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Commit eae260be authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Paolo Bonzini
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KVM: selftests: Make hyperv_clock selftest more stable 



hyperv_clock doesn't always give a stable test result, especially with
AMD CPUs. The test compares Hyper-V MSR clocksource (acquired either
with rdmsr() from within the guest or KVM_GET_MSRS from the host)
against rdtsc(). To increase the accuracy, increase the measured delay
(done with nop loop) by two orders of magnitude and take the mean rdtsc()
value before and after rdmsr()/KVM_GET_MSRS.

Reported-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Tested-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220601144322.1968742-1-vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 5ba7c4c6
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