On Wed, 17 Mar 2021 14:29:39 +0000,
Will Deacon <will@xxxxxxxxxx> wrote:
>
> On Tue, Mar 16, 2021 at 10:13:07AM +0000, Marc Zyngier wrote:
> > In order to keep the code readable, move the host-save/guest-restore
> > sequences in their own functions, with the following changes:
> > - the hypervisor ZCR is now set from C code
> > - ZCR_EL2 is always used as the EL2 accessor
> >
> > This results in some minor assembler macro rework.
> > No functional change intended.
> >
> > Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
> > ---
> > arch/arm64/include/asm/fpsimdmacros.h | 8 +++--
> > arch/arm64/include/asm/kvm_hyp.h | 2 +-
> > arch/arm64/kvm/hyp/fpsimd.S | 2 +-
> > arch/arm64/kvm/hyp/include/hyp/switch.h | 41 +++++++++++++++----------
> > 4 files changed, 33 insertions(+), 20 deletions(-)
>
> [...]
>
> > diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
> > index fb68271c1a0f..d34dc220a1ce 100644
> > --- a/arch/arm64/kvm/hyp/include/hyp/switch.h
> > +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
> > @@ -196,6 +196,25 @@ static inline bool __populate_fault_info(struct kvm_vcpu *vcpu)
> > return true;
> > }
> >
> > +static inline void __hyp_sve_save_host(struct kvm_vcpu *vcpu)
> > +{
> > + struct thread_struct *thread;
> > +
> > + thread = container_of(vcpu->arch.host_fpsimd_state, struct thread_struct,
> > + uw.fpsimd_state);
> > +
> > + __sve_save_state(sve_pffr(thread), &vcpu->arch.host_fpsimd_state->fpsr);
> > +}
> > +
> > +static inline void __hyp_sve_restore_guest(struct kvm_vcpu *vcpu)
> > +{
> > + if (read_sysreg_s(SYS_ZCR_EL2) != (vcpu_sve_vq(vcpu) - 1))
>
> Strictly speaking, we should probably be extracting the LEN field from
> ZCR_EL2, otherwise this has the potential to go horribly wrong if any of
> the RES0 bits are allocated in future.
Good point, the equivalent asm macro has a BIC to that effect. I'll
fix that in the next round, as there are similar patterns in a number
of places.
> Other than that:
>
> Acked-by: Will Deacon <will@xxxxxxxxxx>
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
_______________________________________________
kvmarm mailing list
kvmarm@xxxxxxxxxxxxxxxxxxxxx
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
