diff options
Diffstat (limited to 'kvm/kernel/paging_tmpl.h')
| -rw-r--r-- | kvm/kernel/paging_tmpl.h | 260 |
1 files changed, 168 insertions, 92 deletions
diff --git a/kvm/kernel/paging_tmpl.h b/kvm/kernel/paging_tmpl.h index 09bb9b4ed..2dbf4307e 100644 --- a/kvm/kernel/paging_tmpl.h +++ b/kvm/kernel/paging_tmpl.h @@ -32,6 +32,11 @@ #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level) #define PT_LEVEL_MASK(level) PT64_LEVEL_MASK(level) #define PT_PTE_COPY_MASK PT64_PTE_COPY_MASK + #ifdef CONFIG_X86_64 + #define PT_MAX_FULL_LEVELS 4 + #else + #define PT_MAX_FULL_LEVELS 2 + #endif #elif PTTYPE == 32 #define pt_element_t u32 #define guest_walker guest_walker32 @@ -42,6 +47,7 @@ #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level) #define PT_LEVEL_MASK(level) PT32_LEVEL_MASK(level) #define PT_PTE_COPY_MASK PT32_PTE_COPY_MASK + #define PT_MAX_FULL_LEVELS 2 #else #error Invalid PTTYPE value #endif @@ -52,93 +58,126 @@ */ struct guest_walker { int level; + gfn_t table_gfn[PT_MAX_FULL_LEVELS]; pt_element_t *table; + pt_element_t *ptep; pt_element_t inherited_ar; + gfn_t gfn; }; -static void FNAME(init_walker)(struct guest_walker *walker, - struct kvm_vcpu *vcpu) +/* + * Fetch a guest pte for a guest virtual address + */ +static void FNAME(walk_addr)(struct guest_walker *walker, + struct kvm_vcpu *vcpu, gva_t addr) { hpa_t hpa; struct kvm_memory_slot *slot; + pt_element_t *ptep; + pt_element_t root; + gfn_t table_gfn; + pgprintk("%s: addr %lx\n", __FUNCTION__, addr); walker->level = vcpu->mmu.root_level; - slot = gfn_to_memslot(vcpu->kvm, - (vcpu->cr3 & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT); - hpa = safe_gpa_to_hpa(vcpu, vcpu->cr3 & PT64_BASE_ADDR_MASK); + walker->table = NULL; + root = vcpu->cr3; +#if PTTYPE == 64 + if (!is_long_mode(vcpu)) { + walker->ptep = &vcpu->pdptrs[(addr >> 30) & 3]; + root = *walker->ptep; + if (!(root & PT_PRESENT_MASK)) + return; + --walker->level; + } +#endif + table_gfn = (root & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT; + walker->table_gfn[walker->level - 1] = table_gfn; + pgprintk("%s: table_gfn[%d] %lx\n", __FUNCTION__, + walker->level - 1, table_gfn); + slot = gfn_to_memslot(vcpu->kvm, table_gfn); + hpa = safe_gpa_to_hpa(vcpu, root & PT64_BASE_ADDR_MASK); walker->table = kmap_atomic(pfn_to_page(hpa >> PAGE_SHIFT), KM_USER0); ASSERT((!is_long_mode(vcpu) && is_pae(vcpu)) || (vcpu->cr3 & ~(PAGE_MASK | CR3_FLAGS_MASK)) == 0); - walker->table = (pt_element_t *)( (unsigned long)walker->table | - (unsigned long)(vcpu->cr3 & ~(PAGE_MASK | CR3_FLAGS_MASK)) ); walker->inherited_ar = PT_USER_MASK | PT_WRITABLE_MASK; + + for (;;) { + int index = PT_INDEX(addr, walker->level); + hpa_t paddr; + + ptep = &walker->table[index]; + ASSERT(((unsigned long)walker->table & PAGE_MASK) == + ((unsigned long)ptep & PAGE_MASK)); + + if (is_present_pte(*ptep) && !