Re: [PATCH v6 04/11] KVM: Move kvm_arch_flush_remote_tlbs_memslot() to common code

Shaoqin Huang <shahuang@xxxxxxxxxx> · Tue, 18 Jul 2023 10:47:11 +0800

On 7/15/23 08:53, Raghavendra Rao Ananta wrote:
From: David Matlack <dmatlack@xxxxxxxxxx>

Move kvm_arch_flush_remote_tlbs_memslot() to common code and drop
"arch_" from the name. kvm_arch_flush_remote_tlbs_memslot() is just a
range-based TLB invalidation where the range is defined by the memslot.
Now that kvm_flush_remote_tlbs_range() can be called from common code we
can just use that and drop a bunch of duplicate code from the arch
directories.

Note this adds a lockdep assertion for slots_lock being held when
calling kvm_flush_remote_tlbs_memslot(), which was previously only
asserted on x86. MIPS has calls to kvm_flush_remote_tlbs_memslot(),
but they all hold the slots_lock, so the lockdep assertion continues to
hold true.

Also drop the CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT ifdef gating
kvm_flush_remote_tlbs_memslot(), since it is no longer necessary.

Signed-off-by: David Matlack <dmatlack@xxxxxxxxxx>
Signed-off-by: Raghavendra Rao Ananta <rananta@xxxxxxxxxx>
Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>
Reviewed-by: Shaoqin Huang <shahuang@xxxxxxxxxx>
---
  arch/arm64/kvm/arm.c     |  6 ------
  arch/mips/kvm/mips.c     | 10 ++--------
  arch/riscv/kvm/mmu.c     |  6 ------
  arch/x86/kvm/mmu/mmu.c   | 16 +---------------
  arch/x86/kvm/x86.c       |  2 +-
  include/linux/kvm_host.h |  7 +++----
  virt/kvm/kvm_main.c      | 18 ++++++++++++++++--
  7 files changed, 23 insertions(+), 42 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index c2c14059f6a8..ed7bef4d970b 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1525,12 +1525,6 @@ void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
  
  }
  
-void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
-					const struct kvm_memory_slot *memslot)
-{
-	kvm_flush_remote_tlbs(kvm);
-}
-
  static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm,
  					struct kvm_arm_device_addr *dev_addr)
  {
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 4b7bc39a4173..231ac052b506 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -199,7 +199,7 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
  	/* Flush slot from GPA */
  	kvm_mips_flush_gpa_pt(kvm, slot->base_gfn,
  			      slot->base_gfn + slot->npages - 1);
-	kvm_arch_flush_remote_tlbs_memslot(kvm, slot);
+	kvm_flush_remote_tlbs_memslot(kvm, slot);
  	spin_unlock(&kvm->mmu_lock);
  }
  
@@ -235,7 +235,7 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
  		needs_flush = kvm_mips_mkclean_gpa_pt(kvm, new->base_gfn,
  					new->base_gfn + new->npages - 1);
  		if (needs_flush)
-			kvm_arch_flush_remote_tlbs_memslot(kvm, new);
+			kvm_flush_remote_tlbs_memslot(kvm, new);
  		spin_unlock(&kvm->mmu_lock);
  	}
  }
@@ -987,12 +987,6 @@ int kvm_arch_flush_remote_tlbs(struct kvm *kvm)
  	return 1;
  }
  
-void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
-					const struct kvm_memory_slot *memslot)
-{
-	kvm_flush_remote_tlbs(kvm);
-}
-
  int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
  {
  	int r;
diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c
index f2eb47925806..97e129620686 100644
--- a/arch/riscv/kvm/mmu.c
+++ b/arch/riscv/kvm/mmu.c
@@ -406,12 +406,6 @@ void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
  {
  }
  
