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From: "Ahmed S. Darwish" <darwi@linutronix.de>
To: Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Andrew Cooper <andrew.cooper3@citrix.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Sean Christopherson <seanjc@google.com>,
	David Woodhouse <dwmw2@infradead.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Christian Ludloff <ludloff@gmail.com>,
	Sohil Mehta <sohil.mehta@intel.com>,
	Maciej Wieczor-Retman <m.wieczorretman@pm.me>,
	John Ogness <john.ogness@linutronix.de>,
	x86@kernel.org, x86-cpuid@lists.linux.dev,
	LKML <linux-kernel@vger.kernel.org>
Subject: [ANNOUNCE] x86-cpuid-db: Release v3.0
Date: Fri, 27 Mar 2026 04:05:50 +0100	[thread overview]
Message-ID: <acX0Drk_6qD97nbq@lx-t490> (raw)

Hi,

I'm happy to announce release 3.0 of the x86-cpuid-db project:

   https://gitlab.com/x86-cpuid.org/x86-cpuid-db
   https://gitlab.com/x86-cpuid.org/x86-cpuid-db/-/releases/v3.0

Changelog v3.0
--------------

Introduce the Linux-defined synthetic CPUID leaves 0x4c780001 and
0x4c780002.  The range ID prefix 0x4c78 is for Linux in its shorthand ASCII
form "Lx", where Linux becomes a virtual vendor akin to hardware vendors
like AMD or Intel.

In these leaves, provide a 1:1 bitfield mapping for what Linux defines in
its synthetic X86_FEATURE words at <asm/cpufeatures.h>.  Designate leaf
0x4c780001 for feature words in a linear order; i.e., subleaf 0 registers
EAX to EDX, then subleaf 1 registers, and so on.  Similarly, designate leaf
0x4c780001 for the X86_BUG words.

Here is the synthetic leaves bitfield listing:

   https://gitlab.com/x86-cpuid.org/x86-cpuid-db/-/blob/v3.0/db/xml/leaf_4c780001.xml
   https://gitlab.com/x86-cpuid.org/x86-cpuid-db/-/blob/v3.0/db/xml/leaf_4c780002.xml

With that, the Linux kernel x86 feature query code can have zero special
cases.  The synthetic CPUID leaves and X86_FEATURE words are collected,
parsed, modified, and queried just like their hardware-backed counterparts.

Update the CPUID database:

 - Leaf 0x23: Introduce subleaf 2, Auto Counter Reload (ACR)
 - Leaf 0x23: Introduce subleaf 4/5, PEBS capabilities and counters
 - Leaf 0x1c: Return LBR depth as a bitmask instead of individual bits
 - Leaf 0x0a: Define more descriptive PMU bitfield names

Thanks to Dave Hansen (Intel), also add the bits:

 - Leaf 0x0a: Various missing PMU events
 - Leaf 0x06: Missing IA32_HWP_CTL flag
 - Leaf 0x0f: Missing non-CPU (IO) Intel RDT bits

Release coverage
----------------

   CPUID leaves:        64 leaves
   CPUID bitfields:     1104 entries
   Linux feature flags: 465 entries
   Xen feature flags:   198 entries

Artifacts
---------

The generated CSV and C header files can be quickly checked in full from
the release artifacts at:

   https://gitlab.com/x86-cpuid.org/x86-cpuid-db/-/releases/v3.0

Thanks!
Ahmed

             reply	other threads:[~2026-03-27  3:05 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-27  3:05 Ahmed S. Darwish [this message]
2026-03-27  9:17 ` [ANNOUNCE] x86-cpuid-db: Release v3.0 David Woodhouse
2026-03-30 20:22   ` Ahmed S. Darwish

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