Re: [PATCH 0/2] KVM: x86: Fix REP-string effect on RCX/RSI/RDI

[Paolo Bonzini <pbonzini@redhat.com>]

On 28/04/2015 12:05, Nadav Amit wrote:
> This patch-set fixes KVM behavior when handling a REP-string instruction that
> runs with an address-size of 32-bit.  In this case ECX/EDI/ESI are used as
> counter and pointers, and the high 32-bits should be cleared.
> 
> The first patch handles with the simple case. The second one handles the
> corner-case in which ECX is initially zero.  It appears that Intel and AMD
> behave differently in this case (and some experiments suggest even different
> Intel generations act differently), and I could not find any documentation that
> describes it. Yet, the behavior of INS/OUTS can be observed by the guest and
> VMware appears to get it right.
> 
> Thanks for reviewing the patches.
> 
> Nadav Amit (2):
>   KVM: x86: Fix update RCX/RDI/RSI on REP-string
>   KVM: x86: Fix zero iterations REP-string
> 
>  arch/x86/kvm/emulate.c | 33 +++++++++++++++++++++++++++------
>  1 file changed, 27 insertions(+), 6 deletions(-)
> 

Applied, thanks.

Paolo