KVM
Macros | Functions | Variables
spte.c File Reference
#include <linux/kvm_host.h>
#include "mmu.h"
#include "mmu_internal.h"
#include "x86.h"
#include "spte.h"
#include <asm/e820/api.h>
#include <asm/memtype.h>
#include <asm/vmx.h>
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Go to the source code of this file.

Macros

#define pr_fmt(fmt)   KBUILD_MODNAME ": " fmt
 

Functions

 module_param_named (mmio_caching, enable_mmio_caching, bool, 0444)
 
 EXPORT_SYMBOL_GPL (enable_mmio_caching)
 
void __init kvm_mmu_spte_module_init (void)
 
static u64 generation_mmio_spte_mask (u64 gen)
 
u64 make_mmio_spte (struct kvm_vcpu *vcpu, u64 gfn, unsigned int access)
 
static bool kvm_is_mmio_pfn (kvm_pfn_t pfn)
 
bool spte_has_volatile_bits (u64 spte)
 
bool make_spte (struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, const struct kvm_memory_slot *slot, unsigned int pte_access, gfn_t gfn, kvm_pfn_t pfn, u64 old_spte, bool prefetch, bool can_unsync, bool host_writable, u64 *new_spte)
 
static u64 make_spte_executable (u64 spte)
 
u64 make_huge_page_split_spte (struct kvm *kvm, u64 huge_spte, union kvm_mmu_page_role role, int index)
 
u64 make_nonleaf_spte (u64 *child_pt, bool ad_disabled)
 
u64 kvm_mmu_changed_pte_notifier_make_spte (u64 old_spte, kvm_pfn_t new_pfn)
 
u64 mark_spte_for_access_track (u64 spte)
 
void kvm_mmu_set_mmio_spte_mask (u64 mmio_value, u64 mmio_mask, u64 access_mask)
 
 EXPORT_SYMBOL_GPL (kvm_mmu_set_mmio_spte_mask)
 
void kvm_mmu_set_me_spte_mask (u64 me_value, u64 me_mask)
 
 EXPORT_SYMBOL_GPL (kvm_mmu_set_me_spte_mask)
 
void kvm_mmu_set_ept_masks (bool has_ad_bits, bool has_exec_only)
 
 EXPORT_SYMBOL_GPL (kvm_mmu_set_ept_masks)
 
void kvm_mmu_reset_all_pte_masks (void)
 

Variables

bool __read_mostly enable_mmio_caching = true
 
static bool __ro_after_init allow_mmio_caching
 
u64 __read_mostly shadow_host_writable_mask
 
u64 __read_mostly shadow_mmu_writable_mask
 
u64 __read_mostly shadow_nx_mask
 
u64 __read_mostly shadow_x_mask
 
u64 __read_mostly shadow_user_mask
 
u64 __read_mostly shadow_accessed_mask
 
u64 __read_mostly shadow_dirty_mask
 
u64 __read_mostly shadow_mmio_value
 
u64 __read_mostly shadow_mmio_mask
 
u64 __read_mostly shadow_mmio_access_mask
 
u64 __read_mostly shadow_present_mask
 
u64 __read_mostly shadow_memtype_mask
 
u64 __read_mostly shadow_me_value
 
u64 __read_mostly shadow_me_mask
 
u64 __read_mostly shadow_acc_track_mask
 
u64 __read_mostly shadow_nonpresent_or_rsvd_mask
 
u64 __read_mostly shadow_nonpresent_or_rsvd_lower_gfn_mask
 
u8 __read_mostly shadow_phys_bits
 

Macro Definition Documentation

◆ pr_fmt

#define pr_fmt (   fmt)    KBUILD_MODNAME ": " fmt

Definition at line 10 of file spte.c.

