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KVM: mmu: extract spte.h and spte.c

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The SPTE format will be common to both the shadow and the TDP MMU.

Extract code that implements the format to a separate module, as a
first step towards adding the TDP MMU and putting mmu.c on a diet.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2020-10-16 10:29:37 -04:00
parent cb3eedab45
commit 5a9624affe
5 changed files with 607 additions and 548 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
arch/x86/kvm/Makefile
View File

@ -15,7 +15,8 @@ kvm-$(CONFIG_KVM_ASYNC_PF) += $(KVM)/async_pf.o
kvm-y += x86.o emulate.o i8259.o irq.o lapic.o \
i8254.o ioapic.o irq_comm.o cpuid.o pmu.o mtrr.o \
hyperv.o debugfs.o mmu/mmu.o mmu/page_track.o
hyperv.o debugfs.o mmu/mmu.o mmu/page_track.o \
mmu/spte.o
kvm-intel-y += vmx/vmx.o vmx/vmenter.o vmx/pmu_intel.o vmx/vmcs12.o \
vmx/evmcs.o vmx/nested.o vmx/posted_intr.o

551
arch/x86/kvm/mmu/mmu.c
View File

@ -23,6 +23,7 @@
#include "kvm_cache_regs.h"
#include "kvm_emulate.h"
#include "cpuid.h"
#include "spte.h"
#include <linux/kvm_host.h>
#include <linux/types.h>
@ -45,7 +46,6 @@
#include <asm/page.h>
#include <asm/memtype.h>
#include <asm/cmpxchg.h>
#include <asm/e820/api.h>
#include <asm/io.h>
#include <asm/vmx.h>
#include <asm/kvm_page_track.h>
@ -104,45 +104,13 @@ enum {
AUDIT_POST_SYNC
};
#undef MMU_DEBUG
#ifdef MMU_DEBUG
static bool dbg = 0;
bool dbg = 0;
module_param(dbg, bool, 0644);
#define pgprintk(x...) do { if (dbg) printk(x); } while (0)
#define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
#define MMU_WARN_ON(x) WARN_ON(x)
#else
#define pgprintk(x...) do { } while (0)
#define rmap_printk(x...) do { } while (0)
#define MMU_WARN_ON(x) do { } while (0)
#endif
#define PTE_PREFETCH_NUM 8
#define PT_FIRST_AVAIL_BITS_SHIFT 10
#define PT64_SECOND_AVAIL_BITS_SHIFT 54
/*
* The mask used to denote special SPTEs, which can be either MMIO SPTEs or
* Access Tracking SPTEs.
*/
#define SPTE_SPECIAL_MASK (3ULL << 52)
#define SPTE_AD_ENABLED_MASK (0ULL << 52)
#define SPTE_AD_DISABLED_MASK (1ULL << 52)
#define SPTE_AD_WRPROT_ONLY_MASK (2ULL << 52)
#define SPTE_MMIO_MASK (3ULL << 52)
#define PT64_LEVEL_BITS 9
#define PT64_LEVEL_SHIFT(level) \
(PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
#define PT64_INDEX(address, level)\
(((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
#define PT32_LEVEL_BITS 10
#define PT32_LEVEL_SHIFT(level) \
@ -156,18 +124,6 @@ module_param(dbg, bool, 0644);
(((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
#ifdef CONFIG_DYNAMIC_PHYSICAL_MASK
#define PT64_BASE_ADDR_MASK (physical_mask & ~(u64)(PAGE_SIZE-1))
#else
#define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
#endif
#define PT64_LVL_ADDR_MASK(level) \
(PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
* PT64_LEVEL_BITS))) - 1))
#define PT64_LVL_OFFSET_MASK(level) \
(PT64_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
* PT64_LEVEL_BITS))) - 1))
#define PT32_BASE_ADDR_MASK PAGE_MASK
#define PT32_DIR_BASE_ADDR_MASK \
(PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
@ -175,25 +131,8 @@ module_param(dbg, bool, 0644);
(PAGE_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
* PT32_LEVEL_BITS))) - 1))
#define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | shadow_user_mask \
| shadow_x_mask | shadow_nx_mask | shadow_me_mask)
#define ACC_EXEC_MASK 1
#define ACC_WRITE_MASK PT_WRITABLE_MASK
#define ACC_USER_MASK PT_USER_MASK
#define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
/* The mask for the R/X bits in EPT PTEs */
#define PT64_EPT_READABLE_MASK 0x1ull
#define PT64_EPT_EXECUTABLE_MASK 0x4ull
#include <trace/events/kvm.h>
#define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
#define SPTE_MMU_WRITEABLE (1ULL << (PT_FIRST_AVAIL_BITS_SHIFT + 1))
#define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
/* make pte_list_desc fit well in cache line */
#define PTE_LIST_EXT 3
@ -248,62 +187,7 @@ static struct kmem_cache *pte_list_desc_cache;
static struct kmem_cache *mmu_page_header_cache;
static struct percpu_counter kvm_total_used_mmu_pages;
static u64 __read_mostly shadow_nx_mask;
static u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */
static u64 __read_mostly shadow_user_mask;
static u64 __read_mostly shadow_accessed_mask;
static u64 __read_mostly shadow_dirty_mask;
static u64 __read_mostly shadow_mmio_value;
static u64 __read_mostly shadow_mmio_access_mask;
static u64 __read_mostly shadow_present_mask;
static u64 __read_mostly shadow_me_mask;
/*
* SPTEs used by MMUs without A/D bits are marked with SPTE_AD_DISABLED_MASK;
* shadow_acc_track_mask is the set of bits to be cleared in non-accessed
* pages.
*/
static u64 __read_mostly shadow_acc_track_mask;
/*
* The mask/shift to use for saving the original R/X bits when marking the PTE
* as not-present for access tracking purposes. We do not save the W bit as the
* PTEs being access tracked also need to be dirty tracked, so the W bit will be
* restored only when a write is attempted to the page.
