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.

Reviewed-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 56be337..88a1a79 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1917,16 +1917,13 @@ 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;
@@ -1956,7 +1953,7 @@ 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;
@@ -1972,7 +1969,8 @@ 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 */