Re: [PATCH v3 4/6] KVM: PPC: mmio: Queue interrupt at kvmppc_emulate_mmio

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 08/01/2022 08:00, Fabiano Rosas wrote:
> If MMIO emulation fails, we queue a Program interrupt to the
> guest. Move that line up into kvmppc_emulate_mmio, which is where we
> set RESUME_GUEST/HOST. This allows the removal of the 'advance'
> variable.
> 
> No functional change, just separation of responsibilities.
> 
> Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>


Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>


> ---
>   arch/powerpc/kvm/emulate_loadstore.c | 8 +-------
>   arch/powerpc/kvm/powerpc.c           | 2 +-
>   2 files changed, 2 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/powerpc/kvm/emulate_loadstore.c b/arch/powerpc/kvm/emulate_loadstore.c
> index 48272a9b9c30..4dec920fe4c9 100644
> --- a/arch/powerpc/kvm/emulate_loadstore.c
> +++ b/arch/powerpc/kvm/emulate_loadstore.c
> @@ -73,7 +73,6 @@ int kvmppc_emulate_loadstore(struct kvm_vcpu *vcpu)
>   {
>   	u32 inst;
>   	enum emulation_result emulated = EMULATE_FAIL;
> -	int advance = 1;
>   	struct instruction_op op;
>   
>   	/* this default type might be overwritten by subcategories */
> @@ -355,15 +354,10 @@ int kvmppc_emulate_loadstore(struct kvm_vcpu *vcpu)
>   		}
>   	}
>   
> -	if (emulated == EMULATE_FAIL) {
> -		advance = 0;
> -		kvmppc_core_queue_program(vcpu, 0);
> -	}
> -
>   	trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
>   
>   	/* Advance past emulated instruction. */
> -	if (advance)
> +	if (emulated != EMULATE_FAIL)
>   		kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
>   
>   	return emulated;
> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
> index 4d7d0d080232..6daeea4a7de1 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -307,7 +307,7 @@ int kvmppc_emulate_mmio(struct kvm_vcpu *vcpu)
>   		u32 last_inst;
>   
>   		kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
> -		/* XXX Deliver Program interrupt to guest. */
> +		kvmppc_core_queue_program(vcpu, 0);
>   		pr_info("%s: emulation failed (%08x)\n", __func__, last_inst);
>   		r = RESUME_HOST;
>   		break;