KVM: MMU: shadow support for 1gb pages
[safe/jmp/linux-2.6] / arch / x86 / kvm / paging_tmpl.h
index 776fb6d..d2fec9c 100644 (file)
 #if PTTYPE == 64
        #define pt_element_t u64
        #define guest_walker guest_walker64
-       #define shadow_walker shadow_walker64
        #define FNAME(name) paging##64_##name
        #define PT_BASE_ADDR_MASK PT64_BASE_ADDR_MASK
-       #define PT_DIR_BASE_ADDR_MASK PT64_DIR_BASE_ADDR_MASK
+       #define PT_LVL_ADDR_MASK(lvl) PT64_LVL_ADDR_MASK(lvl)
+       #define PT_LVL_OFFSET_MASK(lvl) PT64_LVL_OFFSET_MASK(lvl)
        #define PT_INDEX(addr, level) PT64_INDEX(addr, level)
        #define PT_LEVEL_MASK(level) PT64_LEVEL_MASK(level)
        #define PT_LEVEL_BITS PT64_LEVEL_BITS
 #elif PTTYPE == 32
        #define pt_element_t u32
        #define guest_walker guest_walker32
-       #define shadow_walker shadow_walker32
        #define FNAME(name) paging##32_##name
        #define PT_BASE_ADDR_MASK PT32_BASE_ADDR_MASK
-       #define PT_DIR_BASE_ADDR_MASK PT32_DIR_BASE_ADDR_MASK
+       #define PT_LVL_ADDR_MASK(lvl) PT32_LVL_ADDR_MASK(lvl)
+       #define PT_LVL_OFFSET_MASK(lvl) PT32_LVL_OFFSET_MASK(lvl)
        #define PT_INDEX(addr, level) PT32_INDEX(addr, level)
        #define PT_LEVEL_MASK(level) PT32_LEVEL_MASK(level)
        #define PT_LEVEL_BITS PT32_LEVEL_BITS
@@ -55,8 +55,8 @@
        #error Invalid PTTYPE value
 #endif
 
-#define gpte_to_gfn FNAME(gpte_to_gfn)
-#define gpte_to_gfn_pde FNAME(gpte_to_gfn_pde)
+#define gpte_to_gfn_lvl FNAME(gpte_to_gfn_lvl)
+#define gpte_to_gfn(pte) gpte_to_gfn_lvl((pte), PT_PAGE_TABLE_LEVEL)
 
 /*
  * The guest_walker structure emulates the behavior of the hardware page
@@ -73,25 +73,9 @@ struct guest_walker {
        u32 error_code;
 };
 
-struct shadow_walker {
-       struct kvm_shadow_walk walker;
-       struct guest_walker *guest_walker;
-       int user_fault;
-       int write_fault;
-       int largepage;
-       int *ptwrite;
-       pfn_t pfn;
-       u64 *sptep;
-};
-
-static gfn_t gpte_to_gfn(pt_element_t gpte)
+static gfn_t gpte_to_gfn_lvl(pt_element_t gpte, int lvl)
 {
-       return (gpte & PT_BASE_ADDR_MASK) >> PAGE_SHIFT;
-}
-
-static gfn_t gpte_to_gfn_pde(pt_element_t gpte)
-{
-       return (gpte & PT_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT;
+       return (gpte & PT_LVL_ADDR_MASK(lvl)) >> PAGE_SHIFT;
 }
 
 static bool FNAME(cmpxchg_gpte)(struct kvm *kvm,
@@ -136,15 +120,18 @@ static int FNAME(walk_addr)(struct guest_walker *walker,
        gfn_t table_gfn;
        unsigned index, pt_access, pte_access;
        gpa_t pte_gpa;
+       int rsvd_fault = 0;
 
