From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lorenzo Pieralisi Subject: [PATCH 1/6] ARM: kvm: psci: fix handling of unimplemented functions Date: Fri, 29 May 2015 13:16:34 +0100 Message-ID: <1432901799-18359-2-git-send-email-lorenzo.pieralisi@arm.com> References: <1432901799-18359-1-git-send-email-lorenzo.pieralisi@arm.com> Return-path: In-Reply-To: <1432901799-18359-1-git-send-email-lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: Lorenzo Pieralisi , Christoffer Dall , Anup Patel , Marc Zyngier , Will Deacon , Sudeep Holla , Catalin Marinas , Mark Rutland List-Id: devicetree@vger.kernel.org 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. Signed-off-by: Lorenzo Pieralisi Reported-by: Sudeep Holla Cc: Christoffer Dall Cc: Anup Patel Cc: Marc Zyngier --- arch/arm/kvm/psci.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 7e9398c..ec5943b 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -273,7 +273,8 @@ 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; @@ -295,10 +296,9 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *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; -- 2.2.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: lorenzo.pieralisi@arm.com (Lorenzo Pieralisi) Date: Fri, 29 May 2015 13:16:34 +0100 Subject: [PATCH 1/6] ARM: kvm: psci: fix handling of unimplemented functions In-Reply-To: <1432901799-18359-1-git-send-email-lorenzo.pieralisi@arm.com> References: <1432901799-18359-1-git-send-email-lorenzo.pieralisi@arm.com> Message-ID: <1432901799-18359-2-git-send-email-lorenzo.pieralisi@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. Signed-off-by: Lorenzo Pieralisi Reported-by: Sudeep Holla Cc: Christoffer Dall Cc: Anup Patel Cc: Marc Zyngier --- arch/arm/kvm/psci.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 7e9398c..ec5943b 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -273,7 +273,8 @@ 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; @@ -295,10 +296,9 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *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; -- 2.2.1