Add an entry in struct cpuinfo_x86 to track VMX capabilities and fill the capabilities during IA32_FEATURE_CONTROL MSR initialization.
Make the VMX capabilities dependent on X86_FEATURE_CONTROL_MSR and X86_FEATURE_NAMES so as to avoid unnecessary overhead on CPUs that can't possibly support VMX, or when /proc/cpuinfo is not available.
Signed-off-by: Sean Christopherson sean.j.christopherson@intel.com --- arch/x86/Kconfig.cpu | 4 ++ arch/x86/include/asm/processor.h | 3 ++ arch/x86/include/asm/vmxfeatures.h | 5 ++ arch/x86/kernel/cpu/common.c | 3 ++ arch/x86/kernel/cpu/feature_control.c | 70 +++++++++++++++++++++++++++ 5 files changed, 85 insertions(+)
diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu index e78f39adae7b..e7571bd0f515 100644 --- a/arch/x86/Kconfig.cpu +++ b/arch/x86/Kconfig.cpu @@ -391,6 +391,10 @@ config X86_FEATURE_CONTROL_MSR def_bool y depends on CPU_SUP_INTEL || CPU_SUP_CENTAUR || CPU_SUP_ZHAOXIN
+config X86_VMX_FEATURE_NAMES + def_bool y + depends on X86_FEATURE_CONTROL_MSR && X86_FEATURE_NAMES + menuconfig PROCESSOR_SELECT bool "Supported processor vendors" if EXPERT ---help--- diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 772de8917430..5b27877c4477 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -85,6 +85,9 @@ struct cpuinfo_x86 { #ifdef CONFIG_X86_64 /* Number of 4K pages in DTLB/ITLB combined(in pages): */ int x86_tlbsize; +#endif +#ifdef CONFIG_X86_VMX_FEATURE_NAMES + __u32 vmx_capability[NVMXINTS]; #endif __u8 x86_virt_bits; __u8 x86_phys_bits; diff --git a/arch/x86/include/asm/vmxfeatures.h b/arch/x86/include/asm/vmxfeatures.h index aea39b9f1587..bfc96d4049a7 100644 --- a/arch/x86/include/asm/vmxfeatures.h +++ b/arch/x86/include/asm/vmxfeatures.h @@ -2,6 +2,11 @@ #ifndef _ASM_X86_VMXFEATURES_H #define _ASM_X86_VMXFEATURES_H
+/* + * Defines VMX CPU feature bits + */ +#define NVMXINTS 3 /* N 32-bit words worth of info */ + /* * Note: If the comment begins with a quoted string, that string is used * in /proc/cpuinfo instead of the macro name. If the string is "", diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index baa2fed8deb6..f0aff0ab4ef5 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1448,6 +1448,9 @@ static void identify_cpu(struct cpuinfo_x86 *c) #endif c->x86_cache_alignment = c->x86_clflush_size; memset(&c->x86_capability, 0, sizeof(c->x86_capability)); +#ifdef CONFIG_X86_VMX_FEATURE_NAMES + memset(&c->vmx_capability, 0, sizeof(c->vmx_capability)); +#endif
generic_identify(c);
diff --git a/arch/x86/kernel/cpu/feature_control.c b/arch/x86/kernel/cpu/feature_control.c index 2bd1a9e6021a..d49c42e1166c 100644 --- a/arch/x86/kernel/cpu/feature_control.c +++ b/arch/x86/kernel/cpu/feature_control.c @@ -4,6 +4,72 @@ #include <asm/cpufeature.h> #include <asm/msr-index.h> #include <asm/processor.h> +#include <asm/vmx.h> + +#ifdef CONFIG_X86_VMX_FEATURE_NAMES +enum vmx_feature_leafs { + MISC_FEATURES = 0, + PRIMARY_PROC_CTLS, + SECONDARY_PROC_CTLS, + NR_VMX_FEATURE_WORDS, +}; + +#define F(x) BIT(VMX_FEATURE_##x & 0x1f) + +static void init_vmx_capabilities(struct cpuinfo_x86 *c) +{ + u32 supported, funcs, ept, vpid, ign; + + BUILD_BUG_ON(NVMXINTS != NR_VMX_FEATURE_WORDS); + + /* + * The high bits contain the allowed-1 settings, i.e. features that can + * be turned on. The low bits contain the allowed-0 settings, i.e. + * features that can be turned off. Ignore the allowed-0 settings, + * if a feature can be turned on then it's supported. + */ + rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, ign, supported); + c->vmx_capability[PRIMARY_PROC_CTLS] = supported; + + rdmsr_safe(MSR_IA32_VMX_PROCBASED_CTLS2, &ign, &supported); + c->vmx_capability[SECONDARY_PROC_CTLS] = supported; + + rdmsr(MSR_IA32_VMX_PINBASED_CTLS, ign, supported); + rdmsr_safe(MSR_IA32_VMX_VMFUNC, &ign, &funcs); + + /* + * Except for EPT+VPID, which enumerates support for both in a single + * MSR, low for EPT, high for VPID. + */ + rdmsr_safe(MSR_IA32_VMX_EPT_VPID_CAP, &ept, &vpid); + + /* Pin, EPT, VPID and VM-Func are merged into a single word. */ + WARN_ON_ONCE(supported >> 16); + WARN_ON_ONCE(funcs >> 4); + c->vmx_capability[MISC_FEATURES] = (supported & 0xffff) | + ((vpid & 0x1) << 16) | + ((funcs & 0xf) << 28); + + /* EPT bits are full on scattered and must be manually handled. */ + if (ept & VMX_EPT_EXECUTE_ONLY_BIT) + c->vmx_capability[MISC_FEATURES] |= F(EPT_EXECUTE_ONLY); + if (ept & VMX_EPT_AD_BIT) + c->vmx_capability[MISC_FEATURES] |= F(EPT_AD); + if (ept & VMX_EPT_1GB_PAGE_BIT) + c->vmx_capability[MISC_FEATURES] |= F(EPT_1GB); + + /* Synthetic APIC features that are aggregates of multiple features. */ + if ((c->vmx_capability[PRIMARY_PROC_CTLS] & F(VIRTUAL_TPR)) && + (c->vmx_capability[SECONDARY_PROC_CTLS] & F(VIRT_APIC_ACCESSES))) + c->vmx_capability[MISC_FEATURES] |= F(FLEXPRIORITY); + + if ((c->vmx_capability[PRIMARY_PROC_CTLS] & F(VIRTUAL_TPR)) && + (c->vmx_capability[SECONDARY_PROC_CTLS] & F(APIC_REGISTER_VIRT)) && + (c->vmx_capability[SECONDARY_PROC_CTLS] & F(VIRT_INTR_DELIVERY)) && + (c->vmx_capability[MISC_FEATURES] & F(POSTED_INTR))) + c->vmx_capability[MISC_FEATURES] |= F(APICV); +} +#endif /* CONFIG_X86_VMX_FEATURE_NAMES */
#undef pr_fmt #define pr_fmt(fmt) "x86/cpu: " fmt @@ -53,5 +119,9 @@ void init_feature_control_msr(struct cpuinfo_x86 *c) pr_err_once("VMX (%s TXT) disabled by BIOS\n", tboot ? "inside" : "outside"); clear_cpu_cap(c, X86_FEATURE_VMX); + } else { +#ifdef CONFIG_X86_VMX_FEATURE_NAMES + init_vmx_capabilities(c); +#endif } }