-       pgprintk("%s: addr %lx\n", __func__, addr);
+       trace_kvm_mmu_pagetable_walk(addr, write_fault, user_fault,
+                                    fetch_fault);
 walk:
        walker->level = vcpu->arch.mmu.root_level;
        pte = vcpu->arch.cr3;
 #if PTTYPE == 64
        if (!is_long_mode(vcpu)) {
-               pte = vcpu->arch.pdptrs[(addr >> 30) & 3];
-               if (!is_present_pte(pte))
+               pte = kvm_pdptr_read(vcpu, (addr >> 30) & 3);
+               trace_kvm_mmu_paging_element(pte, walker->level);
+               if (!is_present_gpte(pte))
                        goto not_present;
                --walker->level;
        }
@@ -162,14 +149,17 @@ walk:
                pte_gpa += index * sizeof(pt_element_t);
                walker->table_gfn[walker->level - 1] = table_gfn;
                walker->pte_gpa[walker->level - 1] = pte_gpa;
-               pgprintk("%s: table_gfn[%d] %lx\n", __func__,
-                        walker->level - 1, table_gfn);
 
                kvm_read_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte));
+               trace_kvm_mmu_paging_element(pte, walker->level);
 
-               if (!is_present_pte(pte))
+               if (!is_present_gpte(pte))
                        goto not_present;
 
+               rsvd_fault = is_rsvd_bits_set(vcpu, pte, walker->level);
+               if (rsvd_fault)
+                       goto access_error;
+
                if (write_fault && !is_writeble_pte(pte))
                        if (user_fault || is_write_protection(vcpu))
                                goto access_error;
@@ -183,6 +173,8 @@ walk:
 #endif
 
                if (!(pte & PT_ACCESSED_MASK)) {
+                       trace_kvm_mmu_set_accessed_bit(table_gfn, index,
+                                                      sizeof(pte));
                        mark_page_dirty(vcpu->kvm, table_gfn);
                        if (FNAME(cmpxchg_gpte)(vcpu->kvm, table_gfn,
                            index, pte, pte|PT_ACCESSED_MASK))
@@ -194,18 +186,24 @@ walk:
 
                walker->ptes[walker->level - 1] = pte;
 
-               if (walker->level == PT_PAGE_TABLE_LEVEL) {
-                       walker->gfn = gpte_to_gfn(pte);
-                       break;
-               }
-
-               if (walker->level == PT_DIRECTORY_LEVEL
-                   && (pte & PT_PAGE_SIZE_MASK)
-                   && (PTTYPE == 64 || is_pse(vcpu))) {
-                       walker->gfn = gpte_to_gfn_pde(pte);
-                       walker->gfn += PT_INDEX(addr, PT_PAGE_TABLE_LEVEL);
-                       if (PTTYPE == 32 && is_cpuid_PSE36())
+               if ((walker->level == PT_PAGE_TABLE_LEVEL) ||
+                   ((walker->level == PT_DIRECTORY_LEVEL) &&
+                               (pte & PT_PAGE_SIZE_MASK)  &&
+                               (PTTYPE == 64 || is_pse(vcpu))) ||
+                   ((walker->level == PT_PDPE_LEVEL) &&
+                               (pte & PT_PAGE_SIZE_MASK)  &&
+                               is_long_mode(vcpu))) {
+                       int lvl = walker->level;
+
+                       walker->gfn = gpte_to_gfn_lvl(pte, lvl);
+                       walker->gfn += (addr & PT_LVL_OFFSET_MASK(lvl))
+                                       >> PAGE_SHIFT;
+
+                       if (PTTYPE == 32 &&
+                           walker->level == PT_DIRECTORY_LEVEL &&
+                           is_cpuid_PSE36())
                                walker->gfn += pse36_gfn_delta(pte);
+
                        break;
                }
 
@@ -213,16 +211,16 @@ walk:
                --walker->level;
        }
 
-       if (write_fault && !is_dirty_pte(pte)) {
+       if (write_fault && !is_dirty_gpte(pte)) {
                bool ret;
 
