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Commit e38e05a8 authored by Sheng Yang's avatar Sheng Yang Committed by Ingo Molnar
Browse files

x86: extended "flags" to show virtualization HW feature 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 digging into the source code.

The patch add a new catagory in "flags" under /proc/cpuinfo. Now "flags"
can indicate the (important) HW virtulization features the CPU supported
as well.

Current implementation just cover Intel VMX side.

Signed-off-by: default avatarSheng Yang <sheng.yang@intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 315a6558

arch/x86/kernel/cpu/intel.c

+41 −0
Original line number Diff line number Diff line
@@ -196,6 +196,44 @@ static int __cpuinit intel_num_cpu_cores(struct cpuinfo_x86 *c) 
		return 1;

}



static void __cpuinit detect_vmx_virtcap(struct cpuinfo_x86 *c)

{

	/* 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



	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);



	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 __cpuinit init_intel(struct cpuinfo_x86 *c)

{

	unsigned int l2 = 0;
@@ -289,6 +327,9 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c) 


	/* Work around errata */

	srat_detect_node();



	if (cpu_has(c, X86_FEATURE_VMX))

		detect_vmx_virtcap(c);

}



#ifdef CONFIG_X86_32

include/asm-x86/cpufeature.h

+8 −1
Original line number Diff line number Diff line
@@ -6,7 +6,7 @@ 


#include <asm/required-features.h>



#define NCAPINTS	8	/* N 32-bit words worth of info */

#define NCAPINTS	9	/* N 32-bit words worth of info */



/*

 * Note: If the comment begins with a quoted string, that string is used
@@ -150,6 +150,13 @@ 
 */

#define X86_FEATURE_IDA		(7*32+ 0) /* Intel Dynamic Acceleration */



/* Virtualization flags: Linux defined */

#define X86_FEATURE_TPR_SHADOW  (8*32+ 0) /* Intel TPR Shadow */

#define X86_FEATURE_VNMI        (8*32+ 1) /* Intel Virtual NMI */

#define X86_FEATURE_FLEXPRIORITY (8*32+ 2) /* Intel FlexPriority */

#define X86_FEATURE_EPT         (8*32+ 3) /* Intel Extended Page Table */

#define X86_FEATURE_VPID        (8*32+ 4) /* Intel Virtual Processor ID */



#if defined(__KERNEL__) && !defined(__ASSEMBLY__)



#include <linux/bitops.h>