Messages in this thread |  | | | Date | Thu, 17 Sep 2009 07:22:44 +0100 | | Subject | Re: [Xen-devel] [RFC][PATCH 03/10] xen/hybrid: Xen Hybrid Extension initialization | | From | Keir Fraser <> |
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On 16/09/2009 21:24, "Jeremy Fitzhardinge" <jeremy@goop.org> wrote:
>> Guest would detect Hybrid capability using CPUID 0x40000002.edx, then call >> HVMOP_enable_hybrid hypercall to enable hybrid support in hypervisor. >> > > I think having an option to put PV guests into an HVM container is a > good one, but as I mentioned in the other mail, I don't think this is > the right approach. > > It would be much better to make it so that an unmodified guest works in > such a mode; even with no specific optimisations the guest would get > benefit from faster kernel<->usermode switches.
By unmodified you mean ordinary PV guest? It's an interesting comparison -- PVing an HVM guest, versus HVMing (to some extent) a PV guest.
-- Keir
> Then we can add specific optimisations to take advantage of, say, > running in ring 0 (=fast syscalls) and having access to HAP hardware > (=direct pagetable updates, no pinning).
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