KVM: MMU: introduce some macros to cleanup hlist traverseing

Introduce for_each_gfn_sp() and for_each_gfn_indirect_valid_sp() to
cleanup hlist traverseing

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 3ac51153bc4721ef6521d5e4d75d27be57f71c95..881ad918455c51efa1b6d712739a9a4d7cc7a761 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1201,6 +1201,17 @@ static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 
 static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp);
 
+#define for_each_gfn_sp(kvm, sp, gfn, pos, n)                          \
+  hlist_for_each_entry_safe(sp, pos, n,                                        \
+   &(kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)], hash_link)  \
+       if ((sp)->gfn != (gfn)) {} else
+
+#define for_each_gfn_indirect_valid_sp(kvm, sp, gfn, pos, n)           \
+  hlist_for_each_entry_safe(sp, pos, n,                                        \
+   &(kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)], hash_link)  \
+               if ((sp)->gfn != (gfn) || (sp)->role.direct ||          \
+                       (sp)->role.invalid) {} else
+
 static int __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
                           bool clear_unsync)
 {
@@ -1244,16 +1255,12 @@ static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
 /* @gfn should be write-protected at the call site */
 static void kvm_sync_pages(struct kvm_vcpu *vcpu,  gfn_t gfn)
 {
-       struct hlist_head *bucket;
        struct kvm_mmu_page *s;
        struct hlist_node *node, *n;
-       unsigned index;
        bool flush = false;
 
-       index = kvm_page_table_hashfn(gfn);
-       bucket = &vcpu->kvm->arch.mmu_page_hash[index];
-       hlist_for_each_entry_safe(s, node, n, bucket, hash_link) {
-               if (s->gfn != gfn || !s->unsync || s->role.invalid)
+       for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn, node, n) {
+               if (!s->unsync)
                        continue;
 
                WARN_ON(s->role.level != PT_PAGE_TABLE_LEVEL);
@@ -1365,9 +1372,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
                                             u64 *parent_pte)
 {
        union kvm_mmu_page_role role;
-       unsigned index;
        unsigned quadrant;
-       struct hlist_head *bucket;
        struct kvm_mmu_page *sp;
        struct hlist_node *node, *tmp;
        bool need_sync = false;
@@ -1383,36 +1388,34 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
                quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
                role.quadrant = quadrant;
        }
-       index = kvm_page_table_hashfn(gfn);
-       bucket = &vcpu->kvm->arch.mmu_page_hash[index];
-       hlist_for_each_entry_safe(sp, node, tmp, bucket, hash_link)
-               if (sp->gfn == gfn) {
-                       if (!need_sync && sp->unsync)
-                               need_sync = true;
+       for_each_gfn_sp(vcpu->kvm, sp, gfn, node, tmp) {
+               if (!need_sync && sp->unsync)
+                       need_sync = true;
 
-                       if (sp->role.word != role.word)
-                               continue;
+               if (sp->role.word != role.word)
+                       continue;
 
-                       if (sp->unsync && kvm_sync_page_transient(vcpu, sp))
-                               break;
+               if (sp->unsync && kvm_sync_page_transient(vcpu, sp))
+                       break;
 
-                       mmu_page_add_parent_pte(vcpu, sp, parent_pte);
-                       if (sp->unsync_children) {
-                               set_bit(KVM_REQ_MMU_SYNC, &vcpu->requests);
-                               kvm_mmu_mark_parents_unsync(sp);
-                       } else if (sp->unsync)
-                               kvm_mmu_mark_parents_unsync(sp);
+               mmu_page_add_parent_pte(vcpu, sp, parent_pte);
+               if (sp->unsync_children) {
+                       set_bit(KVM_REQ_MMU_SYNC, &vcpu->requests);
+                       kvm_mmu_mark_parents_unsync(sp);
+               } else if (sp->unsync)
+                       kvm_mmu_mark_parents_unsync(sp);
 
-                       trace_kvm_mmu_get_page(sp, false);
-                       return sp;
-               }
+               trace_kvm_mmu_get_page(sp, false);
+               return sp;
+       }
        ++vcpu->kvm->stat.mmu_cache_miss;
        sp = kvm_mmu_alloc_page(vcpu, parent_pte, direct);
        if (!sp)
                return sp;
        sp->gfn = gfn;
        sp->role = role;
-       hlist_add_head(&sp->hash_link, bucket);
+       hlist_add_head(&sp->hash_link,
+               &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]);
        if (!direct) {
                if (rmap_write_protect(vcpu->kvm, gfn))
                        kvm_flush_remote_tlbs(vcpu->kvm);
@@ -1617,46 +1620,34 @@ void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages)
 
