svn commit: r220584 - in head/sys: amd64/amd64 i386/i386

[Ivan Voras]

On 14 April 2011 00:27, Jung-uk Kim <jkim at freebsd.org> wrote:

>
> That means your VM has broken CPUID support.  To get there, it has to
> meet two conditions, i.e., TSC is invariant and it has APERF/MPERF
> MSRs.  A simple workaround is setting "machdep.disable_tsc=1"
> tuanable from loader but your VM is the real culprit here.

You are probably right but fixing VMs is not going to happen (or not
soon enough) so workarounds must be implemented.

I don't know if it is called early enough for this purpose, but
detect_virtual() in kern/subr_param.c initializes the vm_guest
variable which could be useful for such workarounds (also see how
vm_guest is used in init_param1() in the same file to scale down HZ).