(*ptep & PT_ACCESSED_MASK)) + *ptep |= PT_ACCESSED_MASK; + + if (!is_present_pte(*ptep)) + break; + + if (walker->level == PT_PAGE_TABLE_LEVEL) { + walker->gfn = (*ptep & PT_BASE_ADDR_MASK) + >> PAGE_SHIFT; + break; + } + + if (walker->level == PT_DIRECTORY_LEVEL + && (*ptep & PT_PAGE_SIZE_MASK) + && (PTTYPE == 64 || is_pse(vcpu))) { + walker->gfn = (*ptep & PT_DIR_BASE_ADDR_MASK) + >> PAGE_SHIFT; + walker->gfn += PT_INDEX(addr, PT_PAGE_TABLE_LEVEL); + break; + } + + if (walker->level != 3 || is_long_mode(vcpu)) + walker->inherited_ar &= walker->table[index]; + table_gfn = (*ptep & PT_BASE_ADDR_MASK) >> PAGE_SHIFT; + paddr = safe_gpa_to_hpa(vcpu, *ptep & PT_BASE_ADDR_MASK); + kunmap_atomic(walker->table, KM_USER0); + walker->table = kmap_atomic(pfn_to_page(paddr >> PAGE_SHIFT), + KM_USER0); + --walker->level; + walker->table_gfn[walker->level - 1 ] = table_gfn; + pgprintk("%s: table_gfn[%d] %lx\n", __FUNCTION__, + walker->level - 1, table_gfn); + } + walker->ptep = ptep; + pgprintk("%s: pte %llx\n", __FUNCTION__, (u64)*ptep); } static void FNAME(release_walker)(struct guest_walker *walker) { - kunmap_atomic(walker->table, KM_USER0); + if (walker->table) + kunmap_atomic(walker->table, KM_USER0); } static void FNAME(set_pte)(struct kvm_vcpu *vcpu, u64 guest_pte, - u64 *shadow_pte, u64 access_bits) + u64 *shadow_pte, u64 access_bits, gfn_t gfn) { ASSERT(*shadow_pte == 0); access_bits &= guest_pte; *shadow_pte = (guest_pte & PT_PTE_COPY_MASK); set_pte_common(vcpu, shadow_pte, guest_pte & PT_BASE_ADDR_MASK, - guest_pte & PT_DIRTY_MASK, access_bits); + guest_pte & PT_DIRTY_MASK, access_bits, gfn); } static void FNAME(set_pde)(struct kvm_vcpu *vcpu, u64 guest_pde, - u64 *shadow_pte, u64 access_bits, - int index) + u64 *shadow_pte, u64 access_bits, gfn_t gfn) { gpa_t gaddr; ASSERT(*shadow_pte == 0); access_bits &= guest_pde; - gaddr = (guest_pde & PT_DIR_BASE_ADDR_MASK) + PAGE_SIZE * index; + gaddr = (gpa_t)gfn << PAGE_SHIFT; if (PTTYPE == 32 && is_cpuid_PSE36()) gaddr |= (guest_pde & PT32_DIR_PSE36_MASK) << (32 - PT32_DIR_PSE36_SHIFT); *shadow_pte = guest_pde & PT_PTE_COPY_MASK; set_pte_common(vcpu, shadow_pte, gaddr, - guest_pde & PT_DIRTY_MASK, access_bits); -} - -/* - * Fetch a guest pte from a specific level in the paging hierarchy. - */ -static pt_element_t *FNAME(fetch_guest)(struct kvm_vcpu *vcpu, - struct guest_walker *walker, - int level, - gva_t addr) -{ - - ASSERT(level > 0 && level <= walker->level); - - for (;;) { - int index = PT_INDEX(addr, walker->level); - hpa_t paddr; - - ASSERT(((unsigned long)walker->table & PAGE_MASK) == - ((unsigned long)&walker->table[index] & PAGE_MASK)); - if (level == walker->level || - !is_present_pte(walker->table[index]) || - (walker->level == PT_DIRECTORY_LEVEL && - (walker->table[index] & PT_PAGE_SIZE_MASK) && - (PTTYPE == 64 || is_pse(vcpu)))) - return &walker->table[index]; - if (walker->level != 3 || is_long_mode(vcpu)) - walker->inherited_ar &= walker->table[index]; - paddr = safe_gpa_to_hpa(vcpu, walker->table[index] & PT_BASE_ADDR_MASK); - kunmap_atomic(walker->table, KM_USER0); - walker->table = kmap_atomic(pfn_to_page(paddr >> PAGE_SHIFT), - KM_USER0); - --walker->level; - } + guest_pde & PT_DIRTY_MASK, access_bits, gfn); } /* @@ -150,15 +189,26 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, hpa_t shadow_addr; int level; u64 *prev_shadow_ent = NULL; + pt_element_t *guest_ent = walker->ptep; + + if (!is_present_pte(*guest_ent)) + return NULL; shadow_addr = vcpu->mmu.root_hpa; level = vcpu->mmu.shadow_root_level; + if (level == PT32E_ROOT_LEVEL) { + shadow_addr = vcpu->mmu.pae_root[(addr >> 30) & 3]; + shadow_addr &= PT64_BASE_ADDR_MASK; + --level; + } for (; ; level--) { u32 index = SHADOW_PT_INDEX(addr, level); u64 *shadow_ent = ((u64 *)__va(shadow_addr)) + index; - pt_element_t *guest_ent; + struct kvm_mmu_page *shadow_page; u64 shadow_pte; + int metaphysical; + gfn_t table_gfn; if (is_present_pte(*shadow_ent) || is_io_pte(*shadow_ent)) { if (level == PT_PAGE_TABLE_LEVEL) @@ -168,21 +218,6 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, continue; } - if (PTTYPE == 32 && level > PT32_ROOT_LEVEL) { - ASSERT(level == PT32E_ROOT_LEVEL); - guest_ent = FNAME(fetch_guest)(vcpu, walker, - PT32_ROOT_LEVEL, addr); - } else - guest_ent = FNAME(fetch_guest)(vcpu, walker, - level, addr); - - if (!is_present_pte(*guest_ent)) - return NULL; - - /* Don't set accessed bit on PAE PDPTRs */ - if (vcpu->mmu.root_level != 3 || walker->level != 3) - *guest_ent |= PT_ACCESSED_MASK; - if (level == PT_PAGE_TABLE_LEVEL) { if (walker->level == PT_DIRECTORY_LEVEL) { @@ -190,21 +225,30 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, *prev_shadow_ent |= PT_SHADOW_PS_MARK; FNAME(set_pde)(vcpu, *guest_ent, shadow_ent, walker->inherited_ar, - PT_INDEX(addr, PT_PAGE_TABLE_LEVEL)); + walker->gfn); } else { ASSERT(walker->level == PT_PAGE_TABLE_LEVEL); - FNAME(set_pte)(vcpu, *guest_ent, shadow_ent, walker->inherited_ar); + FNAME(set_pte)(vcpu, *guest_ent, shadow_ent, + walker->inherited_ar, + walker->gfn); } return shadow_ent; } - shadow_addr = kvm_mmu_alloc_page(vcpu, shadow_ent); - if (!VALID_PAGE(shadow_addr)) - return ERR_PTR(-ENOMEM); - shadow_pte = shadow_addr | PT_PRESENT_MASK; - if (vcpu->mmu.root_level > 3 || level != 3) - shadow_pte |= PT_ACCESSED_MASK - | PT_WRITABLE_MASK | PT_USER_MASK; + if (level - 1 == PT_PAGE_TABLE_LEVEL + && walker->level == PT_DIRECTORY_LEVEL) { + metaphysical = 1; + table_gfn = (*guest_ent & PT_BASE_ADDR_MASK) + >> PAGE_SHIFT; + } else { + metaphysical = 0; + table_gfn = walker->table_gfn[level - 2]; + } + shadow_page = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1, + metaphysical, shadow_ent); + shadow_addr = shadow_page->page_hpa; + shadow_pte = shadow_addr | PT_PRESENT_MASK | PT_ACCESSED_MASK + | PT_WRITABLE_MASK | PT_USER_MASK; *shadow_ent = shadow_pte; prev_shadow_ent = shadow_ent; } @@ -221,11 +265,13 @@ static int FNAME(fix_write_pf)(struct kvm_vcpu *vcpu, u64 *shadow_ent, struct guest_walker *walker, gva_t addr, - int user) + int user, + int *write_pt) { pt_element_t *guest_ent; int writable_shadow; gfn_t gfn; + struct kvm_mmu_page *page; if (is_writeble_pte(*shadow_ent)) return 0; @@ -250,17 +296,35 @@ static int FNAME(fix_write_pf)(struct kvm_vcpu *vcpu, *shadow_ent &= ~PT_USER_MASK; } - guest_ent = FNAME(fetch_guest)(vcpu, walker, PT_PAGE_TABLE_LEVEL, addr); + guest_ent = walker->ptep; if (!is_present_pte(*guest_ent)) { *shadow_ent = 0; return 0; } - gfn = (*guest_ent & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT; + gfn = walker->gfn; + + if (user) { + /* + * Usermode page faults won't be for page table updates. + */ + while ((page = kvm_mmu_lookup_page(vcpu, gfn)) != NULL) { + pgprintk("%s: zap %lx %x\n", + __FUNCTION__, gfn, page->role.word); + kvm_mmu_zap_page(vcpu, page); + } + } else if (kvm_mmu_lookup_page(vcpu, gfn)) { + pgprintk("%s: found shadow page for %lx, marking ro\n", + __FUNCTION__, gfn); + *guest_ent |= PT_DIRTY_MASK; + *write_pt = 1; + return 0; + } mark_page_dirty(vcpu->kvm, gfn); *shadow_ent |= PT_WRITABLE_MASK; *guest_ent |= PT_DIRTY_MASK; + rmap_add(vcpu, shadow_ent); return 1; } @@ -276,7 +340,8 @@ static int FNAME(fix_write_pf)(struct kvm_vcpu *vcpu, * - normal guest page fault due to the guest pte marked not present, not * writable, or not executable * - * Returns: 1 if we need to emulate the instruction, 0 otherwise + * Returns: 1 if we need to emulate the instruction, 0 otherwise, or + * a negative value on error. */ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code) @@ -287,39 +352,47 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, struct guest_walker walker; u64 *shadow_pte; int fixed; + int write_pt = 0; + int r; + + pgprintk("%s: addr %lx err %x\n", __FUNCTION__, addr, error_code); + kvm_mmu_audit(vcpu, "pre page fault"); + + r = mmu_topup_memory_caches(vcpu); + if (r) + return r; /* * Look up the shadow pte for the faulting address. */ - for (;;) { - FNAME(init_walker)(&walker, vcpu); - shadow_pte = FNAME(fetch)(vcpu, addr, &walker); - if (IS_ERR(shadow_pte)) { /* must be -ENOMEM */ - nonpaging_flush(vcpu); - FNAME(release_walker)(&walker); - continue; - } - break; - } + FNAME(walk_addr)(&walker, vcpu, addr); + shadow_pte = FNAME(fetch)(vcpu, addr, &walker); /* * The page is not mapped by the guest. Let the guest handle it. */ if (!shadow_pte) { + pgprintk("%s: not mapped\n", __FUNCTION__); inject_page_fault(vcpu, addr, error_code); FNAME(release_walker)(&walker); return 0; } + pgprintk("%s: shadow pte %p %llx\n", __FUNCTION__, + shadow_pte, *shadow_pte); + /* * Update the shadow pte. */ if (write_fault) fixed = FNAME(fix_write_pf)(vcpu, shadow_pte, &walker, addr, - user_fault); + user_fault, &write_pt); else fixed = fix_read_pf(shadow_pte); + pgprintk("%s: updated shadow pte %p %llx\n", __FUNCTION__, + shadow_pte, *shadow_pte); + FNAME(release_walker)(&walker); /* @@ -331,20 +404,23 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, pgprintk("%s: io work, no access\n", __FUNCTION__); inject_page_fault(vcpu, addr, error_code | PFERR_PRESENT_MASK); + kvm_mmu_audit(vcpu, "post page fault (io)"); return 0; } /* * pte not present, guest page fault. */ - if (pte_present && !fixed) { + if (pte_present && !fixed && !write_pt) { inject_page_fault(vcpu, addr, error_code); + kvm_mmu_audit(vcpu, "post page fault (guest)"); return 0; } ++kvm_stat.pf_fixed; + kvm_mmu_audit(vcpu, "post page fault (fixed)"); - return 0; + return write_pt; } static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr) @@ -353,9 +429,8 @@ static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr) pt_element_t guest_pte; gpa_t gpa; - FNAME(init_walker)(&walker, vcpu); - guest_pte = *FNAME(fetch_guest)(vcpu, &walker, PT_PAGE_TABLE_LEVEL, - vaddr); + FNAME(walk_addr)(&walker, vcpu, vaddr); + guest_pte = *walker.ptep; FNAME(release_walker)(&walker); if (!is_present_pte(guest_pte)) @@ -389,3 +464,4 @@ static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr) #undef PT_PTE_COPY_MASK #undef PT_NON_PTE_COPY_MASK #undef PT_DIR_BASE_ADDR_MASK +#undef PT_MAX_FULL_LEVELS |