*/
static const u64 shadow_acc_track_saved_bits_mask = PT64_EPT_READABLE_MASK |
PT64_EPT_EXECUTABLE_MASK;
static const u64 shadow_acc_track_saved_bits_shift = PT64_SECOND_AVAIL_BITS_SHIFT;
/*
* This mask must be set on all non-zero Non-Present or Reserved SPTEs in order
* to guard against L1TF attacks.
*/
static u64 __read_mostly shadow_nonpresent_or_rsvd_mask;
/*
* The number of high-order 1 bits to use in the mask above.
*/
static const u64 shadow_nonpresent_or_rsvd_mask_len = 5;
/*
* In some cases, we need to preserve the GFN of a non-present or reserved
* SPTE when we usurp the upper five bits of the physical address space to
* defend against L1TF, e.g. for MMIO SPTEs. To preserve the GFN, we'll
* shift bits of the GFN that overlap with shadow_nonpresent_or_rsvd_mask
* left into the reserved bits, i.e. the GFN in the SPTE will be split into
* high and low parts. This mask covers the lower bits of the GFN.
*/
static u64 __read_mostly shadow_nonpresent_or_rsvd_lower_gfn_mask;
/*
* The number of non-reserved physical address bits irrespective of features
* that repurpose legal bits, e.g. MKTME.
*/
static u8 __read_mostly shadow_phys_bits;
static void mmu_spte_set(u64 *sptep, u64 spte);
static bool is_executable_pte(u64 spte);
static union kvm_mmu_page_role
kvm_mmu_calc_root_page_role(struct kvm_vcpu *vcpu);
@ -339,134 +223,11 @@ static void kvm_flush_remote_tlbs_with_address(struct kvm *kvm,
kvm_flush_remote_tlbs_with_range(kvm, &range);
}
void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 access_mask)
{
BUG_ON((u64)(unsigned)access_mask != access_mask);
WARN_ON(mmio_value & (shadow_nonpresent_or_rsvd_mask << shadow_nonpresent_or_rsvd_mask_len));
WARN_ON(mmio_value & shadow_nonpresent_or_rsvd_lower_gfn_mask);
shadow_mmio_value = mmio_value | SPTE_MMIO_MASK;
shadow_mmio_access_mask = access_mask;
}
EXPORT_SYMBOL_GPL(kvm_mmu_set_mmio_spte_mask);
static bool is_mmio_spte(u64 spte)
{
return (spte & SPTE_SPECIAL_MASK) == SPTE_MMIO_MASK;
}
static inline bool sp_ad_disabled(struct kvm_mmu_page *sp)
{
return sp->role.ad_disabled;
}
static inline bool kvm_vcpu_ad_need_write_protect(struct kvm_vcpu *vcpu)
{
/*
* When using the EPT page-modification log, the GPAs in the log
* would come from L2 rather than L1. Therefore, we need to rely
* on write protection to record dirty pages. This also bypasses
* PML, since writes now result in a vmexit.
*/
return vcpu->arch.mmu == &vcpu->arch.guest_mmu;
}
static inline bool spte_ad_enabled(u64 spte)
{
MMU_WARN_ON(is_mmio_spte(spte));
return (spte & SPTE_SPECIAL_MASK) != SPTE_AD_DISABLED_MASK;
}
static inline bool spte_ad_need_write_protect(u64 spte)
{
MMU_WARN_ON(is_mmio_spte(spte));
return (spte & SPTE_SPECIAL_MASK) != SPTE_AD_ENABLED_MASK;
}
static bool is_nx_huge_page_enabled(void)
bool is_nx_huge_page_enabled(void)
{
return READ_ONCE(nx_huge_pages);
}
static inline u64 spte_shadow_accessed_mask(u64 spte)
{
MMU_WARN_ON(is_mmio_spte(spte));
return spte_ad_enabled(spte) ? shadow_accessed_mask : 0;
}
static inline u64 spte_shadow_dirty_mask(u64 spte)
{
MMU_WARN_ON(is_mmio_spte(spte));
return spte_ad_enabled(spte) ? shadow_dirty_mask : 0;
}
static inline bool is_access_track_spte(u64 spte)
{
return !spte_ad_enabled(spte) && (spte & shadow_acc_track_mask) == 0;
}
/*
* Due to limited space in PTEs, the MMIO generation is a 19 bit subset of
* the memslots generation and is derived as follows:
*
* Bits 0-8 of the MMIO generation are propagated to spte bits 3-11
* Bits 9-18 of the MMIO generation are propagated to spte bits 52-61
*
* The KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS flag is intentionally not included in
* the MMIO generation number, as doing so would require stealing a bit from
* the "real" generation number and thus effectively halve the maximum number
* of MMIO generations that can be handled before encountering a wrap (which
* requires a full MMU zap). The flag is instead explicitly queried when
* checking for MMIO spte cache hits.
*/
#define MMIO_SPTE_GEN_MASK GENMASK_ULL(17, 0)
#define MMIO_SPTE_GEN_LOW_START 3
#define MMIO_SPTE_GEN_LOW_END 11
#define MMIO_SPTE_GEN_LOW_MASK GENMASK_ULL(MMIO_SPTE_GEN_LOW_END, \
MMIO_SPTE_GEN_LOW_START)
#define MMIO_SPTE_GEN_HIGH_START PT64_SECOND_AVAIL_BITS_SHIFT
#define MMIO_SPTE_GEN_HIGH_END 62
#define MMIO_SPTE_GEN_HIGH_MASK GENMASK_ULL(MMIO_SPTE_GEN_HIGH_END, \
MMIO_SPTE_GEN_HIGH_START)
static u64 generation_mmio_spte_mask(u64 gen)
{
u64 mask;
WARN_ON(gen & ~MMIO_SPTE_GEN_MASK);
BUILD_BUG_ON((MMIO_SPTE_GEN_HIGH_MASK | MMIO_SPTE_GEN_LOW_MASK) & SPTE_SPECIAL_MASK);
mask = (gen << MMIO_SPTE_GEN_LOW_START) & MMIO_SPTE_GEN_LOW_MASK;
mask |= (gen << MMIO_SPTE_GEN_HIGH_START) & MMIO_SPTE_GEN_HIGH_MASK;
return mask;
}
static u64 get_mmio_spte_generation(u64 spte)
{
u64 gen;
gen = (spte & MMIO_SPTE_GEN_LOW_MASK) >> MMIO_SPTE_GEN_LOW_START;
gen |= (spte & MMIO_SPTE_GEN_HIGH_MASK) >> MMIO_SPTE_GEN_HIGH_START;
return gen;
}
static u64 make_mmio_spte(struct kvm_vcpu *vcpu, u64 gfn, unsigned int access)
{
u64 gen = kvm_vcpu_memslots(vcpu)->generation & MMIO_SPTE_GEN_MASK;
u64 mask = generation_mmio_spte_mask(gen);
u64 gpa = gfn << PAGE_SHIFT;
access &= shadow_mmio_access_mask;
mask |= shadow_mmio_value | access;
mask |= gpa | shadow_nonpresent_or_rsvd_mask;
mask |= (gpa & shadow_nonpresent_or_rsvd_mask)
<< shadow_nonpresent_or_rsvd_mask_len;
return mask;
}
static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn,
unsigned int access)
{
@ -532,90 +293,6 @@ static gpa_t translate_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access,
return gpa;
}
/*
* Sets the shadow PTE masks used by the MMU.
