[PATCH 02/13] powerpc/64s: remove KVM SKIP test from instruction breakpoint handler

[Fabiano Rosas]

Nicholas Piggin <npiggin at gmail.com> writes:

> The code being executed in KVM_GUEST_MODE_SKIP is hypervisor code with
> MSR[IR]=0, so the faults of concern are the d-side ones caused by access
> to guest context by the hypervisor.
>
> Instruction breakpoint interrupts are not a concern here. It's unlikely
> any good would come of causing breaks in this code, but skipping the
> instruction that caused it won't help matters (e.g., skip the mtmsr that
> sets MSR[DR]=0 or clears KVM_GUEST_MODE_SKIP).
>
> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>

Reviewed-by: Fabiano Rosas <farosas at linux.ibm.com>

> ---
>  arch/powerpc/kernel/exceptions-64s.S | 1 -
>  1 file changed, 1 deletion(-)
>
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index 5d0ad3b38e90..5bc689a546ae 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -2597,7 +2597,6 @@ EXC_VIRT_NONE(0x5200, 0x100)
>  INT_DEFINE_BEGIN(instruction_breakpoint)
>  	IVEC=0x1300
>  #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
> -	IKVM_SKIP=1
>  	IKVM_REAL=1
>  #endif
>  INT_DEFINE_END(instruction_breakpoint)