[PATCH v4 09/46] powerpc/64s: remove KVM SKIP test from instruction breakpoint handler

[Paul Mackerras]

On Tue, Mar 23, 2021 at 11:02:28AM +1000, Nicholas Piggin wrote:
> 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).
> 
> Reviewed-by: Daniel Axtens <dja at axtens.net>
> Reviewed-by: Fabiano Rosas <farosas at linux.ibm.com>
> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>

It might be worth noting in the commit message that the 0x1300
interrupt was dropped from the architecture a long time ago and is not
generated by P7, P8, P9 or P10.

Acked-by: Paul Mackerras <paulus at ozlabs.org>