On Wednesday, March 20, 2013 11:28:49 AM Dirk Brandewie wrote:
> On 03/20/2013 11:28 AM, Rafael J. Wysocki wrote:
> > On Wednesday, March 20, 2013 09:17:24 AM dirk.brande...@gmail.com wrote:
> >> From: Dirk Brandewie <dirk.brande...@gmail.com>
> >>
> >> Some VMs seem to try to implement some MSRs but not all the registers
> >> the driver needs. Check to make sure all the MSR that we need are
> >> available. If any of the required MSRs are not available refuse to
> >> load.
> >>
> >> Signed-off-by: Dirk Brandewie <dirk.j.brande...@intel.com>
> >
> > Is this needed for v3.9? Any pointers to bug reports etc.?
> >
>
> Sorry I saw right after I sent the mail that the bug report was missing
>
> https://bugzilla.redhat.com/show_bug.cgi?id=922923
> Reported-by: Josh Stone <jist...@redhat.com>
>
> Would you like me to spin the patch?
No, thanks, this information is sufficient.
Thanks,
Rafael
> >> ---
> >> drivers/cpufreq/intel_pstate.c | 26 ++++++++++++++++++++++++++
> >> 1 files changed, 26 insertions(+), 0 deletions(-)
> >>
> >> diff --git a/drivers/cpufreq/intel_pstate.c
> >> b/drivers/cpufreq/intel_pstate.c
> >> index f6dd1e7..cd9c5f4 100644
> >> --- a/drivers/cpufreq/intel_pstate.c
> >> +++ b/drivers/cpufreq/intel_pstate.c
> >> @@ -752,6 +752,29 @@ static struct cpufreq_driver intel_pstate_driver = {
> >>
> >> static int __initdata no_load;
> >>
> >> +static int intel_pstate_msrs_not_valid(void)
> >> +{
> >> + /* Check that all the msr's we are using are valid. */
> >> + u64 aperf, mperf, tmp;
> >> +
> >> + rdmsrl(MSR_IA32_APERF, aperf);
> >> + rdmsrl(MSR_IA32_MPERF, mperf);
> >> +
> >> + if (!intel_pstate_min_pstate() ||
> >> + !intel_pstate_max_pstate() ||
> >> + !intel_pstate_turbo_pstate())
> >> + return -ENODEV;
> >> +
> >> + rdmsrl(MSR_IA32_APERF, tmp);
> >> + if (!(tmp - aperf))
> >> + return -ENODEV;
> >> +
> >> + rdmsrl(MSR_IA32_MPERF, tmp);
> >> + if (!(tmp - mperf))
> >> + return -ENODEV;
> >> +
> >> + return 0;
> >> +}
> >> static int __init intel_pstate_init(void)
> >> {
> >> int cpu, rc = 0;
> >> @@ -764,6 +787,9 @@ static int __init intel_pstate_init(void)
> >> if (!id)
> >> return -ENODEV;
> >>
> >> + if (intel_pstate_msrs_not_valid())
> >> + return -ENODEV;
> >> +
> >> pr_info("Intel P-state driver initializing.\n");
> >>
> >> all_cpu_data = vmalloc(sizeof(void *) * num_possible_cpus());
> >>
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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