*
* Assumptions:
* - Setting either @accessed_mask or @dirty_mask requires setting both
* - At least one of @accessed_mask or @acc_track_mask must be set
*/
void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
u64 dirty_mask, u64 nx_mask, u64 x_mask, u64 p_mask,
u64 acc_track_mask, u64 me_mask)
{
BUG_ON(!dirty_mask != !accessed_mask);
BUG_ON(!accessed_mask && !acc_track_mask);
BUG_ON(acc_track_mask & SPTE_SPECIAL_MASK);
shadow_user_mask = user_mask;
shadow_accessed_mask = accessed_mask;
shadow_dirty_mask = dirty_mask;
shadow_nx_mask = nx_mask;
shadow_x_mask = x_mask;
shadow_present_mask = p_mask;
shadow_acc_track_mask = acc_track_mask;
shadow_me_mask = me_mask;
}
EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes);
static u8 kvm_get_shadow_phys_bits(void)
{
/*
* boot_cpu_data.x86_phys_bits is reduced when MKTME or SME are detected
* in CPU detection code, but the processor treats those reduced bits as
* 'keyID' thus they are not reserved bits. Therefore KVM needs to look at
* the physical address bits reported by CPUID.
*/
if (likely(boot_cpu_data.extended_cpuid_level >= 0x80000008))
return cpuid_eax(0x80000008) & 0xff;
/*
* Quite weird to have VMX or SVM but not MAXPHYADDR; probably a VM with
* custom CPUID. Proceed with whatever the kernel found since these features
* aren't virtualizable (SME/SEV also require CPUIDs higher than 0x80000008).
*/
return boot_cpu_data.x86_phys_bits;
}
static void kvm_mmu_reset_all_pte_masks(void)
{
u8 low_phys_bits;
shadow_user_mask = 0;
shadow_accessed_mask = 0;
shadow_dirty_mask = 0;
shadow_nx_mask = 0;
shadow_x_mask = 0;
shadow_present_mask = 0;
shadow_acc_track_mask = 0;
shadow_phys_bits = kvm_get_shadow_phys_bits();
/*
* If the CPU has 46 or less physical address bits, then set an
* appropriate mask to guard against L1TF attacks. Otherwise, it is
* assumed that the CPU is not vulnerable to L1TF.
*
* Some Intel CPUs address the L1 cache using more PA bits than are
* reported by CPUID. Use the PA width of the L1 cache when possible
* to achieve more effective mitigation, e.g. if system RAM overlaps
* the most significant bits of legal physical address space.
*/
shadow_nonpresent_or_rsvd_mask = 0;
low_phys_bits = boot_cpu_data.x86_phys_bits;
if (boot_cpu_has_bug(X86_BUG_L1TF) &&
!WARN_ON_ONCE(boot_cpu_data.x86_cache_bits >=
52 - shadow_nonpresent_or_rsvd_mask_len)) {
low_phys_bits = boot_cpu_data.x86_cache_bits
- shadow_nonpresent_or_rsvd_mask_len;
shadow_nonpresent_or_rsvd_mask =
rsvd_bits(low_phys_bits, boot_cpu_data.x86_cache_bits - 1);
}
shadow_nonpresent_or_rsvd_lower_gfn_mask =
GENMASK_ULL(low_phys_bits - 1, PAGE_SHIFT);
}
static int is_cpuid_PSE36(void)
{
return 1;
@ -626,35 +303,6 @@ static int is_nx(struct kvm_vcpu *vcpu)
return vcpu->arch.efer & EFER_NX;
}
static int is_shadow_present_pte(u64 pte)
{
return (pte != 0) && !is_mmio_spte(pte);
}
static int is_large_pte(u64 pte)
{
return pte & PT_PAGE_SIZE_MASK;
}
static int is_last_spte(u64 pte, int level)
{
if (level == PG_LEVEL_4K)
return 1;
if (is_large_pte(pte))
return 1;
return 0;
}
static bool is_executable_pte(u64 spte)
{
return (spte & (shadow_x_mask | shadow_nx_mask)) == shadow_x_mask;
}
static kvm_pfn_t spte_to_pfn(u64 pte)
{
return (pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
}
static gfn_t pse36_gfn_delta(u32 gpte)
{
int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT;
@ -799,12 +447,6 @@ retry:
}
#endif
static bool spte_can_locklessly_be_made_writable(u64 spte)
{
return (spte & (SPTE_HOST_WRITEABLE | SPTE_MMU_WRITEABLE)) ==
(SPTE_HOST_WRITEABLE | SPTE_MMU_WRITEABLE);
}
static bool spte_has_volatile_bits(u64 spte)
{
if (!is_shadow_present_pte(spte))
@ -829,21 +471,6 @@ static bool spte_has_volatile_bits(u64 spte)
return false;
}
static bool is_accessed_spte(u64 spte)
{
u64 accessed_mask = spte_shadow_accessed_mask(spte);
return accessed_mask ? spte & accessed_mask
: !is_access_track_spte(spte);
}
static bool is_dirty_spte(u64 spte)
{
u64 dirty_mask = spte_shadow_dirty_mask(spte);
return dirty_mask ? spte & dirty_mask : spte & PT_WRITABLE_MASK;
}
/* Rules for using mmu_spte_set:
* Set the sptep from nonpresent to present.
