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

* NBD and chardev conversion to QIONetListener (Daniel)
* MTTCG fixes (David)
* Hyper-V fixes (Roman, Evgeny)
* share-rw option (Fam)
* Mux chardev event bugfix (Marc-André)
* Add systemd unit files in contrib/ (me)
* SCSI and block/iscsi.c bugfixes (me, Peter L.)
* unassigned_mem_ops fixes (Peter M.)
* VEX decoding fix (Peter M.)
* "info pic" and "info irq" improvements (Peter Xu)
* vmport trace events (Philippe)
* Braille chardev bugfix (Samuel)
* Compiler warnings fix (Stefan)
* initial support for TCG smoke test of more boards (Thomas)
* New CPU features (Yang)
* Reduce startup memory usage (Yang)
* QemuThread race fix (linhecheng)

# gpg: Signature made Thu 21 Dec 2017 08:30:49 GMT
# gpg:                using RSA key 0xBFFBD25F78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>"
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>"
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* remotes/bonzini/tags/for-upstream: (41 commits)
  chardev: convert the socket server to QIONetListener
  blockdev: convert qemu-nbd server to QIONetListener
  blockdev: convert internal NBD server to QIONetListener
  test: add some chardev mux event tests
  chardev: fix backend events regression with mux chardev
  rcu: reduce more than 7MB heap memory by malloc_trim()
  checkpatch: volatile with a comment or sig_atomic_t is okay
  i8259: move TYPE_INTERRUPT_STATS_PROVIDER upper
  kvm-i8259: support "info pic" and "info irq"
  i8259: generalize statistics into common code
  i8259: use DEBUG_IRQ_COUNT always
  i8259: convert DPRINTFs into trace
  Remove legacy -no-kvm-pit option
  scsi: replace hex constants with #defines
  scsi: provide general-purpose functions to manage sense data
  hw/i386/vmport: replace fprintf() by trace events or LOG_UNIMP
  hw/mips/boston: Remove workaround for writes to ROM aborting
  exec: Don't reuse unassigned_mem_ops for io_mem_rom
  block/iscsi: only report an iSCSI Failure if we don't handle it gracefully
  block/iscsi: dont leave allocmap in an invalid state on UNMAP failure
  ...

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

1 files changed, 3 insertions, 9 deletions

diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index 9b544d88c8..4452cd9856 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -525,19 +525,13 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
                                         TranslationBlock **last_tb)
 {
     CPUClass *cc = CPU_GET_CLASS(cpu);
-    int32_t insns_left;
 
     /* Clear the interrupt flag now since we're processing
      * cpu->interrupt_request and cpu->exit_request.
+     * Ensure zeroing happens before reading cpu->exit_request or
+     * cpu->interrupt_request (see also smp_wmb in cpu_exit())
      */
-    insns_left = atomic_read(&cpu->icount_decr.u32);
-    atomic_set(&cpu->icount_decr.u16.high, 0);
-    if (unlikely(insns_left < 0)) {
-        /* Ensure the zeroing of icount_decr comes before the next read
-         * of cpu->exit_request or cpu->interrupt_request.
-         */
-        smp_mb();
-    }
+    atomic_mb_set(&cpu->icount_decr.u16.high, 0);
 
     if (unlikely(atomic_read(&cpu->interrupt_request))) {
         int interrupt_request;