From c2821c8213e294ec20e4b7509ecae7ed864d505c Mon Sep 17 00:00:00 2001 From: Fuad Tabba Date: Wed, 27 Apr 2022 11:25:01 +0000 Subject: [PATCH] ANDROID: KVM: arm64: Initialize hypervisor vm state at EL2 Do not rely on the state of the vm as provided by the host, but initialize it instead at EL2 to a known good and safe state. Bug: 357781595 Change-Id: I8e0e9fd7cdf0b5b4d422260be06920d0550d5f91 Signed-off-by: Fuad Tabba --- arch/arm64/kvm/hyp/nvhe/pkvm.c | 84 ++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c index 6f27efc409f9..7727e3f514a5 100644 --- a/arch/arm64/kvm/hyp/nvhe/pkvm.c +++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c @@ -6,6 +6,9 @@ #include #include + +#include + #include #include #include @@ -358,6 +361,65 @@ struct pkvm_hyp_vcpu *pkvm_get_loaded_hyp_vcpu(void) return __this_cpu_read(loaded_hyp_vcpu); } +static void pkvm_init_features_from_host(struct pkvm_hyp_vm *hyp_vm, const struct kvm *host_kvm) +{ + struct kvm *kvm = &hyp_vm->kvm; + DECLARE_BITMAP(allowed_features, KVM_VCPU_MAX_FEATURES); + + /* No restrictions for non-protected VMs. */ + if (!kvm_vm_is_protected(kvm)) { + bitmap_copy(kvm->arch.vcpu_features, + host_kvm->arch.vcpu_features, + KVM_VCPU_MAX_FEATURES); + return; + } + + bitmap_zero(allowed_features, KVM_VCPU_MAX_FEATURES); + + /* + * For protected vms, always allow: + * - CPU starting in poweroff state + * - PSCI v0.2 + */ + set_bit(KVM_ARM_VCPU_POWER_OFF, allowed_features); + set_bit(KVM_ARM_VCPU_PSCI_0_2, allowed_features); + + /* + * Check if remaining features are allowed: + * - Performance Monitoring + * - Scalable Vectors + * - Pointer Authentication + */ + if (FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer), PVM_ID_AA64DFR0_ALLOW)) + set_bit(KVM_ARM_VCPU_PMU_V3, allowed_features); + + if (FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_SVE), PVM_ID_AA64PFR0_ALLOW)) + set_bit(KVM_ARM_VCPU_SVE, allowed_features); + + if (FIELD_GET(ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_API), PVM_ID_AA64ISAR1_RESTRICT_UNSIGNED) && + FIELD_GET(ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_APA), PVM_ID_AA64ISAR1_RESTRICT_UNSIGNED)) + set_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, allowed_features); + + if (FIELD_GET(ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_GPI), PVM_ID_AA64ISAR1_ALLOW) && + FIELD_GET(ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_GPA), PVM_ID_AA64ISAR1_ALLOW)) + set_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, allowed_features); + + bitmap_and(kvm->arch.vcpu_features, host_kvm->arch.vcpu_features, + allowed_features, KVM_VCPU_MAX_FEATURES); +} + +static void pkvm_vcpu_init_ptrauth(struct pkvm_hyp_vcpu *hyp_vcpu) +{ + struct kvm_vcpu *vcpu = &hyp_vcpu->vcpu; + + if (vcpu_has_feature(vcpu, KVM_ARM_VCPU_PTRAUTH_ADDRESS) || + vcpu_has_feature(vcpu, KVM_ARM_VCPU_PTRAUTH_GENERIC)) { + kvm_vcpu_enable_ptrauth(vcpu); + } else { + vcpu_clear_flag(&hyp_vcpu->vcpu, GUEST_HAS_PTRAUTH); + } +} + static void unpin_host_vcpu(struct kvm_vcpu *host_vcpu) { if (host_vcpu) @@ -384,8 +446,23 @@ static void init_pkvm_hyp_vm(struct kvm *host_kvm, struct pkvm_hyp_vm *hyp_vm, hyp_vm->host_kvm = host_kvm; hyp_vm->kvm.created_vcpus = nr_vcpus; hyp_vm->kvm.arch.mmu.vtcr = host_mmu.arch.mmu.vtcr; + hyp_vm->kvm.arch.pkvm.enabled = READ_ONCE(host_kvm->arch.pkvm.enabled); hyp_vm->kvm.arch.mmu.last_vcpu_ran = (int __percpu *)last_ran; memset(last_ran, -1, pkvm_get_last_ran_size()); + pkvm_init_features_from_host(hyp_vm, host_kvm); +} + +static int pkvm_vcpu_init_sve(struct pkvm_hyp_vcpu *hyp_vcpu, struct kvm_vcpu *host_vcpu) +{ + struct kvm_vcpu *vcpu = &hyp_vcpu->vcpu; + + if (!vcpu_has_feature(vcpu, KVM_ARM_VCPU_SVE)) { + vcpu_clear_flag(vcpu, GUEST_HAS_SVE); + vcpu_clear_flag(vcpu, VCPU_SVE_FINALIZED); + return 0; + } + + return 0; } static int init_pkvm_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu, @@ -411,8 +488,15 @@ static int init_pkvm_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu, hyp_vcpu->vcpu.arch.hw_mmu = &hyp_vm->kvm.arch.mmu; hyp_vcpu->vcpu.arch.cflags = READ_ONCE(host_vcpu->arch.cflags); + hyp_vcpu->vcpu.arch.mp_state.mp_state = KVM_MP_STATE_STOPPED; + ret = pkvm_vcpu_init_sve(hyp_vcpu, host_vcpu); + if (ret) + goto done; + + pkvm_vcpu_init_ptrauth(hyp_vcpu); pkvm_vcpu_init_traps(hyp_vcpu); + kvm_reset_pvm_sys_regs(&hyp_vcpu->vcpu); done: if (ret) unpin_host_vcpu(host_vcpu);