[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] XSA-60 - how to get back to a sane state
Jan Beulich wrote: >>>> On 03.12.13 at 15:30, "Liu, Jinsong" <jinsong.liu@xxxxxxxxx> wrote: >> Jan Beulich wrote: >>>>>> On 03.12.13 at 04:06, "Liu, Jinsong" <jinsong.liu@xxxxxxxxx> >>>>>> wrote: >>>> I also vote option 2, but only revert 86d60e85, keeping 62652c00 >>>> (wbinvd at vmx_ctxt_switch_to) since it's used to avoid being >>>> polluted when vcpu migrate to another cpu. >>> >>> Please explain this in more detail. Both Andrew and I are concerned >>> about this extra, but pretty pointless (without being done so too in >>> other cases) wbinvd(). In particular you'd have to explain what its >>> counterpart was in the code prior to your four patch XSA-60 series. >> >> The wbinvd at vmx_ctxt_switch_to is for case like >> 1. vcpu runs at cpu A, flushing cache at vmx_handle_cd; >> 2. then the vcpu may switch out and migrate to cpu B; >> 3. historically cpu B may has cacheline polluted; >> so when the vcpu is scheduled to cpu B, we need flush cache. > > But you didn't clarify whether/how this case was taken care of > _before_ your XSA-60 patches. > I didn't understand your question. What do you mean by 'before my XSA-60 patches'? Thanks, Jinsong _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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