From: Xiao Guangrong <guangrong.x...@linux.intel.com>

It is used to clean up the code between kvm_handle_hva_range and
slot_handle_level, also it will be used by later patch

Signed-off-by: Xiao Guangrong <guangrong.x...@linux.intel.com>
---
 arch/x86/kvm/mmu.c | 144 ++++++++++++++++++++++++++++++++++++-----------------
 1 file changed, 99 insertions(+), 45 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 4d98c6c..fea1e83 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1417,6 +1417,63 @@ restart:
        return 0;
 }
 
+struct slot_rmap_walker {
+       /* input fields. */
+       struct kvm_memory_slot *slot;
+       gfn_t start_gfn;
+       gfn_t end_gfn;
+       int start_level;
+       int end_level;
+
+       /* output fields. */
+       gfn_t gfn;
+       unsigned long *rmap;
+       int level;
+
+       /* private field. */
+       unsigned long *end_rmap;
+};
+
+static void rmap_walk_init_level(struct slot_rmap_walker *walker, int level)
+{
+       struct kvm_memory_slot *slot = walker->slot;
+
+       walker->level = level;
+       walker->gfn = walker->start_gfn;
+       walker->rmap = __gfn_to_rmap(walker->gfn, walker->level, slot);
+       walker->end_rmap = __gfn_to_rmap(walker->end_gfn, walker->level, slot);
+}
+
+static void slot_rmap_walk_init(struct slot_rmap_walker *walker)
+{
+       rmap_walk_init_level(walker, walker->start_level);
+}
+
+static bool slot_rmap_walk_okay(struct slot_rmap_walker *walker)
+{
+       return !!walker->rmap;
+}
+
+static void slot_rmap_walk_next(struct slot_rmap_walker *walker)
+{
+       if (++walker->rmap <= walker->end_rmap) {
+               walker->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(walker->level));
+               return;
+       }
+
+       if (++walker->level > walker->end_level) {
+               walker->rmap = NULL;
+               return;
+       }
+
+       rmap_walk_init_level(walker, walker->level);
+}
+
+#define for_each_slot_rmap(_walker_)                           \
+               for (slot_rmap_walk_init(_walker_);             \
+                       slot_rmap_walk_okay(_walker_);          \
+                               slot_rmap_walk_next(_walker_))
+
 static int kvm_handle_hva_range(struct kvm *kvm,
                                unsigned long start,
                                unsigned long end,
@@ -1428,10 +1485,10 @@ static int kvm_handle_hva_range(struct kvm *kvm,
                                               int level,
                                               unsigned long data))
 {
-       int j;
-       int ret = 0;
        struct kvm_memslots *slots;
        struct kvm_memory_slot *memslot;
+       struct slot_rmap_walker walker;
+       int ret = 0;
 
        slots = kvm_memslots(kvm);
 
@@ -1451,26 +1508,18 @@ static int kvm_handle_hva_range(struct kvm *kvm,
                gfn_start = hva_to_gfn_memslot(hva_start, memslot);
                gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
 
-               for (j = PT_PAGE_TABLE_LEVEL;
-                    j < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++j) {
-                       unsigned long idx, idx_end;
-                       unsigned long *rmapp;
-                       gfn_t gfn = gfn_start;
-
-                       /*
-                        * {idx(page_j) | page_j intersects with
-                        *  [hva_start, hva_end)} = {idx, idx+1, ..., idx_end}.
-                        */
-                       idx = gfn_to_index(gfn_start, memslot->base_gfn, j);
-                       idx_end = gfn_to_index(gfn_end - 1, memslot->base_gfn, 
j);
-
-                       rmapp = __gfn_to_rmap(gfn_start, j, memslot);
-
-                       for (; idx <= idx_end;
-                              ++idx, gfn += (1UL << KVM_HPAGE_GFN_SHIFT(j)))
-                               ret |= handler(kvm, rmapp++, memslot,
-                                              gfn, j, data);
-               }
+               walker = (struct slot_rmap_walker) {
+                       .slot = memslot,
+                       .start_gfn = gfn_start,
+                       .end_gfn = gfn_end - 1,
+                       .start_level = PT_PAGE_TABLE_LEVEL,
+                       .end_level = PT_PAGE_TABLE_LEVEL +
+                                       KVM_NR_PAGE_SIZES - 1,
+               };
+
+               for_each_slot_rmap(&walker)
+                       ret |= handler(kvm, walker.rmap, memslot, walker.gfn,
+                                      walker.level, data);
        }
 
        return ret;
@@ -4404,34 +4453,29 @@ typedef bool (*slot_level_handler) (struct kvm *kvm, 
unsigned long *rmap);
 
 /* The caller should hold mmu-lock before calling this function. */
 static bool
-slot_handle_level(struct kvm *kvm, struct kvm_memory_slot *memslot,
-                 slot_level_handler fn, int min_level, int max_level,
-                 bool lock_flush_tlb)
+slot_handle_level_range(struct kvm *kvm, struct kvm_memory_slot *memslot,
+                        slot_level_handler fn, int min_level, int max_level,
+                        gfn_t start_gfn, gfn_t last_gfn, bool lock_flush_tlb)
 {
-       unsigned long last_gfn;
        bool flush = false;
-       int level;
-
-       last_gfn = memslot->base_gfn + memslot->npages - 1;
-
-       for (level = min_level; level <= max_level; ++level) {
-               unsigned long *rmapp;
-               unsigned long last_index, index;
-
-               rmapp = memslot->arch.rmap[level - PT_PAGE_TABLE_LEVEL];
-               last_index = gfn_to_index(last_gfn, memslot->base_gfn, level);
+       struct slot_rmap_walker walker = {
+               .slot = memslot,
+               .start_gfn = start_gfn,
+               .end_gfn = last_gfn,
+               .start_level = min_level,
+               .end_level = max_level,
+       };
 
-               for (index = 0; index <= last_index; ++index, ++rmapp) {
-                       if (*rmapp)
-                               flush |= fn(kvm, rmapp);
+       for_each_slot_rmap(&walker) {
+               if (*walker.rmap)
+                       flush |= fn(kvm, walker.rmap);
 
-                       if (need_resched() || spin_needbreak(&kvm->mmu_lock)) {
-                               if (flush && lock_flush_tlb) {
-                                       kvm_flush_remote_tlbs(kvm);
-                                       flush = false;
-                               }
-                               cond_resched_lock(&kvm->mmu_lock);
+               if (need_resched() || spin_needbreak(&kvm->mmu_lock)) {
+                       if (flush && lock_flush_tlb) {
+                               kvm_flush_remote_tlbs(kvm);
+                               flush = false;
                        }
+                       cond_resched_lock(&kvm->mmu_lock);
                }
        }
 
@@ -4439,6 +4483,16 @@ slot_handle_level(struct kvm *kvm, struct 
kvm_memory_slot *memslot,
 }
 
 static bool
+slot_handle_level(struct kvm *kvm, struct kvm_memory_slot *memslot,
+                 slot_level_handler fn, int min_level, int max_level,
+                 bool lock_flush_tlb)
+{
+       return slot_handle_level_range(kvm, memslot, fn, min_level,
+               max_level, memslot->base_gfn,
+               memslot->base_gfn + memslot->npages - 1, lock_flush_tlb);
+}
+
+static bool
 slot_handle_all_level(struct kvm *kvm, struct kvm_memory_slot *memslot,
                      slot_level_handler fn, bool lock_flush_tlb)
 {
-- 
1.9.3

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