[PATCH 9/33] KVM: MMU: Shadow page table caching

Avi Kivity
2007-01-04T15:58:06Z

Define a hashtable for caching shadow page tables. Look up the cache on
context switch (cr3 change) or during page faults.

The key to the cache is a combination of
- the guest page table frame number
- the number of paging levels in the guest
* we can cache real mode, 32-bit mode, pae, and long mode page
tables simultaneously. this is useful for smp bootup.
- the guest page table table
* some kernels use a page as both a page table and a page directory. this
allows multiple shadow pages to exist for that page, one per level
- the "quadrant"
* 32-bit mode page tables span 4MB, whereas a shadow page table spans
2MB. similarly, a 32-bit page directory spans 4GB, while a shadow
page directory spans 1GB. the quadrant allows caching up to 4 shadow page
tables for one guest page in one level.
- a "metaphysical" bit
* for real mode, and for pse pages, there is no guest page table, so set
the bit to avoid write protecting the page.

Signed-off-by: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>

Index: linux-2.6/drivers/kvm/mmu.c
===================================================================
--- linux-2.6.orig/drivers/kvm/mmu.c
+++ linux-2.6/drivers/kvm/mmu.c
@@ -26,8 +26,8 @@
#include "vmx.h"
#include "kvm.h"

-#define pgprintk(x...) do { } while (0)
-#define rmap_printk(x...) do { } while (0)
+#define pgprintk(x...) do { printk(x); } while (0)
+#define rmap_printk(x...) do { printk(x); } while (0)

#define ASSERT(x) \
if (!(x)) { \
@@ -35,8 +35,10 @@
__FILE__, __LINE__, #x); \
}

-#define PT64_ENT_PER_PAGE 512
-#define PT32_ENT_PER_PAGE 1024
+#define PT64_PT_BITS 9
+#define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
+#define PT32_PT_BITS 10
+#define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS)

#define PT_WRITABLE_SHIFT 1

@@ -292,6 +294,11 @@ static int is_empty_shadow_page(hpa_t pa
return 1;
}

+static unsigned kvm_page_table_hashfn(gfn_t gfn)
+{
+ return gfn;
+}
+
static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
u64 *parent_pte)
{
@@ -306,10 +313,147 @@ static struct kvm_mmu_page *kvm_mmu_allo
ASSERT(is_empty_shadow_page(page->page_hpa));
page->slot_bitmap = 0;
page->global = 1;
+ page->multimapped = 0;
page->parent_pte = parent_pte;
return page;
}

