| Message ID | 1538976679-1363-31-git-send-email-paulus@ozlabs.org |
|---|---|
| State | Accepted |
| Headers | show |
| Series | KVM: PPC: Book3S HV: Nested HV virtualization | expand |
On Mon, Oct 08, 2018 at 04:31:16PM +1100, 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 (by returning false for the > KVM_CAP_PPC_MMU_HASH_V3 capability), and to prevent userspace from > configuring a guest to use HPT mode. > > Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> > --- > arch/powerpc/kvm/book3s_hv.c | 16 ++++++++++++---- > arch/powerpc/kvm/powerpc.c | 3 ++- > 2 files changed, 14 insertions(+), 5 deletions(-) > > diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c > index 127bb5f..152bf75 100644 > --- a/arch/powerpc/kvm/book3s_hv.c > +++ b/arch/powerpc/kvm/book3s_hv.c > @@ -4807,11 +4807,15 @@ 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 > @@ -5129,6 +5133,10 @@ 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) { > diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c > index eba5756..1f4b128 100644 > --- a/arch/powerpc/kvm/powerpc.c > +++ b/arch/powerpc/kvm/powerpc.c > @@ -594,7 +594,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) > r = !!(hv_enabled && radix_enabled()); > break; > case KVM_CAP_PPC_MMU_HASH_V3: > - r = !!(hv_enabled && cpu_has_feature(CPU_FTR_ARCH_300)); > + r = !!(hv_enabled && cpu_has_feature(CPU_FTR_ARCH_300) && > + cpu_has_feature(CPU_FTR_HVMODE)); > break; > #endif > case KVM_CAP_SYNC_MMU:
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 127bb5f..152bf75 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -4807,11 +4807,15 @@ 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 @@ -5129,6 +5133,10 @@ 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) { diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index eba5756..1f4b128 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -594,7 +594,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = !!(hv_enabled && radix_enabled()); break; case KVM_CAP_PPC_MMU_HASH_V3: - r = !!(hv_enabled && cpu_has_feature(CPU_FTR_ARCH_300)); + r = !!(hv_enabled && cpu_has_feature(CPU_FTR_ARCH_300) && + cpu_has_feature(CPU_FTR_HVMODE)); break; #endif case KVM_CAP_SYNC_MMU:
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 (by returning false for the KVM_CAP_PPC_MMU_HASH_V3 capability), and to prevent userspace from configuring a guest to use HPT mode. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> --- arch/powerpc/kvm/book3s_hv.c | 16 ++++++++++++---- arch/powerpc/kvm/powerpc.c | 3 ++- 2 files changed, 14 insertions(+), 5 deletions(-)