如果需要用到半虚拟化技术肯定就需要查看cpu是否支持了。查看方式就是cat /proc/cpuinfo 查看flags是否有vmx和svm。那这些flags都表示什么呢？
86
32位又名i386-i686和64位又名amd64。这些cpu基本就是你的工作站，笔记本电脑或服务器。
64位（x86_64/AMD64/Intel64）？ lm 硬件虚拟化（VMX/AMD-V）？vmx（英特尔），svm（AMD） 加速AES（AES-NI）？ aes TXT（TPM）？ smx 管理程序（如此宣布）？ hypervisor
所有的flags
完整的flags列表位于文件的内核源代码中 arch/x86/include/asm/cpufeatures.h。
英特尔定义的CPU功能
查看
| flags | 功能 |
|---|---|
| fpu | Onboard FPU (floating point support) |
| vme | Virtual 8086 mode enhancements |
| de | Debugging Extensions (CR4.DE) |
| pse | Page Size Extensions (4MB memory pages) |
| tsc | Time Stamp Counter (RDTSC) |
| msr | Model-Specific Registers (RDMSR, WRMSR) |
| pae | Physical Address Extensions (support for more than 4GB of RAM) |
| mce | Machine Check Exception |
| cx8 | CMPXCHG8 instruction (64-bit compare-and-swap) |
| apic | Onboard APIC |
| sep | SYSENTER/SYSEXIT |
| mtrr | Memory Type Range Registers |
| pge | Page Global Enable (global bit in PDEs and PTEs) |
| mca | Machine Check Architecture |
| cmov | CMOV instructions (conditional move) (also FCMOV) |
| pat | Page Attribute Table |
| pse36 | 36-bit PSEs (huge pages) |
| pn | Processor serial number |
| clflush | Cache Line Flush instruction |
| dts | Debug Store (buffer for debugging and profiling instructions) |
| acpi | ACPI via MSR (temperature monitoring and clock speed modulation) |
| mmx | Multimedia Extensions |
| fxsr | FXSAVE/FXRSTOR, CR4.OSFXSR |
| sse | Intel SSE vector instructions |
| sse2 | SSE2 |
| ss | CPU self snoop |
| ht | Hyper-Threading |
| tm | Automatic clock control (Thermal Monitor) |
| ia64 | Intel Itanium Architecture 64-bit (not to be confused with Intel’s 64-bit x86 architecture with flag x86-64 or “AMD64” bit indicated by flag lm) |
| pbe | Pending Break Enable (PBE# pin) wakeup support |
AMD-defined CPU features, CPUID level 0x80000001 See also Wikipedia and table 2-23 in Intel Advanced Vector Extensions Programming Reference
| flags | 功能 |
|---|---|
| syscall | SYSCALL (Fast System Call) and SYSRET (Return From Fast System Call) |
| mp | Multiprocessing Capable. |
| nx | Execute Disable |
| mmxext | AMD MMX extensions |
| fxsr_opt | FXSAVE/FXRSTOR optimizations |
| pdpe1gb | One GB pages (allows hugepagesz=1G) |
| rdtscp | Read Time-Stamp Counter and Processor ID |
| lm | Long Mode (x86-64 amd64, also known as Intel 64, i.e. 64-bit capable) |
| 3dnowext | AMD 3DNow! extensions |
| 3dnow | 3DNow! (AMD vector instructions, competing with Intel’s SSE1) |
Transmeta-defined CPU features, CPUID level 0x80860001
| flags | 功能 |
|---|---|
| recovery | CPU in recovery mode |
| longrun | Longrun power control |
| lrti | LongRun table interface |
| Other features, Linux-defined mapping | |
| cxmmx | Cyrix MMX extensions |
| k6_mtrr | AMD K6 nonstandard MTRRs |
| cyrix_arr | Cyrix ARRs (= MTRRs) |
| centaur_mcr | Centaur MCRs (= MTRRs) |
| constant_tsc | TSC ticks at a constant rate |
| up | SMP kernel running on UP |
| art | Always-Running Timer |
| arch_perfmon | Intel Architectural PerfMon |
| pebs | Precise-Event Based Sampling |
| bts | Branch Trace Store |
| rep_good | rep microcode works well |
| acc_power | AMD accumulated power mechanism |
| nopl | The NOPL (0F 1F) instructions |
| xtopology | cpu topology enum extensions |
| tsc_reliable | TSC is known to be reliable |
| nonstop_tsc | TSC does not stop in C states |
| cpuid | CPU has CPUID instruction itself |
| extd_apicid | has extended APICID (8 bits) |
