> -----Original Message----- > From: Paolo Bonzini [mailto:paolo.bonzini@xxxxxxxxx] On Behalf Of Paolo > Bonzini > Sent: Friday, August 07, 2015 6:17 PM > To: Wu, Feng; linux-kernel@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx > Cc: Steve Rutherford; rkrcmar@xxxxxxxxxx > Subject: Re: [PATCH 8/9] KVM: x86: Add EOI exit bitmap inference > > > > On 07/08/2015 09:46, Wu, Feng wrote: > > If I understand it correctly, here you reserve the low part of the routing > > table, and insert entries with KVM_IRQ_ROUTING_MSI type in them, > > then you use this as a hint to KVM to set the EOI bit map. I have two > > concerns: > > > > - Currently, GSI 2 is used for MSI routing, I want to make sure after this > > patch, whether GSI 2 can still be used for _real_ MSI routing, if it can, > > does everything work correctly? > > The patch has no effect if you use the in-kernel IOAPIC. If you use a > userspace IOAPIC you won't be able to use GSI 2 for MSI routing because > it falls in the reserved range. Good to know this, it addresses my concern, thanks! > > > - Now, KVM_IRQ_ROUTING_MSI and KVM_IRQ_ROUTING_IRQCHIP > > type entries cannot share the same map[gsi] (pls refer to the following > > code), so where should be the IOAPIC entries exist in the map[] array? > > With split irqchip, only KVM_IRQ_ROUTING_MSI is used. Does this answer > your question? Ah, I got it, since the IOAPIC is in userspace, there is no need to add the IOAPIC routing information in the routing table. Thanks for the clarification! Thanks, Feng > > Paolo > > > static int setup_routing_entry(struct kvm_irq_routing_table *rt, > > struct kvm_kernel_irq_routing_entry > *e, > > const struct kvm_irq_routing_entry > *ue) > > { > > > > ...... > > > > /* > > * Do not allow GSI to be mapped to the same irqchip more than > once. > > * Allow only one to one mapping between GSI and MSI. > > */ > > hlist_for_each_entry(ei, &rt->map[ue->gsi], link) > > if (ei->type == KVM_IRQ_ROUTING_MSI || > > ue->type == KVM_IRQ_ROUTING_MSI || > > ue->u.irqchip.irqchip == ei->irqchip.irqchip) > > return r; > > > > ...... > > } -- 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
