permalink / raw)
  To: Paolo Bonzini; +Cc: qemu-devel, cota


Paolo Bonzini <pbonzini@redhat.com> writes:

> Do not use the somewhat mysterious atomic_mb_read/atomic_mb_set,
> instead make sure that the operations on QemuEvent are annotated
> with the desired acquire and release semantics.
>
> In particular, qemu_event_set wakes up the waiting thread, so it must
> be a release from the POV of the waker (compare with qemu_mutex_unlock).
> And it actually needs a full barrier, because that's the only thing that
> provides something like a "load-release".
>
> Use smp_mb_acquire until we have atomic_load_acquire and
> atomic_store_release in atomic.h.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  util/qemu-thread-posix.c | 15 ++++++++++++---
>  util/qemu-thread-win32.c | 15 ++++++++++++---
>  2 files changed, 24 insertions(+), 6 deletions(-)
>
> diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
> index 74a3023..ce51b37 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) {
>              /*
> diff --git a/util/qemu-thread-win32.c b/util/qemu-thread-win32.c
> index 98a5ddf..dcdc014 100644
> --- a/util/qemu-thread-win32.c
> +++ b/util/qemu-thread-win32.c
> @@ -274,7 +274,11 @@ 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.  */
>              SetEvent(ev->event);
> @@ -284,7 +288,11 @@ 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 (atomic_read(&ev->value) == EV_SET) {
>          /* If there was a concurrent reset (or even reset+wait),
>           * do nothing.  Otherwise change EV_SET->EV_FREE.

Why are we saving value here? We never use it.

>           */
> @@ -296,7 +304,8 @@ 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) {
>              /* qemu_event_set is not yet going to call SetEvent, but we are


--
Alex Bennée

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 5/5] atomic: base mb_read/mb_set on load-acquire and store-release
  2016-10-10 13:59 ` [Qemu-devel] [PATCH 5/5] atomic: base mb_read/mb_set on load-acquire and store-release Paolo Bonzini
@ 2016-10-12  9:28   ` Alex Bennée
  2016-10-12  9:30     ` Paolo Bonzini
  2016-10-20 18:36   ` Pranith Kumar
  1 sibling, 1 reply; 26+ messages in thread
From: Alex Bennée @ 2016-10-12  9:28 UTC (permalink / raw)
  To: Paolo Bonzini; +Cc: qemu-devel, cota


Paolo Bonzini <pbonzini@redhat.com> writes:

> This introduces load-acquire and store-release operations in QEMU.
> For now, just use them as an implementation detail of atomic_mb_read
> and atomic_mb_set.
>
> Since docs/atomics.txt documents that atomic_mb_read only synchronizes
> with an atomic_mb_set of the same variable, we can use the new implementation
> everywhere instead of seq-cst loads and stores.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
<snip>

> +/* This is more efficient than a store plus a fence.  */
> +#if defined(__i386__) || defined(__x86_64__) || defined(__s390x__)
> +#define atomic_mb_set(ptr, i)  ((void)atomic_xchg(ptr, i))
> +#endif

Is this working around a compiler issue? Shouldn't it already be using
the best instructions for the constraint?

> +
> +#ifndef atomic_mb_read
> +#define atomic_mb_read(ptr)                             \
> +    atomic_load_acquire(ptr)
> +#endif
> +
> +#ifndef atomic_mb_set
> +#define atomic_mb_set(ptr, i)  do {                     \
> +    atomic_store_release(ptr, i);                       \
> +    smp_mb();                                           \
> +} while(0)
> +#endif
> +
>  #endif /* QEMU_ATOMIC_H */


--
Alex Bennée

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 5/5] atomic: base mb_read/mb_set on load-acquire and store-release
  2016-10-12  9:28   ` Alex Bennée
@ 2016-10-12  9:30     ` Paolo Bonzini
  0 siblings, 0 replies; 26+ messages in thread
From: Paolo Bonzini @ 2016-10-12  9:30 UTC (permalink / raw)
  To: Alex Bennée; +Cc: qemu-devel, cota



On 12/10/2016 11:28, Alex Bennée wrote:
> 
> Paolo Bonzini <pbonzini@redhat.com> writes:
> 
>> This introduces load-acquire and store-release operations in QEMU.
>> For now, just use them as an implementation detail of atomic_mb_read
>> and atomic_mb_set.
>>
>> Since docs/atomics.txt documents that atomic_mb_read only synchronizes
>> with an atomic_mb_set of the same variable, we can use the new implementation
>> everywhere instead of seq-cst loads and stores.
>>
>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>> ---
> <snip>
> 
>> +/* This is more efficient than a store plus a fence.  */
>> +#if defined(__i386__) || defined(__x86_64__) || defined(__s390x__)
>> +#define atomic_mb_set(ptr, i)  ((void)atomic_xchg(ptr, i))
>> +#endif
> 
> Is this working around a compiler issue? Shouldn't it already be using
> the best instructions for the constraint?

Store release + memory barrier can be compiled into a seqcst store, and
is more efficient if you have a single instruction for that purpose, but
I don't know of any compiler that does it.

Paolo

>> +
>> +#ifndef atomic_mb_read
>> +#define atomic_mb_read(ptr)                             \
>> +    atomic_load_acquire(ptr)
>> +#endif
>> +
>> +#ifndef atomic_mb_set
>> +#define atomic_mb_set(ptr, i)  do {                     \
>> +    atomic_store_release(ptr, i);                       \
>> +    smp_mb();                                           \
>> +} while(0)
>> +#endif
>> +
>>  #endif /* QEMU_ATOMIC_H */
> 
> 
> --
> Alex Bennée
> 

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 3/5] qemu-thread: use acquire/release to clarify semantics of QemuEvent
  2016-10-12  9:21   ` Alex Bennée
@ 2016-10-12  9:31     ` Paolo Bonzini
  0 siblings, 0 replies; 26+ messages in thread
From: Paolo Bonzini @ 2016-10-12  9:31 UTC (permalink / raw)
  To: Alex Bennée; +Cc: qemu-devel, cota



On 12/10/2016 11:21, Alex Bennée wrote:
> 
> Paolo Bonzini <pbonzini@redhat.com> writes:
> 
>> Do not use the somewhat mysterious atomic_mb_read/atomic_mb_set,
>> instead make sure that the operations on QemuEvent are annotated
>> with the desired acquire and release semantics.
>>
>> In particular, qemu_event_set wakes up the waiting thread, so it must
>> be a release from the POV of the waker (compare with qemu_mutex_unlock).
>> And it actually needs a full barrier, because that's the only thing that
>> provides something like a "load-release".
>>
>> Use smp_mb_acquire until we have atomic_load_acquire and
>> atomic_store_release in atomic.h.
>>
>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>> ---
>>  util/qemu-thread-posix.c | 15 ++++++++++++---
>>  util/qemu-thread-win32.c | 15 ++++++++++++---
>>  2 files changed, 24 insertions(+), 6 deletions(-)
>>
>> diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
>> index 74a3023..ce51b37 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) {
>>              /*
>> diff --git a/util/qemu-thread-win32.c b/util/qemu-thread-win32.c
>> index 98a5ddf..dcdc014 100644
>> --- a/util/qemu-thread-win32.c
>> +++ b/util/qemu-thread-win32.c
>> @@ -274,7 +274,11 @@ 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.  */
>>              SetEvent(ev->event);
>> @@ -284,7 +288,11 @@ 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 (atomic_read(&ev->value) == EV_SET) {
>>          /* If there was a concurrent reset (or even reset+wait),
>>           * do nothing.  Otherwise change EV_SET->EV_FREE.
> 
> Why are we saving value here? We never use it.

It should be used in the "if", and patchew rightly complained.  I didn't
run the docker-test-mingw compilation on this series.

