#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
#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
*/
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;
+ u32 error_code;
};
-static void FNAME(init_walker)(struct guest_walker *walker,
- struct kvm_vcpu *vcpu)
+/*
+ * 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)
{
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))
+ goto not_present;
+ --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))
+ goto not_present;
+
+ if (write_fault && !is_writeble_pte(*ptep))
+ if (user_fault || is_write_protection(vcpu))
+ goto access_error;
+
+ if (user_fault && !(*ptep & PT_USER_MASK))
+ goto access_error;
+
+#if PTTYPE == 64
+ if (fetch_fault && is_nx(vcpu) && (*ptep & PT64_NX_MASK))
+ goto access_error;
+#endif
+
+ if (!(*ptep & PT_ACCESSED_MASK))
+ *ptep |= PT_ACCESSED_MASK; /* avoid rmw */
+
+ 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);
+ 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(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);
}
/*
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)
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) {
*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;
}
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;
+ return !user || (*shadow_ent & PT_USER_MASK);
writable_shadow = *shadow_ent & PT_SHADOW_WRITABLE_MASK;
if (user) {
*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;
}
* - 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)
{
int write_fault = error_code & PFERR_WRITE_MASK;
- int pte_present = error_code & PFERR_PRESENT_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 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;
- }
+ 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 (!shadow_pte) {
- inject_page_fault(vcpu, addr, error_code);
+ if (!r) {
+ pgprintk("%s: guest page fault\n", __FUNCTION__);
+ inject_page_fault(vcpu, addr, walker.error_code);
FNAME(release_walker)(&walker);
return 0;
}
+ shadow_pte = FNAME(fetch)(vcpu, addr, &walker);
+ 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);
/*
* mmio: emulate if accessible, otherwise its a guest fault.
*/
if (is_io_pte(*shadow_pte)) {
- if (may_access(*shadow_pte, write_fault, user_fault))
- return 1;
- pgprintk("%s: io work, no access\n", __FUNCTION__);
- inject_page_fault(vcpu, addr,
- error_code | PFERR_PRESENT_MASK);
- return 0;
- }
-
- /*
- * pte not present, guest page fault.
- */
- if (pte_present && !fixed) {
- inject_page_fault(vcpu, addr, error_code);
- return 0;
+ return 1;
}
++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)
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, 0, 0, 0);
+ guest_pte = *walker.ptep;
FNAME(release_walker)(&walker);
if (!is_present_pte(guest_pte))
#undef PT_PTE_COPY_MASK
#undef PT_NON_PTE_COPY_MASK
#undef PT_DIR_BASE_ADDR_MASK
+#undef PT_MAX_FULL_LEVELS
git.openpandora.org / pandora-kernel.git / blobdiff