Function Documentation

◆ EXPORT_SYMBOL_GPL() [1/4]

EXPORT_SYMBOL_GPL ( enable_mmio_caching  )

◆ EXPORT_SYMBOL_GPL() [2/4]

EXPORT_SYMBOL_GPL ( kvm_mmu_set_ept_masks  )

◆ EXPORT_SYMBOL_GPL() [3/4]

EXPORT_SYMBOL_GPL ( kvm_mmu_set_me_spte_mask  )

◆ EXPORT_SYMBOL_GPL() [4/4]

EXPORT_SYMBOL_GPL ( kvm_mmu_set_mmio_spte_mask  )

◆ generation_mmio_spte_mask()

static u64 generation_mmio_spte_mask ( u64  gen)
static

Definition at line 60 of file spte.c.

61 {
62  u64 mask;
63 
64  WARN_ON_ONCE(gen & ~MMIO_SPTE_GEN_MASK);
65 
68  return mask;
69 }
#define MMIO_SPTE_GEN_HIGH_SHIFT
Definition: spte.h:148
#define MMIO_SPTE_GEN_HIGH_MASK
Definition: spte.h:122
#define MMIO_SPTE_GEN_LOW_SHIFT
Definition: spte.h:147
#define MMIO_SPTE_GEN_LOW_MASK
Definition: spte.h:120
#define MMIO_SPTE_GEN_MASK
Definition: spte.h:150
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◆ kvm_is_mmio_pfn()

static bool kvm_is_mmio_pfn ( kvm_pfn_t  pfn)
static

Definition at line 88 of file spte.c.

89 {
90  if (pfn_valid(pfn))
91  return !is_zero_pfn(pfn) && PageReserved(pfn_to_page(pfn)) &&
92  /*
93  * Some reserved pages, such as those from NVDIMM
94  * DAX devices, are not for MMIO, and can be mapped
95  * with cached memory type for better performance.
96  * However, the above check misconceives those pages
97  * as MMIO, and results in KVM mapping them with UC
98  * memory type, which would hurt the performance.
99  * Therefore, we check the host memory type in addition
100  * and only treat UC/UC-/WC pages as MMIO.
101  */
102  (!pat_enabled() || pat_pfn_immune_to_uc_mtrr(pfn));
103 
104  return !e820__mapped_raw_any(pfn_to_hpa(pfn),
105  pfn_to_hpa(pfn + 1) - 1,
106  E820_TYPE_RAM);
107 }
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◆ kvm_mmu_changed_pte_notifier_make_spte()

u64 kvm_mmu_changed_pte_notifier_make_spte ( u64  old_spte,
kvm_pfn_t  new_pfn 
)

Definition at line 325 of file spte.c.

326 {
327  u64 new_spte;
328 
329  new_spte = old_spte & ~SPTE_BASE_ADDR_MASK;
330  new_spte |= (u64)new_pfn << PAGE_SHIFT;
331 
332  new_spte &= ~PT_WRITABLE_MASK;
333  new_spte &= ~shadow_host_writable_mask;
334  new_spte &= ~shadow_mmu_writable_mask;
335 
336  new_spte = mark_spte_for_access_track(new_spte);
337 
338  return new_spte;
339 }
#define PT_WRITABLE_MASK
Definition: mmu.h:15
u64 __read_mostly shadow_host_writable_mask
Definition: spte.c:27
u64 mark_spte_for_access_track(u64 spte)
Definition: spte.c:341
u64 __read_mostly shadow_mmu_writable_mask
Definition: spte.c:28
#define SPTE_BASE_ADDR_MASK
Definition: spte.h:40
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◆ kvm_mmu_reset_all_pte_masks()

void kvm_mmu_reset_all_pte_masks ( void  )

Definition at line 453 of file spte.c.

