i386: interrupt poll processing

This patch updates x86_cpu_exec_interrupt function.
It can process two interrupt request at a time (poll and another one).
This makes its execution non-deterministic. Determinism is requred
for recorded icount execution.

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20150917162410.8676.13042.stgit@PASHA-ISP.def.inno>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

target-i386/seg_helper.c

diff --git a/target-i386/seg_helper.c b/target-i386/seg_helper.c
index 1a3a2e7..1cbe559 100644
--- a/target-i386/seg_helper.c
+++ b/target-i386/seg_helper.c
@@ -1321,6 +1321,9 @@
     if (interrupt_request & CPU_INTERRUPT_POLL) {
         cs->interrupt_request &= ~CPU_INTERRUPT_POLL;
         apic_poll_irq(cpu->apic_state);
+        /* Don't process multiple interrupt requests in a single call.
+           This is required to make icount-driven execution deterministic. */
+        return true;
     }
 #endif
     if (interrupt_request & CPU_INTERRUPT_SIPI) {