Re: [PATCH v2 37/43] KVM: SVM: Unconditionally mark AVIC as running on vCPU load (with APICv)

[Paolo Bonzini]

On 25/10/21 17:48, Sean Christopherson wrote:
> On Mon, Oct 25, 2021, Paolo Bonzini wrote:
> > On 09/10/21 04:12, Sean Christopherson wrote:
> > > +	/* TODO: Document why the unblocking path checks for updates. */
> >
> > Is that a riddle or what? :)
>
> Yes?  I haven't been able to figure out why the unblocking path explicitly
> checks and handles an APICv update.

Challenge accepted.  In the original code, it was because without it 
avic_vcpu_load would do nothing, and nothing would update the IS_RUNNING 
flag.

It shouldn't be necessary anymore since commit df7e4827c549 ("KVM: SVM: 
call avic_vcpu_load/avic_vcpu_put when enabling/disabling AVIC", 
2021-08-20), where svm_refresh_apicv_exec_ctrl takes care of the 
avic_vcpu_load on the next VMRUN.

Paolo