Add an entry in struct cpuinfo_x86 to track VMX capabilities and fill the capabilities during IA32_FEAT_CTL MSR initialization.
Make the VMX capabilities dependent on IA32_FEAT_CTL 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/feat_ctl.c | 74 ++++++++++++++++++++++++++++++ 5 files changed, 89 insertions(+)
diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu index 526425fcaedc..bc3a497c029c 100644 --- a/arch/x86/Kconfig.cpu +++ b/arch/x86/Kconfig.cpu @@ -391,6 +391,10 @@ config IA32_FEAT_CTL def_bool y depends on CPU_SUP_INTEL || CPU_SUP_CENTAUR || CPU_SUP_ZHAOXIN
+config X86_VMX_FEATURE_NAMES + def_bool y + depends on IA32_FEAT_CTL && 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 b49b88bae92f..6fb4870ed759 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 4c743ba40ff1..0d04d8bf15a5 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 9d6a35a4586e..df1eacd26443 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1449,6 +1449,9 @@ 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/feat_ctl.c b/arch/x86/kernel/cpu/feat_ctl.c index a46c9e46f937..cbd8bfe9b87b 100644 --- a/arch/x86/kernel/cpu/feat_ctl.c +++ b/arch/x86/kernel/cpu/feat_ctl.c @@ -4,10 +4,80 @@ #include <asm/cpufeature.h> #include <asm/msr-index.h> #include <asm/processor.h> +#include <asm/vmx.h>
#undef pr_fmt #define pr_fmt(fmt) "x86/cpu: " fmt
+#ifdef CONFIG_X86_VMX_FEATURE_NAMES +enum vmx_feature_leafs { + MISC_FEATURES = 0, + PRIMARY_CTLS, + SECONDARY_CTLS, + NR_VMX_FEATURE_WORDS, +}; + +#define VMX_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. + * + * Use raw rdmsr() for primary processor controls and pin controls MSRs + * as they exist on any CPU that supports VMX, i.e. we want the WARN if + * the RDMSR faults. + */ + rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, ign, supported); + c->vmx_capability[PRIMARY_CTLS] = supported; + + rdmsr_safe(MSR_IA32_VMX_PROCBASED_CTLS2, &ign, &supported); + c->vmx_capability[SECONDARY_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] |= VMX_F(EPT_EXECUTE_ONLY); + if (ept & VMX_EPT_AD_BIT) + c->vmx_capability[MISC_FEATURES] |= VMX_F(EPT_AD); + if (ept & VMX_EPT_1GB_PAGE_BIT) + c->vmx_capability[MISC_FEATURES] |= VMX_F(EPT_1GB); + + /* Synthetic APIC features that are aggregates of multiple features. */ + if ((c->vmx_capability[PRIMARY_CTLS] & VMX_F(VIRTUAL_TPR)) && + (c->vmx_capability[SECONDARY_CTLS] & VMX_F(VIRT_APIC_ACCESSES))) + c->vmx_capability[MISC_FEATURES] |= VMX_F(FLEXPRIORITY); + + if ((c->vmx_capability[PRIMARY_CTLS] & VMX_F(VIRTUAL_TPR)) && + (c->vmx_capability[SECONDARY_CTLS] & VMX_F(APIC_REGISTER_VIRT)) && + (c->vmx_capability[SECONDARY_CTLS] & VMX_F(VIRT_INTR_DELIVERY)) && + (c->vmx_capability[MISC_FEATURES] & VMX_F(POSTED_INTR))) + c->vmx_capability[MISC_FEATURES] |= VMX_F(APICV); +} +#endif /* CONFIG_X86_VMX_FEATURE_NAMES */ + void init_ia32_feat_ctl(struct cpuinfo_x86 *c) { bool tboot = tboot_enabled(); @@ -50,5 +120,9 @@ void init_ia32_feat_ctl(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 } }