+static void mmu_page_add_parent_pte(struct kvm_mmu_page *page, u64 *parent_pte)
+{
+ struct kvm_pte_chain *pte_chain;
+ struct hlist_node *node;
+ int i;
+
+ if (!parent_pte)
+ return;
+ if (!page->multimapped) {
+ u64 *old = page->parent_pte;
+
+ if (!old) {
+ page->parent_pte = parent_pte;
+ return;
+ }
+ page->multimapped = 1;
+ pte_chain = kzalloc(sizeof(struct kvm_pte_chain), GFP_NOWAIT);
+ BUG_ON(!pte_chain);
+ INIT_HLIST_HEAD(&page->parent_ptes);
+ hlist_add_head(&pte_chain->link, &page->parent_ptes);
+ pte_chain->parent_ptes[0] = old;
+ }
+ hlist_for_each_entry(pte_chain, node, &page->parent_ptes, link) {
+ if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
+ continue;
+ for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
+ if (!pte_chain->parent_ptes[i]) {
+ pte_chain->parent_ptes[i] = parent_pte;
+ return;
+ }
+ }
+ pte_chain = kzalloc(sizeof(struct kvm_pte_chain), GFP_NOWAIT);
+ BUG_ON(!pte_chain);
+ hlist_add_head(&pte_chain->link, &page->parent_ptes);
+ pte_chain->parent_ptes[0] = parent_pte;
+}
+
+static void mmu_page_remove_parent_pte(struct kvm_mmu_page *page,
+ u64 *parent_pte)
+{
+ struct kvm_pte_chain *pte_chain;
+ struct hlist_node *node;
+ int i;
+
+ if (!page->multimapped) {
+ BUG_ON(page->parent_pte != parent_pte);
+ page->parent_pte = NULL;
+ return;
+ }
+ hlist_for_each_entry(pte_chain, node, &page->parent_ptes, link)
+ for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
+ if (!pte_chain->parent_ptes[i])
+ break;
+ if (pte_chain->parent_ptes[i] != parent_pte)
+ continue;
+ while (i + 1 < NR_PTE_CHAIN_ENTRIES) {
+ pte_chain->parent_ptes[i]
+ = pte_chain->parent_ptes[i + 1];
+ ++i;
+ }
+ pte_chain->parent_ptes[i] = NULL;
+ return;
+ }
+ BUG();
+}
+
+static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm_vcpu *vcpu,
+ gfn_t gfn)
+{
+ unsigned index;
+ struct hlist_head *bucket;
+ struct kvm_mmu_page *page;
+ struct hlist_node *node;
+
+ pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
+ index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
+ bucket = &vcpu->kvm->mmu_page_hash[index];
+ hlist_for_each_entry(page, node, bucket, hash_link)
+ if (page->gfn == gfn && !page->role.metaphysical) {
+ pgprintk("%s: found role %x\n",
+ __FUNCTION__, page->role.word);
+ return page;
+ }
+ return NULL;
+}
+
+static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
+ gfn_t gfn,
+ gva_t gaddr,
+ unsigned level,
+ int metaphysical,
+ u64 *parent_pte)
+{
+ union kvm_mmu_page_role role;
+ unsigned index;
+ unsigned quadrant;
+ struct hlist_head *bucket;
+ struct kvm_mmu_page *page;
+ struct hlist_node *node;
+
+ role.word = 0;
+ role.glevels = vcpu->mmu.root_level;
+ role.level = level;
+ role.metaphysical = metaphysical;
+ if (vcpu->mmu.root_level <= PT32_ROOT_LEVEL) {
+ quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
+ quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
+ role.quadrant = quadrant;
+ }
+ pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__,
+ gfn, role.word);
+ index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
+ bucket = &vcpu->kvm->mmu_page_hash[index];
+ hlist_for_each_entry(page, node, bucket, hash_link)
+ if (page->gfn == gfn && page->role.word == role.word) {
+ mmu_page_add_parent_pte(page, parent_pte);
+ pgprintk("%s: found\n", __FUNCTION__);
+ return page;
+ }
+ page = kvm_mmu_alloc_page(vcpu, parent_pte);
+ if (!page)
+ return page;
+ pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__, gfn, role.word);
+ page->gfn = gfn;
+ page->role = role;
+ hlist_add_head(&page->hash_link, bucket);
+ return page;
+}
+
+static void kvm_mmu_put_page(struct kvm_vcpu *vcpu,
+ struct kvm_mmu_page *page,
+ u64 *parent_pte)
+{
+ mmu_page_remove_parent_pte(page, parent_pte);
+}
+
static void page_header_update_slot(struct kvm *kvm, void *pte, gpa_t gpa)
{
int slot = memslot_id(kvm, gfn_to_memslot(kvm, gpa >> PAGE_SHIFT));
@@ -389,11 +533,15 @@ static int nonpaging_map(struct kvm_vcpu
for (; ; level--) {
u32 index = PT64_INDEX(v, level);
u64 *table;
+ u64 pte;

ASSERT(VALID_PAGE(table_addr));
table = __va(table_addr);

if (level == 1) {
+ pte = table[index];
+ if (is_present_pte(pte) && is_writeble_pte(pte))
+ return 0;
mark_page_dirty(vcpu->kvm, v >> PAGE_SHIFT);
page_header_update_slot(vcpu->kvm, table, v);
table[index] = p | PT_PRESENT_MASK | PT_WRITABLE_MASK |
@@ -404,8 +552,13 @@ static int nonpaging_map(struct kvm_vcpu

if (table[index] == 0) {
struct kvm_mmu_page *new_table;
+ gfn_t pseudo_gfn;

- new_table = kvm_mmu_alloc_page(vcpu, &table[index]);
+ pseudo_gfn = (v & PT64_DIR_BASE_ADDR_MASK)
+ >> PAGE_SHIFT;
+ new_table = kvm_mmu_get_page(vcpu, pseudo_gfn,
+ v, level - 1,
+ 1, &table[index]);
if (!new_table) {
pgprintk("nonpaging_map: ENOMEM\n");
return -ENOMEM;
@@ -427,7 +580,6 @@ static void mmu_free_roots(struct kvm_vc
hpa_t root = vcpu->mmu.root_hpa;

ASSERT(VALID_PAGE(root));
- release_pt_page_64(vcpu, root, PT64_ROOT_LEVEL);
vcpu->mmu.root_hpa = INVALID_PAGE;
return;
}
@@ -437,7 +589,6 @@ static void mmu_free_roots(struct kvm_vc

ASSERT(VALID_PAGE(root));
root &= PT64_BASE_ADDR_MASK;
- release_pt_page_64(vcpu, root, PT32E_ROOT_LEVEL - 1);
vcpu->mmu.pae_root[i] = INVALID_PAGE;
}
vcpu->mmu.root_hpa = INVALID_PAGE;
@@ -446,13 +597,16 @@ static void mmu_free_roots(struct kvm_vc
static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
{
int i;
+ gfn_t root_gfn;
+ root_gfn = vcpu->cr3 >> PAGE_SHIFT;

#ifdef CONFIG_X86_64
if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) {
hpa_t root = vcpu->mmu.root_hpa;

ASSERT(!VALID_PAGE(root));
- root = kvm_mmu_alloc_page(vcpu, NULL)->page_hpa;
+ root = kvm_mmu_get_page(vcpu, root_gfn, 0,
+ PT64_ROOT_LEVEL, 0, NULL)->page_hpa;
vcpu->mmu.root_hpa = root;
return;
}
@@ -461,7 +615,13 @@ static void mmu_alloc_roots(struct kvm_v
hpa_t root = vcpu->mmu.pae_root[i];

ASSERT(!VALID_PAGE(root));
- root = kvm_mmu_alloc_page(vcpu, NULL)->page_hpa;
+ if (vcpu->mmu.root_level == PT32E_ROOT_LEVEL)
+ root_gfn = vcpu->pdptrs[i] >> PAGE_SHIFT;
+ else if (vcpu->mmu.root_level == 0)
+ root_gfn = 0;
+ root = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
+ PT32_ROOT_LEVEL, !is_paging(vcpu),
+ NULL)->page_hpa;
vcpu->mmu.pae_root[i] = root | PT_PRESENT_MASK;
}
vcpu->mmu.root_hpa = __pa(vcpu->mmu.pae_root);
@@ -529,7 +689,7 @@ static int nonpaging_init_context(struct
context->inval_page = nonpaging_inval_page;
context->gva_to_gpa = nonpaging_gva_to_gpa;
context->free = nonpaging_free;
- context->root_level = PT32E_ROOT_LEVEL;
+ context->root_level = 0;
context->shadow_root_level = PT32E_ROOT_LEVEL;
mmu_alloc_roots(vcpu);
ASSERT(VALID_PAGE(context->root_hpa));
@@ -537,29 +697,18 @@ static int nonpaging_init_context(struct
return 0;
}

