Re: [Xen-devel] [PATCH] Remove a set operation for VCPU_KICK_SOFTIRQ when post interrupt to vm.

["Zhang, Yang Z" <yang.z.zhang@xxxxxxxxx>]

Zhang, Yang Z wrote on 2015-09-24:
> Liuqiming (John) wrote on 2015-09-24:
>> 
>> 
>> On 2015/9/24 11:25, Zhang, Yang Z wrote:
>> it completed, the following vmentry will pick up the pending interrupt.
>> If you send the ipi unconditionally, actually it is received by
>> hypervisor and the interrupt handler dose nothing. You still rely on
>> the vmentry to pick up the interrupt. My confusion is:  when
>> vmentry, does physical CPU inject all interrupts on PIR into VM and
>> clear POSTED_INTR_ON bit? Or just inject the highest index of PIR
>> and may leave POSTED_INTR_ON bit being set to 1?
> 
> I need to say your understanding is wrong. What we need to do is sync
> the pir to irr and let hardware or hypervisor to handle left part. So
> our focus is how to sync pir to irr correctly and timely. We don't
> care how the interrupt in PIR is injected to guest.

Hi Qiming, is there any other question with it? Also, do you have any chance to 
test it?

Best regards,
Yang


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