KVM: MMU: introduce for_each_rmap_spte()

It's used to walk all the sptes on the rmap to clean up the
code

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 44a7d25..7a11585 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1142,6 +1142,11 @@ static u64 *rmap_get_next(struct rmap_iterator *iter)
        return NULL;
 }
 
+#define for_each_rmap_spte(_rmap_, _iter_, _spte_)                         \
+          for (_spte_ = rmap_get_first(*_rmap_, _iter_);                   \
+               _spte_ && ({BUG_ON(!is_shadow_present_pte(*_spte_)); 1;});  \
+                       _spte_ = rmap_get_next(_iter_))
+
 static void drop_spte(struct kvm *kvm, u64 *sptep)
 {
        if (mmu_spte_clear_track_bits(sptep))
@@ -1205,12 +1210,8 @@ static bool __rmap_write_protect(struct kvm *kvm, unsigned long *rmapp,
        struct rmap_iterator iter;
        bool flush = false;
 
-       for (sptep = rmap_get_first(*rmapp, &iter); sptep;) {
-               BUG_ON(!(*sptep & PT_PRESENT_MASK));
-
+       for_each_rmap_spte(rmapp, &iter, sptep)
                flush |= spte_write_protect(kvm, sptep, pt_protect);
-               sptep = rmap_get_next(&iter);
-       }
 
        return flush;
 }
@@ -1232,12 +1233,8 @@ static bool __rmap_clear_dirty(struct kvm *kvm, unsigned long *rmapp)
        struct rmap_iterator iter;
        bool flush = false;
 
-       for (sptep = rmap_get_first(*rmapp, &iter); sptep;) {
-               BUG_ON(!(*sptep & PT_PRESENT_MASK));
-
+       for_each_rmap_spte(rmapp, &iter, sptep)
                flush |= spte_clear_dirty(kvm, sptep);
-               sptep = rmap_get_next(&iter);
-       }
 
        return flush;
 }
@@ -1259,12 +1256,8 @@ static bool __rmap_set_dirty(struct kvm *kvm, unsigned long *rmapp)
        struct rmap_iterator iter;
        bool flush = false;
 
-       for (sptep = rmap_get_first(*rmapp, &iter); sptep;) {
-               BUG_ON(!(*sptep & PT_PRESENT_MASK));
-
+       for_each_rmap_spte(rmapp, &iter, sptep)
                flush |= spte_set_dirty(kvm, sptep);
-               sptep = rmap_get_next(&iter);
-       }
 
        return flush;
 }
@@ -1394,8 +1387,8 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp,
        WARN_ON(pte_huge(*ptep));
        new_pfn = pte_pfn(*ptep);
 
-       for (sptep = rmap_get_first(*rmapp, &iter); sptep;) {
-               BUG_ON(!is_shadow_present_pte(*sptep));
+restart:
+       for_each_rmap_spte(rmapp, &iter, sptep) {
                rmap_printk("kvm_set_pte_rmapp: spte %p %llx gfn %llx (%d)\n",
                             sptep, *sptep, gfn, level);
 
@@ -1403,7 +1396,7 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp,
 
                if (pte_write(*ptep)) {
                        drop_spte(kvm, sptep);
-                       sptep = rmap_get_first(*rmapp, &iter);
+                       goto restart;
                } else {
                        new_spte = *sptep & ~PT64_BASE_ADDR_MASK;
                        new_spte |= (u64)new_pfn << PAGE_SHIFT;
@@ -1414,7 +1407,6 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp,
 
                        mmu_spte_clear_track_bits(sptep);
                        mmu_spte_set(sptep, new_spte);
-                       sptep = rmap_get_next(&iter);
                }
        }
 
@@ -1518,16 +1510,13 @@ static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
 
        BUG_ON(!shadow_accessed_mask);
 
-       for (sptep = rmap_get_first(*rmapp, &iter); sptep;
-            sptep = rmap_get_next(&iter)) {
-               BUG_ON(!is_shadow_present_pte(*sptep));
-
+       for_each_rmap_spte(rmapp, &iter, sptep)
                if (*sptep & shadow_accessed_mask) {
                        young = 1;
                        clear_bit((ffs(shadow_accessed_mask) - 1),
                                 (unsigned long *)sptep);
                }
-       }
+
        trace_kvm_age_page(gfn, level, slot, young);
        return young;
 }
@@ -1548,15 +1537,11 @@ static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
        if (!shadow_accessed_mask)
                goto out;
 
-       for (sptep = rmap_get_first(*rmapp, &iter); sptep;
-            sptep = rmap_get_next(&iter)) {
-               BUG_ON(!is_shadow_present_pte(*sptep));
-
+       for_each_rmap_spte(rmapp, &iter, sptep)
                if (*sptep & shadow_accessed_mask) {
                        young = 1;
                        break;
                }
-       }
 out:
        return young;
 }
@@ -4482,9 +4467,8 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm,
        pfn_t pfn;
        struct kvm_mmu_page *sp;
 
-       for (sptep = rmap_get_first(*rmapp, &iter); sptep;) {
-               BUG_ON(!(*sptep & PT_PRESENT_MASK));
-
+restart:
+       for_each_rmap_spte(rmapp, &iter, sptep) {
                sp = page_header(__pa(sptep));
                pfn = spte_to_pfn(*sptep);
 
@@ -4499,10 +4483,9 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm,
                        !kvm_is_reserved_pfn(pfn) &&
                        PageTransCompound(pfn_to_page(pfn))) {
                        drop_spte(kvm, sptep);
-                       sptep = rmap_get_first(*rmapp, &iter);
                        need_tlb_flush = 1;
-               } else
-                       sptep = rmap_get_next(&iter);
+                       goto restart;
+               }
        }
 
        return need_tlb_flush;

diff --git a/arch/x86/kvm/mmu_audit.c b/arch/x86/kvm/mmu_audit.c
index 9ade5cf..368d534 100644 (file)
--- a/arch/x86/kvm/mmu_audit.c
+++ b/arch/x86/kvm/mmu_audit.c
@@ -197,13 +197,11 @@ static void audit_write_protection(struct kvm *kvm, struct kvm_mmu_page *sp)
 
        rmapp = gfn_to_rmap(kvm, sp->gfn, PT_PAGE_TABLE_LEVEL);
 
-       for (sptep = rmap_get_first(*rmapp, &iter); sptep;
-            sptep = rmap_get_next(&iter)) {
+       for_each_rmap_spte(rmapp, &iter, sptep)
                if (is_writable_pte(*sptep))
                        audit_printk(kvm, "shadow page has writable "
                                     "mappings: gfn %llx role %x\n",
                                     sp->gfn, sp->role.word);
-       }
 }
 
 static void audit_sp(struct kvm *kvm, struct kvm_mmu_page *sp)