[PATCH 1/4] KVM: delete .change_pte MMU notifier callback

From: Paolo Bonzini
Date: Fri Apr 05 2024 - 07:59:12 EST


The .change_pte() MMU notifier callback was intended as an
optimization. The original point of it was that KSM could tell KVM to flip
its secondary PTE to a new location without having to first zap it. At
the time there was also an .invalidate_page() callback; both of them were
*not* bracketed by calls to mmu_notifier_invalidate_range_{start,end}(),
and .invalidate_page() also doubled as a fallback implementation of
change_pte().

Later on, however, both callbacks were changed to occur within an
invalidate_range_start/end() block.

In the case of .change_pte(), commit 6bdb913f0a70 ("mm: wrap calls to
set_pte_at_notify with invalidate_range_start and invalidate_range_end",
2012-10-09) did so to remove the fallback from .invalidate_page() to
change_pte() and allow sleepable .invalidate_page() hooks.

This however made KVM's usage of the .change_pte() callback completely
moot, because KVM unmaps the sPTEs during .invalidate_range_start()
and therefore .change_pte() has no hope of finding a sPTE to change.
Drop the generic KVM code that dispatches to kvm_set_spte_gfn(), as
well as all the architecture specific implementations.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/arm64/kvm/mmu.c | 34 -----------------
arch/loongarch/include/asm/kvm_host.h | 1 -
arch/loongarch/kvm/mmu.c | 32 ----------------
arch/mips/kvm/mmu.c | 30 ---------------
arch/powerpc/include/asm/kvm_ppc.h | 1 -
arch/powerpc/kvm/book3s.c | 5 ---
arch/powerpc/kvm/book3s.h | 1 -
arch/powerpc/kvm/book3s_64_mmu_hv.c | 12 ------
arch/powerpc/kvm/book3s_hv.c | 1 -
arch/powerpc/kvm/book3s_pr.c | 7 ----
arch/powerpc/kvm/e500_mmu_host.c | 6 ---
arch/riscv/kvm/mmu.c | 20 ----------
arch/x86/kvm/mmu/mmu.c | 54 +--------------------------
arch/x86/kvm/mmu/spte.c | 16 --------
arch/x86/kvm/mmu/spte.h | 2 -
arch/x86/kvm/mmu/tdp_mmu.c | 46 -----------------------
arch/x86/kvm/mmu/tdp_mmu.h | 1 -
include/linux/kvm_host.h | 2 -
include/trace/events/kvm.h | 15 --------
virt/kvm/kvm_main.c | 43 ---------------------
20 files changed, 2 insertions(+), 327 deletions(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index dc04bc767865..ff17849be9f4 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1768,40 +1768,6 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
return false;
}

-bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
-{
- kvm_pfn_t pfn = pte_pfn(range->arg.pte);
-
- if (!kvm->arch.mmu.pgt)
- return false;
-
- WARN_ON(range->end - range->start != 1);
-
- /*
- * If the page isn't tagged, defer to user_mem_abort() for sanitising
- * the MTE tags. The S2 pte should have been unmapped by
- * mmu_notifier_invalidate_range_end().
- */
- if (kvm_has_mte(kvm) && !page_mte_tagged(pfn_to_page(pfn)))
- return false;
-
- /*
- * We've moved a page around, probably through CoW, so let's treat
- * it just like a translation fault and the map handler will clean
- * the cache to the PoC.
- *
- * The MMU notifiers will have unmapped a huge PMD before calling
- * ->change_pte() (which in turn calls kvm_set_spte_gfn()) and
- * therefore we never need to clear out a huge PMD through this
- * calling path and a memcache is not required.
- */
- kvm_pgtable_stage2_map(kvm->arch.mmu.pgt, range->start << PAGE_SHIFT,
- PAGE_SIZE, __pfn_to_phys(pfn),
- KVM_PGTABLE_PROT_R, NULL, 0);
-
- return false;
-}
-
bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
{
u64 size = (range->end - range->start) << PAGE_SHIFT;
diff --git a/arch/loongarch/include/asm/kvm_host.h b/arch/loongarch/include/asm/kvm_host.h
index 2d62f7b0d377..69305441f40d 100644
--- a/arch/loongarch/include/asm/kvm_host.h
+++ b/arch/loongarch/include/asm/kvm_host.h
@@ -203,7 +203,6 @@ void kvm_flush_tlb_all(void);
void kvm_flush_tlb_gpa(struct kvm_vcpu *vcpu, unsigned long gpa);
int kvm_handle_mm_fault(struct kvm_vcpu *vcpu, unsigned long badv, bool write);