Paolo

> 
>>           */
>> @@ -296,7 +304,8 @@ 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) {
>>              /* qemu_event_set is not yet going to call SetEvent, but we are
> 
> 
> --
> Alex Bennée
> 

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements
  2016-10-10 13:59 [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements Paolo Bonzini
                   ` (6 preceding siblings ...)
  2016-10-11 19:21 ` no-reply
@ 2016-10-12 11:32 ` Alex Bennée
  2016-10-12 11:34   ` Paolo Bonzini
  2016-10-12 22:45 ` Emilio G. Cota
  2016-10-21 17:38 ` Alex Bennée
  9 siblings, 1 reply; 26+ messages in thread
From: Alex Bennée @ 2016-10-12 11:32 UTC (permalink / raw)
  To: Paolo Bonzini; +Cc: qemu-devel, cota


Paolo Bonzini <pbonzini@redhat.com> writes:

> See each patch.  My attempt at fixing whatever I did when I obviously
> didn't know enough^W about the C11 memory model, and at setting a
> better example for future generations...

Have you had a chance to check up on any of the errors "make check"
throws up with the sanitizer on?

>
> Paolo Bonzini (5):
>   atomic: introduce smp_mb_acquire and smp_mb_release
>   cpus: use atomic_read to read seqlock-protected variables
>   qemu-thread: use acquire/release to clarify semantics of QemuEvent
>   rcu: simplify memory barriers
>   atomic: base mb_read/mb_set on load-acquire and store-release
>
>  cpus.c                   |   9 +--
>  docs/atomics.txt         |  84 ++++++++++++++++------------
>  include/qemu/atomic.h    | 139 ++++++++++++++++++++---------------------------
>  util/qemu-thread-posix.c |  15 ++++-
>  util/qemu-thread-win32.c |  15 ++++-
>  util/rcu.c               |  11 ++--
>  6 files changed, 143 insertions(+), 130 deletions(-)


--
Alex Bennée

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements
  2016-10-12 11:32 ` Alex Bennée
@ 2016-10-12 11:34   ` Paolo Bonzini
  0 siblings, 0 replies; 26+ messages in thread
From: Paolo Bonzini @ 2016-10-12 11:34 UTC (permalink / raw)
  To: Alex Bennée; +Cc: qemu-devel, cota



On 12/10/2016 13:32, Alex Bennée wrote:
> > See each patch.  My attempt at fixing whatever I did when I obviously
> > didn't know enough^W about the C11 memory model, and at setting a
> > better example for future generations...
> 
> Have you had a chance to check up on any of the errors "make check"
> throws up with the sanitizer on?

No, I haven't.  This is all stuff that I learnt while preparing my
slides, and except for patch 2 it's unrelated to sanitizer.

Paolo

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements
  2016-10-10 13:59 [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements Paolo Bonzini
                   ` (7 preceding siblings ...)
  2016-10-12 11:32 ` Alex Bennée
@ 2016-10-12 22:45 ` Emilio G. Cota
  2016-10-13  7:39   ` Paolo Bonzini
  2016-10-21 17:38 ` Alex Bennée
  9 siblings, 1 reply; 26+ messages in thread
From: Emilio G. Cota @ 2016-10-12 22:45 UTC (permalink / raw)
  To: Paolo Bonzini; +Cc: qemu-devel, alex.bennee

On Mon, Oct 10, 2016 at 15:59:02 +0200, Paolo Bonzini wrote:
> See each patch.  My attempt at fixing whatever I did when I obviously
> didn't know enough^W about the C11 memory model, and at setting a
> better example for future generations...

Just for context. Building on this patchset, is it now time to
phase out smp_(rw)mb in favour or C11's acq/rel, as you laid
out in your KVM Forum talk [*]?

What is the plan with smp_mb_(sg)et? It's not clear to me from
the slides, but given patch 5 I don't see a reason to keep them.

