linux-kernel - [PATCH 07/12] KVM: MMU: invert return value of FNAME(sync_page) and *kvm_sync

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Message-Id: <1456319873-34182-8-git-send-email-pbonzini@redhat.com>
Date:	Wed, 24 Feb 2016 14:17:48 +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 07/12] KVM: MMU: invert return value of FNAME(sync_page) and *kvm_sync_page*

Return true if the page was synced (and the TLB must be flushed)
and false if the page was zapped.

Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
 arch/x86/kvm/mmu.c         | 29 +++++++++++++----------------
 arch/x86/kvm/paging_tmpl.h |  4 ++--
 2 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 56fa1636c0cf..e3215cc89d97 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1886,20 +1886,20 @@ static void kvm_mmu_commit_zap_page(struct kvm *kvm,
 		if ((_sp)->role.direct || (_sp)->role.invalid) {} else
 
 /* @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)
+static bool __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
+			    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;
+		return false;
 	}
 
-	if (vcpu->arch.mmu.sync_page(vcpu, sp)) {
+	if (vcpu->arch.mmu.sync_page(vcpu, sp) == 0) {
 		kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list);
-		return 1;
+		return false;
 	}
 
-	return 0;
+	return true;
 }
 
 static void kvm_mmu_flush_or_zap(struct kvm_vcpu *vcpu,
@@ -1917,14 +1917,14 @@ static void kvm_mmu_flush_or_zap(struct kvm_vcpu *vcpu,
 		kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
 }
 
-static int kvm_sync_page_transient(struct kvm_vcpu *vcpu,
-				   struct kvm_mmu_page *sp)
+static bool kvm_sync_page_transient(struct kvm_vcpu *vcpu,
+				    struct kvm_mmu_page *sp)
 {
 	LIST_HEAD(invalid_list);
 	int ret;
 
 	ret = __kvm_sync_page(vcpu, sp, &invalid_list);
-	kvm_mmu_flush_or_zap(vcpu, &invalid_list, false, !ret);
+	kvm_mmu_flush_or_zap(vcpu, &invalid_list, false, ret);
 
 	return ret;
 }
@@ -1936,7 +1936,7 @@ static void kvm_mmu_audit(struct kvm_vcpu *vcpu, int point) { }
 static void mmu_audit_disable(void) { }
 #endif
 
-static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
+static bool kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 			 struct list_head *invalid_list)
 {
 	kvm_unlink_unsync_page(vcpu->kvm, sp);
@@ -1955,8 +1955,7 @@ static void kvm_sync_pages(struct kvm_vcpu *vcpu,  gfn_t gfn)
 			continue;
 
 		WARN_ON(s->role.level != PT_PAGE_TABLE_LEVEL);
-		if (!kvm_sync_page(vcpu, s, &invalid_list))
-			flush = true;
+		flush |= kvm_sync_page(vcpu, s, &invalid_list);
 	}
 
 	kvm_mmu_flush_or_zap(vcpu, &invalid_list, false, flush);
@@ -2054,9 +2053,7 @@ static void mmu_sync_children(struct kvm_vcpu *vcpu,
 			kvm_flush_remote_tlbs(vcpu->kvm);
 
 		for_each_sp(pages, sp, parents, i) {
-			if (!kvm_sync_page(vcpu, sp, &invalid_list))
-				flush = true;
-
+			flush |= kvm_sync_page(vcpu, sp, &invalid_list);
 			mmu_pages_clear_parents(&parents);
 		}
 		kvm_mmu_flush_or_zap(vcpu, &invalid_list, false, flush);
@@ -2115,7 +2112,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
 		if (sp->role.word != role.word)
 			continue;
 
-		if (sp->unsync && kvm_sync_page_transient(vcpu, sp))
+		if (sp->unsync && !kvm_sync_page_transient(vcpu, sp))
 			break;
 
 		if (sp->unsync_children)
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 05827ff7bd2e..2e019b103249 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -938,7 +938,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
 
 		if (kvm_vcpu_read_guest_atomic(vcpu, pte_gpa, &gpte,
 					       sizeof(pt_element_t)))
-			return -EINVAL;
+			return 0;
 
 		if (FNAME(prefetch_invalid_gpte)(vcpu, sp, &sp->spt[i], gpte)) {
 			vcpu->kvm->tlbs_dirty++;
@@ -970,7 +970,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
 			 host_writable);
 	}
 
-	return !nr_present;
+	return nr_present;
 }
 
 #undef pt_element_t
-- 
1.8.3.1