KVM: Rename mmu_notifier_* to mmu_invalidate_*

chao-p · bonzini · commit 20ec3ebd707c · 2022-08-19T04:05:41.000-04:00
The motivation of this renaming is to make these variables and related
helper functions less mmu_notifier bound and can also be used for non
mmu_notifier based page invalidation. mmu_invalidate_* was chosen to
better describe the purpose of 'invalidating' a page that those
variables are used for.

  - mmu_notifier_seq/range_start/range_end are renamed to
    mmu_invalidate_seq/range_start/range_end.

  - mmu_notifier_retry{_hva} helper functions are renamed to
    mmu_invalidate_retry{_hva}.

  - mmu_notifier_count is renamed to mmu_invalidate_in_progress to
    avoid confusion with mn_active_invalidate_count.

  - While here, also update kvm_inc/dec_notifier_count() to
    kvm_mmu_invalidate_begin/end() to match the change for
    mmu_notifier_count.

No functional change intended.

Signed-off-by: Chao Peng &lt;chao.p.peng@linux.intel.com&gt;
Message-Id: &lt;20220816125322.1110439-3-chao.p.peng@linux.intel.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
@@ -993,7 +993,7 @@ transparent_hugepage_adjust(struct kvm *kvm, struct kvm_memory_slot *memslot,
 		 * THP doesn't start to split while we are adjusting the
 		 * refcounts.
 		 *
-		 * We are sure this doesn't happen, because mmu_notifier_retry
+		 * We are sure this doesn't happen, because mmu_invalidate_retry
 		 * was successful and we are holding the mmu_lock, so if this
 		 * THP is trying to split, it will be blocked in the mmu
 		 * notifier before touching any of the pages, specifically
@@ -1188,9 +1188,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 			return ret;
 	}
 
-	mmu_seq = vcpu->kvm->mmu_notifier_seq;
+	mmu_seq = vcpu->kvm->mmu_invalidate_seq;
 	/*
-	 * Ensure the read of mmu_notifier_seq happens before we call
+	 * Ensure the read of mmu_invalidate_seq happens before we call
 	 * gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk
 	 * the page we just got a reference to gets unmapped before we have a
 	 * chance to grab the mmu_lock, which ensure that if the page gets
@@ -1246,7 +1246,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 	else
 		write_lock(&kvm->mmu_lock);
 	pgt = vcpu->arch.hw_mmu->pgt;
-	if (mmu_notifier_retry(kvm, mmu_seq))
+	if (mmu_invalidate_retry(kvm, mmu_seq))
 		goto out_unlock;
 
 	/*
diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
@@ -615,17 +615,17 @@ static int kvm_mips_map_page(struct kvm_vcpu *vcpu, unsigned long gpa,
 	 * Used to check for invalidations in progress, of the pfn that is
 	 * returned by pfn_to_pfn_prot below.
 	 */
-	mmu_seq = kvm->mmu_notifier_seq;
+	mmu_seq = kvm->mmu_invalidate_seq;
 	/*
-	 * Ensure the read of mmu_notifier_seq isn't reordered with PTE reads in
-	 * gfn_to_pfn_prot() (which calls get_user_pages()), so that we don't
+	 * Ensure the read of mmu_invalidate_seq isn't reordered with PTE reads
+	 * in gfn_to_pfn_prot() (which calls get_user_pages()), so that we don't
 	 * risk the page we get a reference to getting unmapped before we have a
-	 * chance to grab the mmu_lock without mmu_notifier_retry() noticing.
+	 * chance to grab the mmu_lock without mmu_invalidate_retry() noticing.
 	 *
 	 * This smp_rmb() pairs with the effective smp_wmb() of the combination
 	 * of the pte_unmap_unlock() after the PTE is zapped, and the
 	 * spin_lock() in kvm_mmu_notifier_invalidate_<page|range_end>() before
-	 * mmu_notifier_seq is incremented.
+	 * mmu_invalidate_seq is incremented.
 	 */
 	smp_rmb();
 
