On Tue, Oct 02, 2018 at 09:31:29PM +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 <paulus@xxxxxxxxxx>
> ---
> 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 f630e91..196bff1 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -4237,6 +4237,10 @@ 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,
> @@ -4822,11 +4826,15 @@ 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;
> + /* Can run as nested hypervisor on POWER9 in radix mode. */
> + if (cpu_has_feature(CPU_FTR_ARCH_300) && radix_enabled())
Shouldn't we probe the parent hypervisor for ability to support nested
guests before we say "yes" here?
> + return 0;
> +
> + return -EIO;
> }
>
> #ifdef CONFIG_KVM_XICS
> @@ -5144,6 +5152,10 @@ 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
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