454 {
455  u8 low_phys_bits;
456  u64 mask;
457 
459 
460  /*
461  * If the CPU has 46 or less physical address bits, then set an
462  * appropriate mask to guard against L1TF attacks. Otherwise, it is
463  * assumed that the CPU is not vulnerable to L1TF.
464  *
465  * Some Intel CPUs address the L1 cache using more PA bits than are
466  * reported by CPUID. Use the PA width of the L1 cache when possible
467  * to achieve more effective mitigation, e.g. if system RAM overlaps
468  * the most significant bits of legal physical address space.
469  */
471  low_phys_bits = boot_cpu_data.x86_phys_bits;
472  if (boot_cpu_has_bug(X86_BUG_L1TF) &&
473  !WARN_ON_ONCE(boot_cpu_data.x86_cache_bits >=
475  low_phys_bits = boot_cpu_data.x86_cache_bits
478  rsvd_bits(low_phys_bits, boot_cpu_data.x86_cache_bits - 1);
479  }
480 
482  GENMASK_ULL(low_phys_bits - 1, PAGE_SHIFT);
483 
488  shadow_x_mask = 0;
490 
491  /*
492  * For shadow paging and NPT, KVM uses PAT entry '0' to encode WB
493  * memtype in the SPTEs, i.e. relies on host MTRRs to provide the
494  * correct memtype (WB is the "weakest" memtype).
495  */
498  shadow_me_mask = 0;
499  shadow_me_value = 0;
500 
503 
504  /*
505  * Set a reserved PA bit in MMIO SPTEs to generate page faults with
506  * PFEC.RSVD=1 on MMIO accesses. 64-bit PTEs (PAE, x86-64, and EPT
507  * paging) support a maximum of 52 bits of PA, i.e. if the CPU supports
508  * 52-bit physical addresses then there are no reserved PA bits in the
509  * PTEs and so the reserved PA approach must be disabled.
510  */
511  if (shadow_phys_bits < 52)
512  mask = BIT_ULL(51) | PT_PRESENT_MASK;
513  else
514  mask = 0;
515 
517 }
static __always_inline u64 rsvd_bits(int s, int e)
Definition: mmu.h:45
#define PT_PRESENT_MASK
Definition: mmu.h:14
#define PT_DIRTY_MASK
Definition: mmu.h:22
#define PT_ACCESSED_MASK
Definition: mmu.h:20
static u8 kvm_get_shadow_phys_bits(void)
Definition: mmu.h:84
#define PT64_NX_MASK
Definition: mmu.h:28
#define PT_USER_MASK
Definition: mmu.h:16
u64 __read_mostly shadow_accessed_mask
Definition: spte.c:32
u64 __read_mostly shadow_me_value
Definition: spte.c:39
u64 __read_mostly shadow_acc_track_mask
Definition: spte.c:41
u64 __read_mostly shadow_nonpresent_or_rsvd_mask
Definition: spte.c:43
u8 __read_mostly shadow_phys_bits
Definition: spte.c:46
u64 __read_mostly shadow_dirty_mask
Definition: spte.c:33
u64 __read_mostly shadow_memtype_mask
Definition: spte.c:38
void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 mmio_mask, u64 access_mask)
Definition: spte.c:362
u64 __read_mostly shadow_me_mask
Definition: spte.c:40
u64 __read_mostly shadow_user_mask
Definition: spte.c:31
u64 __read_mostly shadow_nx_mask
Definition: spte.c:29
u64 __read_mostly shadow_nonpresent_or_rsvd_lower_gfn_mask
Definition: spte.c:44
u64 __read_mostly shadow_x_mask
Definition: spte.c:30
u64 __read_mostly shadow_present_mask
Definition: spte.c:37
#define ACC_USER_MASK
Definition: spte.h:48
#define SHADOW_NONPRESENT_OR_RSVD_MASK_LEN
Definition: spte.h:183
#define ACC_WRITE_MASK
Definition: spte.h:47
#define DEFAULT_SPTE_HOST_WRITABLE
Definition: spte.h:80
#define DEFAULT_SPTE_MMU_WRITABLE
Definition: spte.h:81
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◆ kvm_mmu_set_ept_masks()

void kvm_mmu_set_ept_masks ( bool  has_ad_bits,
bool  has_exec_only 
)

Definition at line 425 of file spte.c.

