Messages in this thread | | | Subject | Re: [PATCH v2] x86/ibpb: Skip IBPB when we switch back to same user process | Date | Sun, 28 Jan 2018 10:38:25 +0000 | From | "Woodhouse, David" <> |
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On Sun, 2018-01-28 at 10:56 +0100, Ingo Molnar wrote: > > What tree is this patch against? It doesn't apply to linus's latest, nor to > tip:master.
It's in my tree at http://git.infradead.org/users/dwmw2/linux-retpoline.git/shortlog/refs/heads/ibpb which is gradually being finalized and flushed via tip/x86/pti.
The IBPB on context switch parts are currently the first three patches there, which roughly suggests they might be the next to get sent out for real, if we have reached a consensus. The three patches there probably want collapsing into one, but I've left them as-is for now while we're discussing it.
The other thing that's next on the list is exposing the MSRs to guests. The IBPB one is fairly simple, and Karim is working on exposing IBRS to guests too, using Paolo's per-vCPU MSR bitmap to do the same trick we've done in Xen, to expose it only after the guest first touches it (to avoid the cost of swapping it when it's always 0←→0 in the common case). I think Ashok was talking about doing the same thing? We'll see who gets there first :)[unhandled content-type:application/x-pkcs7-signature] | |