diff options
author | Peng Hao <peng.hao2@zte.com.cn> | 2018-07-14 23:28:29 +0800 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-07-18 11:43:17 +0200 |
commit | e10f7805032365cc11c739a97f226ebb48aee042 (patch) | |
tree | fe7cf33daa3ef5a8fc7ae2a1ae64a417686c9860 /virt | |
parent | 2307af1c4b2e0ad886f30e31739845322cbd328b (diff) |
kvmclock: fix TSC calibration for nested guests
Inside a nested guest, access to hardware can be slow enough that
tsc_read_refs always return ULLONG_MAX, causing tsc_refine_calibration_work
to be called periodically and the nested guest to spend a lot of time
reading the ACPI timer.
However, if the TSC frequency is available from the pvclock page,
we can just set X86_FEATURE_TSC_KNOWN_FREQ and avoid the recalibration.
'refine' operation.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Peng Hao <peng.hao2@zte.com.cn>
[Commit message rewritten. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt')
0 files changed, 0 insertions, 0 deletions