Thanks,

		Emilio

[*] http://events.linuxfoundation.org/sites/events/files/slides/kvmforum16-atomic2.pdf

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements
  2016-10-12 22:45 ` Emilio G. Cota
@ 2016-10-13  7:39   ` Paolo Bonzini
  2016-10-13 19:29     ` Emilio G. Cota
  0 siblings, 1 reply; 26+ messages in thread
From: Paolo Bonzini @ 2016-10-13  7:39 UTC (permalink / raw)
  To: Emilio G. Cota; +Cc: qemu-devel, alex bennee

> On Mon, Oct 10, 2016 at 15:59:02 +0200, Paolo Bonzini wrote:
> > See each patch.  My attempt at fixing whatever I did when I obviously
> > didn't know enough^W about the C11 memory model, and at setting a
> > better example for future generations...
> 
> Just for context. Building on this patchset, is it now time to
> phase out smp_(rw)mb in favour or C11's acq/rel, as you laid
> out in your KVM Forum talk [*]?

Yes, this would be the start of it.  However I'm a bit undecided
because ARMv8 doesn't have acq/rel memory barriers, and its STLR
opcode is stronger than a store release.

> What is the plan with smp_mb_(sg)et? It's not clear to me from
> the slides, but given patch 5 I don't see a reason to keep them.

No plan for now.  It makes sense to phase out at least atomic_mb_read.
atomic_mb_set is more efficient on x86 than store+mfence, so there's
that too.

Paolo

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 2/5] cpus: use atomic_read to read seqlock-protected variables
  2016-10-10 13:59 ` [Qemu-devel] [PATCH 2/5] cpus: use atomic_read to read seqlock-protected variables Paolo Bonzini
  2016-10-12  8:44   ` Alex Bennée
@ 2016-10-13 19:20   ` Emilio G. Cota
  2016-10-13 20:45     ` Paolo Bonzini
  1 sibling, 1 reply; 26+ messages in thread
From: Emilio G. Cota @ 2016-10-13 19:20 UTC (permalink / raw)
  To: Paolo Bonzini; +Cc: qemu-devel, alex.bennee

On Mon, Oct 10, 2016 at 15:59:04 +0200, Paolo Bonzini wrote:
> There is a data race if the variable is written concurrently to the
> read.  In C11 this has undefined behavior.  Use atomic_read.  The
> write side does not need atomic_set, because it is protected by a
> mutex.

Is tsan happy with the way seqlocks are written right now?

According to this message I just found by Dmitry Vyukov, tsan
shouldn't be. Note however that the message is from April'15,
so it might be outdated:

Dmitry Vyukov wrote:
> 1. Tsan is bad at handling stand-alone memory barriers. 
<snip>
> And here is a way to express seqlock that is both correct, is 
> understood by tsan and is no overhead on x86: 
> 
> // writer 
> atomic_store(&seq, seq+1, memory_order_relaxed); 
> atomic_store(&data[0], ..., memory_order_release); 
> ... 
> atomic_store(&data[N], ..., memory_order_release); 
> atomic_store(&seq, seq+1, memory_order_release); 
> 
> // reader 
> atomic_load(&seq, memory_order_acquire); 
> d0 = atomic_load(&data[0], memory_order_acquire); 
> ... 
> dN = atomic_load(&data[N], memory_order_acquire); 
> atomic_load(&seq, memory_order_relaxed); 

Source: https://groups.google.com/forum/#!topic/thread-sanitizer/B4i9EMQ4BQE

Thanks,

		Emilio

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements
  2016-10-13  7:39   ` Paolo Bonzini
@ 2016-10-13 19:29     ` Emilio G. Cota
  2016-10-14  9:55       ` Paolo Bonzini
  0 siblings, 1 reply; 26+ messages in thread
From: Emilio G. Cota @ 2016-10-13 19:29 UTC (permalink / raw)
  To: Paolo Bonzini; +Cc: qemu-devel, alex bennee

