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>

1 files changed, 47 insertions, 75 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 3ac51153bc47..881ad918455c 100644
--- 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;