Re: [PATCH v5 30/33] KVM: PPC: Book3S HV: Allow HV module to load without hypervisor mode
From: David Gibson <hidden>
Date: 2018-10-09 00:59:11
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kvm
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 <redacted>
Reviewed-by: David Gibson <redacted>
quoted hunk ↗ jump to hunk
--- 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:
-- 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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