Re: [PATCH 1/7] hyperv: Detect Nested virtualization support for SVM

[Sean Christopherson]

On Wed, Apr 07, 2021, Michael Kelley wrote:
> From: Vineeth Pillai <viremana@xxxxxxxxxxxxxxxxxxx> Sent: Wednesday, April 7, 2021 7:41 AM
> > 
> > Detect nested features exposed by Hyper-V if SVM is enabled.
> > 
> > Signed-off-by: Vineeth Pillai <viremana@xxxxxxxxxxxxxxxxxxx>
> > ---
> >  arch/x86/kernel/cpu/mshyperv.c | 10 +++++++++-
> >  1 file changed, 9 insertions(+), 1 deletion(-)
> > 
> > diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
> > index 3546d3e21787..4d364acfe95d 100644
> > --- a/arch/x86/kernel/cpu/mshyperv.c
> > +++ b/arch/x86/kernel/cpu/mshyperv.c
> > @@ -325,9 +325,17 @@ static void __init ms_hyperv_init_platform(void)
> >  			ms_hyperv.isolation_config_a, ms_hyperv.isolation_config_b);
> >  	}
> > 
> > -	if (ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED) {
> > +	/*
> > +	 * AMD does not need enlightened VMCS as VMCB is already a
> > +	 * datastructure in memory. We need to get the nested
> > +	 * features if SVM is enabled.
> > +	 */
> > +	if (boot_cpu_has(X86_FEATURE_SVM) ||
> > +	    ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED) {
> >  		ms_hyperv.nested_features =
> >  			cpuid_eax(HYPERV_CPUID_NESTED_FEATURES);
> > +		pr_info("Hyper-V nested_features: 0x%x\n",
> 
> Nit:  Most other similar lines put the colon in a different place:
> 
> 		pr_info("Hyper-V: nested features 0x%x\n",
> 
> One of these days, I'm going to fix the ones that don't follow this
> pattern. :-)

Any reason not to use pr_fmt?