-
static void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
{
- struct kvm_mmu_page *page, *npage;
-
- list_for_each_entry_safe(page, npage, &vcpu->kvm->active_mmu_pages,
- link) {
- if (page->global)
- continue;
-
- if (!page->parent_pte)
- continue;
-
- *page->parent_pte = 0;
- release_pt_page_64(vcpu, page->page_hpa, 1);
- }
++kvm_stat.tlb_flush;
kvm_arch_ops->tlb_flush(vcpu);
}

static void paging_new_cr3(struct kvm_vcpu *vcpu)
{
+ mmu_free_roots(vcpu);
+ mmu_alloc_roots(vcpu);
kvm_mmu_flush_tlb(vcpu);
+ kvm_arch_ops->set_cr3(vcpu, vcpu->mmu.root_hpa);
}

static void mark_pagetable_nonglobal(void *shadow_pte)
@@ -578,6 +727,16 @@ static inline void set_pte_common(struct
*shadow_pte |= access_bits << PT_SHADOW_BITS_OFFSET;
if (!dirty)
access_bits &= ~PT_WRITABLE_MASK;
+ if (access_bits & PT_WRITABLE_MASK) {
+ struct kvm_mmu_page *shadow;
+
+ shadow = kvm_mmu_lookup_page(vcpu, gaddr >> PAGE_SHIFT);
+ if (shadow)
+ pgprintk("%s: found shadow page for %lx, marking ro\n",
+ __FUNCTION__, (gfn_t)(gaddr >> PAGE_SHIFT));
+ if (shadow)
+ access_bits &= ~PT_WRITABLE_MASK;
+ }

if (access_bits & PT_WRITABLE_MASK)
mark_page_dirty(vcpu->kvm, gaddr >> PAGE_SHIFT);
Index: linux-2.6/drivers/kvm/kvm.h
===================================================================
--- linux-2.6.orig/drivers/kvm/kvm.h
+++ linux-2.6/drivers/kvm/kvm.h
@@ -89,14 +89,53 @@ typedef unsigned long hva_t;
typedef u64 hpa_t;
typedef unsigned long hfn_t;

+#define NR_PTE_CHAIN_ENTRIES 5
+
+struct kvm_pte_chain {
+ u64 *parent_ptes[NR_PTE_CHAIN_ENTRIES];
+ struct hlist_node link;
+};
+
+/*
+ * kvm_mmu_page_role, below, is defined as:
+ *
+ * bits 0:3 - total guest paging levels (2-4, or zero for real mode)
+ * bits 4:7 - page table level for this shadow (1-4)
+ * bits 8:9 - page table quadrant for 2-level guests
+ * bit 16 - "metaphysical" - gfn is not a real page (huge page/real mode)
+ */
+union kvm_mmu_page_role {
+ unsigned word;
+ struct {
+ unsigned glevels : 4;
+ unsigned level : 4;
+ unsigned quadrant : 2;
+ unsigned pad_for_nice_hex_output : 6;
+ unsigned metaphysical : 1;
+ };
+};
+
struct kvm_mmu_page {
struct list_head link;
+ struct hlist_node hash_link;
+
+ /*
+ * The following two entries are used to key the shadow page in the
+ * hash table.
+ */
+ gfn_t gfn;
+ union kvm_mmu_page_role role;
+
hpa_t page_hpa;
unsigned long slot_bitmap; /* One bit set per slot which has memory
* in this shadow page.
*/
int global; /* Set if all ptes in this page are global */
- u64 *parent_pte;
+ int multimapped; /* More than one parent_pte? */
+ union {
+ u64 *parent_pte; /* !multimapped */
+ struct hlist_head parent_ptes; /* multimapped, kvm_pte_chain */
+ };
};