+               trace_kvm_mmu_set_dirty_bit(table_gfn, index, sizeof(pte));
                mark_page_dirty(vcpu->kvm, table_gfn);
                ret = FNAME(cmpxchg_gpte)(vcpu->kvm, table_gfn, index, pte,
                            pte|PT_DIRTY_MASK);
                if (ret)
                        goto walk;
                pte |= PT_DIRTY_MASK;
-               kvm_mmu_pte_write(vcpu, pte_gpa, (u8 *)&pte, sizeof(pte));
                walker->ptes[walker->level - 1] = pte;
        }
 
@@ -246,6 +244,9 @@ err:
                walker->error_code |= PFERR_USER_MASK;
        if (fetch_fault)
                walker->error_code |= PFERR_FETCH_MASK;
+       if (rsvd_fault)
+               walker->error_code |= PFERR_RSVD_MASK;
+       trace_kvm_mmu_walker_error(walker->error_code);
        return 0;
 }
 
@@ -255,12 +256,11 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
        pt_element_t gpte;
        unsigned pte_access;
        pfn_t pfn;
-       int largepage = vcpu->arch.update_pte.largepage;
 
        gpte = *(const pt_element_t *)pte;
        if (~gpte & (PT_PRESENT_MASK | PT_ACCESSED_MASK)) {
-               if (!is_present_pte(gpte))
-                       set_shadow_pte(spte, shadow_notrap_nonpresent_pte);
+               if (!is_present_gpte(gpte))
+                       __set_spte(spte, shadow_notrap_nonpresent_pte);
                return;
        }
        pgprintk("%s: gpte %llx spte %p\n", __func__, (u64)gpte, spte);
@@ -274,96 +274,87 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
                return;
        kvm_get_pfn(pfn);
        mmu_set_spte(vcpu, spte, page->role.access, pte_access, 0, 0,
-                    gpte & PT_DIRTY_MASK, NULL, largepage, gpte_to_gfn(gpte),
-                    pfn, true);
+                    gpte & PT_DIRTY_MASK, NULL, PT_PAGE_TABLE_LEVEL,
+                    gpte_to_gfn(gpte), pfn, true);
 }
 
 /*
  * Fetch a shadow pte for a specific level in the paging hierarchy.
  */
-static int FNAME(shadow_walk_entry)(struct kvm_shadow_walk *_sw,
-                                   struct kvm_vcpu *vcpu, u64 addr,
-                                   u64 *sptep, int level)
+static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
+                        struct guest_walker *gw,
+                        int user_fault, int write_fault, int hlevel,
+                        int *ptwrite, pfn_t pfn)
 {
-       struct shadow_walker *sw =
-               container_of(_sw, struct shadow_walker, walker);
-       struct guest_walker *gw = sw->guest_walker;
        unsigned access = gw->pt_access;
        struct kvm_mmu_page *shadow_page;
-       u64 spte;
-       int metaphysical;
+       u64 spte, *sptep = NULL;
+       int direct;
        gfn_t table_gfn;
        int r;
+       int level;
        pt_element_t curr_pte;
+       struct kvm_shadow_walk_iterator iterator;
 
-       if (level == PT_PAGE_TABLE_LEVEL
-           || (sw->largepage && level == PT_DIRECTORY_LEVEL)) {
-               mmu_set_spte(vcpu, sptep, access, gw->pte_access & access,
-                            sw->user_fault, sw->write_fault,
-                            gw->ptes[gw->level-1] & PT_DIRTY_MASK,
-                            sw->ptwrite, sw->largepage, gw->gfn, sw->pfn,
-                            false);
-               sw->sptep = sptep;
-               return 1;
-       }
+       if (!is_present_gpte(gw->ptes[gw->level - 1]))
+               return NULL;
 
