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>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index abda57f..475a122 100644 (file)
--- 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;

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ac4e83a..bd0da8f 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -146,6 +146,11 @@ struct kvm_vcpu {
  */
 #define KVM_MEM_MAX_NR_PAGES ((1UL << 31) - 1)
 
+struct kvm_lpage_info {
+       unsigned long rmap_pde;
+       int write_count;
+};
+
 struct kvm_memory_slot {
        gfn_t base_gfn;
        unsigned long npages;
@@ -153,10 +158,7 @@ struct kvm_memory_slot {
        unsigned long *rmap;
        unsigned long *dirty_bitmap;
        unsigned long *dirty_bitmap_head;
-       struct {
-               unsigned long rmap_pde;
-               int write_count;
-       } *lpage_info[KVM_NR_PAGE_SIZES - 1];
+       struct kvm_lpage_info *lpage_info[KVM_NR_PAGE_SIZES - 1];
        unsigned long userspace_addr;
        int user_alloc;
        int id;