1 files changed, 15 insertions, 1 deletions

diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index ffb236544270..32980b834935 100644
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -1030,7 +1030,21 @@ ENTRY(xen_hypervisor_callback)
         CFI_ADJUST_CFA_OFFSET 4
         SAVE_ALL
         TRACE_IRQS_OFF
-        mov %esp, %eax
+
+        /* Check to see if we got the event in the critical
+           region in xen_iret_direct, after we've reenabled
+           events and checked for pending events.  This simulates
+           iret instruction's behaviour where it delivers a
+           pending interrupt when enabling interrupts. */
+        movl PT_EIP(%esp),%eax
+        cmpl $xen_iret_start_crit,%eax
+        jb   1f
+        cmpl $xen_iret_end_crit,%eax
+        jae  1f
+
+        call xen_iret_crit_fixup
+
+1:      mov %esp, %eax
         call xen_evtchn_do_upcall
         jmp  ret_from_intr
         CFI_ENDPROC