On 11/01/13 17:12, Russell King - ARM Linux wrote: > On Thu, Jan 10, 2013 at 04:06:45PM +0000, Marc Zyngier wrote: >> +int kvm_psci_call(struct kvm_vcpu *vcpu) >> +{ >> + unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); >> + unsigned long val; >> + >> + switch (psci_fn) { >> + case KVM_PSCI_FN_CPU_OFF: >> + kvm_psci_vcpu_off(vcpu); >> + val = KVM_PSCI_RET_SUCCESS; >> + break; >> + case KVM_PSCI_FN_CPU_ON: >> + val = kvm_psci_vcpu_on(vcpu); >> + break; >> + case KVM_PSCI_FN_CPU_SUSPEND: >> + case KVM_PSCI_FN_MIGRATE: >> + val = KVM_PSCI_RET_NI; >> + break; >> + >> + default: >> + return -1; >> + } >> + >> + *vcpu_reg(vcpu, 0) = val; >> + return 0; >> +} > > We were discussing recently on #kernel about kernel APIs and the way that > our integer-returning functions pretty much use 0 for success, and -errno > for failures, whereas our pointer-returning functions are a mess. > > And above we have something returning -1 to some other chunk of code outside > this compilation unit. That doesn't sound particularly clever to me. The original code used to return -EINVAL, see: https://lists.cs.columbia.edu/pipermail/kvmarm/2013-January/004509.html Christoffer (Cc-ed) didn't like this, hence the -1. I'm happy to revert the code to its original state though. M. -- Jazz is not dead. It just smells funny... -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html