| amd_dcm | multi-node processor |
| aperfmperf | APERFMPERF |
| eagerfpu | Non lazy FPU restore |
| nonstop_tsc_s3 | TSC doesn’t stop in S3 state |
| tsc_known_freq | TSC has known frequency |
| mce_recovery | CPU has recoverable machine checks |
Intel-defined CPU features, CPUID level 0x00000001 (ecx) See also Wikipedia and table 2-26 in Intel Advanced Vector Extensions Programming Reference
| flags | 功能 |
|---|---|
| pni | SSE-3 (“Prescott New Instructions”) |
| pclmulqdq | Perform a Carry-Less Multiplication of Quadword instruction — accelerator for GCM) |
| dtes64 | 64-bit Debug Store |
| monitor | Monitor/Mwait support (Intel SSE3 supplements) |
| ds_cpl | CPL Qual. Debug Store |
| vmx | Hardware virtualization, Intel VMX |
| smx | Safer mode, TXT (TPM support) |
| est | Enhanced SpeedStep |
| tm2 | Thermal Monitor 2 |
| ssse3 | Supplemental SSE-3 |
| cid | Context ID |
| sdbg | silicon debug |
| fma | Fused multiply-add |
| cx16 | CMPXCHG16B |
| xtpr | Send Task Priority Messages |
| pdcm | Performance Capabilities |
| pcid | Process Context Identifiers |
| dca | Direct Cache Access |
| sse4_1 | SSE-4.1 |
| sse4_2 | SSE-4.2 |
| x2apic | x2APIC |
| movbe | Move Data After Swapping Bytes instruction |
| popcnt | Return the Count of Number of Bits Set to 1 instruction (Hamming weight, i.e. bit count) |
| tsc_deadline_timer | Tsc deadline timer |
| aes/aes-ni | Advanced Encryption Standard (New Instructions) |
| xsave | Save Processor Extended States, also provides XGETBY,XRSTOR,XSETBY |
| avx | Advanced Vector Extensions |
| f16c | 16-bit fp conversions (CVT16) |
| rdrand | Read Random Number from hardware random number generator instruction |
| hypervisor | Running on a hypervisor |
VIA/Cyrix/Centaur-defined CPU features, CPUID level 0xC0000001
| flags | 功能 |
|---|---|
| rng | Random Number Generator present (xstore) |
| rng_en | Random Number Generator enabled |
| ace | on-CPU crypto (xcrypt) |
| ace_en | on-CPU crypto enabled |
| ace2 | Advanced Cryptography Engine v2 |
| ace2_en | ACE v2 enabled |
| phe | PadLock Hash Engine |
| phe_en | PHE enabled |
| pmm | PadLock Montgomery Multiplier |
| pmm_en | PMM enabled |
More extended AMD flags CPUID level 0x80000001, ecx
| flags | 功能 |
|---|---|
| lahf_lm | Load AH from Flags (LAHF) and Store AH into Flags (SAHF) in long mode |
| cmp_legacy | If yes HyperThreading not valid |
| svm | “Secure virtual machine”, AMD-V |
| extapic | Extended APIC space |
| cr8_legacy | CR8 in 32-bit mode |
| abm | Advanced Bit Manipulation |
| sse4a | SSE-4A |
| misalignsse | indicates if a general-protection exception (#GP) is generated when some legacy SSE instructions operate on unaligned data. Also depends on CR0 and Alignment Checking bit |
| 3dnowprefetch | 3DNow prefetch instructions |
| osvw | indicates OS Visible Workaround, which allows the OS to work around processor errata. |
| ibs | Instruction Based Sampling |
| xop | extended AVX instructions |
| skinit | SKINIT/STGI instructions |
| wdt | Watchdog timer |
| lwp | Light Weight Profiling |
| fma4 | 4 operands MAC instructions |
| tce | translation cache extension |
| nodeid_msr | NodeId MSR |
| tbm | Trailing Bit Manipulation |
| topoext | Topology Extensions CPUID leafs |
| perfctr_core | Core Performance Counter Extensions |
| perfctr_nb | NB Performance Counter Extensions |
| bpext | data breakpoint extension |
