Re: [RFC PATCH v3] tools/x86: add kcpuid tool to show raw CPU features

[Borislav Petkov]

On Thu, Oct 22, 2020 at 01:21:23PM +0800, Feng Tang wrote:
> diff --git a/tools/arch/x86/kcpuid/kcpuid.c b/tools/arch/x86/kcpuid/kcpuid.c
> new file mode 100644
> index 0000000..9bd35b7
> --- /dev/null
> +++ b/tools/arch/x86/kcpuid/kcpuid.c
> @@ -0,0 +1,618 @@
> +// SPDX-License-Identifier: GPL-2.0

You need here:

#define _GNU_SOURCE

otherwise:

cc -Wextra -O2 -Wall -I../../../include -o kcpuid kcpuid.c 
kcpuid.c: In function ‘parse_line’:
kcpuid.c:324:6: warning: implicit declaration of function ‘strcasestr’; did you mean ‘strcasecmp’? [-Wimplicit-function-declaration]
  324 |  if (strcasestr(buf, "EAX"))
      |      ^~~~~~~~~~
      |      strcasecmp


Also, options text needs fixing:

  usage: kcpuid [-abdfhr] [-l leaf] [-s subleaf]
        -a|--all             Show info of all CPUID leafs and subleafs(default on)
        -b|--bitflags        Show boolean flags only
        -d|--detail          Show details of the flag/fields
        -f|--flags           Show boolean flags only

that f is user_csv, above in the "usage" line too.

        -h|--help            Show usage info
        -l|--leaf=index      Specify the leaf you want to check
        -r|--raw             Show raw cpuid data
        -s|--subleaf=sub     Specify the subleaf you want to check

> +/*
> + * Parse text file, and construct the array of all CPUID leafs and subleafs
> + */
> +static void parse_text(void)
> +{
> +	FILE *file;
> +	char *filename, *line = NULL;

Do here:

	char *filename = def_csv;

> +	size_t len = 0;
> +	int ret;
> +
> +	if (show_raw)
> +		return;
> +
> +	filename = user_csv ? user_csv : def_csv;

And now you do:

	if (user_csv)
		filename = user_csv;


But something's not working still. I've added debug output and it chokes
on the test data:

$ ./kcpuid -f cpuid.csv 
This platform has 51 CPUID leafs and subleafs.

parse_text: filename: cpuid.csv
open
parsing [# The basic row format is:
]parsing [# LEAF,SUBLEAF,register_name,bits,short name,long description
]parsing [
]parsing [# Leaf 00H
]parsing [         0,    0,  EAX,   31:0, max_basic_leafs,  Max input value for supported subleafs
]parsing [# Leaf 01H
]parsing [         1,    0,  EAX,    3:0, stepping,  Stepping ID
]parsing [         1,    0,  EAX,    7:4, model,  Model
]parsing [         1,    0,  EAX,   11:8, family,  Family ID
]parsing [         1,    0,  EAX,  13:12, processor,  Processor Type
]parsing [         1,    0,  EAX,  19:16, model_ext,  Extended Model ID
]parsing [         1,    0,  EAX,  27:20, family_ext,  Extended Family ID
]parsing [
]parsing [         1,    0,  EBX,    7:0, brand,  Brand Index
]parsing [         1,    0,  EBX,   15:8, clflush_size,  CLFLUSH line size (value * 8) in bytes
]parsing [         1,    0,  EBX,  23:16, max_cpu_id,  Maxim number of addressable logic cpu in this package
]parsing [         1,    0,  EBX,  31:24, apic_id,  Initial APIC ID
]parsing [
]parsing [         1,    0,  ECX,      0, sse3,  Streaming SIMD Extensions 3(SSE3)
]parsing [         1,    0,  ECX,      1, pclmulqdq,  PCLMULQDQ instruction supported
]parsing [         1,    0,  ECX,      2, dtes64,  DS area uses 64-bit layout
]parsing [         1,    0,  ECX,      3, mwait,  MONITOR/MWAIT supported
]parsing [         1,    0,  ECX,      4, ds_cpl,  CPL Qualified Debug Store which allows for branch message storage qualified by CPL
]parsing [         1,    0,  ECX,      5, vmx,  Virtual Machine Extensions supported
]parsing [         1,    0,  ECX,      6, smx,  Safer Mode Extension supported
]parsing [         1,    0,  ECX,      7, eist,  Enhanced Intel SpeedStep Technology
]parsing [         1,    0,  ECX,      8, tm2,  Thermal Monitor 2
]parsing [         1,    0,  ECX,      9, ssse3,  Supplemental Streaming SIMD Extensions 3 (SSSE3)
]parsing [         1,    0,  ECX,     10, l1_ctx_id,  L1 data cache could be set to either adaptive mode or shared mode (check IA32_MISC_ENABLE bit 24 definition)
]parsing [         1,    0,  ECX,     11, sdbg,  IA32_DEBUG_INTERFACE MSR for silicon debug supported
]parsing [         1,    0,  ECX,     12, fma,  FMA extensions using YMM state supported
]parsing [         1,    0,  ECX,     13, cmpxchg16b,  'CMPXCHG16B - Compare and Exchange Bytes' supported
]parsing [         1,    0,  ECX,     14, xtpr_update,  xTPR Update Control supported
]parsing [         1,    0,  ECX,     15, pdcm,  Perfmon and Debug Capability present
]parsing [         1,    0,  ECX,     17, pcid,  Process-Context Identifiers feature present
]parsing [         1,    0,  ECX,     18, dca,  Prefetching data from a memory mapped device supported
]parsing [         1,    0,  ECX,     19, sss4_1,  SSE4.1 feature present
]parsing [         1,    0,  ECX,     20, sse4_2,  SSE4.2 feature present
]parsing [         1,    0,  ECX,     21, x2apic,  x2APIC supported
]parsing [         1,    0,  ECX,     22, movbe,  MOVBE instruction supported
]parsing [         1,    0,  ECX,     23, popcnt,  POPCNT instruction supported
]parsing [         1,    0,  ECX,     24, tsc_deadline_timer,  LAPIC supports one-shot operation using a TSC deadline value
]parsing [         1,    0,  ECX,     25, aesni,  AESNI instruction supported
]parsing [         1,    0,  ECX,     26, xsave,  XSAVE/XRSTOR processor extended states (XSETBV/XGETBV/XCR0)
]parsing [         1,    0,  ECX,     27, osxsave,  OS has set CR4.OSXSAVE bit to enable XSETBV/XGETBV/XCR0
]parsing [         1,    0,  ECX,     28, avx,  AVX instruction supported
]parsing [         1,    0,  ECX,     29, f16c,  16-bit floating-point conversion instruction supported
]parsing [         1,    0,  ECX,     30, rdrand,  RDRAND instruction supported
]parsing [
]parsing [#
]parsing [# !!! Test data for testing different options, will be updated in formal version
]parsing [#
]parsing [         4,    0,  ECX,      1, aaa,  AAA
Segmentation fault
$

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette