linux-kernel - [PATCH] KVM: Remove duplicated zero clear with dirty

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Date: Thu, 13 Jun 2024 20:54:07 +0800
From: Bibo Mao <maobibo@...ngson.cn>
To: Paolo Bonzini <pbonzini@...hat.com>
Cc: kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH] KVM: Remove duplicated zero clear with dirty_bitmap buffer

Since dirty_bitmap pointer is allocated with function __vcalloc(),
there is __GFP_ZERO flag set in the implementation about this function
__vcalloc_noprof(). It is not necessary to clear dirty_bitmap buffer
with zero again.

Signed-off-by: Bibo Mao <maobibo@...ngson.cn>
---
 virt/kvm/kvm_main.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 14841acb8b95..c7d4a041dcfa 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1669,9 +1669,6 @@ static int kvm_prepare_memory_region(struct kvm *kvm,
 			r = kvm_alloc_dirty_bitmap(new);
 			if (r)
 				return r;
-
-			if (kvm_dirty_log_manual_protect_and_init_set(kvm))
-				bitmap_set(new->dirty_bitmap, 0, new->npages);
 		}
 	}
 

base-commit: 83a7eefedc9b56fe7bfeff13b6c7356688ffa670
-- 
2.39.3