* Note: the sptep being assigned *must* be either not present
@ -979,34 +606,6 @@ static u64 mmu_spte_get_lockless(u64 *sptep)
return __get_spte_lockless(sptep);
}
static u64 mark_spte_for_access_track(u64 spte)
{
if (spte_ad_enabled(spte))
return spte & ~shadow_accessed_mask;
if (is_access_track_spte(spte))
return spte;
/*
* Making an Access Tracking PTE will result in removal of write access
* from the PTE. So, verify that we will be able to restore the write
* access in the fast page fault path later on.
*/
WARN_ONCE((spte & PT_WRITABLE_MASK) &&
!spte_can_locklessly_be_made_writable(spte),
"kvm: Writable SPTE is not locklessly dirty-trackable\n");
WARN_ONCE(spte & (shadow_acc_track_saved_bits_mask <<
shadow_acc_track_saved_bits_shift),
"kvm: Access Tracking saved bit locations are not zero\n");
spte |= (spte & shadow_acc_track_saved_bits_mask) <<
shadow_acc_track_saved_bits_shift;
spte &= ~shadow_acc_track_mask;
return spte;
}
/* Restore an acc-track PTE back to a regular PTE */
static u64 restore_acc_track_spte(u64 spte)
{
@ -1747,21 +1346,6 @@ static int kvm_unmap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
return kvm_zap_rmapp(kvm, rmap_head);
}
static u64 kvm_mmu_changed_pte_notifier_make_spte(u64 old_spte, kvm_pfn_t new_pfn)
{
u64 new_spte;
new_spte = old_spte & ~PT64_BASE_ADDR_MASK;
new_spte |= (u64)new_pfn << PAGE_SHIFT;
new_spte &= ~PT_WRITABLE_MASK;
new_spte &= ~SPTE_HOST_WRITEABLE;
new_spte = mark_spte_for_access_track(new_spte);
return new_spte;
}
static int kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
struct kvm_memory_slot *slot, gfn_t gfn, int level,
unsigned long data)
@ -2583,21 +2167,6 @@ static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator)
__shadow_walk_next(iterator, *iterator->sptep);
}
static u64 make_nonleaf_spte(u64 *child_pt, bool ad_disabled)
{
u64 spte;
spte = __pa(child_pt) | shadow_present_mask | PT_WRITABLE_MASK |
shadow_user_mask | shadow_x_mask | shadow_me_mask;
if (ad_disabled)
spte |= SPTE_AD_DISABLED_MASK;
else
spte |= shadow_accessed_mask;
return spte;
}
static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep,
struct kvm_mmu_page *sp)
{
@ -2919,8 +2488,8 @@ static void kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
kvm_mmu_mark_parents_unsync(sp);
}
static bool mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
bool can_unsync)
bool mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
bool can_unsync)
{
struct kvm_mmu_page *sp;
@ -2980,116 +2549,6 @@ static bool mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
return false;
}
static bool kvm_is_mmio_pfn(kvm_pfn_t pfn)
{
if (pfn_valid(pfn))
return !is_zero_pfn(pfn) && PageReserved(pfn_to_page(pfn)) &&
/*
* Some reserved pages, such as those from NVDIMM
* DAX devices, are not for MMIO, and can be mapped
* with cached memory type for better performance.
* However, the above check misconceives those pages
* as MMIO, and results in KVM mapping them with UC
* memory type, which would hurt the performance.
* Therefore, we check the host memory type in addition
* and only treat UC/UC-/WC pages as MMIO.
*/
(!pat_enabled() || pat_pfn_immune_to_uc_mtrr(pfn));
return !e820__mapped_raw_any(pfn_to_hpa(pfn),
pfn_to_hpa(pfn + 1) - 1,
E820_TYPE_RAM);
}
/* Bits which may be returned by set_spte() */
#define SET_SPTE_WRITE_PROTECTED_PT BIT(0)
#define SET_SPTE_NEED_REMOTE_TLB_FLUSH BIT(1)
#define SET_SPTE_SPURIOUS BIT(2)
static int make_spte(struct kvm_vcpu *vcpu, unsigned int pte_access, int level,
gfn_t gfn, kvm_pfn_t pfn, u64 old_spte, bool speculative,
bool can_unsync, bool host_writable, bool ad_disabled,
u64 *new_spte)
{
u64 spte = 0;
int ret = 0;
if (ad_disabled)
spte |= SPTE_AD_DISABLED_MASK;
else if (kvm_vcpu_ad_need_write_protect(vcpu))
spte |= SPTE_AD_WRPROT_ONLY_MASK;
/*
* For the EPT case, shadow_present_mask is 0 if hardware
* supports exec-only page table entries. In that case,
* ACC_USER_MASK and shadow_user_mask are used to represent
* read access. See FNAME(gpte_access) in paging_tmpl.h.
*/
spte |= shadow_present_mask;
if (!speculative)
spte |= spte_shadow_accessed_mask(spte);
if (level > PG_LEVEL_4K && (pte_access & ACC_EXEC_MASK) &&
is_nx_huge_page_enabled()) {
pte_access &= ~ACC_EXEC_MASK;
}
if (pte_access & ACC_EXEC_MASK)
spte |= shadow_x_mask;
else
spte |= shadow_nx_mask;
if (pte_access & ACC_USER_MASK)
spte |= shadow_user_mask;
if (level > PG_LEVEL_4K)
spte |= PT_PAGE_SIZE_MASK;
if (tdp_enabled)
spte |= kvm_x86_ops.get_mt_mask(vcpu, gfn,
kvm_is_mmio_pfn(pfn));
if (host_writable)
spte |= SPTE_HOST_WRITEABLE;
else
pte_access &= ~ACC_WRITE_MASK;
if (!kvm_is_mmio_pfn(pfn))
spte |= shadow_me_mask;
spte |= (u64)pfn << PAGE_SHIFT;
if (pte_access & ACC_WRITE_MASK) {
spte |= PT_WRITABLE_MASK | SPTE_MMU_WRITEABLE;
/*
* Optimization: for pte sync, if spte was writable the hash
* lookup is unnecessary (and expensive). Write protection
* is responsibility of mmu_get_page / kvm_sync_page.
