Re: [Qemu-devel] [Bug 1180970] *** affects all x86_64 soft emulation

[Luiz Capitulino <lcapitulino@redhat.com>]

On Fri, 24 May 2013 23:23:02 +0200
Laszlo Ersek <lersek@redhat.com> wrote:

> ------------------------------[ proposed fix ]--------------------------
> diff --git a/target-i386/translate.c b/target-i386/translate.c
> index 0e0356f..4fbd6c0 100644
> --- a/target-i386/translate.c
> +++ b/target-i386/translate.c
> @@ -4813,7 +4813,11 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
>              /* 0x66 is ignored if rex.w is set */
>              dflag = 2;
>          }
> -        if (!(prefixes & PREFIX_ADR)) {
> +        if (prefixes & PREFIX_ADR) {
> +            /* flip it back, 0x67 should have no effect */
> +            aflag ^= 1;
> +        }
> +        else {
>              aflag = 2;
>          }
>      }
> ------------------------------[ proposed fix ]--------------------------
> 
> I'll post it separately to the list for review.
> 
> Luiz, can you please test it with Windows guests?

On Windows 8 I can get past the boot loop point and even see Windows' boot
logo, but then I get a black screen (which I guess is the evolution of the
blue screen) asking me to reboot the PC saying "Error Code: 0x0000005D".

That error code is what I get with Windows 2008, with or without or patch.
I googled a bit about it, and it seems to be related to some CPU
incompatibility, which makes me think that this is a difference issue
(meaning that your patch does fix the boot loop bug).