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x86/vmware: Use tsc_khz value for calibrate_cpu()

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Commit aa297292d7 ("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: Alexey Makhalov <amakhalov@vmware.com>
Acked-by: Alok 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.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Alexey Makhalov 2016-10-28 00:54:30 -07:00 committed by Thomas Gleixner
parent 5ccd5f7057
commit 687bca8d66
1 changed files with 1 additions and 0 deletions
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arch/x86/kernel/cpu/vmware.c
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@ -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. */