Re: [Qemu-devel] [Bug 788697] Re: [PowerPC] [patch] mtmsr does not preserve high bits of MSR

[Alexander Graf]

On 26.05.2011, at 18:09, Nathan Whitehorn wrote:

> ** Patch added: "mtmstr.diff"
>   
> https://bugs.launchpad.net/bugs/788697/+attachment/2143748/+files/mtmstr.diff
> 
> -- 
> You received this bug notification because you are a member of qemu-
> devel-ml, which is subscribed to QEMU.
> https://bugs.launchpad.net/bugs/788697
> 
> Title:
>  [PowerPC] [patch] mtmsr does not preserve high bits of MSR
> 
> Status in QEMU:
>  New
> 
> Bug description:
>  The mtmsr instruction on 64-bit PPC does not preserve the high-order
>  32-bits of the MSR the way it is supposed to, instead setting them to
>  0, which takes 64-bit code out of 64-bit mode. There is some code that
>  does the right thing, but it brokenly only preserves these bits when
>  the thread is not in 64-bit mode (i.e. when it doesn't matter). The
>  attached patch unconditionally enables this code when TARGET_PPC64 is
>  set, per the ISA spec, which fixes early boot failures trying to start
>  FreeBSD/powerpc64 under qemu.
> 

Please send the patch as proper patch to the ML and CC me.

Alex