On Tue, May 28, 2024 at 6:15 PM Clément Léger <cleger@xxxxxxxxxxxx> wrote:
>
>
>
> On 24/05/2024 12:33, Yong-Xuan Wang wrote:
> > Add support for SBI_FWFT_PTE_AD_HW_UPDATING to set the PTE A/D bits
> > updating behavior for Guest/VM.
> >
> > Signed-off-by: Yong-Xuan Wang <yongxuan.wang@xxxxxxxxxx>
> > ---
> > arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h | 2 +-
> > arch/riscv/kvm/vcpu_sbi_fwft.c | 38 +++++++++++++++++++++-
> > 2 files changed, 38 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h b/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h
> > index 7b7bcc5c8fee..3614a44e0a4a 100644
> > --- a/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h
> > +++ b/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h
> > @@ -11,7 +11,7 @@
> >
> > #include <asm/sbi.h>
> >
> > -#define KVM_SBI_FWFT_FEATURE_COUNT 1
> > +#define KVM_SBI_FWFT_FEATURE_COUNT 2
> >
> > struct kvm_sbi_fwft_config;
> > struct kvm_vcpu;
> > diff --git a/arch/riscv/kvm/vcpu_sbi_fwft.c b/arch/riscv/kvm/vcpu_sbi_fwft.c
> > index 89ec263c250d..14ef74023340 100644
> > --- a/arch/riscv/kvm/vcpu_sbi_fwft.c
> > +++ b/arch/riscv/kvm/vcpu_sbi_fwft.c
> > @@ -71,6 +71,36 @@ static int kvm_sbi_fwft_get_misaligned_delegation(struct kvm_vcpu *vcpu,
> > return SBI_SUCCESS;
> > }
> >
> > +static int kvm_sbi_fwft_adue_supported(struct kvm_vcpu *vcpu)
> > +{
> > + if (!riscv_isa_extension_available(vcpu->arch.isa, SVADU))
> > + return SBI_ERR_NOT_SUPPORTED;
> > +
> > + return 0;
> > +}
> > +
> > +static int kvm_sbi_fwft_set_adue(struct kvm_vcpu *vcpu, struct kvm_sbi_fwft_config *conf,
> > + unsigned long value)
> > +{
> > + if (value)
> > + vcpu->arch.cfg.henvcfg |= ENVCFG_ADUE;
> > + else
> > + vcpu->arch.cfg.henvcfg &= ~ENVCFG_ADUE;
> > +
> > + return SBI_SUCCESS;
> > +}
> > +
> > +static int kvm_sbi_fwft_get_adue(struct kvm_vcpu *vcpu, struct kvm_sbi_fwft_config *conf,
> > + unsigned long *value)
> > +{
> > + if (!riscv_isa_extension_available(vcpu->arch.isa, SVADU))
> > + return SBI_ERR_NOT_SUPPORTED;
> > +
> > + *value = !!(vcpu->arch.cfg.henvcfg & ENVCFG_ADUE);
> > +
> > + return SBI_SUCCESS;
> > +}
>
> Hi Yong-Xuan,
>
> vcpu->arch.cfg.henvcfg seems to be used to update the HENVCFG CSR only
> during vcpu_load()/vcpu_put(). So if this extension updates it there and
> stays in the execution loop (kvm_arch_vcpu_ioctl_run()) then, it seems
> like the HENVCFG CSR won't be updated immediately but on the next
> vcpu_load(). Is there something I'm missing ?
>
> Thanks,
>
> Clément Léger
>
Hi Clément,
That's right. I will fix it in the next version. Thank you!
Regards,
Yong-Xuan
> > +
> > static struct kvm_sbi_fwft_config *
> > kvm_sbi_fwft_get_config(struct kvm_vcpu *vcpu, enum sbi_fwft_feature_t feature)
> > {
> > @@ -177,7 +207,13 @@ static const struct kvm_sbi_fwft_feature features[] = {
> > .supported = kvm_sbi_fwft_misaligned_delegation_supported,
> > .set = kvm_sbi_fwft_set_misaligned_delegation,
> > .get = kvm_sbi_fwft_get_misaligned_delegation,
> > - }
> > + },
> > + {
> > + .id = SBI_FWFT_PTE_AD_HW_UPDATING,
> > + .supported = kvm_sbi_fwft_adue_supported,
> > + .set = kvm_sbi_fwft_set_adue,
> > + .get = kvm_sbi_fwft_get_adue,
> > + },
> > };
> >
> > static_assert(ARRAY_SIZE(features) == KVM_SBI_FWFT_FEATURE_COUNT);