426 {
427  shadow_user_mask = VMX_EPT_READABLE_MASK;
428  shadow_accessed_mask = has_ad_bits ? VMX_EPT_ACCESS_BIT : 0ull;
429  shadow_dirty_mask = has_ad_bits ? VMX_EPT_DIRTY_BIT : 0ull;
430  shadow_nx_mask = 0ull;
431  shadow_x_mask = VMX_EPT_EXECUTABLE_MASK;
432  shadow_present_mask = has_exec_only ? 0ull : VMX_EPT_READABLE_MASK;
433  /*
434  * EPT overrides the host MTRRs, and so KVM must program the desired
435  * memtype directly into the SPTEs. Note, this mask is just the mask
436  * of all bits that factor into the memtype, the actual memtype must be
437  * dynamically calculated, e.g. to ensure host MMIO is mapped UC.
438  */
439  shadow_memtype_mask = VMX_EPT_MT_MASK | VMX_EPT_IPAT_BIT;
440  shadow_acc_track_mask = VMX_EPT_RWX_MASK;
443 
444  /*
445  * EPT Misconfigurations are generated if the value of bits 2:0
446  * of an EPT paging-structure entry is 110b (write/execute).
447  */
448  kvm_mmu_set_mmio_spte_mask(VMX_EPT_MISCONFIG_WX_VALUE,
449  VMX_EPT_RWX_MASK, 0);
450 }
#define EPT_SPTE_MMU_WRITABLE
Definition: spte.h:89
#define EPT_SPTE_HOST_WRITABLE
Definition: spte.h:88
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◆ kvm_mmu_set_me_spte_mask()

void kvm_mmu_set_me_spte_mask ( u64  me_value,
u64  me_mask 
)

Definition at line 414 of file spte.c.

415 {
416  /* shadow_me_value must be a subset of shadow_me_mask */
417  if (WARN_ON(me_value & ~me_mask))
418  me_value = me_mask = 0;
419 
420  shadow_me_value = me_value;
421  shadow_me_mask = me_mask;
422 }
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◆ kvm_mmu_set_mmio_spte_mask()

void kvm_mmu_set_mmio_spte_mask ( u64  mmio_value,
u64  mmio_mask,
u64  access_mask 
)

Definition at line 362 of file spte.c.

363 {
364  BUG_ON((u64)(unsigned)access_mask != access_mask);
365  WARN_ON(mmio_value & shadow_nonpresent_or_rsvd_lower_gfn_mask);
366 
367  /*
368  * Reset to the original module param value to honor userspace's desire
369  * to (dis)allow MMIO caching. Update the param itself so that
370  * userspace can see whether or not KVM is actually using MMIO caching.
371  */
373  if (!enable_mmio_caching)
374  mmio_value = 0;
375 
376  /*
377  * The mask must contain only bits that are carved out specifically for
378  * the MMIO SPTE mask, e.g. to ensure there's no overlap with the MMIO
379  * generation.
380  */
381  if (WARN_ON(mmio_mask & ~SPTE_MMIO_ALLOWED_MASK))
382  mmio_value = 0;
383 
384  /*
385  * Disable MMIO caching if the MMIO value collides with the bits that
386  * are used to hold the relocated GFN when the L1TF mitigation is
387  * enabled. This should never fire as there is no known hardware that
388  * can trigger this condition, e.g. SME/SEV CPUs that require a custom
389  * MMIO value are not susceptible to L1TF.
390  */
391  if (WARN_ON(mmio_value & (shadow_nonpresent_or_rsvd_mask <<
393  mmio_value = 0;
394 
395  /*
396  * The masked MMIO value must obviously match itself and a removed SPTE
397  * must not get a false positive. Removed SPTEs and MMIO SPTEs should
398  * never collide as MMIO must set some RWX bits, and removed SPTEs must
399  * not set any RWX bits.
400  */
401  if (WARN_ON((mmio_value & mmio_mask) != mmio_value) ||
402  WARN_ON(mmio_value && (REMOVED_SPTE & mmio_mask) == mmio_value))
403  mmio_value = 0;
404 
405  if (!mmio_value)
406  enable_mmio_caching = false;
407 
408  shadow_mmio_value = mmio_value;
409  shadow_mmio_mask = mmio_mask;
410  shadow_mmio_access_mask = access_mask;
411 }
static bool __ro_after_init allow_mmio_caching
Definition: spte.c:23
u64 __read_mostly shadow_mmio_access_mask
Definition: spte.c:36
u64 __read_mostly shadow_mmio_mask
Definition: spte.c:35
bool __read_mostly enable_mmio_caching
Definition: spte.c:22
u64 __read_mostly shadow_mmio_value
Definition: spte.c:34
#define SPTE_MMIO_ALLOWED_MASK
Definition: spte.h:137
#define REMOVED_SPTE
Definition: spte.h:197
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◆ kvm_mmu_spte_module_init()