-       if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep))
-               return 0;
+       for_each_shadow_entry(vcpu, addr, iterator) {
+               level = iterator.level;
+               sptep = iterator.sptep;
+               if (iterator.level == hlevel) {
+                       mmu_set_spte(vcpu, sptep, access,
+                                    gw->pte_access & access,
+                                    user_fault, write_fault,
+                                    gw->ptes[gw->level-1] & PT_DIRTY_MASK,
+                                    ptwrite, level,
+                                    gw->gfn, pfn, false);
+                       break;
+               }
 
-       if (is_large_pte(*sptep)) {
-               set_shadow_pte(sptep, shadow_trap_nonpresent_pte);
-               kvm_flush_remote_tlbs(vcpu->kvm);
-               rmap_remove(vcpu->kvm, sptep);
-       }
+               if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep))
+                       continue;
 
-       if (level == PT_DIRECTORY_LEVEL && gw->level == PT_DIRECTORY_LEVEL) {
-               metaphysical = 1;
-               if (!is_dirty_pte(gw->ptes[level - 1]))
-                       access &= ~ACC_WRITE_MASK;
-               table_gfn = gpte_to_gfn(gw->ptes[level - 1]);
-       } else {
-               metaphysical = 0;
-               table_gfn = gw->table_gfn[level - 2];
-       }
-       shadow_page = kvm_mmu_get_page(vcpu, table_gfn, (gva_t)addr, level-1,
-                                      metaphysical, access, sptep);
-       if (!metaphysical) {
-               r = kvm_read_guest_atomic(vcpu->kvm, gw->pte_gpa[level - 2],
-                                         &curr_pte, sizeof(curr_pte));
-               if (r || curr_pte != gw->ptes[level - 2]) {
-                       kvm_release_pfn_clean(sw->pfn);
-                       sw->sptep = NULL;
-                       return 1;
+               if (is_large_pte(*sptep)) {
+                       rmap_remove(vcpu->kvm, sptep);
+                       __set_spte(sptep, shadow_trap_nonpresent_pte);
+                       kvm_flush_remote_tlbs(vcpu->kvm);
                }
-       }
 
-       spte = __pa(shadow_page->spt) | PT_PRESENT_MASK | PT_ACCESSED_MASK
-               | PT_WRITABLE_MASK | PT_USER_MASK;
-       *sptep = spte;
-       return 0;
-}
-
-static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
-                        struct guest_walker *guest_walker,
-                        int user_fault, int write_fault, int largepage,
-                        int *ptwrite, pfn_t pfn)
-{
-       struct shadow_walker walker = {
-               .walker = { .entry = FNAME(shadow_walk_entry), },
-               .guest_walker = guest_walker,
-               .user_fault = user_fault,
-               .write_fault = write_fault,
-               .largepage = largepage,
-               .ptwrite = ptwrite,
-               .pfn = pfn,
-       };
-
-       if (!is_present_pte(guest_walker->ptes[guest_walker->level - 1]))
-               return NULL;
+               if (level <= gw->level) {
+                       int delta = level - gw->level + 1;
+                       direct = 1;
+                       if (!is_dirty_gpte(gw->ptes[level - delta]))
+                               access &= ~ACC_WRITE_MASK;
+                       table_gfn = gpte_to_gfn(gw->ptes[level - delta]);
+                       /* advance table_gfn when emulating 1gb pages with 4k */
+                       if (delta == 0)
+                               table_gfn += PT_INDEX(addr, level);
+               } else {
+                       direct = 0;
+                       table_gfn = gw->table_gfn[level - 2];
+               }
+               shadow_page = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1,
+                                              direct, access, sptep);
+               if (!direct) {
+                       r = kvm_read_guest_atomic(vcpu->kvm,
+                                                 gw->pte_gpa[level - 2],
+                                                 &curr_pte, sizeof(curr_pte));
+                       if (r || curr_pte != gw->ptes[level - 2]) {
+                               kvm_mmu_put_page(shadow_page, sptep);
+                               kvm_release_pfn_clean(pfn);
+                               sptep = NULL;
+                               break;
+                       }
+               }
 
