From: Ingo Molnar <mingo@kernel.org>
To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: dave.hansen@intel.com, bp@alien8.de, chang.seok.bae@intel.com,
dave.hansen@linux.intel.com, linux-kernel@vger.kernel.org,
mingo@redhat.com, tglx@linutronix.de, x86@kernel.org
Subject: Re: [PATCH RFC v1 02/11] x86/fpu/xstate: Introduce xstate order table and accessor macro
Date: Thu, 27 Feb 2025 20:42:00 +0100 [thread overview]
Message-ID: <Z8DACBJUqZ8WwgpO@gmail.com> (raw)
In-Reply-To: <1a73d33b-e943-4ddd-9373-4678ff85c90a@citrix.com>
* Andrew Cooper <andrew.cooper3@citrix.com> wrote:
> On 2/27/25 19:03, Dave Hansen wrote:
>
> > On 2/27/25 10:44, Chang S. Bae wrote:
> >> The kernel has largely assumed that higher xstate component numbers
> >> correspond to later offsets in the buffer. However, this assumption
> >> does not hold for the non-compacted format, where a newer state
> >> component may have a lower offset.
> > Maybe "no longer holds" instead of "does not hold".
> >
> > This never happened before APX, right?
>
> I'm afraid that AMD beat you there by a decade with LWP, index 63 but
> also overlaps the MPX state.
https://giphy.com/gifs/moodman-TJawtKM6OCKkvwCIqX
> Except LWP support never became mainstream, and it also got
> sacrificed to make room for IBPB in microcode, so you can safely
> ignore it[1].
yay! CPU makers always chose the right solution, once they have
exhaused all the alternatives.
Thanks,
Ingo
next prev parent reply other threads:[~2025-02-27 19:42 UTC|newest]
Thread overview: 112+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-27 18:44 [PATCH RFC v1 00/11] x86: Support Intel Advanced Performance Extensions Chang S. Bae
2025-02-27 18:44 ` [PATCH RFC v1 01/11] x86/fpu/xstate: Simplify print_xstate_features() Chang S. Bae
2025-02-27 18:51 ` Dave Hansen
2025-02-27 18:52 ` Ingo Molnar
2025-02-27 19:04 ` [tip: x86/fpu] " tip-bot2 for Chang S. Bae
2025-02-27 18:44 ` [PATCH RFC v1 02/11] x86/fpu/xstate: Introduce xstate order table and accessor macro Chang S. Bae
2025-02-27 19:03 ` Dave Hansen
2025-02-27 19:34 ` Andrew Cooper
2025-02-27 19:42 ` Ingo Molnar [this message]
2025-03-20 23:46 ` Chang S. Bae
2025-02-27 19:05 ` Ingo Molnar
2025-02-27 19:32 ` Dave Hansen
2025-02-27 19:36 ` Ingo Molnar
2025-02-27 19:49 ` Andrew Cooper
2025-02-27 20:06 ` Ingo Molnar
2025-02-27 21:10 ` Andrew Cooper
2025-02-27 21:28 ` Ingo Molnar
2025-02-27 21:30 ` Ingo Molnar
2025-02-27 22:23 ` Andrew Cooper
2025-02-28 3:10 ` Chang S. Bae
2025-02-28 17:11 ` Ingo Molnar
2025-02-27 19:56 ` Dave Hansen
2025-02-27 20:02 ` Ingo Molnar
2025-02-27 20:19 ` Dave Hansen
2025-02-27 20:29 ` Ingo Molnar
2025-02-27 21:17 ` Dave Hansen
2025-02-27 21:37 ` Ingo Molnar
2025-02-27 23:54 ` Dave Hansen
2025-02-28 15:20 ` Sean Christopherson
2025-02-27 18:44 ` [PATCH RFC v1 03/11] x86/fpu/xstate: Remove xstate offset check Chang S. Bae
2025-02-27 18:44 ` [PATCH RFC v1 04/11] x86/fpu/xstate: Adjust XSAVE buffer size calculation Chang S. Bae
2025-02-27 18:44 ` [PATCH RFC v1 05/11] x86/fpu/xstate: Adjust xstate copying logic for user ABI Chang S. Bae
2025-02-27 18:44 ` [PATCH RFC v1 06/11] x86/fpu/mpx: Remove MPX xstate component support Chang S. Bae
2025-02-27 19:12 ` Ingo Molnar
2025-02-28 3:12 ` Chang S. Bae
2025-03-20 23:47 ` Chang S. Bae
2025-04-01 17:13 ` Chang S. Bae
2025-02-27 18:44 ` [PATCH RFC v1 07/11] x86/cpufeatures: Add X86_FEATURE_APX Chang S. Bae
2025-02-27 18:44 ` [PATCH RFC v1 08/11] x86/fpu/apx: Define APX state component Chang S. Bae
2025-02-27 18:44 ` [PATCH RFC v1 09/11] x86/fpu/apx: Disallow conflicting MPX presence Chang S. Bae
2025-02-27 23:16 ` Dave Hansen
2025-02-27 23:58 ` Chang S. Bae
2025-02-27 18:44 ` [PATCH RFC v1 10/11] x86/fpu/apx: Enable APX state support Chang S. Bae
2025-02-27 18:44 ` [PATCH RFC v1 11/11] selftests/x86/apx: Add APX test Chang S. Bae