@@ -638,7 +638,7 @@ static int kvm_mips_map_page(struct kvm_vcpu *vcpu, unsigned long gpa,
 
 	spin_lock(&kvm->mmu_lock);
 	/* Check if an invalidation has taken place since we got pfn */
-	if (mmu_notifier_retry(kvm, mmu_seq)) {
+	if (mmu_invalidate_retry(kvm, mmu_seq)) {
 		/*
 		 * This can happen when mappings are changed asynchronously, but
 		 * also synchronously if a COW is triggered by
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -666,7 +666,7 @@ static inline pte_t *find_kvm_host_pte(struct kvm *kvm, unsigned long mmu_seq,
 	VM_WARN(!spin_is_locked(&kvm->mmu_lock),
 		"%s called with kvm mmu_lock not held \n", __func__);
 
-	if (mmu_notifier_retry(kvm, mmu_seq))
+	if (mmu_invalidate_retry(kvm, mmu_seq))
 		return NULL;
 
 	pte = __find_linux_pte(kvm->mm->pgd, ea, NULL, hshift);
diff --git a/arch/powerpc/kvm/book3s_64_mmu_host.c b/arch/powerpc/kvm/book3s_64_mmu_host.c
@@ -90,7 +90,7 @@ int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte,
 	unsigned long pfn;
 
 	/* used to check for invalidations in progress */
-	mmu_seq = kvm->mmu_notifier_seq;
+	mmu_seq = kvm->mmu_invalidate_seq;
 	smp_rmb();
 
 	/* Get host physical address for gpa */
@@ -151,7 +151,7 @@ int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte,
 	cpte = kvmppc_mmu_hpte_cache_next(vcpu);
 
 	spin_lock(&kvm->mmu_lock);
-	if (!cpte || mmu_notifier_retry(kvm, mmu_seq)) {
+	if (!cpte || mmu_invalidate_retry(kvm, mmu_seq)) {
 		r = -EAGAIN;
 		goto out_unlock;
 	}
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -578,7 +578,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_vcpu *vcpu,
 		return -EFAULT;
 
 	/* used to check for invalidations in progress */
-	mmu_seq = kvm->mmu_notifier_seq;
+	mmu_seq = kvm->mmu_invalidate_seq;
 	smp_rmb();
 
 	ret = -EFAULT;
@@ -693,7 +693,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_vcpu *vcpu,
 
 	/* Check if we might have been invalidated; let the guest retry if so */
 	ret = RESUME_GUEST;
-	if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) {
+	if (mmu_invalidate_retry(vcpu->kvm, mmu_seq)) {
 		unlock_rmap(rmap);
 		goto out_unlock;
 	}
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -640,7 +640,7 @@ int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
 	/* Check if we might have been invalidated; let the guest retry if so */
 	spin_lock(&kvm->mmu_lock);
 	ret = -EAGAIN;
-	if (mmu_notifier_retry(kvm, mmu_seq))
+	if (mmu_invalidate_retry(kvm, mmu_seq))
 		goto out_unlock;
 
 	/* Now traverse again under the lock and change the tree */
@@ -830,7 +830,7 @@ int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu,
 	bool large_enable;
 
 	/* used to check for invalidations in progress */
-	mmu_seq = kvm->mmu_notifier_seq;
+	mmu_seq = kvm->mmu_invalidate_seq;
 	smp_rmb();
 
 	/*
@@ -1191,7 +1191,7 @@ void kvmppc_radix_flush_memslot(struct kvm *kvm,
 	 * Increase the mmu notifier sequence number to prevent any page
 	 * fault that read the memslot earlier from writing a PTE.
 	 */
-	kvm->mmu_notifier_seq++;
+	kvm->mmu_invalidate_seq++;
 	spin_unlock(&kvm->mmu_lock);
 }
 
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -1580,7 +1580,7 @@ static long int __kvmhv_nested_page_fault(struct kvm_vcpu *vcpu,
 	/* 2. Find the host pte for this L1 guest real address */
 
 	/* Used to check for invalidations in progress */
-	mmu_seq = kvm->mmu_notifier_seq;
+	mmu_seq = kvm->mmu_invalidate_seq;
 	smp_rmb();
 
