[PATCH 08/12] ARM: kvm: psci: fix handling of unimplemented functions
Marc Zyngier
marc.zyngier at arm.com
Fri Jun 19 05:53:12 PDT 2015
From: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
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 at vger.kernel.org> # 3.18+
Cc: Christoffer Dall <christoffer.dall at linaro.org>
Acked-by: Sudeep Holla <sudeep.holla at arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
---
arch/arm/kvm/psci.c | 16 +++-------------
1 file changed, 3 insertions(+), 13 deletions(-)
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
index 02fa8ef..531e922 100644
--- a/arch/arm/kvm/psci.c
+++ b/arch/arm/kvm/psci.c
@@ -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;
--
2.1.4
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