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| author | Avi Kivity <avi@qumranet.com> | 2008-05-29 15:20:16 +0400 |
|---|---|---|
| committer | Avi Kivity <avi@qumranet.com> | 2008-07-20 13:42:28 +0400 |
| commit | eab9f71feb1851b5b700ca12ae614b6a0a441021 (patch) | |
| tree | 9e6f7c60206621ab0f876110e2d57f0f7c8759fb /arch/x86 | |
| parent | 38d5bc6d50a4368be08b39b02efb9cbbe1dd60d0 (diff) | |
| download | linux-eab9f71feb1851b5b700ca12ae614b6a0a441021.tar.xz | |
KVM: MMU: Optimize prefetch_page()
Instead of reading each pte individually, read 256 bytes worth of ptes and
batch process them.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/paging_tmpl.h | 28 |
1 files changed, 15 insertions, 13 deletions
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 934c7b619396..4d918220baeb 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -460,8 +460,9 @@ 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, offset = 0, r = 0; - pt_element_t pt; + int i, j, offset, r; + pt_element_t pt[256 / sizeof(pt_element_t)]; + gpa_t pte_gpa; if (sp->role.metaphysical || (PTTYPE == 32 && sp->role.level > PT_PAGE_TABLE_LEVEL)) { @@ -469,19 +470,20 @@ static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu, return; } - if (PTTYPE == 32) + pte_gpa = gfn_to_gpa(sp->gfn); + if (PTTYPE == 32) { offset = sp->role.quadrant << PT64_LEVEL_BITS; + pte_gpa += offset * sizeof(pt_element_t); + } - for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { - gpa_t pte_gpa = gfn_to_gpa(sp->gfn); - pte_gpa += (i+offset) * sizeof(pt_element_t); - - r = kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &pt, - sizeof(pt_element_t)); - if (r || is_present_pte(pt)) - sp->spt[i] = shadow_trap_nonpresent_pte; - else - sp->spt[i] = shadow_notrap_nonpresent_pte; + for (i = 0; i < PT64_ENT_PER_PAGE; i += ARRAY_SIZE(pt)) { + r = kvm_read_guest_atomic(vcpu->kvm, pte_gpa, pt, sizeof pt); + pte_gpa += ARRAY_SIZE(pt) * sizeof(pt_element_t); + for (j = 0; j < ARRAY_SIZE(pt); ++j) + if (r || is_present_pte(pt[j])) + sp->spt[i+j] = shadow_trap_nonpresent_pte; + else + sp->spt[i+j] = shadow_notrap_nonpresent_pte; } } |