Commit 7f42aa76 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
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KVM: x86/mmu: Consolidate open coded variants of memslot TLB flushes 



Replace open coded instances of kvm_arch_flush_remote_tlbs_memslot()'s
functionality with calls to the aforementioned function.  Update the
comment in kvm_arch_flush_remote_tlbs_memslot() to elaborate on how it
is used and why it asserts that slots_lock is held.

No functional change intended.

Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent cec37648

arch/x86/kvm/mmu/mmu.c

+9 −25
Original line number Diff line number Diff line
@@ -5862,13 +5862,6 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 
				      false);

	spin_unlock(&kvm->mmu_lock);



	/*

	 * kvm_mmu_slot_remove_write_access() and kvm_vm_ioctl_get_dirty_log()

	 * which do tlb flush out of mmu-lock should be serialized by

	 * kvm->slots_lock otherwise tlb flush would be missed.

	 */

	lockdep_assert_held(&kvm->slots_lock);



	/*

	 * We can flush all the TLBs out of the mmu lock without TLB

	 * corruption since we just change the spte from writable to
@@ -5881,8 +5874,7 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 
	 * on PT_WRITABLE_MASK anymore.

	 */

	if (flush)

		kvm_flush_remote_tlbs_with_address(kvm, memslot->base_gfn,

			memslot->npages);

		kvm_arch_flush_remote_tlbs_memslot(kvm, memslot);

}



static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm,
@@ -5938,8 +5930,11 @@ void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, 
					struct kvm_memory_slot *memslot)

{

	/*

	 * All the TLBs can be flushed out of mmu lock, see the comments in

	 * kvm_mmu_slot_remove_write_access().

	 * All current use cases for flushing the TLBs for a specific memslot

	 * are related to dirty logging, and 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_with_address(kvm, memslot->base_gfn,
@@ -5955,8 +5950,6 @@ void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 
	flush = slot_handle_leaf(kvm, memslot, __rmap_clear_dirty, false);

	spin_unlock(&kvm->mmu_lock);



	lockdep_assert_held(&kvm->slots_lock);



	/*

	 * It's also safe to flush TLBs out of mmu lock here as currently this

	 * function is only used for dirty logging, in which case flushing TLB
@@ -5964,8 +5957,7 @@ void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 
	 * dirty_bitmap.

	 */

	if (flush)

		kvm_flush_remote_tlbs_with_address(kvm, memslot->base_gfn,

				memslot->npages);

		kvm_arch_flush_remote_tlbs_memslot(kvm, memslot);

}

EXPORT_SYMBOL_GPL(kvm_mmu_slot_leaf_clear_dirty);
@@ -5979,12 +5971,8 @@ void kvm_mmu_slot_largepage_remove_write_access(struct kvm *kvm, 
					false);

	spin_unlock(&kvm->mmu_lock);



	/* see kvm_mmu_slot_remove_write_access */

	lockdep_assert_held(&kvm->slots_lock);



	if (flush)

		kvm_flush_remote_tlbs_with_address(kvm, memslot->base_gfn,

				memslot->npages);

		kvm_arch_flush_remote_tlbs_memslot(kvm, memslot);

}

EXPORT_SYMBOL_GPL(kvm_mmu_slot_largepage_remove_write_access);
@@ -5997,12 +5985,8 @@ void kvm_mmu_slot_set_dirty(struct kvm *kvm, 
	flush = slot_handle_all_level(kvm, memslot, __rmap_set_dirty, false);

	spin_unlock(&kvm->mmu_lock);



	lockdep_assert_held(&kvm->slots_lock);



	/* see kvm_mmu_slot_leaf_clear_dirty */

	if (flush)

		kvm_flush_remote_tlbs_with_address(kvm, memslot->base_gfn,

				memslot->npages);

		kvm_arch_flush_remote_tlbs_memslot(kvm, memslot);

}

EXPORT_SYMBOL_GPL(kvm_mmu_slot_set_dirty);

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