Re: [PATCH] svm: Fix AVIC incomplete IPI emulation

[Suthikulpanit, Suravee]

Oren

On 3/13/19 8:05 PM, Oren Twaig wrote:
> HiÂSuravee,
> 
> TurnsÂout,Âthe _same_ÂbugÂwasÂalreadyÂdiscussedÂinÂtheÂpastÂby
> yourself,ÂPaoloÂandÂRadimÂ(bothÂnowÂ'cc'-ed)
> 
> PleaseÂreadÂitÂhere:
> https://patchwork.kernel.org/patch/8292231/
> 
> 
> AfterÂreadingÂthatÂthread,ÂIÂhaveÂcoupleÂofÂquestions:
> 
> First,
> 
> YouÂwroteÂ:Â"IÂhaveÂtriedÂNOTÂsettingÂtheÂIRR,ÂandÂonly
> kick_vcpu().ÂAndÂthingsÂseemÂtoÂworkÂfine.ÂTherefore,ÂIÂthinkÂyour
> analysisÂisÂlikelyÂtoÂbeÂcorrect."
> 
> AFAIU,ÂitÂmeansÂthatÂtheÂbelowÂpatchÂisÂwrongÂjustÂasÂPaolo
> suggestedÂinÂhisÂoriginalÂanswerÂandÂyouÂdidÂfixedÂitÂbackÂthan,ÂbutÂthe
> codeÂisÂnowÂbackÂ?

Thanks for the recap. I was chasing a bug and totally forgot about this
discussion. I just found the reason why irr_pending was not set to 1 in my test,
which then causes the target vcpu to never get wake up and scheduled to process
the IRR bit that was set by AVIC as part of sending IPI.

I will send out a patch to revert and clean up this mess. Thanks for catching this.
And sorry for confusion.

Thanks,
Suravee