| Message ID | 1432901799-18359-2-git-send-email-lorenzo.pieralisi@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 29/05/15 13:16, Lorenzo Pieralisi wrote: > 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 <lorenzo.pieralisi@arm.com> > Reported-by: Sudeep Holla <sudeep.holla@arm.com> > Cc: Christoffer Dall <christoffer.dall@linaro.org> > Cc: Anup Patel <anup.patel@linaro.org> > Cc: Marc Zyngier <marc.zyngier@arm.com> > --- > 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; IMO we can remove all the other optional non-implemented PSCI functions (e.g. KVM_PSCI_FN_MIGRATE, KVM_PSCI_FN_CPU_SUSPEND, ..etc) returning PSCI_RET_NOT_SUPPORTED here as they will be then automatically covered by default case. Otherwise looks good to me: Acked-by: Sudeep Holla <sudeep.holla@arm.com> Regards, Sudeep
Hi Lorenzo, On 29/05/15 13:16, Lorenzo Pieralisi wrote: > 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 <lorenzo.pieralisi@arm.com> > Reported-by: Sudeep Holla <sudeep.holla@arm.com> > Cc: Christoffer Dall <christoffer.dall@linaro.org> > Cc: Anup Patel <anup.patel@linaro.org> > Cc: Marc Zyngier <marc.zyngier@arm.com> > --- > 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; > Looks good to me. How do you want to proceed with this one? can I take it independently from the rest of the series? Or would you prefer it being kept as a whole? Thanks, M.
Hi Marc, On Tue, Jun 09, 2015 at 06:18:20PM +0100, Marc Zyngier wrote: > Hi Lorenzo, > > On 29/05/15 13:16, Lorenzo Pieralisi wrote: > > 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 <lorenzo.pieralisi@arm.com> > > Reported-by: Sudeep Holla <sudeep.holla@arm.com> > > Cc: Christoffer Dall <christoffer.dall@linaro.org> > > Cc: Anup Patel <anup.patel@linaro.org> > > Cc: Marc Zyngier <marc.zyngier@arm.com> > > --- > > 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; > > > > Looks good to me. How do you want to proceed with this one? can I take > it independently from the rest of the series? Or would you prefer it > being kept as a whole? I will prepare a v2 to take into account a comment from Sudeep and I will add a stable tag too, yes it should be merged independently. Thanks, Lorenzo
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;
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 <lorenzo.pieralisi@arm.com> Reported-by: Sudeep Holla <sudeep.holla@arm.com> Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Anup Patel <anup.patel@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> --- arch/arm/kvm/psci.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)