Re: [PATCH 08/25] KVM: arm64: Unify HDFG[WR]TR_GROUP FGT identifiers

[Marc Zyngier <maz@kernel.org>]

On Tue, 23 Jan 2024 14:14:33 +0000,
Joey Gouly <joey.gouly@arm.com> wrote:
> 
> Hi,
> 
> On Mon, Jan 22, 2024 at 08:18:35PM +0000, Marc Zyngier wrote:
> > There is no reason to have separate FGT group identifiers for
> > the debug fine grain trapping. The sole requirement is to provide
> > the *names* so that the SR_FGF() macro can do its magic of picking
> > the correct bit definition.
> > 
> > So let's alias HDFGWTR_GROUP and HDFGRTR_GROUP.
> > 
> > Signed-off-by: Marc Zyngier <maz@kernel.org>
> > ---
> >  arch/arm64/kvm/emulate-nested.c | 3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> > 
> > diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c
> > index 7a4a886adb9d..8a1cfcf553a2 100644
> > --- a/arch/arm64/kvm/emulate-nested.c
> > +++ b/arch/arm64/kvm/emulate-nested.c
> > @@ -1010,7 +1010,7 @@ enum fgt_group_id {
> >  	__NO_FGT_GROUP__,
> >  	HFGxTR_GROUP,
> >  	HDFGRTR_GROUP,
> > -	HDFGWTR_GROUP,
> > +	HDFGWTR_GROUP = HDFGRTR_GROUP,
> >  	HFGITR_GROUP,
> >  	HAFGRTR_GROUP,
> >  
> > @@ -1938,7 +1938,6 @@ bool __check_nv_sr_forward(struct kvm_vcpu *vcpu)
> >  		break;
> >  
> >  	case HDFGRTR_GROUP:
> > -	case HDFGWTR_GROUP:
> >  		if (is_read)
> >  			val = __vcpu_sys_reg(vcpu, HDFGRTR_EL2);
> >  		else
> 
> I guess you could rename it to HDFGxTR_GROUP like for HFGxTR_GROUP but that
> means changing all those tables, so I think it's fine.

Not just the tables, but also the arch/arm64/tools/sysreg, which
distinguishes between HDFGRTR and HDFGWTR. I'm pretty sure it isn't
worth the hassle...

> Reviewed-by: Joey Gouly <joey.gouly@arm.com>

Thanks!

	M.

-- 
Without deviation from the norm, progress is not possible.