diff options
| -rw-r--r-- | arch/x86/kvm/paging_tmpl.h | 93 |
1 files changed, 49 insertions, 44 deletions
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index e1c1f9eb1cc..368e4cb6233 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -321,9 +321,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, unsigned access = gw->pt_access; struct kvm_mmu_page *sp; u64 *sptep = NULL; - int direct; - gfn_t table_gfn; - int level; + int uninitialized_var(level); bool dirty = is_dirty_gpte(gw->ptes[gw->level - 1]); unsigned direct_access; struct kvm_shadow_walk_iterator iterator; @@ -335,61 +333,68 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, if (!dirty) direct_access &= ~ACC_WRITE_MASK; - for_each_shadow_entry(vcpu, addr, iterator) { + for (shadow_walk_init(&iterator, vcpu, addr); + shadow_walk_okay(&iterator) && iterator.level > gw->level; + shadow_walk_next(&iterator)) { + gfn_t table_gfn; + level = iterator.level; sptep = iterator.sptep; - if (iterator.level == hlevel) { - mmu_set_spte(vcpu, sptep, access, - gw->pte_access & access, - user_fault, write_fault, - dirty, ptwrite, level, - gw->gfn, pfn, false, true); - break; - } - - if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep) - && level == gw->level) - validate_direct_spte(vcpu, sptep, direct_access); drop_large_spte(vcpu, sptep); if (is_shadow_present_pte(*sptep)) continue; - if (level <= gw->level) { - direct = 1; - access = direct_access; - - /* - * It is a large guest pages backed by small host pages, - * So we set @direct(@sp->role.direct)=1, and set - * @table_gfn(@sp->gfn)=the base page frame for linear - * translations. - */ - table_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(level) - 1); - access &= gw->pte_access; - } else { - direct = 0; - table_gfn = gw->table_gfn[level - 2]; - } + table_gfn = gw->table_gfn[level - 2]; sp = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1, - direct, access, sptep); - if (!direct) - /* - * Verify that the gpte in the page we've just write - * protected is still there. - */ - if (FNAME(gpte_changed)(vcpu, gw, level - 1)) { - kvm_mmu_put_page(sp, sptep); - kvm_release_pfn_clean(pfn); - sptep = NULL; - break; - } + false, access, sptep); + + /* + * Verify that the gpte in the page we've just write + * protected is still there. + */ + if (FNAME(gpte_changed)(vcpu, gw, level - 1)) + goto out_gpte_changed; + + link_shadow_page(sptep, sp); + } + + for (; + shadow_walk_okay(&iterator) && iterator.level > hlevel; + shadow_walk_next(&iterator)) { + gfn_t direct_gfn; + level = iterator.level; + sptep = iterator.sptep; + + validate_direct_spte(vcpu, sptep, direct_access); + + drop_large_spte(vcpu, sptep); + + if (is_shadow_present_pte(*sptep)) + continue; + + direct_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(level) - 1); + + sp = kvm_mmu_get_page(vcpu, direct_gfn, addr, level-1, + true, direct_access, sptep); link_shadow_page(sptep, sp); } + sptep = iterator.sptep; + level = iterator.level; + + mmu_set_spte(vcpu, sptep, access, gw->pte_access & access, + user_fault, write_fault, dirty, ptwrite, level, + gw->gfn, pfn, false, true); + return sptep; + +out_gpte_changed: + kvm_mmu_put_page(sp, sptep); + kvm_release_pfn_clean(pfn); + return NULL; } /* |