Re: [PATCH 2/2] x86: Add "virt flag" in /proc/cpuinfo

[Avi Kivity <avi@qumranet.com>]

(copying Ingo)


Yang, Sheng wrote:
> From 54b1bb9fe5d2fe40fc047b43dd4e1a480d41a977 Mon Sep 17 00:00:00 2001
> From: Sheng Yang <sheng.yang@intel.com>
> Date: Tue, 24 Jun 2008 17:03:17 +0800
> Subject: [PATCH] x86: Add "virt flag" in /proc/cpuinfo
>
> The hardware virtualization technology evolves very fast. But currently
> it's hard to tell if your CPU support a certain kind of HW technology without
> dig into the source code.
>
> The patch add a new item under /proc/cpuinfo, named "virt flag". The "virt
> flag" got the similar function as "flag". It is used to indicate what
> features does this CPU supported. It don't cover all features but only the
> important ones.
>
>   

Ingo, do you prefer this as a separate 'virt flags' line or as addition 
to the 'flag' line?

> Current implement just cover Intel VMX side.
>
> Signed-off-by: Sheng Yang <sheng.yang@intel.com>
> ---
>  arch/x86/kernel/cpu/proc.c   |   28 ++++++++++++++++++++++++++++
>  include/asm-x86/cpufeature.h |    9 +++++++++
>  2 files changed, 37 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c
> index 0d0d905..03b30d0 100644
> --- a/arch/x86/kernel/cpu/proc.c
> +++ b/arch/x86/kernel/cpu/proc.c
> @@ -77,6 +77,31 @@ static void show_cpuinfo_misc(struct seq_file *m, struct 
> cpuinfo_x86 *c)
>  }
>  #endif
>
> +static void show_cpuinfo_vmx_virtflag(struct seq_file *m)
> +{
> +	u32 vmx_msr_low, vmx_msr_high, msr_ctl, msr_ctl2;
> +
> +	seq_printf(m, "\nvirt flag\t:");
> +	rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, vmx_msr_low, vmx_msr_high);
> +	msr_ctl = 0xffffffff & vmx_msr_high | vmx_msr_low;
> +	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW)
> +		seq_printf(m, " tpr_shadow");
> +	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_VNMI)
> +		seq_printf(m, " 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 = 0xffffffff & 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))
> +			seq_printf(m, " flexpriority");
> +		if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_EPT)
> +			seq_printf(m, " ept");
> +		if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VPID)
> +			seq_printf(m, " vpid");
> +	}
> +}
> +
>  static int show_cpuinfo(struct seq_file *m, void *v)
>  {
>  	struct cpuinfo_x86 *c = v;
> @@ -123,6 +148,9 @@ static int show_cpuinfo(struct seq_file *m, void *v)
>  		if (cpu_has(c, i) && x86_cap_flags[i] != NULL)
>  			seq_printf(m, " %s", x86_cap_flags[i]);
>
> +	if (cpu_has(c, X86_FEATURE_VMX))
> +		show_cpuinfo_vmx_virtflag(m);
> +
>  	seq_printf(m, "\nbogomips\t: %lu.%02lu\n",
>  		   c->loops_per_jiffy/(500000/HZ),
>  		   (c->loops_per_jiffy/(5000/HZ)) % 100);
> diff --git a/include/asm-x86/cpufeature.h b/include/asm-x86/cpufeature.h
> index 0d609c8..87d8084 100644
> --- a/include/asm-x86/cpufeature.h
> +++ b/include/asm-x86/cpufeature.h
> @@ -84,6 +84,7 @@
>  #define X86_FEATURE_XMM3	(4*32+ 0) /* Streaming SIMD Extensions-3 */
>  #define X86_FEATURE_MWAIT	(4*32+ 3) /* Monitor/Mwait support */
>  #define X86_FEATURE_DSCPL	(4*32+ 4) /* CPL Qualified Debug Store */
> +#define X86_FEATURE_VMX		(4*32+ 5) /* Virtual Machine eXtensions */
>  #define X86_FEATURE_EST		(4*32+ 7) /* Enhanced SpeedStep */
>  #define X86_FEATURE_TM2		(4*32+ 8) /* Thermal Monitor 2 */
>  #define X86_FEATURE_CID		(4*32+10) /* Context ID */
> @@ -113,6 +114,14 @@
>   */
>  #define X86_FEATURE_IDA		(7*32+ 0) /* Intel Dynamic Acceleration */
>
> +/* Intel VMX MSR indicated features */
> +#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
> +
>  #if defined(__KERNEL__) && !defined(__ASSEMBLY__)
>
>  #include <linux/bitops.h>
> --
> 1.5.5
>
>   


-- 
error compiling committee.c: too many arguments to function