> -----Original Mail-----
> Sender: Thomas Gleixner [mailto:t...@linutronix.de]
> Time: 2018/4/17 18:19
> Receiver: David Wang <davidw...@zhaoxin.com>
> CC: mi...@redhat.com; h...@zytor.com; mi...@kernel.org;
> gre...@linuxfoundation.org; x...@kernel.org; linux-
> ker...@vger.kernel.org; brucech...@via-alliance.com;
> cooper...@zhaoxin.com; qiyuanw...@zhaoxin.com;
> benjamin...@viatech.com; luke...@viacpu.com; tim...@zhaoxin.com
> Subject: Re: [PATCH] x86/Centaur: show more HW features in /proc/cpuinfo
>
> On Sun, 8 Apr 2018, David Wang wrote:
>
> > We add this patch to show correct HW features(arch_perfmon,
> > tpr_shadow, vnmi, flexpriority, ept and vpid) when user execute "cat
> /proc/cpuinfo".
>
> See the other mail vs. the changelog.
>
OK. Thanks.
> >
> > Signed-off-by: David Wang <davidw...@zhaoxin.com>
> > ---
> > arch/x86/kernel/cpu/centaur.c | 49
> > +++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 49 insertions(+)
> >
> > diff --git a/arch/x86/kernel/cpu/centaur.c
> > b/arch/x86/kernel/cpu/centaur.c index e5ec0f1..969fb8f 100644
> > --- a/arch/x86/kernel/cpu/centaur.c
> > +++ b/arch/x86/kernel/cpu/centaur.c
> > @@ -112,6 +112,44 @@ static void early_init_centaur(struct cpuinfo_x86
> *c)
> > }
> > }
> >
> > +static void centaur_detect_vmx_virtcap(struct cpuinfo_x86 *c) {
> > +#define X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW 0x00200000
> > +#define X86_VMX_FEATURE_PROC_CTLS_VNMI 0x00400000
> > +#define X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS 0x80000000
> > +#define X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC 0x00000001
> > +#define X86_VMX_FEATURE_PROC_CTLS2_EPT 0x00000002
> > +#define X86_VMX_FEATURE_PROC_CTLS2_VPID 0x00000020
>
> Please move the defines outside the function. This is horrible to read,
OK.
>
> > +
> > + u32 vmx_msr_low, vmx_msr_high, msr_ctl, msr_ctl2;
> > +
> > + clear_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
> > + clear_cpu_cap(c, X86_FEATURE_VNMI);
> > + clear_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
> > + clear_cpu_cap(c, X86_FEATURE_EPT);
> > + clear_cpu_cap(c, X86_FEATURE_VPID);
>
> Why are you clearing the capabilities? They are cleared at boot time.
>
OK. It's really useless.
> > + rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, vmx_msr_low,
> vmx_msr_high);
> > + msr_ctl = vmx_msr_high | vmx_msr_low;
> > +
> > + if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW)
> > + set_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
> > + if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_VNMI)
> > + set_cpu_cap(c, X86_FEATURE_VNMI);
> > + if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS) {
> > + rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
> > + vmx_msr_low, vmx_msr_high);
> > + msr_ctl2 = vmx_msr_high | vmx_msr_low;
> > + if ((msr_ctl2 &
> X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC) &&
> > + (msr_ctl &
> X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW))
> > + set_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
> > + if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_EPT)
> > + set_cpu_cap(c, X86_FEATURE_EPT);
> > + if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VPID)
> > + set_cpu_cap(c, X86_FEATURE_VPID);
> > + }
> > +}
> > +
> > static void init_centaur(struct cpuinfo_x86 *c) { #ifdef
> > CONFIG_X86_32 @@ -128,6 +166,14 @@ static void init_centaur(struct
> > cpuinfo_x86 *c)
> > clear_cpu_cap(c, 0*32+31);
> > #endif
> > early_init_centaur(c);
> > +
> > + if (c->cpuid_level > 9) {
> > + unsigned eax = cpuid_eax(10);
>
> Missing newline between variable declaration and code. checkpatch.pl
> should have told you that.
>
OK.
> > + /* Check for version and the number of counters */
> > + if ((eax & 0xff) && (((eax >> 8) & 0xff) > 1))
>
> Magic constants and a comment which does not explain how the check
> works.
>
OK. I will explain more detail in the comments.
> > + set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
>
> Thanks,
>
> tglx
Thanks,
---
David
