On Mon, 30 Nov 2015 14:56:38 +0300 Pavel Fedin <p.fedin@xxxxxxxxxxx> wrote: > Hello! > > > > case KVM_CAP_INTERNAL_ERROR_DATA: > > > #ifdef CONFIG_HAVE_KVM_MSI > > > case KVM_CAP_SIGNAL_MSI: > > > + /* Fallthrough */ > > > #endif > > > + case KVM_CAP_CHECK_EXTENSION_VM: > > > + return 1; > > > #ifdef CONFIG_HAVE_KVM_IRQFD > > > case KVM_CAP_IRQFD: > > > case KVM_CAP_IRQFD_RESAMPLE: > > > + return kvm_vm_ioctl_check_extension(kvm, KVM_CAP_IRQCHIP); > > > > This won't work for s390, as it doesn't have KVM_CAP_IRQCHIP but > > KVM_CAP_S390_IRQCHIP (which needs to be enabled). > > Thank you for the note, i didn't know about irqchip-specific capability codes. There's the same issue with PowerPC, now i > understand why there's no KVM_CAP_IRQCHIP for them. Because they have KVM_CAP_IRQ_MPIC and KVM_CAP_IRQ_XICS, similar to S390. > But isn't it just weird? I understand that perhaps we have some real need to distinguish between different irqchip types, but > shouldn't the kernel also publish KVM_CAP_IRQCHIP, which stands just for "we support some irqchip virtualization"? > May be we should just add this for PowerPC and S390, to make things less ambiguous? Note that we explicitly need to _enable_ the s390 cap (for compatibility). I'd need to recall the exact details but I came to the conclusion back than that I could not simply enable KVM_CAP_IRQCHIP for s390 (and current qemu would fail to enable the s390 cap if we started advertising KVM_CAP_IRQCHIP now). -- 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
