linux-kernel - [PATCH v5 08/14] KVM: selftests: Always clear dirty bitmap after iteration

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Message-Id: <20200304174947.69595-9-peterx@redhat.com>
Date:   Wed,  4 Mar 2020 12:49:41 -0500
From:   Peter Xu <peterx@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     Yan Zhao <yan.y.zhao@...el.com>, peterx@...hat.com,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        "Michael S . Tsirkin" <mst@...hat.com>,
        Alex Williamson <alex.williamson@...hat.com>,
        Sean Christopherson <sean.j.christopherson@...el.com>,
        "Dr . David Alan Gilbert" <dgilbert@...hat.com>,
        Jason Wang <jasowang@...hat.com>,
        Kevin Tian <kevin.tian@...el.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Christophe de Dinechin <dinechin@...hat.com>
Subject: [PATCH v5 08/14] KVM: selftests: Always clear dirty bitmap after iteration

We don't clear the dirty bitmap before because KVM_GET_DIRTY_LOG will
clear it for us before copying the dirty log onto it.  However we'd
still better to clear it explicitly instead of assuming the kernel
will always do it for us.

More importantly, in the upcoming dirty ring tests we'll start to
fetch dirty pages from a ring buffer, so no one is going to clear the
dirty bitmap for us.

Signed-off-by: Peter Xu <peterx@...hat.com>
---
 tools/testing/selftests/kvm/dirty_log_test.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index 5614222a6628..3c0ffd34b3b0 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -197,7 +197,7 @@ static void vm_dirty_log_verify(unsigned long *bmap)
 				    page);
 		}
 
-		if (test_bit_le(page, bmap)) {
+		if (test_and_clear_bit_le(page, bmap)) {
 			host_dirty_count++;
 			/*
 			 * If the bit is set, the value written onto
-- 
2.24.1