Commit 3cadf681 authored by Lorenzo Pieralisi's avatar Lorenzo Pieralisi Committed by Sasha Levin

ARM: kvm: psci: fix handling of unimplemented functions

[ Upstream commit e2d99736 ]

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: default avatarSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
parent a85076d1
......@@ -237,10 +237,6 @@ 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
......@@ -249,10 +245,6 @@ 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);
/*
......@@ -278,7 +270,8 @@ 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;
......@@ -298,12 +291,9 @@ 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;
......
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