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Reply-To: Gavin Shan <gshan@redhat.com>
Subject: Re: [PATCH 1/2] KVM: selftests: Allow >1 guest mode in
 access_tracking_perf_test
To:     Oliver Upton <oliver.upton@linux.dev>,
        Marc Zyngier <maz@kernel.org>,
        James Morse <james.morse@arm.com>,
        Alexandru Elisei <alexandru.elisei@arm.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Shuah Khan <shuah@kernel.org>
Cc:     kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
        kvmarm@lists.linux.dev, linux-kselftest@vger.kernel.org,
        David Matlack <dmatlack@google.com>,
        kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org
References: <20221111231946.944807-1-oliver.upton@linux.dev>
 <20221111231946.944807-2-oliver.upton@linux.dev>
From:   Gavin Shan <gshan@redhat.com>
Message-ID: <1024da03-46f6-b82f-0c17-ca1d95dd171b@redhat.com>
Date:   Sat, 12 Nov 2022 18:03:45 +0800
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On 11/12/22 7:19 AM, Oliver Upton wrote:
> As the name implies, for_each_guest_mode() will run the test case for
> all supported guest addressing modes. On x86 that doesn't amount to
> anything, but arm64 can handle 4K, 16K, and 64K page sizes on supporting
> hardware.
> 
> Blindly attempting to run access_tracking_perf_test on arm64 stalls on
> the second test case, as the 'done' global remains set between test
> iterations. Clear it after VM teardown in anticipation of a subsequent
> test case.
> 
> Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
> ---
>   tools/testing/selftests/kvm/access_tracking_perf_test.c | 3 +++
>   1 file changed, 3 insertions(+)
> 

Reviewed-by: Gavin Shan <gshan@redhat.com>

> diff --git a/tools/testing/selftests/kvm/access_tracking_perf_test.c b/tools/testing/selftests/kvm/access_tracking_perf_test.c
> index 76c583a07ea2..4da066479e0a 100644
> --- a/tools/testing/selftests/kvm/access_tracking_perf_test.c
> +++ b/tools/testing/selftests/kvm/access_tracking_perf_test.c
> @@ -326,6 +326,9 @@ static void run_test(enum vm_guest_mode mode, void *arg)
>   
>   	perf_test_join_vcpu_threads(nr_vcpus);
>   	perf_test_destroy_vm(vm);
> +
> +	/* Clear done in anticipation of testing another guest mode */
> +	done = false;
>   }
>   
>   static void help(char *name)
>