diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 0b5a33ee71ee..b11b70ae137e 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6894,6 +6894,13 @@ Note that KVM does not skip the faulting instruction as it does for KVM_EXIT_MMIO, but userspace has to emulate any change to the processing state if it decides to decode and emulate the instruction. +This feature isn't available to protected VMs, as userspace does not +have access to the state that is required to perform the emulation. +Instead, a data abort exception is directly injected in the guest. +Note that although KVM_CAP_ARM_NISV_TO_USER will be reported if +queried outside of a protected VM context, the feature will not be +exposed if queried on a protected VM file descriptor. + :: /* KVM_EXIT_X86_RDMSR / KVM_EXIT_X86_WRMSR */ diff --git a/arch/arm64/kvm/mmio.c b/arch/arm64/kvm/mmio.c index 5e1ffb0d5363..cd6b7b83e2c3 100644 --- a/arch/arm64/kvm/mmio.c +++ b/arch/arm64/kvm/mmio.c @@ -133,11 +133,19 @@ int io_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) /* * No valid syndrome? Ask userspace for help if it has * volunteered to do so, and bail out otherwise. + * + * In the protected VM case, there isn't much userspace can do + * though, so directly deliver an exception to the guest. */ if (!kvm_vcpu_dabt_isvalid(vcpu)) { trace_kvm_mmio_nisv(*vcpu_pc(vcpu), kvm_vcpu_get_esr(vcpu), kvm_vcpu_get_hfar(vcpu), fault_ipa); + if (vcpu_is_protected(vcpu)) { + kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu)); + return 1; + } + if (test_bit(KVM_ARCH_FLAG_RETURN_NISV_IO_ABORT_TO_USER, &vcpu->kvm->arch.flags)) { run->exit_reason = KVM_EXIT_ARM_NISV;