Commit a1419f8b authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86: Fold "write-protect large" use case into generic write-protect 



Drop kvm_mmu_slot_largepage_remove_write_access() and refactor its sole
caller to use kvm_mmu_slot_remove_write_access().  Remove the now-unused
slot_handle_large_level() and slot_handle_all_level() helpers.

No functional change intended.

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20210213005015.1651772-14-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent b6e16ae5

arch/x86/kvm/mmu/mmu.c

+0 −32
Original line number Diff line number Diff line
@@ -5204,22 +5204,6 @@ slot_handle_level(struct kvm *kvm, struct kvm_memory_slot *memslot, 
			lock_flush_tlb);

}



static __always_inline bool

slot_handle_all_level(struct kvm *kvm, struct kvm_memory_slot *memslot,

		      slot_level_handler fn, bool lock_flush_tlb)

{

	return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K,

				 KVM_MAX_HUGEPAGE_LEVEL, lock_flush_tlb);

}



static __always_inline bool

slot_handle_large_level(struct kvm *kvm, struct kvm_memory_slot *memslot,

			slot_level_handler fn, bool lock_flush_tlb)

{

	return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K + 1,

				 KVM_MAX_HUGEPAGE_LEVEL, lock_flush_tlb);

}



static __always_inline bool

slot_handle_leaf(struct kvm *kvm, struct kvm_memory_slot *memslot,

		 slot_level_handler fn, bool lock_flush_tlb)
@@ -5584,22 +5568,6 @@ void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 
		kvm_arch_flush_remote_tlbs_memslot(kvm, memslot);

}



void kvm_mmu_slot_largepage_remove_write_access(struct kvm *kvm,

					struct kvm_memory_slot *memslot)

{

	bool flush;



	write_lock(&kvm->mmu_lock);

	flush = slot_handle_large_level(kvm, memslot, slot_rmap_write_protect,

					false);

	if (is_tdp_mmu_enabled(kvm))

		flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, PG_LEVEL_2M);

	write_unlock(&kvm->mmu_lock);



	if (flush)

		kvm_arch_flush_remote_tlbs_memslot(kvm, memslot);

}



void kvm_mmu_zap_all(struct kvm *kvm)

{

	struct kvm_mmu_page *sp, *node;

arch/x86/kvm/x86.c

+17 −15
Original line number Diff line number Diff line
@@ -10829,24 +10829,25 @@ static void kvm_mmu_slot_apply_flags(struct kvm *kvm, 
		 */

		kvm_mmu_zap_collapsible_sptes(kvm, new);

	} else {

		/* By default, write-protect everything to log writes. */

		int level = PG_LEVEL_4K;



		if (kvm_x86_ops.cpu_dirty_log_size) {

			/*

		 * Large sptes are write-protected so they can be split on first

		 * write. New large sptes cannot be created for this slot until

		 * the end of the logging. See the comments in fast_page_fault().

		 *

		 * For small sptes, nothing is done if the dirty log is in the

		 * initial-all-set state.  Otherwise, depending on whether pml

		 * is enabled the D-bit or the W-bit will be cleared.

			 * Clear all dirty bits, unless pages are treated as

			 * dirty from the get-go.

			 */

		if (kvm_x86_ops.cpu_dirty_log_size) {

			if (!kvm_dirty_log_manual_protect_and_init_set(kvm))

				kvm_mmu_slot_leaf_clear_dirty(kvm, new);

			kvm_mmu_slot_largepage_remove_write_access(kvm, new);

		} else {

			int level =

				kvm_dirty_log_manual_protect_and_init_set(kvm) ?

				PG_LEVEL_2M : PG_LEVEL_4K;



			/*

			 * Write-protect large pages on write so that dirty

			 * logging happens at 4k granularity.  No need to

			 * write-protect small SPTEs since write accesses are

			 * logged by the CPU via dirty bits.

			 */

			level = PG_LEVEL_2M;

		} else if (kvm_dirty_log_manual_protect_and_init_set(kvm)) {

			/*

			 * If we're with initial-all-set, we don't need

			 * to write protect any small page because
@@ -10855,8 +10856,9 @@ static void kvm_mmu_slot_apply_flags(struct kvm *kvm, 
			 * so that the page split can happen lazily on

			 * the first write to the huge page.

			 */

			kvm_mmu_slot_remove_write_access(kvm, new, level);

			level = PG_LEVEL_2M;

		}

		kvm_mmu_slot_remove_write_access(kvm, new, level);

	}

}