KVM: MMU: Make the way of accessing lpage_info more generic

Large page information has two elements but one of them, write_count, alone
is accessed by a helper function.

This patch replaces this helper function with more generic one which returns
newly named kvm_lpage_info structure and use it to access the other element
rmap_pde.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 25 insertions, 29 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index abda57fac659..475a1225f6ec 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -477,46 +477,46 @@ static void kvm_mmu_page_set_gfn(struct kvm_mmu_page *sp, int index, gfn_t gfn)
 }
 
 /*
- * Return the pointer to the largepage write count for a given
- * gfn, handling slots that are not large page aligned.
+ * Return the pointer to the large page information for a given gfn,
+ * handling slots that are not large page aligned.
  */
-static int *slot_largepage_idx(gfn_t gfn,
-                               struct kvm_memory_slot *slot,
-                               int level)
+static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn,
+                                              struct kvm_memory_slot *slot,
+                                              int level)
 {
         unsigned long idx;
 
         idx = (gfn >> KVM_HPAGE_GFN_SHIFT(level)) -
               (slot->base_gfn >> KVM_HPAGE_GFN_SHIFT(level));
-        return &slot->lpage_info[level - 2][idx].write_count;
+        return &slot->lpage_info[level - 2][idx];
 }
 
 static void account_shadowed(struct kvm *kvm, gfn_t gfn)
 {
         struct kvm_memory_slot *slot;
-        int *write_count;
+        struct kvm_lpage_info *linfo;
         int i;
 
         slot = gfn_to_memslot(kvm, gfn);
         for (i = PT_DIRECTORY_LEVEL;
              i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
-                write_count   = slot_largepage_idx(gfn, slot, i);
-                *write_count += 1;
+                linfo = lpage_info_slot(gfn, slot, i);
+                linfo->write_count += 1;
         }
 }
 
 static void unaccount_shadowed(struct kvm *kvm, gfn_t gfn)
 {
         struct kvm_memory_slot *slot;
-        int *write_count;
+        struct kvm_lpage_info *linfo;
         int i;
 
         slot = gfn_to_memslot(kvm, gfn);
         for (i = PT_DIRECTORY_LEVEL;
              i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
-                write_count   = slot_largepage_idx(gfn, slot, i);
-                *write_count -= 1;
-                WARN_ON(*write_count < 0);
+                linfo = lpage_info_slot(gfn, slot, i);
+                linfo->write_count -= 1;
+                WARN_ON(linfo->write_count < 0);
         }
 }
 
@@ -525,12 +525,12 @@ static int has_wrprotected_page(struct kvm *kvm,
                                 int level)
 {
         struct kvm_memory_slot *slot;
-        int *largepage_idx;
+        struct kvm_lpage_info *linfo;
 
         slot = gfn_to_memslot(kvm, gfn);
         if (slot) {
-                largepage_idx = slot_largepage_idx(gfn, slot, level);
-                return *largepage_idx;
+                linfo = lpage_info_slot(gfn, slot, level);
+                return linfo->write_count;
         }
 
         return 1;
@@ -585,16 +585,15 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn)
 static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn, int level)
 {
         struct kvm_memory_slot *slot;
-        unsigned long idx;
+        struct kvm_lpage_info *linfo;
 
         slot = gfn_to_memslot(kvm, gfn);
         if (likely(level == PT_PAGE_TABLE_LEVEL))
                 return &slot->rmap[gfn - slot->base_gfn];
 
-        idx = (gfn >> KVM_HPAGE_GFN_SHIFT(level)) -
-                (slot->base_gfn >> KVM_HPAGE_GFN_SHIFT(level));
+        linfo = lpage_info_slot(gfn, slot, level);
 
-        return &slot->lpage_info[level - 2][idx].rmap_pde;
+        return &linfo->rmap_pde;
 }
 
 /*
@@ -882,19 +881,16 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
                 end = start + (memslot->npages << PAGE_SHIFT);
                 if (hva >= start && hva < end) {
                         gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
+                        gfn_t gfn = memslot->base_gfn + gfn_offset;
 
                         ret = handler(kvm, &memslot->rmap[gfn_offset], data);
 
                         for (j = 0; j < KVM_NR_PAGE_SIZES - 1; ++j) {
-                                unsigned long idx;
-                                int sh;
-
-                                sh = KVM_HPAGE_GFN_SHIFT(PT_DIRECTORY_LEVEL+j);
-                                idx = ((memslot->base_gfn+gfn_offset) >> sh) -
-                                        (memslot->base_gfn >> sh);
-                                ret |= handler(kvm,
-                                        &memslot->lpage_info[j][idx].rmap_pde,
-                                        data);
+                                struct kvm_lpage_info *linfo;
+
+                                linfo = lpage_info_slot(gfn, memslot,
+                                                        PT_DIRECTORY_LEVEL + j);
+                                ret |= handler(kvm, &linfo->rmap_pde, data);
                         }
                         trace_kvm_age_page(hva, memslot, ret);
                         retval |= ret;