Messages in this thread | | | Date | Wed, 28 Sep 2022 18:56:54 +0800 | From | Chao Gao <> | Subject | Re: [RFC v2] KVM: x86/vmx: Suppress posted interrupt notification when CPU is in host |
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>> Changes in v2 (addressed comments from Kevin): >> - measure/estimate the impact to non-IPC-intensive cases >> - don't tie PID.SN to vcpu->mode. Instead, clear PID.SN >> right before VM-entry and set it after VM-exit. > >One correction here. My comment in v1 [1] was actually close to Sean's >suggestion, i.e. opposite to above description:
Hi Kevin,
Yes. The changelog is misleading. You suggested using a dedicate hook. And I indeed agreed to follow the suggestion. But as you said, what v2 does is the complete opposite of the suggestion.
The reason is when I started v2 recently, the idea of clearing SN right before VM-entry came to my mind. Since it could also solve some problems of v1 without a hook (hence, more self-contained), I thought it was slightly better. But I missed that clearing SN right before VM-entry can cause unnecessary SN toggling to VM-exit fast-path.
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