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>
This commit is contained in:
Takuya Yoshikawa 2015-11-20 17:43:13 +09:00 committed by Paolo Bonzini
parent 7ee0e5b29d
commit fd9514572f

View File

@ -1809,6 +1809,13 @@ static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp,
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 @@ static int __mmu_unsync_walk(struct kvm_mmu_page *sp,
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 @@ static int __mmu_unsync_walk(struct kvm_mmu_page *sp,
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 @@ static void mmu_pages_clear_parents(struct mmu_page_path *parents)
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);
}