void __init kvm_mmu_spte_module_init ( void  )

Definition at line 48 of file spte.c.

49 {
50  /*
51  * Snapshot userspace's desire to allow MMIO caching. Whether or not
52  * KVM can actually enable MMIO caching depends on vendor-specific
53  * hardware capabilities and other module params that can't be resolved
54  * until the vendor module is loaded, i.e. enable_mmio_caching can and
55  * will change when the vendor module is (re)loaded.
56  */
58 }
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◆ make_huge_page_split_spte()

u64 make_huge_page_split_spte ( struct kvm *  kvm,
u64  huge_spte,
union kvm_mmu_page_role  role,
int  index 
)

Definition at line 274 of file spte.c.

276 {
277  u64 child_spte;
278 
279  if (WARN_ON_ONCE(!is_shadow_present_pte(huge_spte)))
280  return 0;
281 
282  if (WARN_ON_ONCE(!is_large_pte(huge_spte)))
283  return 0;
284 
285  child_spte = huge_spte;
286 
287  /*
288  * The child_spte already has the base address of the huge page being
289  * split. So we just have to OR in the offset to the page at the next
290  * lower level for the given index.
291  */
292  child_spte |= (index * KVM_PAGES_PER_HPAGE(role.level)) << PAGE_SHIFT;
293 
294  if (role.level == PG_LEVEL_4K) {
295  child_spte &= ~PT_PAGE_SIZE_MASK;
296 
297  /*
298  * When splitting to a 4K page where execution is allowed, mark
299  * the page executable as the NX hugepage mitigation no longer
300  * applies.
301  */
302  if ((role.access & ACC_EXEC_MASK) && is_nx_huge_page_enabled(kvm))
303  child_spte = make_spte_executable(child_spte);
304  }
305 
306  return child_spte;
307 }
#define PT_PAGE_SIZE_MASK
Definition: mmu.h:24
static bool is_nx_huge_page_enabled(struct kvm *kvm)
Definition: mmu_internal.h:185
static u64 make_spte_executable(u64 spte)
Definition: spte.c:251
static bool is_shadow_present_pte(u64 pte)
Definition: spte.h:258
#define ACC_EXEC_MASK
Definition: spte.h:46
static bool is_large_pte(u64 pte)
Definition: spte.h:313
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◆ make_mmio_spte()

u64 make_mmio_spte ( struct kvm_vcpu *  vcpu,
u64  gfn,
unsigned int  access 
)

Definition at line 71 of file spte.c.

72 {
73  u64 gen = kvm_vcpu_memslots(vcpu)->generation & MMIO_SPTE_GEN_MASK;
74  u64 spte = generation_mmio_spte_mask(gen);
75  u64 gpa = gfn << PAGE_SHIFT;
76 
77  WARN_ON_ONCE(!shadow_mmio_value);
78 
79  access &= shadow_mmio_access_mask;
80  spte |= shadow_mmio_value | access;
81  spte |= gpa | shadow_nonpresent_or_rsvd_mask;
82  spte |= (gpa & shadow_nonpresent_or_rsvd_mask)
84 
85  return spte;
86 }
static u64 generation_mmio_spte_mask(u64 gen)
Definition: spte.c:60
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◆ make_nonleaf_spte()

u64 make_nonleaf_spte ( u64 *  child_pt,
bool  ad_disabled 
)

Definition at line 310 of file spte.c.

