[PATCH 10/11] KVM: MMU: simplify mmu_need_write_protect

Xiao Guangrong
2016-02-24T10:00:02Z

Now, all non-leaf shadow page are page tracked, if gfn is not tracked
there is no non-leaf shadow page of gfn is existed, we can directly
make the shadow page of gfn to unsync

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
---
arch/x86/kvm/mmu.c | 29 +++++++----------------------
1 file changed, 7 insertions(+), 22 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 74684b2..ddf67e1 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2444,7 +2444,7 @@ int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
}
EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page);

-static void __kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
+static void kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
{
trace_kvm_mmu_unsync_page(sp);
++vcpu->kvm->stat.mmu_unsync;
@@ -2453,39 +2453,24 @@ static void __kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
kvm_mmu_mark_parents_unsync(sp);
}

-static void kvm_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn)
-{
- struct kvm_mmu_page *s;
-
- for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn) {
- if (s->unsync)
- continue;
- WARN_ON(s->role.level != PT_PAGE_TABLE_LEVEL);
- __kvm_unsync_page(vcpu, s);
- }
-}
-
static bool mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
bool can_unsync)
{
- struct kvm_mmu_page *s;
- bool need_unsync = false;
+ struct kvm_mmu_page *sp;

if (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_WRITE))
return true;

- for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn) {
+ for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn) {
if (!can_unsync)
return true;

- if (s->role.level != PT_PAGE_TABLE_LEVEL)
- return true;
+ if (sp->unsync)
+ continue;

- if (!s->unsync)
- need_unsync = true;
+ WARN_ON(sp->role.level != PT_PAGE_TABLE_LEVEL);
+ kvm_unsync_page(vcpu, sp);
}
- if (need_unsync)
- kvm_unsync_pages(vcpu, gfn);

return false;
}
--
1.8.3.1