Messages in this thread | | | Date | Fri, 08 May 2009 14:37:18 +0300 | From | Avi Kivity <> | Subject | Re: [RFC PATCH 0/3] generic hypercall support |
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Marcelo Tosatti wrote: >>> Also it would be interesting to see the MMIO comparison with EPT/NPT, >>> it probably sucks much less than what you're seeing. >>> >>> >> Why would NPT improve mmio? If anything, it would be worse, since the >> processor has to do the nested walk. >> > > I suppose the hardware is much more efficient than walk_addr? There's > all this kmalloc, spinlock, etc overhead in the fault path. >
mmio still has to do a walk_addr, even with npt. We don't take the mmu lock during walk_addr.
-- Do not meddle in the internals of kernels, for they are subtle and quick to panic.
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