From mboxrd@z Thu Jan  1 00:00:00 1970
From: Kevin O'Connor <kevin@koconnor.net>
Subject: Re: [Qemu-devel] E5-2620v2 - emulation stop error
Date: Wed, 11 Mar 2015 15:19:28 -0400
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Cc: Bandan Das <bsd@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>,
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To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
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On Wed, Mar 11, 2015 at 02:45:31PM -0400, Kevin O'Connor wrote:
> On Wed, Mar 11, 2015 at 02:40:39PM -0400, Kevin O'Connor wrote:
> > For what it's worth, I can't seem to trigger the problem if I move the
> > cmos read above the SIPI/LAPIC code (see patch below).
> 
> Ugh!
> 
> That's a seabios bug.  Main processor modifies the rtc index
> (rtc_read()) while APs try to clear the NMI bit by modifying the rtc
> index (romlayout.S:transition32).
> 
> I'll put together a fix.

The seabios patch below resolves the issue for me.

-Kevin


--- a/src/romlayout.S
+++ b/src/romlayout.S
@@ -22,7 +22,8 @@
 // %edx = return location (in 32bit mode)
 // Clobbers: ecx, flags, segment registers, cr0, idt/gdt
         DECLFUNC transition32
-transition32_for_smi:
+transition32_nmi_off:
+        // transition32 when NMI and A20 are already initialized
         movl %eax, %ecx
         jmp 1f
 transition32:
@@ -205,7 +206,7 @@ __farcall16:
 entry_smi:
         // Transition to 32bit mode.
         movl $1f + BUILD_BIOS_ADDR, %edx
-        jmp transition32_for_smi
+        jmp transition32_nmi_off
         .code32
 1:      movl $BUILD_SMM_ADDR + 0x8000, %esp
         calll _cfunc32flat_handle_smi - BUILD_BIOS_ADDR
@@ -216,8 +217,10 @@ entry_smi:
         DECLFUNC entry_smp
 entry_smp:
         // Transition to 32bit mode.
+        cli
+        cld
         movl $2f + BUILD_BIOS_ADDR, %edx
-        jmp transition32
+        jmp transition32_nmi_off
         .code32
         // Acquire lock and take ownership of shared stack
 1:      rep ; nop