KVM: MMU: split kvm_sync_page() function

Split kvm_sync_page() into kvm_sync_page() and kvm_sync_page_transient()
to clarify the code address Avi's suggestion

kvm_sync_page_transient() function only update shadow page but not mark
it sync and not write protect sp->gfn. it will be used by later patch

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 5c9d6df0113e1d48588df889b058d4f1f7af753d..ef5d140a2705aa3dc165150f0183f8453d5c40fb 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1199,16 +1199,20 @@ static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 
 static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp);
 
-static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
+static int __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
+                          bool clear_unsync)
 {
        if (sp->role.cr4_pae != !!is_pae(vcpu)) {
                kvm_mmu_zap_page(vcpu->kvm, sp);
                return 1;
        }
 
-       if (rmap_write_protect(vcpu->kvm, sp->gfn))
-               kvm_flush_remote_tlbs(vcpu->kvm);
-       kvm_unlink_unsync_page(vcpu->kvm, sp);
+       if (clear_unsync) {
+               if (rmap_write_protect(vcpu->kvm, sp->gfn))
+                       kvm_flush_remote_tlbs(vcpu->kvm);
+               kvm_unlink_unsync_page(vcpu->kvm, sp);
+       }
+
        if (vcpu->arch.mmu.sync_page(vcpu, sp)) {
                kvm_mmu_zap_page(vcpu->kvm, sp);
                return 1;
@@ -1218,6 +1222,23 @@ static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
        return 0;
 }
 
+static void mmu_convert_notrap(struct kvm_mmu_page *sp);
+static int kvm_sync_page_transient(struct kvm_vcpu *vcpu,
+                                  struct kvm_mmu_page *sp)
+{
+       int ret;
+
+       ret = __kvm_sync_page(vcpu, sp, false);
+       if (!ret)
+               mmu_convert_notrap(sp);
+       return ret;
+}
+
+static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
+{
+       return __kvm_sync_page(vcpu, sp, true);
+}
+
 struct mmu_page_path {
        struct kvm_mmu_page *parent[PT64_ROOT_LEVEL-1];
        unsigned int idx[PT64_ROOT_LEVEL-1];