2016-01-20 09:42+0800, Feng Wu:
> Use vector-hashing to deliver lowest-priority interrupts for
> VT-d posted-interrupts. This patch extends kvm_intr_is_single_vcpu()
> to support lowest-priority handling.
>
> Signed-off-by: Feng Wu <feng...@intel.com>
> ---
> v3:
> - Remove unnecessary check in fast irq delivery patch
> - print a error message only once for each guest when we find hardware
> disabled LAPIC during interrupt injection.
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> @@ -1316,8 +1316,8 @@ int x86_set_memory_region(struct kvm *kvm, int id,
> gpa_t gpa, u32 size);
> bool kvm_vcpu_is_reset_bsp(struct kvm_vcpu *vcpu);
> bool kvm_vcpu_is_bsp(struct kvm_vcpu *vcpu);
>
> -bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
> - struct kvm_vcpu **dest_vcpu);
> +bool kvm_intr_can_posting(struct kvm *kvm, struct kvm_lapic_irq *irq,
I prefer the original one; I think it's better to describe function
than intent in names -- intention should be obvious from its use.
> + struct kvm_vcpu **dest_vcpu);
>
> void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e,
> struct kvm_lapic_irq *irq);
> diff --git a/arch/x86/kvm/irq_comm.c b/arch/x86/kvm/irq_comm.c
> @@ -300,13 +300,13 @@ out:
> return r;
> }
>
> -bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
> - struct kvm_vcpu **dest_vcpu)
> +bool kvm_intr_can_posting(struct kvm *kvm, struct kvm_lapic_irq *irq,
> + struct kvm_vcpu **dest_vcpu)
> {
> int i, r = 0;
> struct kvm_vcpu *vcpu;
>
> - if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
> + if (kvm_intr_can_posting_fast(kvm, irq, dest_vcpu))
> return true;
There is one pitfall: xAPIC flat logical broadcast returns false, but
lowest priority is defined for it (practically isn't a broadcast) and
the rest of this function doesn't check for lowest priority, so the
interrupt won't be posted.
We could modify our _fast functions to cover 0xff in flat logical, but
ignoring this case isn't bad either ... it can happen only with 8 VCPU
guests. I'd just comment that we did it on purpose. :)
>
> kvm_for_each_vcpu(i, vcpu, kvm) {
[Comments for the rest mirror [2/4].]