-void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end, bool blockable);
int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end);
int kvm_test_age_hva(struct kvm *kvm, unsigned long hva);
diff --git a/arch/loongarch/kvm/mmu.c b/arch/loongarch/kvm/mmu.c
index a556cff35740..98883aa23ab8 100644
--- a/arch/loongarch/kvm/mmu.c
+++ b/arch/loongarch/kvm/mmu.c
@@ -494,38 +494,6 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
range->end << PAGE_SHIFT, &ctx);
}

-bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
-{
- unsigned long prot_bits;
- kvm_pte_t *ptep;
- kvm_pfn_t pfn = pte_pfn(range->arg.pte);
- gpa_t gpa = range->start << PAGE_SHIFT;
-
- ptep = kvm_populate_gpa(kvm, NULL, gpa, 0);
- if (!ptep)
- return false;
-
- /* Replacing an absent or old page doesn't need flushes */
- if (!kvm_pte_present(NULL, ptep) || !kvm_pte_young(*ptep)) {
- kvm_set_pte(ptep, 0);
- return false;
- }
-
- /* Fill new pte if write protected or page migrated */
- prot_bits = _PAGE_PRESENT | __READABLE;
- prot_bits |= _CACHE_MASK & pte_val(range->arg.pte);
-
- /*
- * Set _PAGE_WRITE or _PAGE_DIRTY iff old and new pte both support
- * _PAGE_WRITE for map_page_fast if next page write fault
- * _PAGE_DIRTY since gpa has already recorded as dirty page
- */
- prot_bits |= __WRITEABLE & *ptep & pte_val(range->arg.pte);
- kvm_set_pte(ptep, kvm_pfn_pte(pfn, __pgprot(prot_bits)));
-
- return true;
-}
-
bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
{
kvm_ptw_ctx ctx;
diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
index 467ee6b95ae1..c17157e700c0 100644
--- a/arch/mips/kvm/mmu.c
+++ b/arch/mips/kvm/mmu.c
@@ -444,36 +444,6 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
return true;
}

-bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
-{
- gpa_t gpa = range->start << PAGE_SHIFT;
- pte_t hva_pte = range->arg.pte;
- pte_t *gpa_pte = kvm_mips_pte_for_gpa(kvm, NULL, gpa);
- pte_t old_pte;
-
- if (!gpa_pte)
- return false;
-
- /* Mapping may need adjusting depending on memslot flags */
- old_pte = *gpa_pte;
- if (range->slot->flags & KVM_MEM_LOG_DIRTY_PAGES && !pte_dirty(old_pte))
- hva_pte = pte_mkclean(hva_pte);
- else if (range->slot->flags & KVM_MEM_READONLY)
- hva_pte = pte_wrprotect(hva_pte);
-
- set_pte(gpa_pte, hva_pte);
-
- /* Replacing an absent or old page doesn't need flushes */
- if (!pte_present(old_pte) || !pte_young(old_pte))
- return false;
-
- /* Pages swapped, aged, moved, or cleaned require flushes */
- return !pte_present(hva_pte) ||
- !pte_young(hva_pte) ||
- pte_pfn(old_pte) != pte_pfn(hva_pte) ||
- (pte_dirty(old_pte) && !pte_dirty(hva_pte));
-}
-
bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
{
return kvm_mips_mkold_gpa_pt(kvm, range->start, range->end);
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 3281215097cc..ca3829d47ab7 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -287,7 +287,6 @@ struct kvmppc_ops {
bool (*unmap_gfn_range)(struct kvm *kvm, struct kvm_gfn_range *range);
bool (*age_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);
bool (*test_age_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);
- bool (*set_spte_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);
void (*free_memslot)(struct kvm_memory_slot *slot);
int (*init_vm)(struct kvm *kvm);
void (*destroy_vm)(struct kvm *kvm);
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 8acec144120e..0d0624088e6b 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -899,11 +899,6 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
return kvm->arch.kvm_ops->test_age_gfn(kvm, range);
}

-bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
-{
- return kvm->arch.kvm_ops->set_spte_gfn(kvm, range);
-}
-
int kvmppc_core_init_vm(struct kvm *kvm)
{

diff --git a/arch/powerpc/kvm/book3s.h b/arch/powerpc/kvm/book3s.h
index 58391b4b32ed..4aa2ab89afbc 100644
--- a/arch/powerpc/kvm/book3s.h
+++ b/arch/powerpc/kvm/book3s.h
@@ -12,7 +12,6 @@ extern void kvmppc_core_flush_memslot_hv(struct kvm *kvm,
extern bool kvm_unmap_gfn_range_hv(struct kvm *kvm, struct kvm_gfn_range *range);
extern bool kvm_age_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range);
extern bool kvm_test_age_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range);
-extern bool kvm_set_spte_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range);

extern int kvmppc_mmu_init_pr(struct kvm_vcpu *vcpu);
extern void kvmppc_mmu_destroy_pr(struct kvm_vcpu *vcpu);
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 2b1f0cdd8c18..1b51b1c4713b 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -1010,18 +1010,6 @@ bool kvm_test_age_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range)
return kvm_test_age_rmapp(kvm, range->slot, range->start);
}

