From: Holger Steinhaus <hsteinhaus@gmx.de>
To: xen-devel@lists.xensource.com
Subject: Writing MSRs from Domain0
Date: Fri, 06 Oct 2006 11:11:16 +0200 [thread overview]
Message-ID: <45261DB4.8000009@gmx.de> (raw)
Hello,
I recently tried Xen 3.0.3-testing on my 2x Opteron-244 SMP machine.
Everything works well exept one detail, which is not unimportant to me:
the powernow-k8 driver fails to switch frequencies. A closer look on the
powernow-k8 source reveals, that some MSR write operations seem to be
without any effect. A rdmsr() before and after the wrmsr() call reveals
that no real change on the register ocurrs.
An older PowerNow patch from this list emulates MSR writes by DOM0_MSR
hypercalls, but this call seems to be abandoned some time ago. Other
routines in the kernel simply employ the rdmsr()/wrmsr() macros from the
Linux kernel, as the current PowerNow drivers does. Whats the correct
Xen-like way to maniputate a MSR from a Domain0?
Regards,
Holger
next reply other threads:[~2006-10-06 9:11 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-10-06 9:11 Holger Steinhaus [this message]
2006-10-06 9:20 ` Writing MSRs from Domain0 Keir Fraser
2006-10-06 12:23 ` Holger Steinhaus
2006-10-06 12:54 ` Keir Fraser
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