* Same reasoning can be applied to dirty page accounting.
*/
if (!can_unsync && is_writable_pte(old_spte))
goto out;
if (mmu_need_write_protect(vcpu, gfn, can_unsync)) {
pgprintk("%s: found shadow page for %llx, marking ro\n",
__func__, gfn);
ret |= SET_SPTE_WRITE_PROTECTED_PT;
pte_access &= ~ACC_WRITE_MASK;
spte &= ~(PT_WRITABLE_MASK | SPTE_MMU_WRITEABLE);
}
}
if (pte_access & ACC_WRITE_MASK)
spte |= spte_shadow_dirty_mask(spte);
if (speculative)
spte = mark_spte_for_access_track(spte);
out:
*new_spte = spte;
return ret;
}
static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
unsigned int pte_access, int level,
gfn_t gfn, kvm_pfn_t pfn, bool speculative,

31
arch/x86/kvm/mmu/mmu_internal.h
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@ -3,9 +3,23 @@
#define __KVM_X86_MMU_INTERNAL_H
#include <linux/types.h>
#include <linux/kvm_host.h>
#include <asm/kvm_host.h>
#undef MMU_DEBUG
#ifdef MMU_DEBUG
extern bool dbg;
#define pgprintk(x...) do { if (dbg) printk(x); } while (0)
#define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
#define MMU_WARN_ON(x) WARN_ON(x)
#else
#define pgprintk(x...) do { } while (0)
#define rmap_printk(x...) do { } while (0)
#define MMU_WARN_ON(x) do { } while (0)
#endif
struct kvm_mmu_page {
struct list_head link;
struct hlist_node hash_link;
@ -55,6 +69,21 @@ static inline struct kvm_mmu_page *sptep_to_sp(u64 *sptep)
return to_shadow_page(__pa(sptep));
}
static inline bool kvm_vcpu_ad_need_write_protect(struct kvm_vcpu *vcpu)
{
/*
* When using the EPT page-modification log, the GPAs in the log
* would come from L2 rather than L1. Therefore, we need to rely
* on write protection to record dirty pages. This also bypasses
* PML, since writes now result in a vmexit.
*/
return vcpu->arch.mmu == &vcpu->arch.guest_mmu;
}
bool is_nx_huge_page_enabled(void);
bool mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
bool can_unsync);
void kvm_mmu_gfn_disallow_lpage(struct kvm_memory_slot *slot, gfn_t gfn);
void kvm_mmu_gfn_allow_lpage(struct kvm_memory_slot *slot, gfn_t gfn);
bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,

318
arch/x86/kvm/mmu/spte.c Normal file
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@ -0,0 +1,318 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* Kernel-based Virtual Machine driver for Linux
*
* Macros and functions to access KVM PTEs (also known as SPTEs)
*
* Copyright (C) 2006 Qumranet, Inc.
* Copyright 2020 Red Hat, Inc. and/or its affiliates.
*/
#include <linux/kvm_host.h>
#include "mmu.h"
#include "mmu_internal.h"
#include "x86.h"
#include "spte.h"
#include <asm/e820/api.h>
u64 __read_mostly shadow_nx_mask;
u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_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_access_mask;
u64 __read_mostly shadow_present_mask;
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;
static u64 generation_mmio_spte_mask(u64 gen)
{
u64 mask;
WARN_ON(gen & ~MMIO_SPTE_GEN_MASK);
BUILD_BUG_ON((MMIO_SPTE_GEN_HIGH_MASK | MMIO_SPTE_GEN_LOW_MASK) & SPTE_SPECIAL_MASK);
mask = (gen << MMIO_SPTE_GEN_LOW_START) & MMIO_SPTE_GEN_LOW_MASK;
mask |= (gen << MMIO_SPTE_GEN_HIGH_START) & MMIO_SPTE_GEN_HIGH_MASK;
return mask;
}
u64 make_mmio_spte(struct kvm_vcpu *vcpu, u64 gfn, unsigned int access)
{
u64 gen = kvm_vcpu_memslots(vcpu)->generation & MMIO_SPTE_GEN_MASK;
u64 mask = generation_mmio_spte_mask(gen);
u64 gpa = gfn << PAGE_SHIFT;
access &= shadow_mmio_access_mask;
mask |= shadow_mmio_value | access;
mask |= gpa | shadow_nonpresent_or_rsvd_mask;
mask |= (gpa & shadow_nonpresent_or_rsvd_mask)
<< shadow_nonpresent_or_rsvd_mask_len;
return mask;
}
static bool kvm_is_mmio_pfn(kvm_pfn_t pfn)
{
if (pfn_valid(pfn))
return !is_zero_pfn(pfn) && PageReserved(pfn_to_page(pfn)) &&
/*
* Some reserved pages, such as those from NVDIMM
* DAX devices, are not for MMIO, and can be mapped
* with cached memory type for better performance.
* However, the above check misconceives those pages
* as MMIO, and results in KVM mapping them with UC
* memory type, which would hurt the performance.
* Therefore, we check the host memory type in addition
* and only treat UC/UC-/WC pages as MMIO.
*/
(!pat_enabled() || pat_pfn_immune_to_uc_mtrr(pfn));
return !e820__mapped_raw_any(pfn_to_hpa(pfn),
pfn_to_hpa(pfn + 1) - 1,
E820_TYPE_RAM);
}
int make_spte(struct kvm_vcpu *vcpu, unsigned int pte_access, int level,
gfn_t gfn, kvm_pfn_t pfn, u64 old_spte, bool speculative,
bool can_unsync, bool host_writable, bool ad_disabled,
u64 *new_spte)
{
u64 spte = 0;
int ret = 0;
if (ad_disabled)
spte |= SPTE_AD_DISABLED_MASK;
else if (kvm_vcpu_ad_need_write_protect(vcpu))
spte |= SPTE_AD_WRPROT_ONLY_MASK;
/*
* For the EPT case, shadow_present_mask is 0 if hardware
* supports exec-only page table entries. In that case,
* ACC_USER_MASK and shadow_user_mask are used to represent
* read access. See FNAME(gpte_access) in paging_tmpl.h.