-bool kvm_set_spte_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range)
-{
- WARN_ON(range->start + 1 != range->end);
-
- if (kvm_is_radix(kvm))
- kvm_unmap_radix(kvm, range->slot, range->start);
- else
- kvm_unmap_rmapp(kvm, range->slot, range->start);
-
- return false;
-}
-
static int vcpus_running(struct kvm *kvm)
{
return atomic_read(&kvm->arch.vcpus_running) != 0;
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 8e86eb577eb8..35cb014a0c51 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -6364,7 +6364,6 @@ static struct kvmppc_ops kvm_ops_hv = {
.unmap_gfn_range = kvm_unmap_gfn_range_hv,
.age_gfn = kvm_age_gfn_hv,
.test_age_gfn = kvm_test_age_gfn_hv,
- .set_spte_gfn = kvm_set_spte_gfn_hv,
.free_memslot = kvmppc_core_free_memslot_hv,
.init_vm = kvmppc_core_init_vm_hv,
.destroy_vm = kvmppc_core_destroy_vm_hv,
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 5b92619a05fd..a7d7137ea0c8 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -461,12 +461,6 @@ static bool kvm_test_age_gfn_pr(struct kvm *kvm, struct kvm_gfn_range *range)
return false;
}

-static bool kvm_set_spte_gfn_pr(struct kvm *kvm, struct kvm_gfn_range *range)
-{
- /* The page will get remapped properly on its next fault */
- return do_kvm_unmap_gfn(kvm, range);
-}
-
/*****************************************/

static void kvmppc_set_msr_pr(struct kvm_vcpu *vcpu, u64 msr)
@@ -2071,7 +2065,6 @@ static struct kvmppc_ops kvm_ops_pr = {
.unmap_gfn_range = kvm_unmap_gfn_range_pr,
.age_gfn = kvm_age_gfn_pr,
.test_age_gfn = kvm_test_age_gfn_pr,
- .set_spte_gfn = kvm_set_spte_gfn_pr,
.free_memslot = kvmppc_core_free_memslot_pr,
.init_vm = kvmppc_core_init_vm_pr,
.destroy_vm = kvmppc_core_destroy_vm_pr,
diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index ccb8f16ffe41..c664fdec75b1 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -747,12 +747,6 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
return false;
}

-bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
-{
- /* The page will get remapped properly on its next fault */
- return kvm_e500_mmu_unmap_gfn(kvm, range);
-}
-
/*****************************************/

int e500_mmu_host_init(struct kvmppc_vcpu_e500 *vcpu_e500)
diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c
index a9e2fd7245e1..b63650f9b966 100644
--- a/arch/riscv/kvm/mmu.c
+++ b/arch/riscv/kvm/mmu.c
@@ -550,26 +550,6 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
return false;
}

-bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
-{
- int ret;
- kvm_pfn_t pfn = pte_pfn(range->arg.pte);
-
- if (!kvm->arch.pgd)
- return false;
-
- WARN_ON(range->end - range->start != 1);
-
- ret = gstage_map_page(kvm, NULL, range->start << PAGE_SHIFT,
- __pfn_to_phys(pfn), PAGE_SIZE, true, true);
- if (ret) {
- kvm_debug("Failed to map G-stage page (error %d)\n", ret);
- return true;
- }
-
- return false;
-}
-
bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
{
pte_t *ptep;
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 0049d49aa913..87ba2a9da196 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -432,8 +432,8 @@ static u64 __update_clear_spte_slow(u64 *sptep, u64 spte)
* The idea using the light way get the spte on x86_32 guest is from
* gup_get_pte (mm/gup.c).
*
- * An spte tlb flush may be pending, because kvm_set_pte_rmap
- * coalesces them and we are running out of the MMU lock. Therefore
+ * An spte tlb flush may be pending, because they are coalesced and
+ * we are running out of the MMU lock. Therefore
* we need to protect against in-progress updates of the spte.
*
* Reading the spte while an update is in progress may get the old value
@@ -1454,43 +1454,6 @@ static bool kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
return __kvm_zap_rmap(kvm, rmap_head, slot);
}