-       walk_shadow(&walker.walker, vcpu, addr);
+               spte = __pa(shadow_page->spt)
+                       | PT_PRESENT_MASK | PT_ACCESSED_MASK
+                       | PT_WRITABLE_MASK | PT_USER_MASK;
+               *sptep = spte;
+       }
 
-       return walker.sptep;
+       return sptep;
 }
 
 /*
@@ -387,11 +378,11 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
        int user_fault = error_code & PFERR_USER_MASK;
        int fetch_fault = error_code & PFERR_FETCH_MASK;
        struct guest_walker walker;
-       u64 *shadow_pte;
+       u64 *sptep;
        int write_pt = 0;
        int r;
        pfn_t pfn;
-       int largepage = 0;
+       int level = PT_PAGE_TABLE_LEVEL;
        unsigned long mmu_seq;
 
        pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code);
@@ -402,7 +393,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
                return r;
 
        /*
-        * Look up the shadow pte for the faulting address.
+        * Look up the guest pte for the faulting address.
         */
        r = FNAME(walk_addr)(&walker, vcpu, addr, write_fault, user_fault,
                             fetch_fault);
@@ -417,14 +408,11 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
                return 0;
        }
 
-       if (walker.level == PT_DIRECTORY_LEVEL) {
-               gfn_t large_gfn;
-               large_gfn = walker.gfn & ~(KVM_PAGES_PER_HPAGE-1);
-               if (is_largepage_backed(vcpu, large_gfn)) {
-                       walker.gfn = large_gfn;
-                       largepage = 1;
-               }
+       if (walker.level >= PT_DIRECTORY_LEVEL) {
+               level = min(walker.level, mapping_level(vcpu, walker.gfn));
+               walker.gfn = walker.gfn & ~(KVM_PAGES_PER_HPAGE(level) - 1);
        }
+
        mmu_seq = vcpu->kvm->mmu_notifier_seq;
        smp_rmb();
        pfn = gfn_to_pfn(vcpu->kvm, walker.gfn);
@@ -440,11 +428,10 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
        if (mmu_notifier_retry(vcpu, mmu_seq))
                goto out_unlock;
        kvm_mmu_free_some_pages(vcpu);
-       shadow_pte = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,
-                                 largepage, &write_pt, pfn);
-
+       sptep = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,
+                            level, &write_pt, pfn);
        pgprintk("%s: shadow pte %p %llx ptwrite %d\n", __func__,
-                shadow_pte, *shadow_pte, write_pt);
+                sptep, *sptep, write_pt);
 
        if (!write_pt)
                vcpu->arch.last_pt_write_count = 0; /* reset fork detector */
@@ -461,6 +448,61 @@ out_unlock:
        return 0;
 }
 