On Thu, Oct 13, 2016 at 03:39:55 -0400, Paolo Bonzini wrote:
> > On Mon, Oct 10, 2016 at 15:59:02 +0200, Paolo Bonzini wrote:
> > > See each patch.  My attempt at fixing whatever I did when I obviously
> > > didn't know enough^W about the C11 memory model, and at setting a
> > > better example for future generations...
> > 
> > Just for context. Building on this patchset, is it now time to
> > phase out smp_(rw)mb in favour or C11's acq/rel, as you laid
> > out in your KVM Forum talk [*]?
> 
> Yes, this would be the start of it.  However I'm a bit undecided
> because ARMv8 doesn't have acq/rel memory barriers, and its STLR
> opcode is stronger than a store release.
> 
> > What is the plan with smp_mb_(sg)et? It's not clear to me from
> > the slides, but given patch 5 I don't see a reason to keep them.
> 
> No plan for now.  It makes sense to phase out at least atomic_mb_read.
> atomic_mb_set is more efficient on x86 than store+mfence, so there's
> that too.

I see, thanks.

On a related note: can we squeeze the appended in this patch set? If
we keep the atomic_mb's, at least there should be a good reason for their
use--this is not the case below.

		Emilio

commit cffdc51df4a6346f2b38425f1f1251aa12866fa8
Author: Emilio G. Cota <cota@braap.org>
Date:   Thu Oct 13 15:06:07 2016 -0400

    qht-bench: relax test_start/stop atomic accesses
    
    test_start/stop are used only as flags to loop on. Barriers are unnecessary,
    since no dependent data is transferred among threads apart from the flags
    themselves.
    
    This commit relaxes the three accesses to test_start/stop that were
    not yet relaxed.
    
    Signed-off-by: Emilio G. Cota <cota@braap.org>

diff --git a/tests/qht-bench.c b/tests/qht-bench.c
index 76360a0..2afa09d 100644
--- a/tests/qht-bench.c
+++ b/tests/qht-bench.c
@@ -193,7 +193,7 @@ static void *thread_func(void *p)
     rcu_register_thread();
 
     atomic_inc(&n_ready_threads);
-    while (!atomic_mb_read(&test_start)) {
+    while (!atomic_read(&test_start)) {
         cpu_relax();
     }
 
@@ -393,11 +393,11 @@ static void run_test(void)
     while (atomic_read(&n_ready_threads) != n_rw_threads + n_rz_threads) {
         cpu_relax();
     }
-    atomic_mb_set(&test_start, true);
+    atomic_set(&test_start, true);
     do {
         remaining = sleep(duration);
     } while (remaining);
-    atomic_mb_set(&test_stop, true);
+    atomic_set(&test_stop, true);
 
     for (i = 0; i < n_rw_threads; i++) {
         qemu_thread_join(&rw_threads[i]);

^ permalink raw reply related	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 2/5] cpus: use atomic_read to read seqlock-protected variables
  2016-10-13 19:20   ` Emilio G. Cota
@ 2016-10-13 20:45     ` Paolo Bonzini
  0 siblings, 0 replies; 26+ messages in thread
From: Paolo Bonzini @ 2016-10-13 20:45 UTC (permalink / raw)
  To: Emilio G. Cota; +Cc: qemu-devel, alex bennee

> Is tsan happy with the way seqlocks are written right now?

I honestly don't know.  But if there are tsan bugs there's
not much we can do.  The alternative below has overhead on
ARM and PPC and does not quite fit in atomic.h.

In any case, a bigger issue is that this patch breaks on
32-bit because it does 64-bit atomic_read.  We might have
to fall back to volatile when not running on tsan.