*/
spte |= shadow_present_mask;
if (!speculative)
spte |= spte_shadow_accessed_mask(spte);
if (level > PG_LEVEL_4K && (pte_access & ACC_EXEC_MASK) &&
is_nx_huge_page_enabled()) {
pte_access &= ~ACC_EXEC_MASK;
}
if (pte_access & ACC_EXEC_MASK)
spte |= shadow_x_mask;
else
spte |= shadow_nx_mask;
if (pte_access & ACC_USER_MASK)
spte |= shadow_user_mask;
if (level > PG_LEVEL_4K)
spte |= PT_PAGE_SIZE_MASK;
if (tdp_enabled)
spte |= kvm_x86_ops.get_mt_mask(vcpu, gfn,
kvm_is_mmio_pfn(pfn));
if (host_writable)
spte |= SPTE_HOST_WRITEABLE;
else
pte_access &= ~ACC_WRITE_MASK;
if (!kvm_is_mmio_pfn(pfn))
spte |= shadow_me_mask;
spte |= (u64)pfn << PAGE_SHIFT;
if (pte_access & ACC_WRITE_MASK) {
spte |= PT_WRITABLE_MASK | SPTE_MMU_WRITEABLE;
/*
* Optimization: for pte sync, if spte was writable the hash
* lookup is unnecessary (and expensive). Write protection
* is responsibility of mmu_get_page / kvm_sync_page.
* Same reasoning can be applied to dirty page accounting.
*/
if (!can_unsync && is_writable_pte(old_spte))
goto out;
if (mmu_need_write_protect(vcpu, gfn, can_unsync)) {
pgprintk("%s: found shadow page for %llx, marking ro\n",
__func__, gfn);
ret |= SET_SPTE_WRITE_PROTECTED_PT;
pte_access &= ~ACC_WRITE_MASK;
spte &= ~(PT_WRITABLE_MASK | SPTE_MMU_WRITEABLE);
}
}
if (pte_access & ACC_WRITE_MASK)
spte |= spte_shadow_dirty_mask(spte);
if (speculative)
spte = mark_spte_for_access_track(spte);
out:
*new_spte = spte;
return ret;
}
u64 make_nonleaf_spte(u64 *child_pt, bool ad_disabled)
{
u64 spte;
spte = __pa(child_pt) | shadow_present_mask | PT_WRITABLE_MASK |
shadow_user_mask | shadow_x_mask | shadow_me_mask;
if (ad_disabled)
spte |= SPTE_AD_DISABLED_MASK;
else
spte |= shadow_accessed_mask;
return spte;
}
u64 kvm_mmu_changed_pte_notifier_make_spte(u64 old_spte, kvm_pfn_t new_pfn)
{
u64 new_spte;
new_spte = old_spte & ~PT64_BASE_ADDR_MASK;
new_spte |= (u64)new_pfn << PAGE_SHIFT;
new_spte &= ~PT_WRITABLE_MASK;
new_spte &= ~SPTE_HOST_WRITEABLE;
new_spte = mark_spte_for_access_track(new_spte);
return new_spte;
}
static u8 kvm_get_shadow_phys_bits(void)
{
/*
* boot_cpu_data.x86_phys_bits is reduced when MKTME or SME are detected
* in CPU detection code, but the processor treats those reduced bits as
* 'keyID' thus they are not reserved bits. Therefore KVM needs to look at
* the physical address bits reported by CPUID.
*/
if (likely(boot_cpu_data.extended_cpuid_level >= 0x80000008))
return cpuid_eax(0x80000008) & 0xff;
/*
* Quite weird to have VMX or SVM but not MAXPHYADDR; probably a VM with
* custom CPUID. Proceed with whatever the kernel found since these features
* aren't virtualizable (SME/SEV also require CPUIDs higher than 0x80000008).
*/
return boot_cpu_data.x86_phys_bits;
}
u64 mark_spte_for_access_track(u64 spte)
{
if (spte_ad_enabled(spte))
return spte & ~shadow_accessed_mask;
if (is_access_track_spte(spte))
return spte;
/*
* Making an Access Tracking PTE will result in removal of write access
* from the PTE. So, verify that we will be able to restore the write
* access in the fast page fault path later on.
*/
WARN_ONCE((spte & PT_WRITABLE_MASK) &&
!spte_can_locklessly_be_made_writable(spte),
"kvm: Writable SPTE is not locklessly dirty-trackable\n");
WARN_ONCE(spte & (shadow_acc_track_saved_bits_mask <<
shadow_acc_track_saved_bits_shift),
"kvm: Access Tracking saved bit locations are not zero\n");
spte |= (spte & shadow_acc_track_saved_bits_mask) <<
shadow_acc_track_saved_bits_shift;
spte &= ~shadow_acc_track_mask;
return spte;
}
void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 access_mask)
{
BUG_ON((u64)(unsigned)access_mask != access_mask);
WARN_ON(mmio_value & (shadow_nonpresent_or_rsvd_mask << shadow_nonpresent_or_rsvd_mask_len));
WARN_ON(mmio_value & shadow_nonpresent_or_rsvd_lower_gfn_mask);
shadow_mmio_value = mmio_value | SPTE_MMIO_MASK;
shadow_mmio_access_mask = access_mask;
}
EXPORT_SYMBOL_GPL(kvm_mmu_set_mmio_spte_mask);
/*
* Sets the shadow PTE masks used by the MMU.
