[PATCH] kvm: don't lose the higher 32 bits of tlbs_dirty

From: Lai Jiangshan
Date: Sat Dec 12 2020 - 22:49:40 EST


From: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>

In kvm_mmu_notifier_invalidate_range_start(), tlbs_dirty is used as:
need_tlb_flush |= kvm->tlbs_dirty;
with need_tlb_flush's type being int and tlbs_dirty's type being long.

It means that tlbs_dirty is always used as int and the higher 32 bits
is useless. We can just change need_tlb_flush's type to long to
make full use of tlbs_dirty.

Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>
---
virt/kvm/kvm_main.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 2541a17ff1c4..4e519a517e9f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -470,7 +470,8 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
const struct mmu_notifier_range *range)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
- int need_tlb_flush = 0, idx;
+ long need_tlb_flush = 0;
+ int idx;

idx = srcu_read_lock(&kvm->srcu);
spin_lock(&kvm->mmu_lock);
--
2.19.1.6.gb485710b