On Tue, Jun 15, 2010 at 10:47:04AM +0800, Xiao Guangrong wrote: > Support prefetch ptes when intercept guest #PF, avoid to #PF by later > access > > If we meet any failure in the prefetch path, we will exit it and > not try other ptes to avoid become heavy path > > Signed-off-by: Xiao Guangrong <[email protected]> > --- > arch/x86/kvm/mmu.c | 36 +++++++++++++++++++++ > arch/x86/kvm/paging_tmpl.h | 76 > ++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 112 insertions(+), 0 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index 92ff099..941c86b 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -89,6 +89,8 @@ module_param(oos_shadow, bool, 0644); > } > #endif > > +#define PTE_PREFETCH_NUM 16 > + > #define PT_FIRST_AVAIL_BITS_SHIFT 9 > #define PT64_SECOND_AVAIL_BITS_SHIFT 52 > > @@ -2041,6 +2043,39 @@ static void nonpaging_new_cr3(struct kvm_vcpu *vcpu) > { > } > > +static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) > +{ > + struct kvm_mmu_page *sp; > + int index, i; > + > + sp = page_header(__pa(sptep)); > + WARN_ON(!sp->role.direct); > + index = sptep - sp->spt; > + > + for (i = index + 1; i < min(PT64_ENT_PER_PAGE, > + index + PTE_PREFETCH_NUM); i++) { > + gfn_t gfn; > + pfn_t pfn; > + u64 *spte = sp->spt + i; > + > + if (*spte != shadow_trap_nonpresent_pte) > + continue; > + > + gfn = sp->gfn + (i << ((sp->role.level - 1) * PT64_LEVEL_BITS)); > + > + pfn = gfn_to_pfn_atomic(vcpu->kvm, gfn); > + if (is_error_pfn(pfn)) { > + kvm_release_pfn_clean(pfn); > + break; > + } > + if (pte_prefetch_topup_memory_cache(vcpu)) > + break; > + > + mmu_set_spte(vcpu, spte, ACC_ALL, ACC_ALL, 0, 0, 1, NULL, > + sp->role.level, gfn, pfn, true, false);
Can only map with level > 1 if the host page matches the size. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
