[PATCH] kvm mmu: optimizations when tdp is in use

[Gui Jianfeng <guijianfeng@cn.fujitsu.com>]

In case of using tdp, checking write protected page isn't needed and
quadrant also no need to be calculated.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
---
 arch/x86/kvm/mmu.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 0bb9f17..ce4bbd3 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -495,10 +495,13 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn)
 	max_level = kvm_x86_ops->get_lpage_level() < host_level ?
 		kvm_x86_ops->get_lpage_level() : host_level;
 
+	if (tdp_enabled)
+		goto done;
+
 	for (level = PT_DIRECTORY_LEVEL; level <= max_level; ++level)
 		if (has_wrprotected_page(vcpu->kvm, large_gfn, level))
 			break;
-
+done:
 	return level - 1;
 }
 
@@ -1346,7 +1349,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
 	if (role.direct)
 		role.cr4_pae = 0;
 	role.access = access;
-	if (vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) {
+	if (!tdp_enabled && vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) {
 		quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
 		quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
 		role.quadrant = quadrant;
-- 
1.6.5.2