311 {
312  u64 spte = SPTE_MMU_PRESENT_MASK;
313 
314  spte |= __pa(child_pt) | shadow_present_mask | PT_WRITABLE_MASK |
316 
317  if (ad_disabled)
318  spte |= SPTE_TDP_AD_DISABLED;
319  else
320  spte |= shadow_accessed_mask;
321 
322  return spte;
323 }
#define SPTE_MMU_PRESENT_MASK
Definition: spte.h:16
#define SPTE_TDP_AD_DISABLED
Definition: spte.h:33
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◆ make_spte()

bool make_spte ( struct kvm_vcpu *  vcpu,
struct kvm_mmu_page sp,
const struct kvm_memory_slot *  slot,
unsigned int  pte_access,
gfn_t  gfn,
kvm_pfn_t  pfn,
u64  old_spte,
bool  prefetch,
bool  can_unsync,
bool  host_writable,
u64 *  new_spte 
)

Definition at line 137 of file spte.c.

142 {
143  int level = sp->role.level;
144  u64 spte = SPTE_MMU_PRESENT_MASK;
145  bool wrprot = false;
146 
147  WARN_ON_ONCE(!pte_access && !shadow_present_mask);
148 
149  if (sp->role.ad_disabled)
150  spte |= SPTE_TDP_AD_DISABLED;
152  spte |= SPTE_TDP_AD_WRPROT_ONLY;
153 
154  /*
155  * For the EPT case, shadow_present_mask is 0 if hardware
156  * supports exec-only page table entries. In that case,
157  * ACC_USER_MASK and shadow_user_mask are used to represent
158  * read access. See FNAME(gpte_access) in paging_tmpl.h.
159  */
160  spte |= shadow_present_mask;
161  if (!prefetch)
162  spte |= spte_shadow_accessed_mask(spte);
163 
164  /*
165  * For simplicity, enforce the NX huge page mitigation even if not
166  * strictly necessary. KVM could ignore the mitigation if paging is
167  * disabled in the guest, as the guest doesn't have any page tables to
168  * abuse. But to safely ignore the mitigation, KVM would have to
169  * ensure a new MMU is loaded (or all shadow pages zapped) when CR0.PG
170  * is toggled on, and that's a net negative for performance when TDP is
171  * enabled. When TDP is disabled, KVM will always switch to a new MMU
172  * when CR0.PG is toggled, but leveraging that to ignore the mitigation
173  * would tie make_spte() further to vCPU/MMU state, and add complexity
174  * just to optimize a mode that is anything but performance critical.
175  */
176  if (level > PG_LEVEL_4K && (pte_access & ACC_EXEC_MASK) &&
177  is_nx_huge_page_enabled(vcpu->kvm)) {
178  pte_access &= ~ACC_EXEC_MASK;
179  }
180 
181  if (pte_access & ACC_EXEC_MASK)
182  spte |= shadow_x_mask;
183  else
184  spte |= shadow_nx_mask;
185 
186  if (pte_access & ACC_USER_MASK)
187  spte |= shadow_user_mask;
188 
189  if (level > PG_LEVEL_4K)
190  spte |= PT_PAGE_SIZE_MASK;
191 
193  spte |= static_call(kvm_x86_get_mt_mask)(vcpu, gfn,
194  kvm_is_mmio_pfn(pfn));
195  if (host_writable)
197  else
198  pte_access &= ~ACC_WRITE_MASK;
