From e5a4c8cad952d6e060991841f3632578ab3ae133 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Tue, 20 Nov 2007 21:39:54 +0200 Subject: [PATCH] KVM: MMU: Implement guest page fault bypass for nonpae I spent an hour worrying why I see so many guest page faults on FC6 i386. Turns out bypass wasn't implemented for nonpae. Implement it so it doesn't happen again. Signed-off-by: Avi Kivity --- drivers/kvm/paging_tmpl.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h index bf15d12..92b9313 100644 --- a/drivers/kvm/paging_tmpl.h +++ b/drivers/kvm/paging_tmpl.h @@ -486,19 +486,22 @@ static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr) static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) { - int i; + int i, offset = 0; pt_element_t *gpt; struct page *page; - if (sp->role.metaphysical || PTTYPE == 32) { + if (sp->role.metaphysical + || (PTTYPE == 32 && sp->role.level > PT_PAGE_TABLE_LEVEL)) { nonpaging_prefetch_page(vcpu, sp); return; } + if (PTTYPE == 32) + offset = sp->role.quadrant << PT64_LEVEL_BITS; page = gfn_to_page(vcpu->kvm, sp->gfn); gpt = kmap_atomic(page, KM_USER0); for (i = 0; i < PT64_ENT_PER_PAGE; ++i) - if (is_present_pte(gpt[i])) + if (is_present_pte(gpt[offset + i])) sp->spt[i] = shadow_trap_nonpresent_pte; else sp->spt[i] = shadow_notrap_nonpresent_pte; -- 2.7.4