-static bool kvm_set_pte_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
- struct kvm_memory_slot *slot, gfn_t gfn, int level,
- pte_t pte)
-{
- u64 *sptep;
- struct rmap_iterator iter;
- bool need_flush = false;
- u64 new_spte;
- kvm_pfn_t new_pfn;
-
- WARN_ON_ONCE(pte_huge(pte));
- new_pfn = pte_pfn(pte);
-
-restart:
- for_each_rmap_spte(rmap_head, &iter, sptep) {
- need_flush = true;
-
- if (pte_write(pte)) {
- kvm_zap_one_rmap_spte(kvm, rmap_head, sptep);
- goto restart;
- } else {
- new_spte = kvm_mmu_changed_pte_notifier_make_spte(
- *sptep, new_pfn);
-
- mmu_spte_clear_track_bits(kvm, sptep);
- mmu_spte_set(sptep, new_spte);
- }
- }
-
- if (need_flush && kvm_available_flush_remote_tlbs_range()) {
- kvm_flush_remote_tlbs_gfn(kvm, gfn, level);
- return false;
- }
-
- return need_flush;
-}
-
struct slot_rmap_walk_iterator {
/* input fields. */
const struct kvm_memory_slot *slot;
@@ -1596,19 +1559,6 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
return flush;
}

-bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
-{
- bool flush = false;
-
- if (kvm_memslots_have_rmaps(kvm))
- flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmap);
-
- if (tdp_mmu_enabled)
- flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range);
-
- return flush;
-}
-
static bool kvm_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
struct kvm_memory_slot *slot, gfn_t gfn, int level,
pte_t unused)
diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c
index 318135daf685..283af5b90016 100644
--- a/arch/x86/kvm/mmu/spte.c
+++ b/arch/x86/kvm/mmu/spte.c
@@ -322,22 +322,6 @@ u64 make_nonleaf_spte(u64 *child_pt, bool ad_disabled)
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 & ~SPTE_BASE_ADDR_MASK;
- new_spte |= (u64)new_pfn << PAGE_SHIFT;
-
- new_spte &= ~PT_WRITABLE_MASK;
- new_spte &= ~shadow_host_writable_mask;
- new_spte &= ~shadow_mmu_writable_mask;
-
- new_spte = mark_spte_for_access_track(new_spte);
-
- return new_spte;
-}
-
u64 mark_spte_for_access_track(u64 spte)
{
if (spte_ad_enabled(spte))
diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h
index 1a163aee9ec6..92da4c419171 100644
--- a/arch/x86/kvm/mmu/spte.h
+++ b/arch/x86/kvm/mmu/spte.h
@@ -511,8 +511,6 @@ static inline u64 restore_acc_track_spte(u64 spte)
return spte;
}

-u64 kvm_mmu_changed_pte_notifier_make_spte(u64 old_spte, kvm_pfn_t new_pfn);
-
void __init kvm_mmu_spte_module_init(void);
void kvm_mmu_reset_all_pte_masks(void);

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 3627744fcab6..fbb86932b766 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1250,52 +1250,6 @@ bool kvm_tdp_mmu_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
return kvm_tdp_mmu_handle_gfn(kvm, range, test_age_gfn);
}

-static bool set_spte_gfn(struct kvm *kvm, struct tdp_iter *iter,
- struct kvm_gfn_range *range)
-{
- u64 new_spte;
-
- /* Huge pages aren't expected to be modified without first being zapped. */
- WARN_ON_ONCE(pte_huge(range->arg.pte) || range->start + 1 != range->end);
-
- if (iter->level != PG_LEVEL_4K ||
- !is_shadow_present_pte(iter->old_spte))
- return false;
-
- /*
- * Note, when changing a read-only SPTE, it's not strictly necessary to
- * zero the SPTE before setting the new PFN, but doing so preserves the
- * invariant that the PFN of a present * leaf SPTE can never change.
- * See handle_changed_spte().
- */
- tdp_mmu_iter_set_spte(kvm, iter, SHADOW_NONPRESENT_VALUE);
-
- if (!pte_write(range->arg.pte)) {
- new_spte = kvm_mmu_changed_pte_notifier_make_spte(iter->old_spte,
- pte_pfn(range->arg.pte));
-
- tdp_mmu_iter_set_spte(kvm, iter, new_spte);
- }
-
- return true;
-}
-
-/*
- * Handle the changed_pte MMU notifier for the TDP MMU.
- * data is a pointer to the new pte_t mapping the HVA specified by the MMU
- * notifier.
- * Returns non-zero if a flush is needed before releasing the MMU lock.
- */
-bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
-{
- /*
- * No need to handle the remote TLB flush under RCU protection, the
- * target SPTE _must_ be a leaf SPTE, i.e. cannot result in freeing a
- * shadow page. See the WARN on pfn_changed in handle_changed_spte().
- */
- return kvm_tdp_mmu_handle_gfn(kvm, range, set_spte_gfn);
-}
-
/*
* Remove write access from all SPTEs at or above min_level that map GFNs
* [start, end). Returns true if an SPTE has been changed and the TLBs need to
diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h
index 6e1ea04ca885..58b55e61bd33 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.h
+++ b/arch/x86/kvm/mmu/tdp_mmu.h
@@ -31,7 +31,6 @@ bool kvm_tdp_mmu_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range,
bool flush);
bool kvm_tdp_mmu_age_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range);
bool kvm_tdp_mmu_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
-bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range);

bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm,
const struct kvm_memory_slot *slot, int min_level);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ab439706ea2f..8dea11701ab2 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -259,7 +259,6 @@ int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu);

#ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER
union kvm_mmu_notifier_arg {
- pte_t pte;
unsigned long attributes;
};

@@ -273,7 +272,6 @@ struct kvm_gfn_range {
bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range);
bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
-bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
#endif

enum {
diff --git a/include/trace/events/kvm.h b/include/trace/events/kvm.h
index 011fba6b5552..74e40d5d4af4 100644
--- a/include/trace/events/kvm.h
+++ b/include/trace/events/kvm.h
@@ -456,21 +456,6 @@ TRACE_EVENT(kvm_unmap_hva_range,
__entry->start, __entry->end)
);

-TRACE_EVENT(kvm_set_spte_hva,
- TP_PROTO(unsigned long hva),
- TP_ARGS(hva),
-
- TP_STRUCT__entry(
- __field( unsigned long, hva )
- ),
-
- TP_fast_assign(
- __entry->hva = hva;
- ),
-
- TP_printk("mmu notifier set pte hva: %#016lx", __entry->hva)
-);
-
TRACE_EVENT(kvm_age_hva,
TP_PROTO(unsigned long start, unsigned long end),
TP_ARGS(start, end),
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4eb8afd0b961..2fcd9979752a 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -717,48 +717,6 @@ static __always_inline int kvm_handle_hva_range_no_flush(struct mmu_notifier *mn
return __kvm_handle_hva_range(kvm, &range).ret;
}

-static bool kvm_change_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
-{
- /*
- * Skipping invalid memslots is correct if and only change_pte() is
- * surrounded by invalidate_range_{start,end}(), which is currently
- * guaranteed by the primary MMU. If that ever changes, KVM needs to
- * unmap the memslot instead of skipping the memslot to ensure that KVM
- * doesn't hold references to the old PFN.
- */
- WARN_ON_ONCE(!READ_ONCE(kvm->mn_active_invalidate_count));
-
- if (range->slot->flags & KVM_MEMSLOT_INVALID)
- return false;
-
- return kvm_set_spte_gfn(kvm, range);
-}
-
-static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
- struct mm_struct *mm,
- unsigned long address,
- pte_t pte)
-{
- struct kvm *kvm = mmu_notifier_to_kvm(mn);
- const union kvm_mmu_notifier_arg arg = { .pte = pte };
-
- trace_kvm_set_spte_hva(address);
-
- /*
- * .change_pte() must be surrounded by .invalidate_range_{start,end}().
- * If mmu_invalidate_in_progress is zero, then no in-progress
- * invalidations, including this one, found a relevant memslot at
- * start(); rechecking memslots here is unnecessary. Note, a false
- * positive (count elevated by a different invalidation) is sub-optimal
- * but functionally ok.
- */
- WARN_ON_ONCE(!READ_ONCE(kvm->mn_active_invalidate_count));
- if (!READ_ONCE(kvm->mmu_invalidate_in_progress))
- return;
-
- kvm_handle_hva_range(mn, address, address + 1, arg, kvm_change_spte_gfn);
-}
-
void kvm_mmu_invalidate_begin(struct kvm *kvm)
{
lockdep_assert_held_write(&kvm->mmu_lock);
@@ -976,7 +934,6 @@ static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
.clear_flush_young = kvm_mmu_notifier_clear_flush_young,
.clear_young = kvm_mmu_notifier_clear_young,
.test_young = kvm_mmu_notifier_test_young,
- .change_pte = kvm_mmu_notifier_change_pte,
.release = kvm_mmu_notifier_release,
};

--
2.43.0