On Thu, Oct 04, 2018 at 09:56:07PM +1000, Paul Mackerras wrote:
> With this, the KVM-HV module can be loaded in a guest running under
> KVM-HV, and if the hypervisor supports nested virtualization, this
> guest can now act as a nested hypervisor and run nested guests.
> 
> This also adds some checks to inform userspace that HPT guests are not
> supported by nested hypervisors, and to prevent userspace from
> configuring a guest to use HPT mode.
> 
> Signed-off-by: Paul Mackerras <pau...@ozlabs.org>

Reviewed-by: David Gibson <da...@gibson.dropbear.id.au>

> ---
>  arch/powerpc/kvm/book3s_hv.c | 20 ++++++++++++++++----
>  1 file changed, 16 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 7561c99..7f89b22 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -4214,6 +4214,10 @@ static int kvm_vm_ioctl_get_smmu_info_hv(struct kvm 
> *kvm,
>  {
>       struct kvm_ppc_one_seg_page_size *sps;
>  
> +     /* If we're a nested hypervisor, we only support radix guests */
> +     if (kvmhv_on_pseries())
> +             return -EINVAL;
> +
>       /*
>        * POWER7, POWER8 and POWER9 all support 32 storage keys for data.
>        * POWER7 doesn't support keys for instruction accesses,
> @@ -4799,11 +4803,15 @@ static int kvmppc_core_emulate_mfspr_hv(struct 
> kvm_vcpu *vcpu, int sprn,
>  
>  static int kvmppc_core_check_processor_compat_hv(void)
>  {
> -     if (!cpu_has_feature(CPU_FTR_HVMODE) ||
> -         !cpu_has_feature(CPU_FTR_ARCH_206))
> -             return -EIO;
> +     if (cpu_has_feature(CPU_FTR_HVMODE) &&
> +         cpu_has_feature(CPU_FTR_ARCH_206))
> +             return 0;
>  
> -     return 0;
> +     /* POWER9 in radix mode is capable of being a nested hypervisor. */
> +     if (cpu_has_feature(CPU_FTR_ARCH_300) && radix_enabled())
> +             return 0;
> +
> +     return -EIO;
>  }
>  
>  #ifdef CONFIG_KVM_XICS
> @@ -5121,6 +5129,10 @@ static int kvmhv_configure_mmu(struct kvm *kvm, struct 
> kvm_ppc_mmuv3_cfg *cfg)
>       if (radix && !radix_enabled())
>               return -EINVAL;
>  
> +     /* If we're a nested hypervisor, we currently only support radix */
> +     if (kvmhv_on_pseries() && !radix)
> +             return -EINVAL;
> +
>       mutex_lock(&kvm->lock);
>       if (radix != kvm_is_radix(kvm)) {
>               if (kvm->arch.mmu_ready) {

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

Attachment: signature.asc
Description: PGP signature

Reply via email to