| ptsc | performance time-stamp counter |
| perfctr_l2 | L2 Performance Counter Extensions |
| mwaitx | MWAIT extension (MONITORX/MWAITX) |
Auxiliary flags, Linux defined - For features scattered in various CPUID levels
| flags | 功能 |
|---|---|
| ring3mwait | Ring 3 MONITOR/MWAIT |
| cpuid_fault | Intel CPUID faulting |
| cpb | AMD Core Performance Boost |
| epb | IA32_ENERGY_PERF_BIAS support |
| cat_l3 | Cache Allocation Technology L3 |
| cat_l2 | Cache Allocation Technology L2 |
| cdp_l3 | Code and Data Prioritization L3 |
| invpcid_single | effectively invpcid and CR4.PCIDE=1 |
| hw_pstate | AMD HW-PState |
| proc_feedback | AMD ProcFeedbackInterface |
| sme | AMD Secure Memory Encryption |
| pti | Kernel Page Table Isolation (Kaiser) |
| retpoline | Retpoline mitigation for Spectre variant 2 (indirect branches) |
| retpoline_amd | AMD Retpoline mitigation |
| intel_ppin | Intel Processor Inventory Number |
| avx512_4vnniw | AVX-512 Neural Network Instructions |
| avx512_4fmaps | AVX-512 Multiply Accumulation Single precision |
| mba | Memory Bandwidth Allocation |
| rsb_ctxsw | Fill RSB on context switches |
| Virtualization flags | Linux defined |
| tpr_shadow | Intel TPR Shadow |
| vnmi | Intel Virtual NMI |
| flexpriority | Intel FlexPriority |
| ept | Intel Extended Page Table |
| vpid | Intel Virtual Processor ID |
| vmmcall | prefer VMMCALL to VMCALL |
Intel-defined CPU features, CPUID level 0x00000007:0 (ebx)
| flags | 功能 |
|---|---|
| fsgsbase | {RD/WR}{FS/GS}BASE instructions |
| tsc_adjust | TSC adjustment MSR |
| bmi1 | 1st group bit manipulation extensions |
| hle | Hardware Lock Elision |
| avx2 | AVX2 instructions |
| smep | Supervisor Mode Execution Protection |
| bmi2 | 2nd group bit manipulation extensions |
| erms | Enhanced REP MOVSB/STOSB |
| invpcid | Invalidate Processor Context ID |
| rtm | Restricted Transactional Memory |
| cqm | Cache QoS Monitoring |
| mpx | Memory Protection Extension |
| rdt_a | Resource Director Technology Allocation |
| avx512f | AVX-512 foundation |
| avx512dq | AVX-512 Double/Quad instructions |
| rdseed | The RDSEED instruction |
| adx | The ADCX and ADOX instructions |
| smap | Supervisor Mode Access Prevention |
| clflushopt | CLFLUSHOPT instruction |
| clwb | CLWB instruction |
| intel_pt | Intel Processor Tracing |
| avx512pf | AVX-512 Prefetch |
| avx512er | AVX-512 Exponential and Reciprocal |
| avx512cd | AVX-512 Conflict Detection |
| sha_ni | SHA1/SHA256 Instruction Extensions |
| avx512bw | AVX-512 Byte/Word instructions |
| avx512vl | AVX-512 128/256 Vector Length extensions |
Extended state features, CPUID level 0x0000000d:1 (eax)
| flags | 功能 |
|---|---|
| xsaveopt | Optimized XSAVE |
| xsavec | XSAVEC |
| xgetbv1 | XGETBV with ECX = 1 |
| xsaves | XSAVES/XRSTORS |
Intel-defined CPU QoS sub-leaf, CPUID level 0x0000000F:0 (edx)
| flags | 功能 |
|---|---|
| cqm_llc | LLC QoS |
Intel-defined CPU QoS sub-leaf, CPUID level 0x0000000F:1 (edx)
| flags | 功能 |
|---|---|
| cqm_occup_llc | LLC occupancy monitoring |
| cqm_mbm_total | LLC total MBM monitoring |
| cqm_mbm_local | LLC local MBM monitoring |
AMD-defined CPU features, CPUID level 0x80000008 (ebx)
| flags | 功能 |
|---|---|
| clzero | CLZERO instruction |
| irperf | instructions retired performance counter |
| xsaveerptr | Always save/restore FP error pointers |
Thermal and Power Management leaf, CPUID level 0x00000006 (eax)
| flags | 功能 |