Paolo

> Dmitry Vyukov wrote:
> > 1. Tsan is bad at handling stand-alone memory barriers.
> > And here is a way to express seqlock that is both correct, is
> > understood by tsan and is no overhead on x86:
> > 
> > // writer
> > atomic_store(&seq, seq+1, memory_order_relaxed);
> > atomic_store(&data[0], ..., memory_order_release);
> > ...
> > atomic_store(&data[N], ..., memory_order_release);
> > atomic_store(&seq, seq+1, memory_order_release);
> > 
> > // reader
> > atomic_load(&seq, memory_order_acquire);
> > d0 = atomic_load(&data[0], memory_order_acquire);
> > ...
> > dN = atomic_load(&data[N], memory_order_acquire);
> > atomic_load(&seq, memory_order_relaxed);
> 
> Source: https://groups.google.com/forum/#!topic/thread-sanitizer/B4i9EMQ4BQE
> 
> Thanks,
> 
> 		Emilio
> 

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements
  2016-10-13 19:29     ` Emilio G. Cota
@ 2016-10-14  9:55       ` Paolo Bonzini
  0 siblings, 0 replies; 26+ messages in thread
From: Paolo Bonzini @ 2016-10-14  9:55 UTC (permalink / raw)
  To: Emilio G. Cota; +Cc: qemu-devel, alex bennee



On 13/10/2016 21:29, Emilio G. Cota wrote:
>     qht-bench: relax test_start/stop atomic accesses
>     
>     test_start/stop are used only as flags to loop on. Barriers are unnecessary,
>     since no dependent data is transferred among threads apart from the flags
>     themselves.
>     
>     This commit relaxes the three accesses to test_start/stop that were
>     not yet relaxed.
>     
>     Signed-off-by: Emilio G. Cota <cota@braap.org>

Sure, added this as a separate patch.

Paolo

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 5/5] atomic: base mb_read/mb_set on load-acquire and store-release
  2016-10-10 13:59 ` [Qemu-devel] [PATCH 5/5] atomic: base mb_read/mb_set on load-acquire and store-release Paolo Bonzini
  2016-10-12  9:28   ` Alex Bennée
@ 2016-10-20 18:36   ` Pranith Kumar
  1 sibling, 0 replies; 26+ messages in thread
From: Pranith Kumar @ 2016-10-20 18:36 UTC (permalink / raw)
  To: Paolo Bonzini; +Cc: qemu-devel, Emilio G. Cota, Alex Bennée

Hi,

On Mon, Oct 10, 2016 at 9:59 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> This introduces load-acquire and store-release operations in QEMU.
> For now, just use them as an implementation detail of atomic_mb_read
> and atomic_mb_set.
>
> Since docs/atomics.txt documents that atomic_mb_read only synchronizes
> with an atomic_mb_set of the same variable, we can use the new implementation
> everywhere instead of seq-cst loads and stores.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  docs/atomics.txt      |  5 +--
>  include/qemu/atomic.h | 93 +++++++++++++++++----------------------------------
>  2 files changed, 34 insertions(+), 64 deletions(-)
>
> diff --git a/docs/atomics.txt b/docs/atomics.txt
> index 5cd8e32..9a1f8aa 100644
> --- a/docs/atomics.txt
> +++ b/docs/atomics.txt
> @@ -374,8 +374,9 @@ and memory barriers, and the equivalents in QEMU:
>    note that smp_store_mb() is a little weaker than atomic_mb_set().
>    atomic_mb_read() compiles to the same instructions as Linux's
>    smp_load_acquire(), but this should be treated as an implementation
> -  detail.  If required, QEMU might later add atomic_load_acquire() and
> -  atomic_store_release() macros.
> +  detail.  QEMU does have atomic_load_acquire() and atomic_store_release()
> +  macros, but for now they are only used within atomic.h.  This may
> +  change in the future.
>
>
>  SOURCES
> diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h
> index b108df0..d940e98 100644
> --- a/include/qemu/atomic.h
> +++ b/include/qemu/atomic.h
> @@ -135,44 +135,18 @@
>      __atomic_store_n(ptr, i, __ATOMIC_RELEASE);       \
>  } while(0)
>
> -/* atomic_mb_read/set semantics map Java volatile variables. They are
> - * less expensive on some platforms (notably POWER & ARMv7) than fully
> - * sequentially consistent operations.
> - *
> - * As long as they are used as paired operations they are safe to
> - * use. See docs/atomic.txt for more discussion.
> - */
> -
> -#if defined(_ARCH_PPC)
> -#define atomic_mb_read(ptr)                             \
> -    ({                                                  \
> -    QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *));   \
> -    typeof_strip_qual(*ptr) _val;                       \
> -     __atomic_load(ptr, &_val, __ATOMIC_RELAXED);       \
> -     smp_mb_acquire();                                  \
> -    _val;                                               \
> -    })
> -
> -#define atomic_mb_set(ptr, i)  do {                     \
> -    QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *));   \
> -    smp_mb_release();                                   \
> -    __atomic_store_n(ptr, i, __ATOMIC_RELAXED);         \
> -    smp_mb();                                           \
> -} while(0)
> -#else
> -#define atomic_mb_read(ptr)                             \
> +#define atomic_load_acquire(ptr)                        \
>      ({                                                  \
>      QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *));   \
>      typeof_strip_qual(*ptr) _val;                       \
> -    __atomic_load(ptr, &_val, __ATOMIC_SEQ_CST);        \
> +    __atomic_load(ptr, &_val, __ATOMIC_ACQUIRE);        \
>      _val;                                               \
>      })
>

