ARM: kvm: psci: fix handling of unimplemented functions (e2d99736) · Commits · 戴 / test

According to the PSCI specification and the SMC/HVC calling convention, PSCI function_ids that are not implemented must return NOT_SUPPORTED as return value. Current KVM implementation takes an unhandled PSCI function_id as an error and injects an undefined instruction into the guest if PSCI implementation is called with a function_id that is not handled by the resident PSCI version (ie it is not implemented), which is not the behaviour expected by a guest when calling a PSCI function_id that is not implemented. This patch fixes this issue by returning NOT_SUPPORTED whenever the kvm PSCI call is executed for a function_id that is not implemented by the PSCI kvm layer. Cc: <stable@vger.kernel.org> # 3.18+ Cc: Christoffer Dall <christoffer.dall@linaro.org> Acked-by:

Sudeep Holla <sudeep.holla@arm.com> Signed-off-by:

Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by:

Marc Zyngier <marc.zyngier@arm.com>

arch/arm/kvm/psci.c

+3 −13

Original line number	Diff line number	Diff line
		@@ -230,10 +230,6 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
		case PSCI_0_2_FN64_AFFINITY_INFO:
		val = kvm_psci_vcpu_affinity_info(vcpu);
		break;
		case PSCI_0_2_FN_MIGRATE:
		case PSCI_0_2_FN64_MIGRATE:
		val = PSCI_RET_NOT_SUPPORTED;
		break;
		case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
		/*
		* Trusted OS is MP hence does not require migration
		@@ -242,10 +238,6 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
		*/
		val = PSCI_0_2_TOS_MP;
		break;
		case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU:
		case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU:
		val = PSCI_RET_NOT_SUPPORTED;
		break;
		case PSCI_0_2_FN_SYSTEM_OFF:
		kvm_psci_system_off(vcpu);
		/*
		@@ -271,7 +263,8 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
		ret = 0;
		break;
		default:
		return -EINVAL;
		val = PSCI_RET_NOT_SUPPORTED;
		break;
		}

		*vcpu_reg(vcpu, 0) = val;
		@@ -291,12 +284,9 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
		case KVM_PSCI_FN_CPU_ON:
		val = kvm_psci_vcpu_on(vcpu);
		break;
		case KVM_PSCI_FN_CPU_SUSPEND:
		case KVM_PSCI_FN_MIGRATE:
		default:
		val = PSCI_RET_NOT_SUPPORTED;
		break;
		default:
		return -EINVAL;
		}

		*vcpu_reg(vcpu, 0) = val;

Admin message