 	/* See if can find translation in our partition scoped tables for L1 */
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -219,7 +219,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
 	g_ptel = ptel;
 
 	/* used later to detect if we might have been invalidated */
-	mmu_seq = kvm->mmu_notifier_seq;
+	mmu_seq = kvm->mmu_invalidate_seq;
 	smp_rmb();
 
 	/* Find the memslot (if any) for this address */
@@ -366,7 +366,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
 			rmap = real_vmalloc_addr(rmap);
 		lock_rmap(rmap);
 		/* Check for pending invalidations under the rmap chain lock */
-		if (mmu_notifier_retry(kvm, mmu_seq)) {
+		if (mmu_invalidate_retry(kvm, mmu_seq)) {
 			/* inval in progress, write a non-present HPTE */
 			pteh |= HPTE_V_ABSENT;
 			pteh &= ~HPTE_V_VALID;
@@ -932,7 +932,7 @@ static long kvmppc_do_h_page_init_zero(struct kvm_vcpu *vcpu,
 	int i;
 
 	/* Used later to detect if we might have been invalidated */
-	mmu_seq = kvm->mmu_notifier_seq;
+	mmu_seq = kvm->mmu_invalidate_seq;
 	smp_rmb();
 
 	arch_spin_lock(&kvm->mmu_lock.rlock.raw_lock);
@@ -960,7 +960,7 @@ static long kvmppc_do_h_page_init_copy(struct kvm_vcpu *vcpu,
 	long ret = H_SUCCESS;
 
 	/* Used later to detect if we might have been invalidated */
-	mmu_seq = kvm->mmu_notifier_seq;
+	mmu_seq = kvm->mmu_invalidate_seq;
 	smp_rmb();
 
 	arch_spin_lock(&kvm->mmu_lock.rlock.raw_lock);
diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
@@ -339,7 +339,7 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
 	unsigned long flags;
 
 	/* used to check for invalidations in progress */
-	mmu_seq = kvm->mmu_notifier_seq;
+	mmu_seq = kvm->mmu_invalidate_seq;
 	smp_rmb();
 
 	/*
@@ -460,7 +460,7 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
 	}
 
 	spin_lock(&kvm->mmu_lock);
-	if (mmu_notifier_retry(kvm, mmu_seq)) {
+	if (mmu_invalidate_retry(kvm, mmu_seq)) {
 		ret = -EAGAIN;
 		goto out;
 	}
diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c
@@ -666,7 +666,7 @@ int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu,
 		return ret;
 	}
 
-	mmu_seq = kvm->mmu_notifier_seq;
+	mmu_seq = kvm->mmu_invalidate_seq;
 
 	hfn = gfn_to_pfn_prot(kvm, gfn, is_write, &writable);
 	if (hfn == KVM_PFN_ERR_HWPOISON) {
@@ -686,7 +686,7 @@ int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu,
 
 	spin_lock(&kvm->mmu_lock);
 
-	if (mmu_notifier_retry(kvm, mmu_seq))
+	if (mmu_invalidate_retry(kvm, mmu_seq))
 		goto out_unlock;
 
 	if (writable) {
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
@@ -2914,7 +2914,7 @@ static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep)
 	 * If addresses are being invalidated, skip prefetching to avoid
 	 * accidentally prefetching those addresses.
 	 */
-	if (unlikely(vcpu->kvm->mmu_notifier_count))
+	if (unlikely(vcpu->kvm->mmu_invalidate_in_progress))
 		return;
 
 	__direct_pte_prefetch(vcpu, sp, sptep);
@@ -2928,7 +2928,7 @@ static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep)
  *
  * There are several ways to safely use this helper:
  *
- * - Check mmu_notifier_retry_hva() after grabbing the mapping level, before
+ * - Check mmu_invalidate_retry_hva() after grabbing the mapping level, before
  *   consuming it.  In this case, mmu_lock doesn't need to be held during the
  *   lookup, but it does need to be held while checking the MMU notifier.
  *
@@ -3056,7 +3056,7 @@ void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 		return;
 
