KVM: x86: MMU: Add helper function to clear a bit in unsync child bitmap
Both __mmu_unsync_walk() and mmu_pages_clear_parents() have three line
code which clears a bit in the unsync child bitmap; the former places it
inside a loop block and uses a few goto statements to jump to it.
A new helper function, clear_unsync_child_bit(), makes the code cleaner.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 8a1593f..9832bc9 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1809,6 +1809,13 @@
return (pvec->nr == KVM_PAGE_ARRAY_NR);
}
+static inline void clear_unsync_child_bit(struct kvm_mmu_page *sp, int idx)
+{
+ --sp->unsync_children;
+ WARN_ON((int)sp->unsync_children < 0);
+ __clear_bit(idx, sp->unsync_child_bitmap);
+}
+
static int __mmu_unsync_walk(struct kvm_mmu_page *sp,
struct kvm_mmu_pages *pvec)
{
@@ -1818,8 +1825,10 @@
struct kvm_mmu_page *child;
u64 ent = sp->spt[i];
- if (!is_shadow_present_pte(ent) || is_large_pte(ent))
- goto clear_child_bitmap;
+ if (!is_shadow_present_pte(ent) || is_large_pte(ent)) {
+ clear_unsync_child_bit(sp, i);
+ continue;
+ }
child = page_header(ent & PT64_BASE_ADDR_MASK);
@@ -1828,28 +1837,21 @@
return -ENOSPC;
ret = __mmu_unsync_walk(child, pvec);
- if (!ret)
- goto clear_child_bitmap;
- else if (ret > 0)
+ if (!ret) {
+ clear_unsync_child_bit(sp, i);
+ continue;
+ } else if (ret > 0) {
nr_unsync_leaf += ret;
- else
+ } else
return ret;
} else if (child->unsync) {
nr_unsync_leaf++;
if (mmu_pages_add(pvec, child, i))
return -ENOSPC;
} else
- goto clear_child_bitmap;
-
- continue;
-
-clear_child_bitmap:
- __clear_bit(i, sp->unsync_child_bitmap);
- sp->unsync_children--;
- WARN_ON((int)sp->unsync_children < 0);
+ clear_unsync_child_bit(sp, i);
}
-
return nr_unsync_leaf;
}
@@ -2012,9 +2014,7 @@
if (!sp)
return;
- --sp->unsync_children;
- WARN_ON((int)sp->unsync_children < 0);
- __clear_bit(idx, sp->unsync_child_bitmap);
+ clear_unsync_child_bit(sp, idx);
level++;
} while (level < PT64_ROOT_LEVEL-1 && !sp->unsync_children);
}