Messages in this thread |  | | | Date | Thu, 29 Apr 2010 21:43:40 +0300 | | From | Avi Kivity <> | | Subject | Re: [PATCH] kvm mmu: reduce 50% memory usage |
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On 04/29/2010 09:09 PM, Marcelo Tosatti wrote: > > You missed quadrant on 4mb large page emulation with shadow (see updated > patch below).
Good catch.
> Also for some reason i can't understand the assumption > does not hold for large sptes with TDP, so reverted for now. >
It's unrelated to TDP, same issue with shadow. I think the calculation is correct. For example the 4th spte for a level=2 page will yield gfn=4*512.
> @@ -393,6 +393,27 @@ static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd) > kfree(rd); > } > > +static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index) > +{ > + gfn_t gfn; > + > + if (!sp->role.direct) > + return sp->gfns[index]; > + > + gfn = sp->gfn + index * (1<< (sp->role.level - 1) * PT64_LEVEL_BITS); > + gfn += sp->role.quadrant<< PT64_LEVEL_BITS; >
PT64_LEVEL_BITS * level
> + > + return gfn; > +} > + > >
-- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.
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