From: Marc Zyngier The --nested option allows a guest to boot at EL2 without FEAT_E2H0 (i.e. mandating VHE support). While this is great for "modern" operating systems and hypervisors, a few legacy guests are stuck in a distant past. To support those, add the --e2h0 command line option, that exposes FEAT_E2H0 to the guest, at the expense of a number of other features, such as FEAT_NV2. This is conditioned on the host itself supporting FEAT_E2H0. Signed-off-by: Marc Zyngier Signed-off-by: Andre Przywara --- arm64/include/kvm/kvm-config-arch.h | 5 ++++- arm64/kvm-cpu.c | 5 +++++ 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/arm64/include/kvm/kvm-config-arch.h b/arm64/include/kvm/kvm-config-arch.h index 44c43367b..73bf4211a 100644 --- a/arm64/include/kvm/kvm-config-arch.h +++ b/arm64/include/kvm/kvm-config-arch.h @@ -11,6 +11,7 @@ struct kvm_config_arch { bool has_pmuv3; bool mte_disabled; bool nested_virt; + bool e2h0; u64 kaslr_seed; enum irqchip_type irqchip; u64 fw_addr; @@ -63,6 +64,8 @@ int sve_vl_parser(const struct option *opt, const char *arg, int unset); OPT_U64('\0', "counter-offset", &(cfg)->counter_offset, \ "Specify the counter offset, defaulting to 0"), \ OPT_BOOLEAN('\0', "nested", &(cfg)->nested_virt, \ - "Start VCPUs in EL2 (for nested virt)"), + "Start VCPUs in EL2 (for nested virt)"), \ + OPT_BOOLEAN('\0', "e2h0", &(cfg)->e2h0, \ + "Create guest without VHE support"), #endif /* ARM_COMMON__KVM_CONFIG_ARCH_H */ diff --git a/arm64/kvm-cpu.c b/arm64/kvm-cpu.c index 42dc11dad..5e4f3a7dd 100644 --- a/arm64/kvm-cpu.c +++ b/arm64/kvm-cpu.c @@ -76,6 +76,11 @@ static void kvm_cpu__select_features(struct kvm *kvm, struct kvm_vcpu_init *init if (!kvm__supports_extension(kvm, KVM_CAP_ARM_EL2)) die("EL2 (nested virt) is not supported"); init->features[0] |= 1UL << KVM_ARM_VCPU_HAS_EL2; + if (kvm->cfg.arch.e2h0) { + if (!kvm__supports_extension(kvm, KVM_CAP_ARM_EL2_E2H0)) + die("FEAT_E2H0 is not supported"); + init->features[0] |= 1UL << KVM_ARM_VCPU_HAS_EL2_E2H0; + } } } -- 2.25.1