Re: [PATCH v7 01/12] xen/arm: enable SVE extension for Xen

[Julien Grall <julien@xxxxxxx>]

Hi,

On 24/05/2023 10:01, Bertrand Marquis wrote:
> > diff --git a/xen/arch/arm/cpufeature.c b/xen/arch/arm/cpufeature.c
> > index c4ec38bb2554..83b84368f6d5 100644
> > --- a/xen/arch/arm/cpufeature.c
> > +++ b/xen/arch/arm/cpufeature.c
> > @@ -9,6 +9,7 @@
> > #include <xen/init.h>
> > #include <xen/smp.h>
> > #include <xen/stop_machine.h>
> > +#include <asm/arm64/sve.h>
> > #include <asm/cpufeature.h>
> >
> > DECLARE_BITMAP(cpu_hwcaps, ARM_NCAPS);
> > @@ -143,6 +144,9 @@ void identify_cpu(struct cpuinfo_arm *c)
> >
> >      c->zfr64.bits[0] = READ_SYSREG(ID_AA64ZFR0_EL1);
> >
> > +    if ( cpu_has_sve )
> > +        c->zcr64.bits[0] = compute_max_zcr();
> > +
> >      c->dczid.bits[0] = READ_SYSREG(DCZID_EL0);
> >
> >      c->ctr.bits[0] = READ_SYSREG(CTR_EL0);
> > @@ -199,7 +203,7 @@ static int __init create_guest_cpuinfo(void)
> >      guest_cpuinfo.pfr64.mpam = 0;
> >      guest_cpuinfo.pfr64.mpam_frac = 0;
> >
> > -    /* Hide SVE as Xen does not support it */
> > +    /* Hide SVE by default to the guests */
> Everything is for guests and as Jan mentioned in an other comment
> this could be wrongly interpreted.
(Not directly related to this patch, so no changes expected here)

Hmmm... The name of the function/variable is confusing as well given 
that the cpuinfo should also apply to dom0. Should we s/guest/domain/?
Cheers,

--
Julien Grall