 	/*
-	 * mmu_notifier_retry() was successful and mmu_lock is held, so
+	 * mmu_invalidate_retry() was successful and mmu_lock is held, so
 	 * the pmd can't be split from under us.
 	 */
 	fault->goal_level = fault->req_level;
@@ -4203,7 +4203,7 @@ static bool is_page_fault_stale(struct kvm_vcpu *vcpu,
 		return true;
 
 	return fault->slot &&
-	       mmu_notifier_retry_hva(vcpu->kvm, mmu_seq, fault->hva);
+	       mmu_invalidate_retry_hva(vcpu->kvm, mmu_seq, fault->hva);
 }
 
 static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
@@ -4227,7 +4227,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 	if (r)
 		return r;
 
-	mmu_seq = vcpu->kvm->mmu_notifier_seq;
+	mmu_seq = vcpu->kvm->mmu_invalidate_seq;
 	smp_rmb();
 
 	r = kvm_faultin_pfn(vcpu, fault);
@@ -6055,7 +6055,7 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
 
 	write_lock(&kvm->mmu_lock);
 
-	kvm_inc_notifier_count(kvm, gfn_start, gfn_end);
+	kvm_mmu_invalidate_begin(kvm, gfn_start, gfn_end);
 
 	flush = kvm_rmap_zap_gfn_range(kvm, gfn_start, gfn_end);
 
@@ -6069,7 +6069,7 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
 		kvm_flush_remote_tlbs_with_address(kvm, gfn_start,
 						   gfn_end - gfn_start);
 
-	kvm_dec_notifier_count(kvm, gfn_start, gfn_end);
+	kvm_mmu_invalidate_end(kvm, gfn_start, gfn_end);
 
 	write_unlock(&kvm->mmu_lock);
 }
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -589,7 +589,7 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw,
 	 * If addresses are being invalidated, skip prefetching to avoid
 	 * accidentally prefetching those addresses.
 	 */
-	if (unlikely(vcpu->kvm->mmu_notifier_count))
+	if (unlikely(vcpu->kvm->mmu_invalidate_in_progress))
 		return;
 
 	if (sp->role.direct)
@@ -838,7 +838,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 	else
 		fault->max_level = walker.level;
 
-	mmu_seq = vcpu->kvm->mmu_notifier_seq;
+	mmu_seq = vcpu->kvm->mmu_invalidate_seq;
 	smp_rmb();
 
 	r = kvm_faultin_pfn(vcpu, fault);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
@@ -765,10 +765,10 @@ struct kvm {
 
 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
 	struct mmu_notifier mmu_notifier;
-	unsigned long mmu_notifier_seq;
-	long mmu_notifier_count;
-	unsigned long mmu_notifier_range_start;
-	unsigned long mmu_notifier_range_end;
+	unsigned long mmu_invalidate_seq;
+	long mmu_invalidate_in_progress;
+	unsigned long mmu_invalidate_range_start;
+	unsigned long mmu_invalidate_range_end;
 #endif
 	struct list_head devices;
 	u64 manual_dirty_log_protect;
@@ -1357,10 +1357,10 @@ void kvm_mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc);
 void *kvm_mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc);
 #endif
 
-void kvm_inc_notifier_count(struct kvm *kvm, unsigned long start,
-				   unsigned long end);
-void kvm_dec_notifier_count(struct kvm *kvm, unsigned long start,
-				   unsigned long end);
+void kvm_mmu_invalidate_begin(struct kvm *kvm, unsigned long start,
+			      unsigned long end);
+void kvm_mmu_invalidate_end(struct kvm *kvm, unsigned long start,
+			    unsigned long end);
 
 long kvm_arch_dev_ioctl(struct file *filp,
 			unsigned int ioctl, unsigned long arg);
@@ -1907,42 +1907,44 @@ extern const struct kvm_stats_header kvm_vcpu_stats_header;
 extern const struct _kvm_stats_desc kvm_vcpu_stats_desc[];
 