-void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
-					const struct kvm_memory_slot *memslot)
-{
-	kvm_flush_remote_tlbs(kvm);
-}
-
  void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free)
  {
  }
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index aaa5e336703a..b320a4254a2b 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -6669,7 +6669,7 @@ static void kvm_rmap_zap_collapsible_sptes(struct kvm *kvm,
  	 */
  	if (walk_slot_rmaps(kvm, slot, kvm_mmu_zap_collapsible_spte,
  			    PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL - 1, true))
-		kvm_arch_flush_remote_tlbs_memslot(kvm, slot);
+		kvm_flush_remote_tlbs_memslot(kvm, slot);
  }
  
  void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm,
@@ -6688,20 +6688,6 @@ void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm,
  	}
  }
  
-void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
-					const struct kvm_memory_slot *memslot)
-{
-	/*
-	 * All current use cases for flushing the TLBs for a specific memslot
-	 * related to dirty logging, and many do the TLB flush out of mmu_lock.
-	 * The interaction between the various operations on memslot must be
-	 * serialized by slots_locks to ensure the TLB flush from one operation
-	 * is observed by any other operation on the same memslot.
-	 */
-	lockdep_assert_held(&kvm->slots_lock);
-	kvm_flush_remote_tlbs_range(kvm, memslot->base_gfn, memslot->npages);
-}
-
  void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm,
  				   const struct kvm_memory_slot *memslot)
  {
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a6b9bea62fb8..faeb2e307b36 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -12751,7 +12751,7 @@ static void kvm_mmu_slot_apply_flags(struct kvm *kvm,
  		 * See is_writable_pte() for more details (the case involving
  		 * access-tracked SPTEs is particularly relevant).
  		 */
-		kvm_arch_flush_remote_tlbs_memslot(kvm, new);
+		kvm_flush_remote_tlbs_memslot(kvm, new);
  	}
  }
  
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index a731967b24ff..45899ce9ed31 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1360,6 +1360,8 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu, bool yield_to_kernel_mode);
  
  void kvm_flush_remote_tlbs(struct kvm *kvm);
  void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t gfn, u64 pages);
+void kvm_flush_remote_tlbs_memslot(struct kvm *kvm,
+				   const struct kvm_memory_slot *memslot);
  
  #ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE
  int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min);
@@ -1388,10 +1390,7 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
  					unsigned long mask);
  void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot);
  
-#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
-void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
-					const struct kvm_memory_slot *memslot);
-#else /* !CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */
+#ifndef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
  int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log);
  int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log,
  		      int *is_dirty, struct kvm_memory_slot **memslot);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 804470fccac7..58213cc4b9b9 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -379,6 +379,20 @@ void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t gfn, u64 pages)
  	kvm_flush_remote_tlbs(kvm);
  }
  
+void kvm_flush_remote_tlbs_memslot(struct kvm *kvm,
+				   const struct kvm_memory_slot *memslot)
+{
+	/*
+	 * All current use cases for flushing the TLBs for a specific memslot
+	 * related to dirty logging, and many do the TLB flush out of mmu_lock.
+	 * The interaction between the various operations on memslot must be
+	 * serialized by slots_locks to ensure the TLB flush from one operation
+	 * is observed by any other operation on the same memslot.
+	 */
+	lockdep_assert_held(&kvm->slots_lock);
+	kvm_flush_remote_tlbs_range(kvm, memslot->base_gfn, memslot->npages);
+}
+
  static void kvm_flush_shadow_all(struct kvm *kvm)
  {
  	kvm_arch_flush_shadow_all(kvm);
@@ -2191,7 +2205,7 @@ static int kvm_get_dirty_log_protect(struct kvm *kvm, struct kvm_dirty_log *log)
  	}
  
  	if (flush)
-		kvm_arch_flush_remote_tlbs_memslot(kvm, memslot);
+		kvm_flush_remote_tlbs_memslot(kvm, memslot);
  
  	if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n))
  		return -EFAULT;
@@ -2308,7 +2322,7 @@ static int kvm_clear_dirty_log_protect(struct kvm *kvm,
  	KVM_MMU_UNLOCK(kvm);
  
  	if (flush)
-		kvm_arch_flush_remote_tlbs_memslot(kvm, memslot);
+		kvm_flush_remote_tlbs_memslot(kvm, memslot);
  
  	return 0;
  }

--
Shaoqin







