KVM: Unify kvm_mmu_pre_write() and kvm_mmu_post_write()

Instead of calling two functions and repeating expensive checks, call one
function and provide it with before/after information.

Signed-off-by: Avi Kivity <avi@qumranet.com>

3 files changed, 8 insertions, 11 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 7facebd1911d..11c519e8085a 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -525,8 +525,8 @@ int kvm_write_guest(struct kvm_vcpu *vcpu,
 
 unsigned long segment_base(u16 selector);
 
-void kvm_mmu_pre_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes);
-void kvm_mmu_post_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes);
+void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
+                       const u8 *old, const u8 *new, int bytes);
 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva);
 void kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu);
 
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 7d682586423b..b6ad9c6f2efe 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -1071,18 +1071,18 @@ static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
 {
         struct page *page;
         void *virt;
+        unsigned offset = offset_in_page(gpa);
 
         if (((gpa + bytes - 1) >> PAGE_SHIFT) != (gpa >> PAGE_SHIFT))
                 return 0;
         page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
         if (!page)
                 return 0;
-        kvm_mmu_pre_write(vcpu, gpa, bytes);
         mark_page_dirty(vcpu->kvm, gpa >> PAGE_SHIFT);
         virt = kmap_atomic(page, KM_USER0);
+        kvm_mmu_pte_write(vcpu, gpa, virt + offset, val, bytes);
         memcpy(virt + offset_in_page(gpa), val, bytes);
         kunmap_atomic(virt, KM_USER0);
-        kvm_mmu_post_write(vcpu, gpa, bytes);
         return 1;
 }
 
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index 2277b7cd118c..b3a83ef2cf07 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -1118,7 +1118,7 @@ out:
         return r;
 }
 
-static void mmu_pre_write_zap_pte(struct kvm_vcpu *vcpu,
+static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
                                   struct kvm_mmu_page *page,
                                   u64 *spte)
 {
@@ -1137,7 +1137,8 @@ static void mmu_pre_write_zap_pte(struct kvm_vcpu *vcpu,
         *spte = 0;
 }
 
-void kvm_mmu_pre_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes)
+void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
+                       const u8 *old, const u8 *new, int bytes)
 {
         gfn_t gfn = gpa >> PAGE_SHIFT;
         struct kvm_mmu_page *page;
@@ -1206,16 +1207,12 @@ void kvm_mmu_pre_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes)
                 spte = __va(page->page_hpa);
                 spte += page_offset / sizeof(*spte);
                 while (npte--) {
-                        mmu_pre_write_zap_pte(vcpu, page, spte);
+                        mmu_pte_write_zap_pte(vcpu, page, spte);
                         ++spte;
                 }
         }
 }
 
-void kvm_mmu_post_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes)
-{
-}
-
 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
 {
         gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);