[PATCH 5/9] KVM: MMU: fask check write-protect for direct mmu

[Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>]

If it have no indirect shadow pages we need not protect any gfn,
this is always true for direct mmu without nested

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
---
 arch/x86/kvm/mmu.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 28b12e2..a846a9c 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2294,6 +2294,9 @@ static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
 	struct hlist_node *node;
 	bool need_unsync = false;

+	if (!vcpu->kvm->arch.indirect_shadow_pages)
+		return 0;
+
 	for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn, node) {
 		if (!can_unsync)
 			return 1;
-- 
1.7.7.6