diff options
Diffstat (limited to 'drivers/kvm/paging_tmpl.h')
-rw-r--r-- | drivers/kvm/paging_tmpl.h | 461 |
1 files changed, 0 insertions, 461 deletions
diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h deleted file mode 100644 index 56b88f7e83ef..000000000000 --- a/drivers/kvm/paging_tmpl.h +++ /dev/null @@ -1,461 +0,0 @@ -/* - * Kernel-based Virtual Machine driver for Linux - * - * This module enables machines with Intel VT-x extensions to run virtual - * machines without emulation or binary translation. - * - * MMU support - * - * Copyright (C) 2006 Qumranet, Inc. - * - * Authors: - * Yaniv Kamay <yaniv@qumranet.com> - * Avi Kivity <avi@qumranet.com> - * - * This work is licensed under the terms of the GNU GPL, version 2. See - * the COPYING file in the top-level directory. - * - */ - -/* - * We need the mmu code to access both 32-bit and 64-bit guest ptes, - * so the code in this file is compiled twice, once per pte size. - */ - -#if PTTYPE == 64 - #define pt_element_t u64 - #define guest_walker guest_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_INDEX(addr, level) PT64_INDEX(addr, level) - #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level) - #define PT_LEVEL_MASK(level) PT64_LEVEL_MASK(level) - #define PT_LEVEL_BITS PT64_LEVEL_BITS - #ifdef CONFIG_X86_64 - #define PT_MAX_FULL_LEVELS 4 - #define CMPXCHG cmpxchg - #else - #define CMPXCHG cmpxchg64 - #define PT_MAX_FULL_LEVELS 2 - #endif -#elif PTTYPE == 32 - #define pt_element_t u32 - #define guest_walker guest_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_INDEX(addr, level) PT32_INDEX(addr, level) - #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level) - #define PT_LEVEL_MASK(level) PT32_LEVEL_MASK(level) - #define PT_LEVEL_BITS PT32_LEVEL_BITS - #define PT_MAX_FULL_LEVELS 2 - #define CMPXCHG cmpxchg -#else - #error Invalid PTTYPE value -#endif - -#define gpte_to_gfn FNAME(gpte_to_gfn) -#define gpte_to_gfn_pde FNAME(gpte_to_gfn_pde) - -/* - * The guest_walker structure emulates the behavior of the hardware page - * table walker. - */ -struct guest_walker { - int level; - gfn_t table_gfn[PT_MAX_FULL_LEVELS]; - pt_element_t ptes[PT_MAX_FULL_LEVELS]; - gpa_t pte_gpa[PT_MAX_FULL_LEVELS]; - unsigned pt_access; - unsigned pte_access; - gfn_t gfn; - u32 error_code; -}; - -static gfn_t gpte_to_gfn(pt_element_t gpte) -{ - 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; -} - -static bool FNAME(cmpxchg_gpte)(struct kvm *kvm, - gfn_t table_gfn, unsigned index, - pt_element_t orig_pte, pt_element_t new_pte) -{ - pt_element_t ret; - pt_element_t *table; - struct page *page; - - page = gfn_to_page(kvm, table_gfn); - table = kmap_atomic(page, KM_USER0); - - ret = CMPXCHG(&table[index], orig_pte, new_pte); - - kunmap_atomic(table, KM_USER0); - - kvm_release_page_dirty(page); - - return (ret != orig_pte); -} - -static unsigned FNAME(gpte_access)(struct kvm_vcpu *vcpu, pt_element_t gpte) -{ - unsigned access; - - access = (gpte & (PT_WRITABLE_MASK | PT_USER_MASK)) | ACC_EXEC_MASK; -#if PTTYPE == 64 - if (is_nx(vcpu)) - access &= ~(gpte >> PT64_NX_SHIFT); -#endif - return access; -} - -/* - * Fetch a guest pte for a guest virtual address - */ -static int FNAME(walk_addr)(struct guest_walker *walker, - struct kvm_vcpu *vcpu, gva_t addr, - int write_fault, int user_fault, int fetch_fault) -{ - pt_element_t pte; - gfn_t table_gfn; - unsigned index, pt_access, pte_access; - gpa_t pte_gpa; - - pgprintk("%s: addr %lx\n", __FUNCTION__, addr); -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)) - goto not_present; - --walker->level; - } -#endif - ASSERT((!is_long_mode(vcpu) && is_pae(vcpu)) || - (vcpu->cr3 & CR3_NONPAE_RESERVED_BITS) == 0); - - pt_access = ACC_ALL; - - for (;;) { - index = PT_INDEX(addr, walker->level); - - table_gfn = gpte_to_gfn(pte); - pte_gpa = gfn_to_gpa(table_gfn); - 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", __FUNCTION__, - walker->level - 1, table_gfn); - - kvm_read_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte)); - - if (!is_present_pte(pte)) - goto not_present; - - if (write_fault && !is_writeble_pte(pte)) - if (user_fault || is_write_protection(vcpu)) - goto access_error; - - if (user_fault && !(pte & PT_USER_MASK)) - goto access_error; - -#if PTTYPE == 64 - if (fetch_fault && is_nx(vcpu) && (pte & PT64_NX_MASK)) - goto access_error; -#endif - - if (!(pte & PT_ACCESSED_MASK)) { - mark_page_dirty(vcpu->kvm, table_gfn); - if (FNAME(cmpxchg_gpte)(vcpu->kvm, table_gfn, - index, pte, pte|PT_ACCESSED_MASK)) - goto walk; - pte |= PT_ACCESSED_MASK; - } - - pte_access = pt_access & FNAME(gpte_access)(vcpu, pte); - - 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()) - walker->gfn += pse36_gfn_delta(pte); - break; - } - - pt_access = pte_access; - --walker->level; - } - - if (write_fault && !is_dirty_pte(pte)) { - bool ret; - - 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; - } - - walker->pt_access = pt_access; - walker->pte_access = pte_access; - pgprintk("%s: pte %llx pte_access %x pt_access %x\n", - __FUNCTION__, (u64)pte, pt_access, pte_access); - return 1; - -not_present: - walker->error_code = 0; - goto err; - -access_error: - walker->error_code = PFERR_PRESENT_MASK; - -err: - if (write_fault) - walker->error_code |= PFERR_WRITE_MASK; - if (user_fault) - walker->error_code |= PFERR_USER_MASK; - if (fetch_fault) - walker->error_code |= PFERR_FETCH_MASK; - return 0; -} - -static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page, - u64 *spte, const void *pte, int bytes, - int offset_in_pte) -{ - pt_element_t gpte; - unsigned pte_access; - - gpte = *(const pt_element_t *)pte; - if (~gpte & (PT_PRESENT_MASK | PT_ACCESSED_MASK)) { - if (!offset_in_pte && !is_present_pte(gpte)) - set_shadow_pte(spte, shadow_notrap_nonpresent_pte); - return; - } - if (bytes < sizeof(pt_element_t)) - return; - pgprintk("%s: gpte %llx spte %p\n", __FUNCTION__, (u64)gpte, spte); - pte_access = page->role.access & FNAME(gpte_access)(vcpu, gpte); - mmu_set_spte(vcpu, spte, page->role.access, pte_access, 0, 0, - gpte & PT_DIRTY_MASK, NULL, gpte_to_gfn(gpte)); -} - -/* - * Fetch a shadow pte for a specific level in the paging hierarchy. - */ -static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, - struct guest_walker *walker, - int user_fault, int write_fault, int *ptwrite) -{ - hpa_t shadow_addr; - int level; - u64 *shadow_ent; - unsigned access = walker->pt_access; - - if (!is_present_pte(walker->ptes[walker->level - 1])) - return NULL; - - shadow_addr = vcpu->arch.mmu.root_hpa; - level = vcpu->arch.mmu.shadow_root_level; - if (level == PT32E_ROOT_LEVEL) { - shadow_addr = vcpu->arch.mmu.pae_root[(addr >> 30) & 3]; - shadow_addr &= PT64_BASE_ADDR_MASK; - --level; - } - - for (; ; level--) { - u32 index = SHADOW_PT_INDEX(addr, level); - struct kvm_mmu_page *shadow_page; - u64 shadow_pte; - int metaphysical; - gfn_t table_gfn; - bool new_page = 0; - - shadow_ent = ((u64 *)__va(shadow_addr)) + index; - if (is_shadow_present_pte(*shadow_ent)) { - if (level == PT_PAGE_TABLE_LEVEL) - break; - shadow_addr = *shadow_ent & PT64_BASE_ADDR_MASK; - continue; - } - - if (level == PT_PAGE_TABLE_LEVEL) - break; - - if (level - 1 == PT_PAGE_TABLE_LEVEL - && walker->level == PT_DIRECTORY_LEVEL) { - metaphysical = 1; - if (!is_dirty_pte(walker->ptes[level - 1])) - access &= ~ACC_WRITE_MASK; - table_gfn = gpte_to_gfn(walker->ptes[level - 1]); - } else { - metaphysical = 0; - table_gfn = walker->table_gfn[level - 2]; - } - shadow_page = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1, - metaphysical, access, - shadow_ent, &new_page); - if (new_page && !metaphysical) { - pt_element_t curr_pte; - kvm_read_guest(vcpu->kvm, walker->pte_gpa[level - 2], - &curr_pte, sizeof(curr_pte)); - if (curr_pte != walker->ptes[level - 2]) - return NULL; - } - shadow_addr = __pa(shadow_page->spt); - shadow_pte = shadow_addr | PT_PRESENT_MASK | PT_ACCESSED_MASK - | PT_WRITABLE_MASK | PT_USER_MASK; - *shadow_ent = shadow_pte; - } - - mmu_set_spte(vcpu, shadow_ent, access, walker->pte_access & access, - user_fault, write_fault, - walker->ptes[walker->level-1] & PT_DIRTY_MASK, - ptwrite, walker->gfn); - - return shadow_ent; -} - -/* - * Page fault handler. There are several causes for a page fault: - * - there is no shadow pte for the guest pte - * - write access through a shadow pte marked read only so that we can set - * the dirty bit - * - write access to a shadow pte marked read only so we can update the page - * dirty bitmap, when userspace requests it - * - mmio access; in this case we will never install a present shadow pte - * - 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, or - * a negative value on error. - */ -static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, - u32 error_code) -{ - int write_fault = error_code & PFERR_WRITE_MASK; - int user_fault = error_code & PFERR_USER_MASK; - int fetch_fault = error_code & PFERR_FETCH_MASK; - struct guest_walker walker; - u64 *shadow_pte; - 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. - */ - r = FNAME(walk_addr)(&walker, vcpu, addr, write_fault, user_fault, - fetch_fault); - - /* - * The page is not mapped by the guest. Let the guest handle it. - */ - if (!r) { - pgprintk("%s: guest page fault\n", __FUNCTION__); - inject_page_fault(vcpu, addr, walker.error_code); - vcpu->arch.last_pt_write_count = 0; /* reset fork detector */ - return 0; - } - - shadow_pte = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault, - &write_pt); - pgprintk("%s: shadow pte %p %llx ptwrite %d\n", __FUNCTION__, - shadow_pte, *shadow_pte, write_pt); - - if (!write_pt) - vcpu->arch.last_pt_write_count = 0; /* reset fork detector */ - - /* - * mmio: emulate if accessible, otherwise its a guest fault. - */ - if (shadow_pte && is_io_pte(*shadow_pte)) - return 1; - - ++vcpu->stat.pf_fixed; - kvm_mmu_audit(vcpu, "post page fault (fixed)"); - - return write_pt; -} - -static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr) -{ - struct guest_walker walker; - gpa_t gpa = UNMAPPED_GVA; - int r; - - r = FNAME(walk_addr)(&walker, vcpu, vaddr, 0, 0, 0); - - if (r) { - gpa = gfn_to_gpa(walker.gfn); - gpa |= vaddr & ~PAGE_MASK; - } - - return gpa; -} - -static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu, - struct kvm_mmu_page *sp) -{ - int i, offset = 0; - pt_element_t *gpt; - struct page *page; - - 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[offset + i])) - sp->spt[i] = shadow_trap_nonpresent_pte; - else - sp->spt[i] = shadow_notrap_nonpresent_pte; - kunmap_atomic(gpt, KM_USER0); - kvm_release_page_clean(page); -} - -#undef pt_element_t -#undef guest_walker -#undef FNAME -#undef PT_BASE_ADDR_MASK -#undef PT_INDEX -#undef SHADOW_PT_INDEX -#undef PT_LEVEL_MASK -#undef PT_DIR_BASE_ADDR_MASK -#undef PT_LEVEL_BITS -#undef PT_MAX_FULL_LEVELS -#undef gpte_to_gfn -#undef gpte_to_gfn_pde -#undef CMPXCHG |