 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
-static inline int mmu_notifier_retry(struct kvm *kvm, unsigned long mmu_seq)
+static inline int mmu_invalidate_retry(struct kvm *kvm, unsigned long mmu_seq)
 {
-	if (unlikely(kvm->mmu_notifier_count))
+	if (unlikely(kvm->mmu_invalidate_in_progress))
 		return 1;
 	/*
-	 * Ensure the read of mmu_notifier_count happens before the read
-	 * of mmu_notifier_seq.  This interacts with the smp_wmb() in
-	 * mmu_notifier_invalidate_range_end to make sure that the caller
-	 * either sees the old (non-zero) value of mmu_notifier_count or
-	 * the new (incremented) value of mmu_notifier_seq.
-	 * PowerPC Book3s HV KVM calls this under a per-page lock
-	 * rather than under kvm->mmu_lock, for scalability, so
-	 * can't rely on kvm->mmu_lock to keep things ordered.
+	 * Ensure the read of mmu_invalidate_in_progress happens before
+	 * the read of mmu_invalidate_seq.  This interacts with the
+	 * smp_wmb() in mmu_notifier_invalidate_range_end to make sure
+	 * that the caller either sees the old (non-zero) value of
+	 * mmu_invalidate_in_progress or the new (incremented) value of
+	 * mmu_invalidate_seq.
+	 *
+	 * PowerPC Book3s HV KVM calls this under a per-page lock rather
+	 * than under kvm->mmu_lock, for scalability, so can't rely on
+	 * kvm->mmu_lock to keep things ordered.
 	 */
 	smp_rmb();
-	if (kvm->mmu_notifier_seq != mmu_seq)
+	if (kvm->mmu_invalidate_seq != mmu_seq)
 		return 1;
 	return 0;
 }
 
-static inline int mmu_notifier_retry_hva(struct kvm *kvm,
-					 unsigned long mmu_seq,
-					 unsigned long hva)
+static inline int mmu_invalidate_retry_hva(struct kvm *kvm,
+					   unsigned long mmu_seq,
+					   unsigned long hva)
 {
 	lockdep_assert_held(&kvm->mmu_lock);
 	/*
-	 * If mmu_notifier_count is non-zero, then the range maintained by
-	 * kvm_mmu_notifier_invalidate_range_start contains all addresses that
-	 * might be being invalidated. Note that it may include some false
+	 * If mmu_invalidate_in_progress is non-zero, then the range maintained
+	 * by kvm_mmu_notifier_invalidate_range_start contains all addresses
+	 * that might be being invalidated. Note that it may include some false
 	 * positives, due to shortcuts when handing concurrent invalidations.
 	 */
-	if (unlikely(kvm->mmu_notifier_count) &&
-	    hva >= kvm->mmu_notifier_range_start &&
-	    hva < kvm->mmu_notifier_range_end)
+	if (unlikely(kvm->mmu_invalidate_in_progress) &&
+	    hva >= kvm->mmu_invalidate_range_start &&
+	    hva < kvm->mmu_invalidate_range_end)
 		return 1;
-	if (kvm->mmu_notifier_seq != mmu_seq)
+	if (kvm->mmu_invalidate_seq != mmu_seq)
 		return 1;
 	return 0;
 }
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c

Original file line number	Diff line number	Diff line change
`@@ -339,7 +339,7 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,`
`339`	`339`	`unsigned long flags;`
`340`	`340`
`341`	`341`	`/* used to check for invalidations in progress */`
`342`		`- mmu_seq = kvm->mmu_notifier_seq;`
	`342`	`+ mmu_seq = kvm->mmu_invalidate_seq;`
`343`	`343`	`smp_rmb();`
`344`	`344`
`345`	`345`	`/*`
`@@ -460,7 +460,7 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,`
`460`	`460`	`}`
`461`	`461`
`462`	`462`	`spin_lock(&kvm->mmu_lock);`
`463`		`- if (mmu_notifier_retry(kvm, mmu_seq)) {`
	`463`	`+ if (mmu_invalidate_retry(kvm, mmu_seq)) {`
`464`	`464`	`ret = -EAGAIN;`
`465`	`465`	`goto out;`
`466`	`466`	`}`