*
* Assumptions:
* - Setting either @accessed_mask or @dirty_mask requires setting both
* - At least one of @accessed_mask or @acc_track_mask must be set
*/
void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
u64 dirty_mask, u64 nx_mask, u64 x_mask, u64 p_mask,
u64 acc_track_mask, u64 me_mask)
{
BUG_ON(!dirty_mask != !accessed_mask);
BUG_ON(!accessed_mask && !acc_track_mask);
BUG_ON(acc_track_mask & SPTE_SPECIAL_MASK);
shadow_user_mask = user_mask;
shadow_accessed_mask = accessed_mask;
shadow_dirty_mask = dirty_mask;
shadow_nx_mask = nx_mask;
shadow_x_mask = x_mask;
shadow_present_mask = p_mask;
shadow_acc_track_mask = acc_track_mask;
shadow_me_mask = me_mask;
}
EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes);
void kvm_mmu_reset_all_pte_masks(void)
{
u8 low_phys_bits;
shadow_user_mask = 0;
shadow_accessed_mask = 0;
shadow_dirty_mask = 0;
shadow_nx_mask = 0;
shadow_x_mask = 0;
shadow_present_mask = 0;
shadow_acc_track_mask = 0;
shadow_phys_bits = kvm_get_shadow_phys_bits();
/*
* If the CPU has 46 or less physical address bits, then set an
* appropriate mask to guard against L1TF attacks. Otherwise, it is
* assumed that the CPU is not vulnerable to L1TF.
*
* Some Intel CPUs address the L1 cache using more PA bits than are
* reported by CPUID. Use the PA width of the L1 cache when possible
* to achieve more effective mitigation, e.g. if system RAM overlaps
* the most significant bits of legal physical address space.
*/
shadow_nonpresent_or_rsvd_mask = 0;
low_phys_bits = boot_cpu_data.x86_phys_bits;
if (boot_cpu_has_bug(X86_BUG_L1TF) &&
!WARN_ON_ONCE(boot_cpu_data.x86_cache_bits >=
52 - shadow_nonpresent_or_rsvd_mask_len)) {
low_phys_bits = boot_cpu_data.x86_cache_bits
- shadow_nonpresent_or_rsvd_mask_len;
shadow_nonpresent_or_rsvd_mask =
rsvd_bits(low_phys_bits, boot_cpu_data.x86_cache_bits - 1);
}
shadow_nonpresent_or_rsvd_lower_gfn_mask =
GENMASK_ULL(low_phys_bits - 1, PAGE_SHIFT);
}

252
arch/x86/kvm/mmu/spte.h Normal file
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@ -0,0 +1,252 @@
// SPDX-License-Identifier: GPL-2.0-only
#ifndef KVM_X86_MMU_SPTE_H
#define KVM_X86_MMU_SPTE_H
#include "mmu_internal.h"
#define PT_FIRST_AVAIL_BITS_SHIFT 10
#define PT64_SECOND_AVAIL_BITS_SHIFT 54
/*
* The mask used to denote special SPTEs, which can be either MMIO SPTEs or
* Access Tracking SPTEs.
*/
#define SPTE_SPECIAL_MASK (3ULL << 52)
#define SPTE_AD_ENABLED_MASK (0ULL << 52)
#define SPTE_AD_DISABLED_MASK (1ULL << 52)
#define SPTE_AD_WRPROT_ONLY_MASK (2ULL << 52)
#define SPTE_MMIO_MASK (3ULL << 52)
#ifdef CONFIG_DYNAMIC_PHYSICAL_MASK
#define PT64_BASE_ADDR_MASK (physical_mask & ~(u64)(PAGE_SIZE-1))
#else
#define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
#endif
#define PT64_LVL_ADDR_MASK(level) \
(PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
* PT64_LEVEL_BITS))) - 1))
#define PT64_LVL_OFFSET_MASK(level) \
(PT64_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
* PT64_LEVEL_BITS))) - 1))
#define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | shadow_user_mask \
| shadow_x_mask | shadow_nx_mask | shadow_me_mask)
#define ACC_EXEC_MASK 1
#define ACC_WRITE_MASK PT_WRITABLE_MASK
#define ACC_USER_MASK PT_USER_MASK
#define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
/* The mask for the R/X bits in EPT PTEs */
#define PT64_EPT_READABLE_MASK 0x1ull
#define PT64_EPT_EXECUTABLE_MASK 0x4ull
#define PT64_LEVEL_BITS 9
#define PT64_LEVEL_SHIFT(level) \
(PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
#define PT64_INDEX(address, level)\
(((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
#define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
#define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
#define SPTE_MMU_WRITEABLE (1ULL << (PT_FIRST_AVAIL_BITS_SHIFT + 1))
/*
* Due to limited space in PTEs, the MMIO generation is a 19 bit subset of
* the memslots generation and is derived as follows:
*
* Bits 0-8 of the MMIO generation are propagated to spte bits 3-11
* Bits 9-18 of the MMIO generation are propagated to spte bits 52-61
*
* The KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS flag is intentionally not included in
* the MMIO generation number, as doing so would require stealing a bit from
* the "real" generation number and thus effectively halve the maximum number
* of MMIO generations that can be handled before encountering a wrap (which
* requires a full MMU zap). The flag is instead explicitly queried when
* checking for MMIO spte cache hits.
*/
#define MMIO_SPTE_GEN_MASK GENMASK_ULL(17, 0)
#define MMIO_SPTE_GEN_LOW_START 3
#define MMIO_SPTE_GEN_LOW_END 11
#define MMIO_SPTE_GEN_LOW_MASK GENMASK_ULL(MMIO_SPTE_GEN_LOW_END, \
MMIO_SPTE_GEN_LOW_START)
#define MMIO_SPTE_GEN_HIGH_START PT64_SECOND_AVAIL_BITS_SHIFT
#define MMIO_SPTE_GEN_HIGH_END 62
#define MMIO_SPTE_GEN_HIGH_MASK GENMASK_ULL(MMIO_SPTE_GEN_HIGH_END, \
MMIO_SPTE_GEN_HIGH_START)
extern u64 __read_mostly shadow_nx_mask;
extern u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */
extern u64 __read_mostly shadow_user_mask;
extern u64 __read_mostly shadow_accessed_mask;
extern u64 __read_mostly shadow_dirty_mask;
extern u64 __read_mostly shadow_mmio_value;
extern u64 __read_mostly shadow_mmio_access_mask;
extern u64 __read_mostly shadow_present_mask;
extern u64 __read_mostly shadow_me_mask;
/*
* SPTEs used by MMUs without A/D bits are marked with SPTE_AD_DISABLED_MASK;
* shadow_acc_track_mask is the set of bits to be cleared in non-accessed
* pages.
