KVM: MMU: cleanup pte write path

This patch does:
- call vcpu->arch.mmu.update_pte directly
- use gfn_to_pfn_atomic in update_pte path

The suggestion is from Avi.

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

1 files changed, 7 insertions, 5 deletions

diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 86eb8160bcb..751405097d8 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -325,7 +325,7 @@ no_present:
 }
 
 static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
-                              u64 *spte, const void *pte)
+                              u64 *spte, const void *pte, unsigned long mmu_seq)
 {
         pt_element_t gpte;
         unsigned pte_access;
@@ -337,12 +337,14 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 
         pgprintk("%s: gpte %llx spte %p\n", __func__, (u64)gpte, spte);
         pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte);
-        pfn = vcpu->arch.update_pte.pfn;
-        if (is_error_pfn(pfn))
+        pfn = gfn_to_pfn_atomic(vcpu->kvm, gpte_to_gfn(gpte));
+        if (is_error_pfn(pfn)) {
+                kvm_release_pfn_clean(pfn);
                 return;
-        if (mmu_notifier_retry(vcpu, vcpu->arch.update_pte.mmu_seq))
+        }
+        if (mmu_notifier_retry(vcpu, mmu_seq))
                 return;
-        kvm_get_pfn(pfn);
+
         /*
          * we call mmu_set_spte() with host_writable = true beacuse that
          * vcpu->arch.update_pte.pfn was fetched from get_user_pages(write = 1).