+static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
+{
+       struct kvm_shadow_walk_iterator iterator;
+       pt_element_t gpte;
+       gpa_t pte_gpa = -1;
+       int level;
+       u64 *sptep;
+       int need_flush = 0;
+
+       spin_lock(&vcpu->kvm->mmu_lock);
+
+       for_each_shadow_entry(vcpu, gva, iterator) {
+               level = iterator.level;
+               sptep = iterator.sptep;
+
+               /* FIXME: properly handle invlpg on large guest pages */
+               if (level == PT_PAGE_TABLE_LEVEL  ||
+                   ((level == PT_DIRECTORY_LEVEL && is_large_pte(*sptep))) ||
+                   ((level == PT_PDPE_LEVEL && is_large_pte(*sptep)))) {
+                       struct kvm_mmu_page *sp = page_header(__pa(sptep));
+
+                       pte_gpa = (sp->gfn << PAGE_SHIFT);
+                       pte_gpa += (sptep - sp->spt) * sizeof(pt_element_t);
+
+                       if (is_shadow_present_pte(*sptep)) {
+                               rmap_remove(vcpu->kvm, sptep);
+                               if (is_large_pte(*sptep))
+                                       --vcpu->kvm->stat.lpages;
+                               need_flush = 1;
+                       }
+                       __set_spte(sptep, shadow_trap_nonpresent_pte);
+                       break;
+               }
+
+               if (!is_shadow_present_pte(*sptep))
+                       break;
+       }
+
+       if (need_flush)
+               kvm_flush_remote_tlbs(vcpu->kvm);
+       spin_unlock(&vcpu->kvm->mmu_lock);
+
+       if (pte_gpa == -1)
+               return;
+       if (kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &gpte,
+                                 sizeof(pt_element_t)))
+               return;
+       if (is_present_gpte(gpte) && (gpte & PT_ACCESSED_MASK)) {
+               if (mmu_topup_memory_caches(vcpu))
+                       return;
+               kvm_mmu_pte_write(vcpu, pte_gpa, (const u8 *)&gpte,
+                                 sizeof(pt_element_t), 0);
+       }
+}
+
 static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr)
 {
        struct guest_walker walker;
@@ -484,7 +526,7 @@ static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu,
        pt_element_t pt[256 / sizeof(pt_element_t)];
        gpa_t pte_gpa;
 
-       if (sp->role.metaphysical
+       if (sp->role.direct
            || (PTTYPE == 32 && sp->role.level > PT_PAGE_TABLE_LEVEL)) {
                nonpaging_prefetch_page(vcpu, sp);
                return;
@@ -500,7 +542,7 @@ static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu,
                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]))
+                       if (r || is_present_gpte(pt[j]))
                                sp->spt[i+j] = shadow_trap_nonpresent_pte;
                        else
                                sp->spt[i+j] = shadow_notrap_nonpresent_pte;
@@ -538,24 +580,24 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
                                          sizeof(pt_element_t)))
                        return -EINVAL;
 
-               if (gpte_to_gfn(gpte) != gfn || !is_present_pte(gpte) ||
+               if (gpte_to_gfn(gpte) != gfn || !is_present_gpte(gpte) ||
                    !(gpte & PT_ACCESSED_MASK)) {
                        u64 nonpresent;
 
                        rmap_remove(vcpu->kvm, &sp->spt[i]);
-                       if (is_present_pte(gpte))
+                       if (is_present_gpte(gpte))
                                nonpresent = shadow_trap_nonpresent_pte;
                        else
                                nonpresent = shadow_notrap_nonpresent_pte;
-                       set_shadow_pte(&sp->spt[i], nonpresent);
+                       __set_spte(&sp->spt[i], nonpresent);
                        continue;
                }
 
                nr_present++;
                pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte);
                set_spte(vcpu, &sp->spt[i], pte_access, 0, 0,
-                        is_dirty_pte(gpte), 0, gfn,
-                        spte_to_pfn(sp->spt[i]), true);
+                        is_dirty_gpte(gpte), PT_PAGE_TABLE_LEVEL, gfn,
+                        spte_to_pfn(sp->spt[i]), true, false);
        }
 
        return !nr_present;
@@ -563,14 +605,14 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
 
 #undef pt_element_t
 #undef guest_walker
-#undef shadow_walker
 #undef FNAME
 #undef PT_BASE_ADDR_MASK
 #undef PT_INDEX
 #undef PT_LEVEL_MASK
-#undef PT_DIR_BASE_ADDR_MASK
+#undef PT_LVL_ADDR_MASK
+#undef PT_LVL_OFFSET_MASK
 #undef PT_LEVEL_BITS
 #undef PT_MAX_FULL_LEVELS
 #undef gpte_to_gfn
-#undef gpte_to_gfn_pde
+#undef gpte_to_gfn_lvl
 #undef CMPXCHG