Gleb Natapov wrote on 2013-03-21:
> On Thu, Mar 21, 2013 at 12:12:06PM +0000, Zhang, Yang Z wrote:
>> Gleb Natapov wrote on 2013-03-21:
>>> On Thu, Mar 21, 2013 at 11:56:05AM +0000, Zhang, Yang Z wrote:
>>>> Gleb Natapov wrote on 2013-03-21:
>>>>> On Thu, Mar 21, 2013 at 06:49:21PM +0800, Yang Zhang wrote:
>>>>>> From: Yang Zhang <yang.z.zhang@xxxxxxxxx>
>>>>>>
>>>>>> Add a new parameter to know vcpus who received the interrupt.
>>>>>>
>>>>>> Signed-off-by: Yang Zhang <yang.z.zhang@xxxxxxxxx>
>>>>>> ---
>>>>>> arch/x86/kvm/lapic.c | 21 ++++++++++++++++-----
>>>>>> arch/x86/kvm/lapic.h | 5 +++--
>>>>>> virt/kvm/ioapic.c | 2 +-
>>>>>> virt/kvm/ioapic.h | 2 +-
>>>>>> virt/kvm/irq_comm.c | 12 ++++++------
>>>>>> 5 files changed, 27 insertions(+), 15 deletions(-)
>>>>>> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
>>>>>> index d3e322a..5f6b1d0 100644
>>>>>> --- a/arch/x86/kvm/lapic.c
>>>>>> +++ b/arch/x86/kvm/lapic.c
>>>>>> @@ -433,10 +433,21 @@ int kvm_lapic_find_highest_irr(struct kvm_vcpu
>>>>> *vcpu)
>>>>>> static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
>>>>>> int vector, int level, int trig_mode);
>>>>>> -int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq
>>>>>> *irq) +static void kvm_set_irq_dest_map(struct kvm_vcpu *vcpu,
>>>>>> unsigned long *dest_map) +{ + if (!kvm_lapic_enabled(vcpu))
>>>>>> + return;
>>>>> Why this check here?
>>>> The vcpu who didn't enable apic should not account as destination vcpu.
>>>> Without this check, if broadcast interrupt, all cpus will treat as
>>>> destination vcpu, but only those who enabled apic will receive the
>>>> interrupt. There are same check in __apic_accept_irq(): if
>>>> (unlikely(!apic_enabled(apic)))
>>>> break;
>>> I see, but you use more strict check that also checks that apic is
>>> emulated by the kernel and we wouldn't be here if it wasn't. Anyway lets
>> Do you mean the check add in here will block "userspace apic"?
>> Shouldn't only in-kernel apic will get here?
>>
> No, it will not block. It checks for in kernel apic needlessly. Since we
> patch all those checks out anyway using jump labels it is not really
> affects performance, but I prefer to make only necessary checks for
> consistency.
Make sense.
>>> move bitmap update into __apic_accept_irq().
>> Sure.
>>
>
> --
> Gleb.
Best regards,
Yang
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