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: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 5f76bf1..99468db 100644 (file)
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -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

diff --git a/include/asm-x86/cpufeature.h b/include/asm-x86/cpufeature.h
index 7ac4d93..8d45690 100644 (file)
--- a/include/asm-x86/cpufeature.h
+++ b/include/asm-x86/cpufeature.h
@@ -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>