199 
200  if (shadow_me_value && !kvm_is_mmio_pfn(pfn))
201  spte |= shadow_me_value;
202 
203  spte |= (u64)pfn << PAGE_SHIFT;
204 
205  if (pte_access & ACC_WRITE_MASK) {
207 
208  /*
209  * Optimization: for pte sync, if spte was writable the hash
210  * lookup is unnecessary (and expensive). Write protection
211  * is responsibility of kvm_mmu_get_page / kvm_mmu_sync_roots.
212  * Same reasoning can be applied to dirty page accounting.
213  */
214  if (is_writable_pte(old_spte))
215  goto out;
216 
217  /*
218  * Unsync shadow pages that are reachable by the new, writable
219  * SPTE. Write-protect the SPTE if the page can't be unsync'd,
220  * e.g. it's write-tracked (upper-level SPs) or has one or more
221  * shadow pages and unsync'ing pages is not allowed.
222  */
223  if (mmu_try_to_unsync_pages(vcpu->kvm, slot, gfn, can_unsync, prefetch)) {
224  wrprot = true;
225  pte_access &= ~ACC_WRITE_MASK;
227  }
228  }
229 
230  if (pte_access & ACC_WRITE_MASK)
231  spte |= spte_shadow_dirty_mask(spte);
232 
233 out:
234  if (prefetch)
235  spte = mark_spte_for_access_track(spte);
236 
237  WARN_ONCE(is_rsvd_spte(&vcpu->arch.mmu->shadow_zero_check, spte, level),
238  "spte = 0x%llx, level = %d, rsvd bits = 0x%llx", spte, level,
239  get_rsvd_bits(&vcpu->arch.mmu->shadow_zero_check, spte, level));
240 
241  if ((spte & PT_WRITABLE_MASK) && kvm_slot_dirty_track_enabled(slot)) {
242  /* Enforced by kvm_mmu_hugepage_adjust. */
243  WARN_ON_ONCE(level > PG_LEVEL_4K);
244  mark_page_dirty_in_slot(vcpu->kvm, slot, gfn);
245  }
246 
247  *new_spte = spte;
248  return wrprot;
249 }
void mark_page_dirty_in_slot(struct kvm *kvm, const struct kvm_memory_slot *memslot, gfn_t gfn)
Definition: kvm_main.c:3635
int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, gfn_t gfn, bool can_unsync, bool prefetch)
Definition: mmu.c:2805
static bool kvm_mmu_page_ad_need_write_protect(struct kvm_mmu_page *sp)
Definition: mmu_internal.h:148
static bool kvm_is_mmio_pfn(kvm_pfn_t pfn)
Definition: spte.c:88
#define SPTE_TDP_AD_WRPROT_ONLY
Definition: spte.h:34
static __always_inline bool is_rsvd_spte(struct rsvd_bits_validate *rsvd_check, u64 spte, int level)
Definition: spte.h:368
static bool is_writable_pte(unsigned long pte)
Definition: spte.h:441
static u64 spte_shadow_accessed_mask(u64 spte)
Definition: spte.h:296
static u64 get_rsvd_bits(struct rsvd_bits_validate *rsvd_check, u64 pte, int level)
Definition: spte.h:348
static u64 spte_shadow_dirty_mask(u64 spte)
Definition: spte.h:302
union kvm_mmu_page_role role
Definition: mmu_internal.h:80
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◆ make_spte_executable()