struct vmcs {
@@ -235,7 +274,11 @@ struct kvm {
spinlock_t lock; /* protects everything except vcpus */
int nmemslots;
struct kvm_memory_slot memslots[KVM_MEMORY_SLOTS];
+ /*
+ * Hash table of struct kvm_mmu_page.
+ */
struct list_head active_mmu_pages;
+ struct hlist_head mmu_page_hash[KVM_NUM_MMU_PAGES];
struct kvm_vcpu vcpus[KVM_MAX_VCPUS];
int memory_config_version;
int busy;
Index: linux-2.6/drivers/kvm/paging_tmpl.h
===================================================================
--- linux-2.6.orig/drivers/kvm/paging_tmpl.h
+++ linux-2.6/drivers/kvm/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
@@ -52,7 +58,7 @@
*/
struct guest_walker {
int level;
- gfn_t table_gfn;
+ gfn_t table_gfn[PT_MAX_FULL_LEVELS];
pt_element_t *table;
pt_element_t *ptep;
pt_element_t inherited_ar;
@@ -68,7 +74,9 @@ static void FNAME(walk_addr)(struct gues
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;
walker->table = NULL;
root = vcpu->cr3;
@@ -81,8 +89,11 @@ static void FNAME(walk_addr)(struct gues
--walker->level;
}
#endif
- walker->table_gfn = (root & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
- slot = gfn_to_memslot(vcpu->kvm, walker->table_gfn);
+ 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);

@@ -111,12 +122,15 @@ static void FNAME(walk_addr)(struct gues

if (walker->level != 3 || is_long_mode(vcpu))
walker->inherited_ar &= walker->table[index];
- walker->table_gfn = (*ptep & PT_BASE_ADDR_MASK) >> PAGE_SHIFT;
+ 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;
}
@@ -181,6 +195,8 @@ static u64 *FNAME(fetch)(struct kvm_vcpu
u64 *shadow_ent = ((u64 *)__va(shadow_addr)) + index;
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)
@@ -205,7 +221,17 @@ static u64 *FNAME(fetch)(struct kvm_vcpu
return shadow_ent;
}

- shadow_page = kvm_mmu_alloc_page(vcpu, shadow_ent);
+ 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);
if (!shadow_page)
return ERR_PTR(-ENOMEM);
shadow_addr = shadow_page->page_hpa;
@@ -227,7 +253,8 @@ static int FNAME(fix_write_pf)(struct kv
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;
@@ -264,6 +291,12 @@ static int FNAME(fix_write_pf)(struct kv
}

gfn = (*guest_ent & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
+ if (kvm_mmu_lookup_page(vcpu, gfn)) {
+ pgprintk("%s: found shadow page for %lx, marking ro\n",
+ __FUNCTION__, gfn);
+ *write_pt = 1;
+ return 0;
+ }
mark_page_dirty(vcpu->kvm, gfn);
*shadow_ent |= PT_WRITABLE_MASK;
*guest_ent |= PT_DIRTY_MASK;
@@ -294,7 +327,9 @@ static int FNAME(page_fault)(struct kvm_
struct guest_walker walker;
u64 *shadow_pte;
int fixed;
+ int write_pt = 0;

+ pgprintk("%s: addr %lx err %x\n", __FUNCTION__, addr, error_code);
/*
* Look up the shadow pte for the faulting address.
*/
@@ -302,6 +337,7 @@ static int FNAME(page_fault)(struct kvm_
FNAME(walk_addr)(&walker, vcpu, addr);
shadow_pte = FNAME(fetch)(vcpu, addr, &walker);
if (IS_ERR(shadow_pte)) { /* must be -ENOMEM */
+ printk("%s: oom\n", __FUNCTION__);
nonpaging_flush(vcpu);
FNAME(release_walker)(&walker);
continue;
@@ -313,20 +349,27 @@ static int FNAME(page_fault)(struct kvm_
* 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);

/*
@@ -344,14 +387,14 @@ static int FNAME(page_fault)(struct kvm_
/*
* pte not present, guest page fault.
*/
- if (pte_present && !fixed) {
+ if (pte_present && !fixed && !write_pt) {
inject_page_fault(vcpu, addr, error_code);
return 0;
}

++kvm_stat.pf_fixed;

- return 0;
+ return write_pt;
}

static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr)
@@ -395,3 +438,4 @@ static gpa_t FNAME(gva_to_gpa)(struct kv
#undef PT_PTE_COPY_MASK
#undef PT_NON_PTE_COPY_MASK
#undef PT_DIR_BASE_ADDR_MASK
+#undef PT_MAX_FULL_LEVELS