Messages in this thread | | | Date | Fri, 27 Sep 2013 17:10:26 +0200 | From | Olaf Hering <> | Subject | Re: [PATCH V2 1/1] X86: Hyper-V: Get the local APIC timer frequency from the hypervisor |
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On Tue, Sep 03, K. Y. Srinivasan wrote:
> Hyper-V supports a mechanism for retrieving the local APIC frequency.Use this and bypass > the calibration code in the kernel. This would allow us to boot the Linux kernel as a > "modern VM" on Hyper-V where many of the legacy devices (such as PIT) are not emulated.
> + if (ms_hyperv.features & HV_X64_MSR_APIC_FREQUENCY_AVAILABLE) { > + /* > + * Get the APIC frequency. > + */ > + rdmsrl(HV_X64_MSR_APIC_FREQUENCY, hv_lapic_frequency); > + hv_lapic_frequency /= HZ;
This leads to build errors on 32bit:
linux-3.12-rc2/arch/x86/kernel/cpu/mshyperv.c:88: undefined reference to `__udivdi3'
Up to now I have only tested on 64bit, sorry for that.
Olaf
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