linux-kernel - [PATCH v10 08/14] KVM: selftests: Always clear dirty bitmap after iteration

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Message-Id: <20200601115957.1581250-9-peterx@redhat.com>
Date:   Mon,  1 Jun 2020 07:59:51 -0400
From:   Peter Xu <peterx@...hat.com>
To:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     "Dr . David Alan Gilbert" <dgilbert@...hat.com>,
        Andrew Jones <drjones@...hat.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        "Michael S . Tsirkin" <mst@...hat.com>,
        Jason Wang <jasowang@...hat.com>, peterx@...hat.com,
        Sean Christopherson <sean.j.christopherson@...el.com>,
        Kevin Tian <kevin.tian@...el.com>
Subject: [PATCH v10 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.

Reviewed-by: Andrew Jones <drjones@...hat.com>
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 752ec158ac59..6a8275a22861 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -195,7 +195,7 @@ static void vm_dirty_log_verify(enum vm_guest_mode mode, 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
-- 
2.26.2