2016-07-21 23:10+0200, Auger Eric: > On 21/07/2016 18:33, Radim Krčmář wrote: >> 2016-07-18 13:25+0000, Eric Auger: >>> If the ITS modality is not available, let's simply support MSI >>> injection by transforming the MSI.data into an SPI ID. >>> >>> This becomes possible to use KVM_SIGNAL_MSI ioctl and MSI >>> routing for arm too. >>> >>> Signed-off-by: Eric Auger <eric.au...@redhat.com> >>> >>> --- >>> diff --git a/virt/kvm/arm/vgic/vgic-irqfd.c b/virt/kvm/arm/vgic/vgic-irqfd.c >>> +static int vgic_v2m_inject_msi(struct kvm *kvm, struct kvm_msi *msi) >>> +{ >>> + if (msi->flags & KVM_MSI_VALID_DEVID) >>> + return -EINVAL; >>> + if (!vgic_valid_spi(kvm, msi->data)) >>> + return -EINVAL; >>> + >>> + return kvm_vgic_inject_irq(kvm, 0, msi->data, 1); >> >> Hm, this isn't very MSI related ... >> >> arm already has KVM_IRQ_LINE/kvm_vm_ioctl_irq_line with >> KVM_ARM_IRQ_TYPE_SPI that does >> kvm_vgic_inject_irq(kvm, 0, irq_num, level) >> >> Is that interface lacking? > > You mean KVM_SIGNAL_MSI? Well at QEMU level, for ARM/ARM64 is doesn't.
No, I meant KVM_IRQ_LINE, the one that is used to deliver SPI today. Or isn't it? > For kvm-tools I guess, Andre manages without. > > My first feeling was it is part of the KVM API and we can implement it > easily for GICv2M, as we do for GICv3 ITS . This can avoid a user app to > do what QEMU implements as "kvm_gsi_direct_mapping" and manage the > translation into the semantic of the ARM GSI. I think that reusing KVM_SIGNAL_MSI and KVM_IRQ_ROUTING_MSI for SPI is unfortunate. SPI only uses msi.data, which makes remaining fields in the msi struct arbitrary and [5/7] defined KVM_IRQ_ROUTING_IRQCHIP for SPI, so two route types now do the same, but only sometimes (without ITS), which makes the situation even less understandable ... Delivering SPI as KVM_IRQ_ROUTING_IRQCHIP seems more sensible and if we wanted ad-hoc delivery of KVM_IRQ_ROUTING_IRQCHIP, then I would prefer a new interface to two different meanings for KVM_SIGNAL_MSI: KVM_SIGNAL_MSI was created because we didn't have anything that could inject an interrupt without setting up a route with KVM_SET_GSI_ROUTING and we are still missing a generic interface to do that. > But Well, if you prefer we do not implement it for GICv2M, since > considered as far fetched I can remove this patch. I do, thanks. Documentation in [6/7] was ahead and needs changing then. _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm