Messages in this thread |  | | Subject | Re: [PATCH] kvm: VMX: do not use vm-exit instruction length for fast MMIO | From | Paolo Bonzini <> | Date | Fri, 18 Aug 2017 14:35:09 +0200 |
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On 18/08/2017 13:57, David Hildenbrand wrote: > What about a hack: > > 1. clear instruction length when entering > 2. check if instruction length is set when trying to forward the RIP > 2a. if set, use it > 2b. if not set, compute it
It's undefined, so we don't know that the instruction length remains zero (also, on older processors and possibly some nested setups the field is read-only).
Testing the hypervisor bit is the first line of action.
Paolo
> this at least should give full speedup in existing setups. Not 99% > architecturally correct but might just work. >
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