Commit 7d919c7a authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
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KVM: x86/mmu: Refactor the zap loop for recovering NX lpages 



Refactor the zap loop in kvm_recover_nx_lpages() to be a for loop that
iterates on to_zap and drop the !to_zap check that leads to the in-loop
calling of kvm_mmu_commit_zap_page().  The in-loop commit when to_zap
hits zero is superfluous now that there's an unconditional commit after
the loop to handle the case where lpage_disallowed_mmu_pages is emptied.

Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200923183735.584-3-sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent e8950569

arch/x86/kvm/mmu/mmu.c

+6 −4
Original line number Diff line number Diff line
@@ -6375,7 +6375,10 @@ static void kvm_recover_nx_lpages(struct kvm *kvm) 


	ratio = READ_ONCE(nx_huge_pages_recovery_ratio);

	to_zap = ratio ? DIV_ROUND_UP(kvm->stat.nx_lpage_splits, ratio) : 0;

	while (to_zap && !list_empty(&kvm->arch.lpage_disallowed_mmu_pages)) {

	for ( ; to_zap; --to_zap) {

		if (list_empty(&kvm->arch.lpage_disallowed_mmu_pages))

			break;



		/*

		 * We use a separate list instead of just using active_mmu_pages

		 * because the number of lpage_disallowed pages is expected to
@@ -6388,9 +6391,8 @@ static void kvm_recover_nx_lpages(struct kvm *kvm) 
		kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list);

		WARN_ON_ONCE(sp->lpage_disallowed);



		if (!--to_zap || need_resched() || spin_needbreak(&kvm->mmu_lock)) {

		if (need_resched() || spin_needbreak(&kvm->mmu_lock)) {

			kvm_mmu_commit_zap_page(kvm, &invalid_list);

			if (to_zap)

			cond_resched_lock(&kvm->mmu_lock);

		}

	}