Is there any reason we are not using __atomic_load_n() here?

--
Pranith

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements
  2016-10-10 13:59 [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements Paolo Bonzini
                   ` (8 preceding siblings ...)
  2016-10-12 22:45 ` Emilio G. Cota
@ 2016-10-21 17:38 ` Alex Bennée
  2016-10-22  9:10   ` Paolo Bonzini
  9 siblings, 1 reply; 26+ messages in thread
From: Alex Bennée @ 2016-10-21 17:38 UTC (permalink / raw)
  To: Paolo Bonzini; +Cc: qemu-devel, cota


Paolo Bonzini <pbonzini@redhat.com> writes:

> See each patch.  My attempt at fixing whatever I did when I obviously
> didn't know enough^W about the C11 memory model, and at setting a
> better example for future generations...

Are you posting a v2 of this? Alternatively I can slurp them into my
next patch set as I've got a whole bunch more tsan related fixes that
are not directly MTTCG related currently in my MTTCG tree:

  https://github.com/stsquad/qemu/commits/mttcg/base-patches-v5

>
> Paolo Bonzini (5):
>   atomic: introduce smp_mb_acquire and smp_mb_release
>   cpus: use atomic_read to read seqlock-protected variables
>   qemu-thread: use acquire/release to clarify semantics of QemuEvent
>   rcu: simplify memory barriers
>   atomic: base mb_read/mb_set on load-acquire and store-release
>
>  cpus.c                   |   9 +--
>  docs/atomics.txt         |  84 ++++++++++++++++------------
>  include/qemu/atomic.h    | 139 ++++++++++++++++++++---------------------------
>  util/qemu-thread-posix.c |  15 ++++-
>  util/qemu-thread-win32.c |  15 ++++-
>  util/rcu.c               |  11 ++--
>  6 files changed, 143 insertions(+), 130 deletions(-)


--
Alex Bennée

^ permalink raw reply	[flat|nested] 26+ messages in thread

* Re: [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements
  2016-10-21 17:38 ` Alex Bennée
@ 2016-10-22  9:10   ` Paolo Bonzini
  0 siblings, 0 replies; 26+ messages in thread
From: Paolo Bonzini @ 2016-10-22  9:10 UTC (permalink / raw)
  To: Alex Bennée; +Cc: qemu-devel, cota



