Re: [Qemu-devel] Win2k broken by kvmvapic

[Jan Kiszka <jan.kiszka@web.de>]

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On 2012-10-07 17:23, Blue Swirl wrote:
> Hi,
> 
> Win2k does not work in HEAD, it resets the machine. I bisected this to
> 0b57e287138728f72d88b06e69b970c5d745c44a, but that does not look so
> buggy.
> 
> Digging deeper, the problem is introduced by kvmvapic:
> Breakpoint 1, cpu_physical_memory_write_rom (addr=0xca300,
>     buf=0x7fffec66b500 "", len=0x5) at /src/qemu/exec.c:3536
> 3536                invalidate_and_set_dirty(addr1, l);
> (gdb) bt
> #0  cpu_physical_memory_write_rom (addr=0xca300, buf=0x7fffec66b500 "",
>     len=0x5) at /src/qemu/exec.c:3536
> #1  0x0000000000644089 in apic_sync_vapic (s=0x1a6ba60, sync_type=0x2)
>     at /src/qemu/hw/i386/../apic.c:132
> 
> It looks like vapic is enabled even with KVM disabled

Which is intentional. The VAPIC is provided in a KVM-independent way to
the guest. Used to work fine with XP, but I never had my finger on a 2k
version.

> and this causes
> chaos. With -global apic.vapic=false Win2k works.

And that means we have a bug somewhere. Can you specify the chaos you
see in more details? Does your Win2k boot with KVM (and kvmvapic)?

Jan


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