From: Dave Hansen <dave.hansen@intel.com>
To: "Ahmed S. Darwish" <darwi@linutronix.de>,
Borislav Petkov <bp@alien8.de>, Ingo Molnar <mingo@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Andrew Cooper <andrew.cooper3@citrix.com>,
"H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, John Ogness <john.ogness@linutronix.de>,
x86-cpuid@lists.linux.dev, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1 07/12] tools/x86/kcpuid: Add rudimentary CPU vendor detection
Date: Fri, 7 Mar 2025 07:03:43 -0800 [thread overview]
Message-ID: <0ade78e7-7a3c-459d-bf1c-f0bb1f24baee@intel.com> (raw)
In-Reply-To: <20250306205000.227399-8-darwi@linutronix.de>
On 3/6/25 12:49, Ahmed S. Darwish wrote:
> The kcpuid CSV file will soon be updated with CPUID indices that are only
> valid for certain CPU vendors, such as Centaur or Transmeta. Thus,
> introduce rudimentary x86 vendor detection to kcpuid.
Do we really need the vendor detection? For example, look at the end of
cpuid(1)'s output:
# cpuid -1 --raw
...
0x20000000 0x00: eax=0x00000000 ebx=0x00000000 ecx=0x00000000
edx=0x00000000
...
0x80860000 0x00: eax=0x00000000 ebx=0x00000000 ecx=0x00000000
edx=0x00000000
0xc0000000 0x00: eax=0x00000000 ebx=0x00000000 ecx=0x00000000
edx=0x00000000
It seems to just blindly poke at all of the CPUID regions. There are
only a handful of these and there's no hard in poking at them other
than an extra couple of executions of CPUID.
next prev parent reply other threads:[~2025-03-07 15:03 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-06 20:49 [PATCH v1 00/12] tools/x86/kcpuid: x86-cpuid-db v2.2 update Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 01/12] tools/x86/kcpuid: Fix error handling Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 02/12] tools/x86/kcpuid: Remove unused local variable Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 03/12] tools/x86/kcpuid: Remove unused global variable Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 04/12] tools/x86/kcpuid: Simplify usage() handling Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 05/12] tools/x86/kcpuid: Refactor CPUID range handling for future expansion Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 06/12] tools/x86/kcpuid: Extend CPUID index mask macro Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 07/12] tools/x86/kcpuid: Add rudimentary CPU vendor detection Ahmed S. Darwish
2025-03-06 21:07 ` Andrew Cooper
2025-03-07 14:06 ` Ahmed S. Darwish
2025-03-06 22:00 ` Dave Hansen
2025-03-07 13:48 ` Ahmed S. Darwish
2025-03-07 15:46 ` H. Peter Anvin
2025-03-07 15:03 ` Dave Hansen [this message]
2025-03-10 14:21 ` Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 08/12] tools/x86/kcpuid: Restrict CPUID scanning to valid vendor ranges Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 09/12] tools/x86/kcpuid: Define Transmeta and Centaur index ranges Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 10/12] tools/x86/kcpuid: Update bitfields to x86-cpuid-db v2.0 Ahmed S. Darwish
2025-03-07 3:18 ` H. Peter Anvin
2025-03-07 15:07 ` Ahmed S. Darwish
2025-03-07 15:27 ` H. Peter Anvin
2025-03-10 14:47 ` Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 11/12] tools/x86/kcpuid: Update bitfields to x86-cpuid-db v2.2 Ahmed S. Darwish
2025-03-06 20:50 ` [PATCH v1 12/12] MAINTAINERS: Include kcpuid under X86 CPUID DATABASE Ahmed S. Darwish
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=0ade78e7-7a3c-459d-bf1c-f0bb1f24baee@intel.com \
--to=dave.hansen@intel.com \
--cc=andrew.cooper3@citrix.com \
--cc=bp@alien8.de \
--cc=darwi@linutronix.de \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=john.ogness@linutronix.de \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=tglx@linutronix.de \
--cc=x86-cpuid@lists.linux.dev \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.