#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_PTE_COPY_MASK PT64_PTE_COPY_MASK
#ifdef CONFIG_X86_64
#define PT_MAX_FULL_LEVELS 4
#else
#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_PTE_COPY_MASK PT32_PTE_COPY_MASK
#define PT_MAX_FULL_LEVELS 2
#else
#error Invalid PTTYPE value
int level;
gfn_t table_gfn[PT_MAX_FULL_LEVELS];
pt_element_t *table;
+ pt_element_t pte;
pt_element_t *ptep;
+ struct page *page;
+ int index;
pt_element_t inherited_ar;
gfn_t gfn;
u32 error_code;
pgprintk("%s: addr %lx\n", __FUNCTION__, addr);
walker->level = vcpu->mmu.root_level;
walker->table = NULL;
+ walker->page = NULL;
+ walker->ptep = NULL;
root = vcpu->cr3;
#if PTTYPE == 64
if (!is_long_mode(vcpu)) {
walker->ptep = &vcpu->pdptrs[(addr >> 30) & 3];
root = *walker->ptep;
+ walker->pte = root;
if (!(root & PT_PRESENT_MASK))
goto not_present;
--walker->level;
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);
+ walker->page = pfn_to_page(hpa >> PAGE_SHIFT);
+ walker->table = kmap_atomic(walker->page, KM_USER0);
ASSERT((!is_long_mode(vcpu) && is_pae(vcpu)) ||
- (vcpu->cr3 & ~(PAGE_MASK | CR3_FLAGS_MASK)) == 0);
+ (vcpu->cr3 & CR3_NONPAE_RESERVED_BITS) == 0);
walker->inherited_ar = PT_USER_MASK | PT_WRITABLE_MASK;
hpa_t paddr;
ptep = &walker->table[index];
+ walker->index = index;
ASSERT(((unsigned long)walker->table & PAGE_MASK) ==
((unsigned long)ptep & PAGE_MASK));
break;
}
- if (walker->level != 3 || is_long_mode(vcpu))
- walker->inherited_ar &= walker->table[index];
+ 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);
+ paddr = safe_gpa_to_hpa(vcpu, table_gfn << PAGE_SHIFT);
+ walker->page = pfn_to_page(paddr >> PAGE_SHIFT);
+ walker->table = kmap_atomic(walker->page, 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;
+ walker->pte = *ptep;
+ if (walker->page)
+ walker->ptep = NULL;
+ if (walker->table)
+ kunmap_atomic(walker->table, KM_USER0);
pgprintk("%s: pte %llx\n", __FUNCTION__, (u64)*ptep);
return 1;
walker->error_code |= PFERR_USER_MASK;
if (fetch_fault)
walker->error_code |= PFERR_FETCH_MASK;
- return 0;
-}
-
-static void FNAME(release_walker)(struct guest_walker *walker)
-{
if (walker->table)
kunmap_atomic(walker->table, KM_USER0);
+ return 0;
}
static void FNAME(mark_pagetable_dirty)(struct kvm *kvm,
mark_page_dirty(kvm, walker->table_gfn[walker->level - 1]);
}
-static void FNAME(set_pte)(struct kvm_vcpu *vcpu, u64 guest_pte,
- u64 *shadow_pte, u64 access_bits, gfn_t gfn)
+static void FNAME(set_pte_common)(struct kvm_vcpu *vcpu,
+ u64 *shadow_pte,
+ gpa_t gaddr,
+ pt_element_t gpte,
+ u64 access_bits,
+ int user_fault,
+ int write_fault,
+ int *ptwrite,
+ struct guest_walker *walker,
+ gfn_t gfn)
+{
+ hpa_t paddr;
+ int dirty = gpte & PT_DIRTY_MASK;
+ u64 spte = *shadow_pte;
+ int was_rmapped = is_rmap_pte(spte);
+
+ pgprintk("%s: spte %llx gpte %llx access %llx write_fault %d"
+ " user_fault %d gfn %lx\n",
+ __FUNCTION__, spte, (u64)gpte, access_bits,
+ write_fault, user_fault, gfn);
+
+ if (write_fault && !dirty) {
+ pt_element_t *guest_ent, *tmp = NULL;
+
+ if (walker->ptep)
+ guest_ent = walker->ptep;
+ else {
+ tmp = kmap_atomic(walker->page, KM_USER0);
+ guest_ent = &tmp[walker->index];
+ }
+
+ *guest_ent |= PT_DIRTY_MASK;
+ if (!walker->ptep)
+ kunmap_atomic(tmp, KM_USER0);
+ dirty = 1;
+ FNAME(mark_pagetable_dirty)(vcpu->kvm, walker);
+ }
+
+ spte |= PT_PRESENT_MASK | PT_ACCESSED_MASK | PT_DIRTY_MASK;
+ spte |= gpte & PT64_NX_MASK;
+ if (!dirty)
+ access_bits &= ~PT_WRITABLE_MASK;
+
+ paddr = gpa_to_hpa(vcpu, gaddr & PT64_BASE_ADDR_MASK);
+
+ spte |= PT_PRESENT_MASK;
+ if (access_bits & PT_USER_MASK)
+ spte |= PT_USER_MASK;
+
+ if (is_error_hpa(paddr)) {
+ spte |= gaddr;
+ spte |= PT_SHADOW_IO_MARK;
+ spte &= ~PT_PRESENT_MASK;
+ set_shadow_pte(shadow_pte, spte);
+ return;
+ }
+
+ spte |= paddr;
+
+ if ((access_bits & PT_WRITABLE_MASK)
+ || (write_fault && !is_write_protection(vcpu) && !user_fault)) {
+ struct kvm_mmu_page *shadow;
+
+ spte |= PT_WRITABLE_MASK;
+ if (user_fault) {
+ mmu_unshadow(vcpu, gfn);
+ goto unshadowed;
+ }
+
+ shadow = kvm_mmu_lookup_page(vcpu, gfn);
+ if (shadow) {
+ pgprintk("%s: found shadow page for %lx, marking ro\n",
+ __FUNCTION__, gfn);
+ access_bits &= ~PT_WRITABLE_MASK;
+ if (is_writeble_pte(spte)) {
+ spte &= ~PT_WRITABLE_MASK;
+ kvm_arch_ops->tlb_flush(vcpu);
+ }
+ if (write_fault)
+ *ptwrite = 1;
+ }
+ }
+
+unshadowed:
+
+ if (access_bits & PT_WRITABLE_MASK)
+ mark_page_dirty(vcpu->kvm, gaddr >> PAGE_SHIFT);
+
+ set_shadow_pte(shadow_pte, spte);
+ page_header_update_slot(vcpu->kvm, shadow_pte, gaddr);
+ if (!was_rmapped)
+ rmap_add(vcpu, shadow_pte);
+}
+
+static void FNAME(set_pte)(struct kvm_vcpu *vcpu, pt_element_t gpte,
+ u64 *shadow_pte, u64 access_bits,
+ int user_fault, int write_fault, int *ptwrite,
+ struct guest_walker *walker, 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, gfn);
+ access_bits &= gpte;
+ FNAME(set_pte_common)(vcpu, shadow_pte, gpte & PT_BASE_ADDR_MASK,
+ gpte, access_bits, user_fault, write_fault,
+ ptwrite, walker, gfn);
}
-static void FNAME(set_pde)(struct kvm_vcpu *vcpu, u64 guest_pde,
- u64 *shadow_pte, u64 access_bits, gfn_t gfn)
+static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
+ u64 *spte, const void *pte, int bytes)
+{
+ pt_element_t gpte;
+
+ if (bytes < sizeof(pt_element_t))
+ return;
+ gpte = *(const pt_element_t *)pte;
+ if (~gpte & (PT_PRESENT_MASK | PT_ACCESSED_MASK))
+ return;
+ pgprintk("%s: gpte %llx spte %p\n", __FUNCTION__, (u64)gpte, spte);
+ FNAME(set_pte)(vcpu, gpte, spte, PT_USER_MASK | PT_WRITABLE_MASK, 0,
+ 0, NULL, NULL,
+ (gpte & PT_BASE_ADDR_MASK) >> PAGE_SHIFT);
+}
+
+static void FNAME(set_pde)(struct kvm_vcpu *vcpu, pt_element_t gpde,
+ u64 *shadow_pte, u64 access_bits,
+ int user_fault, int write_fault, int *ptwrite,