*/
extern u64 __read_mostly shadow_acc_track_mask;
/*
* This mask must be set on all non-zero Non-Present or Reserved SPTEs in order
* to guard against L1TF attacks.
*/
extern u64 __read_mostly shadow_nonpresent_or_rsvd_mask;
/*
* The mask/shift to use for saving the original R/X bits when marking the PTE
* as not-present for access tracking purposes. We do not save the W bit as the
* PTEs being access tracked also need to be dirty tracked, so the W bit will be
* restored only when a write is attempted to the page.
*/
static const u64 shadow_acc_track_saved_bits_mask = PT64_EPT_READABLE_MASK |
PT64_EPT_EXECUTABLE_MASK;
static const u64 shadow_acc_track_saved_bits_shift = PT64_SECOND_AVAIL_BITS_SHIFT;
/*
* The number of high-order 1 bits to use in the mask above.
*/
static const u64 shadow_nonpresent_or_rsvd_mask_len = 5;
/*
* In some cases, we need to preserve the GFN of a non-present or reserved
* SPTE when we usurp the upper five bits of the physical address space to
* defend against L1TF, e.g. for MMIO SPTEs. To preserve the GFN, we'll
* shift bits of the GFN that overlap with shadow_nonpresent_or_rsvd_mask
* left into the reserved bits, i.e. the GFN in the SPTE will be split into
* high and low parts. This mask covers the lower bits of the GFN.
*/
extern u64 __read_mostly shadow_nonpresent_or_rsvd_lower_gfn_mask;
/*
* The number of non-reserved physical address bits irrespective of features
* that repurpose legal bits, e.g. MKTME.
*/
extern u8 __read_mostly shadow_phys_bits;
static inline bool is_mmio_spte(u64 spte)
{
return (spte & SPTE_SPECIAL_MASK) == SPTE_MMIO_MASK;
}
static inline bool sp_ad_disabled(struct kvm_mmu_page *sp)
{
return sp->role.ad_disabled;
}
static inline bool spte_ad_enabled(u64 spte)
{
MMU_WARN_ON(is_mmio_spte(spte));
return (spte & SPTE_SPECIAL_MASK) != SPTE_AD_DISABLED_MASK;
}
static inline bool spte_ad_need_write_protect(u64 spte)
{
MMU_WARN_ON(is_mmio_spte(spte));
return (spte & SPTE_SPECIAL_MASK) != SPTE_AD_ENABLED_MASK;
}
static inline u64 spte_shadow_accessed_mask(u64 spte)
{
MMU_WARN_ON(is_mmio_spte(spte));
return spte_ad_enabled(spte) ? shadow_accessed_mask : 0;
}
static inline u64 spte_shadow_dirty_mask(u64 spte)
{
MMU_WARN_ON(is_mmio_spte(spte));
return spte_ad_enabled(spte) ? shadow_dirty_mask : 0;
}
static inline bool is_access_track_spte(u64 spte)
{
return !spte_ad_enabled(spte) && (spte & shadow_acc_track_mask) == 0;
}
static inline int is_shadow_present_pte(u64 pte)
{
return (pte != 0) && !is_mmio_spte(pte);
}
static inline int is_large_pte(u64 pte)
{
return pte & PT_PAGE_SIZE_MASK;
}
static inline int is_last_spte(u64 pte, int level)
{
if (level == PG_LEVEL_4K)
return 1;
if (is_large_pte(pte))
return 1;
return 0;
}
static inline bool is_executable_pte(u64 spte)
{
return (spte & (shadow_x_mask | shadow_nx_mask)) == shadow_x_mask;
}
static inline kvm_pfn_t spte_to_pfn(u64 pte)
{
return (pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
}
static inline bool is_accessed_spte(u64 spte)
{
u64 accessed_mask = spte_shadow_accessed_mask(spte);
return accessed_mask ? spte & accessed_mask
: !is_access_track_spte(spte);
}
static inline bool is_dirty_spte(u64 spte)
{
u64 dirty_mask = spte_shadow_dirty_mask(spte);
return dirty_mask ? spte & dirty_mask : spte & PT_WRITABLE_MASK;
}
static inline bool spte_can_locklessly_be_made_writable(u64 spte)
{
return (spte & (SPTE_HOST_WRITEABLE | SPTE_MMU_WRITEABLE)) ==
(SPTE_HOST_WRITEABLE | SPTE_MMU_WRITEABLE);
}
static inline u64 get_mmio_spte_generation(u64 spte)
{
u64 gen;
gen = (spte & MMIO_SPTE_GEN_LOW_MASK) >> MMIO_SPTE_GEN_LOW_START;
gen |= (spte & MMIO_SPTE_GEN_HIGH_MASK) >> MMIO_SPTE_GEN_HIGH_START;
return gen;
}
/* Bits which may be returned by set_spte() */
#define SET_SPTE_WRITE_PROTECTED_PT BIT(0)
#define SET_SPTE_NEED_REMOTE_TLB_FLUSH BIT(1)
#define SET_SPTE_SPURIOUS BIT(2)
int make_spte(struct kvm_vcpu *vcpu, unsigned int pte_access, int level,
gfn_t gfn, kvm_pfn_t pfn, u64 old_spte, bool speculative,
bool can_unsync, bool host_writable, bool ad_disabled,
u64 *new_spte);
u64 make_nonleaf_spte(u64 *child_pt, bool ad_disabled);
u64 make_mmio_spte(struct kvm_vcpu *vcpu, u64 gfn, unsigned int access);
u64 mark_spte_for_access_track(u64 spte);
u64 kvm_mmu_changed_pte_notifier_make_spte(u64 old_spte, kvm_pfn_t new_pfn);
void kvm_mmu_reset_all_pte_masks(void);
#endif