Re: SpeedStep in DomUs?

[Stefan Groà <kong%kong74.org@localhost>]

Thanks a lot, now i got realcpu0 pinned to vcpu0 and dom0 has only this
cpu, i think that matches the restriction for using cpufreq=dom0-kernel.
But sysctl still doesn't give me any est-options. So i looked at the
kernel-config and found out that "option ENHANCED_SPEEDSTEP" is missing
in the amd64 XEN3_DOM0. Trying to compile with the optionline simply
added to a copy of XEN3_DOM0 config named LENA gives the following error:

#      link  LENA/netbsd
ld -Map netbsd.map --cref -T
../../../../arch/amd64/conf/kern.ldscript.Xen -Ttext 0xffffffff80100000
-e start -X -o netbsd ${SYSTEM_OBJ} ${EXTRA_OBJ} vers.o
identcpu.o: In function `cpu_identify':
../../../../arch/x86/x86/identcpu.c:713: undefined reference to `est_init'
*** Error code 1

Stop.
make: stopped in /usr/src/sys/arch/amd64/compile/LENA

The relevant lines in identcpu.c seem to be these:

#ifdef ENHANCED_SPEEDSTEP
        if (cpu_feature2 & CPUID2_EST) {
                if (rdmsr(MSR_MISC_ENABLE) & (1 << 16))
                        est_init(cpu_vendor);
        }
#endif /* ENHANCED_SPEEDSTEP */

Am i right, that "est_init(cpu_vendor)" is a function call, and the
linker stops for not knowing the function? Can i do something about it
(well, i'm a newbie in these things)? Maybe est isn't enabled by default
just for cautiousness -- or is it for harder reasons?

Greetings, Stefan