Commit 687bca8d authored by Alexey Makhalov's avatar Alexey Makhalov Committed by Thomas Gleixner

x86/vmware: Use tsc_khz value for calibrate_cpu()

Commit aa297292 ("x86/tsc: Enumerate SKL cpu_khz and tsc_khz via
CPUID") separated the calibration mechanisms for cpu_khz and tsc_khz.

Since the vmware hypervisor provides a constant frequency TSC to the guest,
this change can lead to divergence between the tsc and the cpu frequency
after vmotion, which might confuse the user.

Solve this by overriding the x86 platform cpu calibration callback with the
vmware specific tsc calibration function.
Signed-off-by: default avatarAlexey Makhalov <amakhalov@vmware.com>
Acked-by: default avatarAlok N Kataria <akataria@vmware.com>
Cc: linux-doc@vger.kernel.org
Cc: pv-drivers@vmware.com
Cc: corbet@lwn.net
Cc: virtualization@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/20161028075432.90579-2-amakhalov@vmware.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 5ccd5f70
......@@ -83,6 +83,7 @@ static void __init vmware_platform_setup(void)
vmware_tsc_khz = tsc_khz;
x86_platform.calibrate_tsc = vmware_get_tsc_khz;
x86_platform.calibrate_cpu = vmware_get_tsc_khz;
#ifdef CONFIG_X86_LOCAL_APIC
/* Skip lapic calibration since we know the bus frequency. */
......
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