[PATCH] powerpc/kvm: Enable support for ISA v3.1 guests

[Jordan Niethe]

On Tue, Jun 2, 2020 at 3:55 PM Alistair Popple <alistair at popple.id.au> wrote:
>
> Adds support for emulating ISAv3.1 guests by adding the appropriate PCR
> and FSCR bits.
>
> Signed-off-by: Alistair Popple <alistair at popple.id.au>
> ---
>  arch/powerpc/include/asm/reg.h |  1 +
>  arch/powerpc/kvm/book3s_hv.c   | 11 ++++++++---
>  2 files changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
> index 773f76402392..d77040d0588a 100644
> --- a/arch/powerpc/include/asm/reg.h
> +++ b/arch/powerpc/include/asm/reg.h
> @@ -1348,6 +1348,7 @@
>  #define PVR_ARCH_206p  0x0f100003
>  #define PVR_ARCH_207   0x0f000004
>  #define PVR_ARCH_300   0x0f000005
> +#define PVR_ARCH_31    0x0f000006
>
>  /* Macros for setting and retrieving special purpose registers */
>  #ifndef __ASSEMBLY__
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 93493f0cbfe8..359bb2ed43e1 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -345,7 +345,7 @@ static void kvmppc_set_pvr_hv(struct kvm_vcpu *vcpu, u32 pvr)
>  }
>
>  /* Dummy value used in computing PCR value below */
> -#define PCR_ARCH_300   (PCR_ARCH_207 << 1)
> +#define PCR_ARCH_31    (PCR_ARCH_300 << 1)
>
>  static int kvmppc_set_arch_compat(struct kvm_vcpu *vcpu, u32 arch_compat)
>  {
> @@ -353,7 +353,9 @@ static int kvmppc_set_arch_compat(struct kvm_vcpu *vcpu, u32 arch_compat)
>         struct kvmppc_vcore *vc = vcpu->arch.vcore;
>
>         /* We can (emulate) our own architecture version and anything older */
> -       if (cpu_has_feature(CPU_FTR_ARCH_300))
> +       if (cpu_has_feature(CPU_FTR_ARCH_31))
> +               host_pcr_bit = PCR_ARCH_31;
> +       else if (cpu_has_feature(CPU_FTR_ARCH_300))
>                 host_pcr_bit = PCR_ARCH_300;
>         else if (cpu_has_feature(CPU_FTR_ARCH_207S))
>                 host_pcr_bit = PCR_ARCH_207;
> @@ -379,6 +381,9 @@ static int kvmppc_set_arch_compat(struct kvm_vcpu *vcpu, u32 arch_compat)
>                 case PVR_ARCH_300:
>                         guest_pcr_bit = PCR_ARCH_300;
>                         break;
> +               case PVR_ARCH_31:
> +                       guest_pcr_bit = PCR_ARCH_31;
> +                       break;
>                 default:
>                         return -EINVAL;
>                 }
> @@ -2318,7 +2323,7 @@ static int kvmppc_core_vcpu_create_hv(struct kvm_vcpu *vcpu)
>          * to trap and then we emulate them.
>          */
The comment above this:
"...
     * Set the default HFSCR for the guest from the host value.
     * This value is only used on POWER9..."
would need to be updated.
>         vcpu->arch.hfscr = HFSCR_TAR | HFSCR_EBB | HFSCR_PM | HFSCR_BHRB |
> -               HFSCR_DSCR | HFSCR_VECVSX | HFSCR_FP;
> +               HFSCR_DSCR | HFSCR_VECVSX | HFSCR_FP | HFSCR_PREFIX;
>         if (cpu_has_feature(CPU_FTR_HVMODE)) {
>                 vcpu->arch.hfscr &= mfspr(SPRN_HFSCR);
>                 if (cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
> --
> 2.20.1
>