static u64 make_spte_executable ( u64  spte)
static

Definition at line 251 of file spte.c.

252 {
253  bool is_access_track = is_access_track_spte(spte);
254 
255  if (is_access_track)
256  spte = restore_acc_track_spte(spte);
257 
258  spte &= ~shadow_nx_mask;
259  spte |= shadow_x_mask;
260 
261  if (is_access_track)
262  spte = mark_spte_for_access_track(spte);
263 
264  return spte;
265 }
static bool is_access_track_spte(u64 spte)
Definition: spte.h:308
static u64 restore_acc_track_spte(u64 spte)
Definition: spte.h:486
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◆ mark_spte_for_access_track()

u64 mark_spte_for_access_track ( u64  spte)

Definition at line 341 of file spte.c.

342 {
343  if (spte_ad_enabled(spte))
344  return spte & ~shadow_accessed_mask;
345 
346  if (is_access_track_spte(spte))
347  return spte;
348 
350 
351  WARN_ONCE(spte & (SHADOW_ACC_TRACK_SAVED_BITS_MASK <<
353  "Access Tracking saved bit locations are not zero\n");
354 
355  spte |= (spte & SHADOW_ACC_TRACK_SAVED_BITS_MASK) <<
357  spte &= ~shadow_acc_track_mask;
358 
359  return spte;
360 }
#define SHADOW_ACC_TRACK_SAVED_BITS_SHIFT
Definition: spte.h:69
static void check_spte_writable_invariants(u64 spte)
Definition: spte.h:447
#define SHADOW_ACC_TRACK_SAVED_BITS_MASK
Definition: spte.h:67
static bool spte_ad_enabled(u64 spte)
Definition: spte.h:279
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◆ module_param_named()

module_param_named ( mmio_caching  ,
enable_mmio_caching  ,
bool  ,
0444   
)

◆ spte_has_volatile_bits()

bool spte_has_volatile_bits ( u64  spte)

Definition at line 114 of file spte.c.

115 {
116  /*
117  * Always atomically update spte if it can be updated
118  * out of mmu-lock, it can ensure dirty bit is not lost,
119  * also, it can help us to get a stable is_writable_pte()
120  * to ensure tlb flush is not missed.
121  */
122  if (!is_writable_pte(spte) && is_mmu_writable_spte(spte))
123  return true;
124 
125  if (is_access_track_spte(spte))
126  return true;
127 
128  if (spte_ad_enabled(spte)) {
129  if (!(spte & shadow_accessed_mask) ||
130  (is_writable_pte(spte) && !(spte & shadow_dirty_mask)))
131  return true;
132  }
133 
134  return false;
135 }
static bool is_mmu_writable_spte(u64 spte)
Definition: spte.h:458
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Variable Documentation

◆ allow_mmio_caching

bool __ro_after_init allow_mmio_caching
static

Definition at line 23 of file spte.c.

◆ enable_mmio_caching

bool __read_mostly enable_mmio_caching = true

Definition at line 22 of file spte.c.

◆ shadow_acc_track_mask

u64 __read_mostly shadow_acc_track_mask

Definition at line 41 of file spte.c.

◆ shadow_accessed_mask

u64 __read_mostly shadow_accessed_mask

Definition at line 32 of file spte.c.

◆ shadow_dirty_mask

u64 __read_mostly shadow_dirty_mask

Definition at line 33 of file spte.c.

◆ shadow_host_writable_mask

u64 __read_mostly shadow_host_writable_mask

Definition at line 27 of file spte.c.

◆ shadow_me_mask

u64 __read_mostly shadow_me_mask

Definition at line 40 of file spte.c.

◆ shadow_me_value

u64 __read_mostly shadow_me_value

Definition at line 39 of file spte.c.

◆ shadow_memtype_mask

u64 __read_mostly shadow_memtype_mask

Definition at line 38 of file spte.c.

◆ shadow_mmio_access_mask

u64 __read_mostly shadow_mmio_access_mask

Definition at line 36 of file spte.c.

◆ shadow_mmio_mask

u64 __read_mostly shadow_mmio_mask

Definition at line 35 of file spte.c.

◆ shadow_mmio_value

u64 __read_mostly shadow_mmio_value

Definition at line 34 of file spte.c.

◆ shadow_mmu_writable_mask

u64 __read_mostly shadow_mmu_writable_mask

Definition at line 28 of file spte.c.

◆ shadow_nonpresent_or_rsvd_lower_gfn_mask

u64 __read_mostly shadow_nonpresent_or_rsvd_lower_gfn_mask

Definition at line 44 of file spte.c.

◆ shadow_nonpresent_or_rsvd_mask

u64 __read_mostly shadow_nonpresent_or_rsvd_mask

Definition at line 43 of file spte.c.

◆ shadow_nx_mask

u64 __read_mostly shadow_nx_mask

Definition at line 29 of file spte.c.

◆ shadow_phys_bits

u8 __read_mostly shadow_phys_bits

Definition at line 46 of file spte.c.

◆ shadow_present_mask

u64 __read_mostly shadow_present_mask

Definition at line 37 of file spte.c.

◆ shadow_user_mask

u64 __read_mostly shadow_user_mask

Definition at line 31 of file spte.c.

◆ shadow_x_mask

u64 __read_mostly shadow_x_mask

Definition at line 30 of file spte.c.