+ struct guest_walker *walker, gfn_t gfn)
{
gpa_t gaddr;
- ASSERT(*shadow_pte == 0);
- access_bits &= guest_pde;
+ access_bits &= gpde;
gaddr = (gpa_t)gfn << PAGE_SHIFT;
if (PTTYPE == 32 && is_cpuid_PSE36())
- gaddr |= (guest_pde & PT32_DIR_PSE36_MASK) <<
+ gaddr |= (gpde & 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, gfn);
+ FNAME(set_pte_common)(vcpu, shadow_pte, gaddr,
+ gpde, access_bits, user_fault, write_fault,
+ ptwrite, walker, gfn);
}
/*
* 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)
+ struct guest_walker *walker,
+ int user_fault, int write_fault, int *ptwrite)
{
hpa_t shadow_addr;
int level;
+ u64 *shadow_ent;
u64 *prev_shadow_ent = NULL;
- pt_element_t *guest_ent = walker->ptep;
- if (!is_present_pte(*guest_ent))
+ if (!is_present_pte(walker->pte))
return NULL;
shadow_addr = vcpu->mmu.root_hpa;
for (; ; level--) {
u32 index = SHADOW_PT_INDEX(addr, level);
- u64 *shadow_ent = ((u64 *)__va(shadow_addr)) + index;
struct kvm_mmu_page *shadow_page;
u64 shadow_pte;
int metaphysical;
gfn_t table_gfn;
+ unsigned hugepage_access = 0;
+ shadow_ent = ((u64 *)__va(shadow_addr)) + index;
if (is_present_pte(*shadow_ent) || is_io_pte(*shadow_ent)) {
if (level == PT_PAGE_TABLE_LEVEL)
- return shadow_ent;
+ break;
shadow_addr = *shadow_ent & PT64_BASE_ADDR_MASK;
prev_shadow_ent = shadow_ent;
continue;
}
- if (level == PT_PAGE_TABLE_LEVEL) {
-
- if (walker->level == PT_DIRECTORY_LEVEL) {
- if (prev_shadow_ent)
- *prev_shadow_ent |= PT_SHADOW_PS_MARK;
- FNAME(set_pde)(vcpu, *guest_ent, shadow_ent,
- walker->inherited_ar,
- walker->gfn);
- } else {
- ASSERT(walker->level == PT_PAGE_TABLE_LEVEL);
- FNAME(set_pte)(vcpu, *guest_ent, shadow_ent,
- walker->inherited_ar,
- walker->gfn);
- }
- return shadow_ent;
- }
+ if (level == PT_PAGE_TABLE_LEVEL)
+ break;
if (level - 1 == PT_PAGE_TABLE_LEVEL
&& walker->level == PT_DIRECTORY_LEVEL) {
metaphysical = 1;
- table_gfn = (*guest_ent & PT_BASE_ADDR_MASK)
+ hugepage_access = walker->pte;
+ hugepage_access &= PT_USER_MASK | PT_WRITABLE_MASK;
+ if (walker->pte & PT64_NX_MASK)
+ hugepage_access |= (1 << 2);
+ hugepage_access >>= PT_WRITABLE_SHIFT;
+ table_gfn = (walker->pte & 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;
+ metaphysical, hugepage_access,
+ shadow_ent);
+ 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;
prev_shadow_ent = shadow_ent;
}
-}
-
-/*
- * The guest faulted for write. We need to
- *
- * - check write permissions
- * - update the guest pte dirty bit
- * - update our own dirty page tracking structures
- */
-static int FNAME(fix_write_pf)(struct kvm_vcpu *vcpu,
- u64 *shadow_ent,
- struct guest_walker *walker,
- gva_t addr,
- 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 !user || (*shadow_ent & PT_USER_MASK);
-
- writable_shadow = *shadow_ent & PT_SHADOW_WRITABLE_MASK;
- if (user) {
- /*
- * User mode access. Fail if it's a kernel page or a read-only
- * page.
