linux-kernel - [PATCH 06/12] KVM: MMU: cleanup __kvm_sync

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Date:	Wed, 24 Feb 2016 14:17:47 +0100
From:	Paolo Bonzini <pbonzini@...hat.com>
To:	linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:	yoshikawa_takuya_b1@....ntt.co.jp, guangrong.xiao@...ux.intel.com,
	mtosatti@...hat.com
Subject: [PATCH 06/12] KVM: MMU: cleanup __kvm_sync_page and its callers

Calling kvm_unlink_unsync_page in the middle of __kvm_sync_page makes
things unnecessarily tricky.  If kvm_mmu_prepare_zap_page is called,
it will call kvm_unlink_unsync_page too.  So kvm_unlink_unsync_page can
be called just as well at the beginning or the end of __kvm_sync_page...
which means that we might do it in kvm_sync_page too and remove the
parameter.

kvm_sync_page ends up being the same code that kvm_sync_pages used
to have before the previous patch.

Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
 arch/x86/kvm/mmu.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 240c0dbb140f..56fa1636c0cf 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1887,16 +1887,13 @@ static void kvm_mmu_commit_zap_page(struct kvm *kvm,
 
 /* @sp->gfn should be write-protected at the call site */
 static int __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
-			   struct list_head *invalid_list, bool clear_unsync)
+			   struct list_head *invalid_list)
 {
 	if (sp->role.cr4_pae != !!is_pae(vcpu)) {
 		kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list);
 		return 1;
 	}
 
-	if (clear_unsync)
-		kvm_unlink_unsync_page(vcpu->kvm, sp);
-
 	if (vcpu->arch.mmu.sync_page(vcpu, sp)) {
 		kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list);
 		return 1;
@@ -1926,7 +1923,7 @@ static int kvm_sync_page_transient(struct kvm_vcpu *vcpu,
 	LIST_HEAD(invalid_list);
 	int ret;
 
-	ret = __kvm_sync_page(vcpu, sp, &invalid_list, false);
+	ret = __kvm_sync_page(vcpu, sp, &invalid_list);
 	kvm_mmu_flush_or_zap(vcpu, &invalid_list, false, !ret);
 
 	return ret;
@@ -1942,7 +1939,8 @@ static void mmu_audit_disable(void) { }
 static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 			 struct list_head *invalid_list)
 {
-	return __kvm_sync_page(vcpu, sp, invalid_list, true);
+	kvm_unlink_unsync_page(vcpu->kvm, sp);
+	return __kvm_sync_page(vcpu, sp, invalid_list);
 }
 
 /* @gfn should be write-protected at the call site */
-- 
1.8.3.1