----- Original Message -----
> From: "Alex Bennée" <alex.bennee@linaro.org>
> To: "Paolo Bonzini" <pbonzini@redhat.com>
> Cc: qemu-devel@nongnu.org, cota@braap.org
> Sent: Friday, October 21, 2016 7:38:13 PM
> Subject: Re: [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements
> 
> 
> Paolo Bonzini <pbonzini@redhat.com> writes:
> 
> > See each patch.  My attempt at fixing whatever I did when I obviously
> > didn't know enough^W about the C11 memory model, and at setting a
> > better example for future generations...
> 
> Are you posting a v2 of this? Alternatively I can slurp them into my
> next patch set as I've got a whole bunch more tsan related fixes that
> are not directly MTTCG related currently in my MTTCG tree:
> 
>   https://github.com/stsquad/qemu/commits/mttcg/base-patches-v5

I'm posting a pull request early next week.

Paolo

> >
> > Paolo Bonzini (5):
> >   atomic: introduce smp_mb_acquire and smp_mb_release
> >   cpus: use atomic_read to read seqlock-protected variables
> >   qemu-thread: use acquire/release to clarify semantics of QemuEvent
> >   rcu: simplify memory barriers
> >   atomic: base mb_read/mb_set on load-acquire and store-release
> >
> >  cpus.c                   |   9 +--
> >  docs/atomics.txt         |  84 ++++++++++++++++------------
> >  include/qemu/atomic.h    | 139
> >  ++++++++++++++++++++---------------------------
> >  util/qemu-thread-posix.c |  15 ++++-
> >  util/qemu-thread-win32.c |  15 ++++-
> >  util/rcu.c               |  11 ++--
> >  6 files changed, 143 insertions(+), 130 deletions(-)
> 
> 
> --
> Alex Bennée
> 

^ permalink raw reply	[flat|nested] 26+ messages in thread

end of thread, other threads:[~2016-10-22  9:10 UTC | newest]

Thread overview: 26+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-10-10 13:59 [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements Paolo Bonzini
2016-10-10 13:59 ` [Qemu-devel] [PATCH 1/5] atomic: introduce smp_mb_acquire and smp_mb_release Paolo Bonzini
2016-10-10 15:29   ` Eric Blake
2016-10-10 16:38     ` Paolo Bonzini
2016-10-10 13:59 ` [Qemu-devel] [PATCH 2/5] cpus: use atomic_read to read seqlock-protected variables Paolo Bonzini
2016-10-12  8:44   ` Alex Bennée
2016-10-13 19:20   ` Emilio G. Cota
2016-10-13 20:45     ` Paolo Bonzini
2016-10-10 13:59 ` [Qemu-devel] [PATCH 3/5] qemu-thread: use acquire/release to clarify semantics of QemuEvent Paolo Bonzini
2016-10-12  9:21   ` Alex Bennée
2016-10-12  9:31     ` Paolo Bonzini
2016-10-10 13:59 ` [Qemu-devel] [PATCH 4/5] rcu: simplify memory barriers Paolo Bonzini
2016-10-10 13:59 ` [Qemu-devel] [PATCH 5/5] atomic: base mb_read/mb_set on load-acquire and store-release Paolo Bonzini
2016-10-12  9:28   ` Alex Bennée
2016-10-12  9:30     ` Paolo Bonzini
2016-10-20 18:36   ` Pranith Kumar
2016-10-10 16:53 ` [Qemu-devel] [PATCH 0/5] More thread sanitizer fixes and atomic.h improvements no-reply
2016-10-11 19:21 ` no-reply
2016-10-12 11:32 ` Alex Bennée
2016-10-12 11:34   ` Paolo Bonzini
2016-10-12 22:45 ` Emilio G. Cota
2016-10-13  7:39   ` Paolo Bonzini
2016-10-13 19:29     ` Emilio G. Cota
2016-10-14  9:55       ` Paolo Bonzini
2016-10-21 17:38 ` Alex Bennée
2016-10-22  9:10   ` Paolo Bonzini

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