- */
- if (!(*shadow_ent & PT_SHADOW_USER_MASK) || !writable_shadow)
- return 0;
- ASSERT(*shadow_ent & PT_USER_MASK);
- } else
- /*
- * Kernel mode access. Fail if it's a read-only page and
- * supervisor write protection is enabled.
- */
- if (!writable_shadow) {
- if (is_write_protection(vcpu))
- return 0;
- *shadow_ent &= ~PT_USER_MASK;
- }
- guest_ent = walker->ptep;
-
- if (!is_present_pte(*guest_ent)) {
- *shadow_ent = 0;
- return 0;
+ if (walker->level == PT_DIRECTORY_LEVEL) {
+ FNAME(set_pde)(vcpu, walker->pte, shadow_ent,
+ walker->inherited_ar, user_fault, write_fault,
+ ptwrite, walker, walker->gfn);
+ } else {
+ ASSERT(walker->level == PT_PAGE_TABLE_LEVEL);
+ FNAME(set_pte)(vcpu, walker->pte, shadow_ent,
+ walker->inherited_ar, user_fault, write_fault,
+ ptwrite, walker, walker->gfn);
}
-
- 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);
- mark_page_dirty(vcpu->kvm, gfn);
- FNAME(mark_pagetable_dirty)(vcpu->kvm, walker);
- *guest_ent |= PT_DIRTY_MASK;
- *write_pt = 1;
- return 0;
- }
- mark_page_dirty(vcpu->kvm, gfn);
- *shadow_ent |= PT_WRITABLE_MASK;
- FNAME(mark_pagetable_dirty)(vcpu->kvm, walker);
- *guest_ent |= PT_DIRTY_MASK;
- rmap_add(vcpu, shadow_ent);
-
- return 1;
+ return shadow_ent;
}
/*
int fetch_fault = error_code & PFERR_FETCH_MASK;
struct guest_walker walker;
u64 *shadow_pte;
- int fixed;
int write_pt = 0;
int r;
if (!r) {
pgprintk("%s: guest page fault\n", __FUNCTION__);
inject_page_fault(vcpu, addr, walker.error_code);
- FNAME(release_walker)(&walker);
+ vcpu->last_pt_write_count = 0; /* reset fork detector */
return 0;
}
- shadow_pte = FNAME(fetch)(vcpu, addr, &walker);
- pgprintk("%s: shadow pte %p %llx\n", __FUNCTION__,
- shadow_pte, *shadow_pte);
+ 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);
- /*
- * Update the shadow pte.
- */
- if (write_fault)
- fixed = FNAME(fix_write_pf)(vcpu, shadow_pte, &walker, addr,
- 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);
+ if (!write_pt)
+ vcpu->last_pt_write_count = 0; /* reset fork detector */
/*
* mmio: emulate if accessible, otherwise its a guest fault.
*/
- if (is_io_pte(*shadow_pte)) {
+ if (is_io_pte(*shadow_pte))
return 1;
- }
- ++kvm_stat.pf_fixed;
+ ++vcpu->stat.pf_fixed;
kvm_mmu_audit(vcpu, "post page fault (fixed)");
return write_pt;
gpa |= vaddr & ~PAGE_MASK;
}
- FNAME(release_walker)(&walker);
return gpa;
}
#undef PT_INDEX
#undef SHADOW_PT_INDEX
#undef PT_LEVEL_MASK
-#undef PT_PTE_COPY_MASK
-#undef PT_NON_PTE_COPY_MASK
#undef PT_DIR_BASE_ADDR_MASK
#undef PT_MAX_FULL_LEVELS
projects / linux-2.6 / blobdiff