|---|---|
| dtherm (formerly dts) | digital thermal sensor |
| ida | Intel Dynamic Acceleration |
| arat | Always Running APIC Timer |
| pln | Intel Power Limit Notification |
| pts | Intel Package Thermal Status |
| hwp | Intel Hardware P-states |
| hwp_notify | HWP notification |
| hwp_act_window | HWP Activity Window |
| hwp_epp | HWP Energy Performance Preference |
| hwp_pkg_req | HWP package-level request |
AMD SVM Feature Identification, CPUID level 0x8000000a (edx)
| flags | 功能 |
|---|---|
| npt | AMD Nested Page Table support |
| lbrv | AMD LBR Virtualization support |
| svm_lock | AMD SVM locking MSR |
| nrip_save | AMD SVM next_rip save |
| tsc_scale | AMD TSC scaling support |
| vmcb_clean | AMD VMCB clean bits support |
| flushbyasid | AMD flush-by-ASID support |
| decodeassists | AMD Decode Assists support |
| pausefilter | AMD filtered pause intercept |
| pfthreshold | AMD pause filter threshold |
| avic | Virtual Interrupt Controller |
| vmsave_vmload | Virtual VMSAVE VMLOAD |
| vgif | Virtual GIF |
Intel-defined CPU features, CPUID level 0x00000007:0 (ecx)
| flags | 功能 |
|---|---|
| avx512vbmi | AVX512 Vector Bit Manipulation instructions |
| umip | User Mode Instruction Protection |
| pku | Protection Keys for Userspace |
| ospke | OS Protection Keys Enable |
| avx512_vbmi2 | Additional AVX512 Vector Bit Manipulation instructions |
| gfni | Galois Field New Instructions |
| vaes | Vector AES |
| vpclmulqdq | Carry-Less Multiplication Double Quadword |
| avx512_vnni | Vector Neural Network Instructions |
| avx512_bitalg | VPOPCNT[B,W] and VPSHUF-BITQMB instructions |
| avx512_vpopcntdq | POPCNT for vectors of DW/QW |
| la57 | 5-level page tables |
| rdpid | RDPID instruction |
| AMD-defined CPU features, CPUID level 0x80000007 (ebx) |
| flags | 功能 |
|---|---|
| overflow_recov | MCA overflow recovery support |
| succor | uncorrectable error containment and recovery |
| smca | Scalable MCA |
Detected CPU bugs (Linux-defined)
| flags | 功能 |
|---|---|
| f00f | Intel F00F |
| fdiv | CPU FDIV |
| coma | Cyrix 6x86 coma |
| amd_tlb_mmatch | tlb_mmatch AMD Erratum 383 |
| amd_apic_c1e | apic_c1e AMD Erratum 400 |
| 11ap | Bad local APIC aka 11AP |
| fxsave_leak | FXSAVE leaks FOP/FIP/FOP |
| clflush_monitor | AAI65, CLFLUSH required before MONITOR |
| sysret_ss_attrs | SYSRET doesn’t fix up SS attrs |
| espfix | ”” IRET to 16-bit SS corrupts ESP/RSP high bits |
| null_seg | Nulling a selector preserves the base |
| swapgs_fence | SWAPGS without input dep on GS |
| monitor | IPI required to wake up remote CPU |
| amd_e400 | CPU is among the affected by Erratum 400 |
| cpu_meltdown | CPU is affected by meltdown attack and needs kernel page table isolation |
| spectre_v1 | CPU is affected by Spectre variant 1 attack with conditional branches |
| spectre_v2 | CPU is affected by Spectre variant 2 attack with indirect branches |
| spec_store_bypass | CPU is affected by the Speculative Store Bypass vulnerability (Spectre variant 4). |
P.S. This listing was derived from arch/x86/include/asm/cpufeatures.h in the kernel source. The flags are listed in the same order as the source code. Please help by adding links to descriptions of features when they’re missing, by writing a short description of features that have an unexpressive names, and by updating the list for new kernel versions. The current list is from Linux 4.15 plus some later additions.