 static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
 {
-       unsigned index;
-       struct hlist_head *bucket;
        struct kvm_mmu_page *sp;
        struct hlist_node *node, *n;
        int r;
 
        pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
        r = 0;
-       index = kvm_page_table_hashfn(gfn);
-       bucket = &kvm->arch.mmu_page_hash[index];
 restart:
-       hlist_for_each_entry_safe(sp, node, n, bucket, hash_link)
-               if (sp->gfn == gfn && !sp->role.direct && !sp->role.invalid) {
-                       pgprintk("%s: gfn %lx role %x\n", __func__, gfn,
-                                sp->role.word);
-                       r = 1;
-                       if (kvm_mmu_zap_page(kvm, sp))
-                               goto restart;
-               }
+       for_each_gfn_indirect_valid_sp(kvm, sp, gfn, node, n) {
+               pgprintk("%s: gfn %lx role %x\n", __func__, gfn,
+                        sp->role.word);
+               r = 1;
+               if (kvm_mmu_zap_page(kvm, sp))
+                       goto restart;
+       }
        return r;
 }
 
 static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
 {
-       unsigned index;
-       struct hlist_head *bucket;
        struct kvm_mmu_page *sp;
        struct hlist_node *node, *nn;
 
-       index = kvm_page_table_hashfn(gfn);
-       bucket = &kvm->arch.mmu_page_hash[index];
 restart:
-       hlist_for_each_entry_safe(sp, node, nn, bucket, hash_link) {
-               if (sp->gfn == gfn && !sp->role.direct
-                   && !sp->role.invalid) {
-                       pgprintk("%s: zap %lx %x\n",
-                                __func__, gfn, sp->role.word);
-                       if (kvm_mmu_zap_page(kvm, sp))
-                               goto restart;
-               }
+       for_each_gfn_indirect_valid_sp(kvm, sp, gfn, node, nn) {
+               pgprintk("%s: zap %lx %x\n",
+                        __func__, gfn, sp->role.word);
+               if (kvm_mmu_zap_page(kvm, sp))
+                       goto restart;
        }
 }
 
@@ -1799,17 +1790,11 @@ static void __kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
 
 static void kvm_unsync_pages(struct kvm_vcpu *vcpu,  gfn_t gfn)
 {
-       struct hlist_head *bucket;
        struct kvm_mmu_page *s;
        struct hlist_node *node, *n;
-       unsigned index;
-
-       index = kvm_page_table_hashfn(gfn);
-       bucket = &vcpu->kvm->arch.mmu_page_hash[index];
 
-       hlist_for_each_entry_safe(s, node, n, bucket, hash_link) {
-               if (s->gfn != gfn || s->role.direct || s->unsync ||
-                     s->role.invalid)
+       for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn, node, n) {
+               if (s->unsync)
                        continue;
                WARN_ON(s->role.level != PT_PAGE_TABLE_LEVEL);
                __kvm_unsync_page(vcpu, s);
@@ -1819,18 +1804,11 @@ static void kvm_unsync_pages(struct kvm_vcpu *vcpu,  gfn_t gfn)
 static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
                                  bool can_unsync)
 {
-       unsigned index;
-       struct hlist_head *bucket;
        struct kvm_mmu_page *s;
        struct hlist_node *node, *n;
        bool need_unsync = false;
 
-       index = kvm_page_table_hashfn(gfn);
-       bucket = &vcpu->kvm->arch.mmu_page_hash[index];
-       hlist_for_each_entry_safe(s, node, n, bucket, hash_link) {
-               if (s->gfn != gfn || s->role.direct || s->role.invalid)
-                       continue;
-
+       for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn, node, n) {
                if (s->role.level != PT_PAGE_TABLE_LEVEL)
                        return 1;
 
@@ -2703,8 +2681,6 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
        gfn_t gfn = gpa >> PAGE_SHIFT;
        struct kvm_mmu_page *sp;
        struct hlist_node *node, *n;
-       struct hlist_head *bucket;
-       unsigned index;
        u64 entry, gentry;
        u64 *spte;
        unsigned offset = offset_in_page(gpa);
@@ -2772,13 +2748,9 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
                        vcpu->arch.last_pte_updated = NULL;
                }
        }
-       index = kvm_page_table_hashfn(gfn);
-       bucket = &vcpu->kvm->arch.mmu_page_hash[index];
 
 restart:
-       hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) {
-               if (sp->gfn != gfn || sp->role.direct || sp->role.invalid)
-                       continue;
+       for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn, node, n) {
                pte_size = sp->role.cr4_pae ? 8 : 4;
                misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
                misaligned |= bytes < 4;