2025-02-27 19:15 ` [PATCH RFC v1 00/11] x86: Support Intel Advanced Performance Extensions Ingo Molnar
2025-02-27 19:36 ` Dave Hansen
2025-02-28 3:10 ` Chang S. Bae
2025-03-20 23:42 ` [PATCH RFC v2 0/9] " Chang S. Bae
2025-03-20 23:42 ` [PATCH RFC v2 1/9] x86/fpu/xstate: Remove xstate offset check Chang S. Bae
2025-03-25 10:18 ` [tip: x86/fpu] " tip-bot2 for Chang S. Bae
2025-04-14 7:34 ` [tip: x86/merge] " tip-bot2 for Chang S. Bae
2025-03-20 23:42 ` [PATCH RFC v2 2/9] x86/fpu/xstate: Introduce xfeature order table and accessor macro Chang S. Bae
2025-03-25 10:18 ` [tip: x86/fpu] " tip-bot2 for Chang S. Bae
2025-04-14 7:34 ` [tip: x86/merge] " tip-bot2 for Chang S. Bae
2025-03-20 23:42 ` [PATCH RFC v2 3/9] x86/fpu/xstate: Adjust XSAVE buffer size calculation Chang S. Bae
2025-03-25 10:28 ` [tip: x86/fpu] " tip-bot2 for Chang S. Bae
2025-04-14 7:34 ` [tip: x86/merge] " tip-bot2 for Chang S. Bae
2025-03-20 23:42 ` [PATCH RFC v2 4/9] x86/fpu/xstate: Adjust xstate copying logic for user ABI Chang S. Bae
2025-03-25 10:18 ` [tip: x86/fpu] " tip-bot2 for Chang S. Bae
2025-03-25 10:28 ` tip-bot2 for Chang S. Bae
2025-04-14 7:34 ` [tip: x86/merge] " tip-bot2 for Chang S. Bae
2025-03-20 23:42 ` [PATCH RFC v2 5/9] x86/cpufeatures: Add X86_FEATURE_APX Chang S. Bae
2025-04-11 16:12 ` [PATCH RFC v2a " Chang S. Bae
2025-04-11 16:54 ` Sohil Mehta
2025-04-11 18:23 ` Chang S. Bae
2025-04-11 21:57 ` Sohil Mehta
2025-04-12 8:43 ` Ingo Molnar
2025-04-14 8:23 ` Ingo Molnar
2025-04-14 17:28 ` Sohil Mehta
2025-04-14 17:32 ` Dave Hansen
2025-04-14 17:45 ` Sohil Mehta
2025-04-14 18:02 ` Chang S. Bae
2025-04-14 18:12 ` Sohil Mehta
2025-04-14 18:31 ` Chang S. Bae
2025-04-16 2:16 ` [PATCH 00/10] x86/fpu: APX enablement and assorted FPU code improvements Chang S. Bae
2025-04-16 2:16 ` [PATCH 01/10] x86/cpufeatures: Add X86_FEATURE_APX Chang S. Bae
2025-04-16 8:17 ` [tip: x86/fpu] " tip-bot2 for Chang S. Bae
2025-04-16 2:16 ` [PATCH 02/10] x86/fpu/apx: Define APX state component Chang S. Bae
2025-04-16 8:17 ` [tip: x86/fpu] " tip-bot2 for Chang S. Bae
2025-04-16 2:16 ` [PATCH 03/10] x86/fpu/apx: Disallow conflicting MPX presence Chang S. Bae
2025-04-16 8:17 ` [tip: x86/fpu] " tip-bot2 for Chang S. Bae
2025-04-16 2:16 ` [PATCH 04/10] x86/fpu/apx: Enable APX state support Chang S. Bae
2025-04-16 8:17 ` [tip: x86/fpu] " tip-bot2 for Chang S. Bae
2025-04-16 2:16 ` [PATCH 05/10] selftests/x86/apx: Add APX test Chang S. Bae
2025-04-16 8:17 ` [tip: x86/fpu] " tip-bot2 for Chang S. Bae
2025-04-16 2:16 ` [PATCH 06/10] x86/fpu: Log XSAVE disablement consistently Chang S. Bae
2025-04-16 8:17 ` [tip: x86/fpu] " tip-bot2 for Chang S. Bae
2025-04-16 16:56 ` [PATCH 06/10] " Sohil Mehta
2025-04-16 17:03 ` Chang S. Bae
2025-04-16 18:04 ` Sohil Mehta
2025-04-16 2:16 ` [PATCH 07/10] x86/fpu: Refactor xfeature bitmask update code for sigframe XSAVE Chang S. Bae
2025-04-16 8:05 ` Ingo Molnar
2025-04-16 16:55 ` Chang S. Bae
2025-04-16 8:17 ` [tip: x86/fpu] " tip-bot2 for Chang S. Bae
2025-04-16 2:16 ` [PATCH 08/10] x86/pkeys: Simplify PKRU update in signal frame Chang S. Bae
2025-04-16 8:17 ` [tip: x86/fpu] " tip-bot2 for Chang S. Bae
2025-04-16 2:16 ` [PATCH 09/10] x86/fpu: Remove export of mxcsr_feature_mask Chang S. Bae
2025-04-16 8:17 ` [tip: x86/fpu] " tip-bot2 for Chang S. Bae
2025-04-16 2:17 ` [PATCH 10/10] x86/fpu: Rename fpu_reset_fpregs() to fpu_reset_fpstate_regs() Chang S. Bae
2025-04-16 8:17 ` [tip: x86/fpu] " tip-bot2 for Chang S. Bae
2025-04-16 8:07 ` [PATCH 00/10] x86/fpu: APX enablement and assorted FPU code improvements Ingo Molnar
2025-04-16 16:56 ` Chang S. Bae
2025-03-20 23:42 ` [PATCH RFC v2 6/9] x86/fpu/apx: Define APX state component Chang S. Bae
2025-04-11 22:54 ` Sohil Mehta
2025-03-20 23:42 ` [PATCH RFC v2 7/9] x86/fpu/apx: Disallow conflicting MPX presence Chang S. Bae
2025-04-14 17:09 ` Sohil Mehta
2025-04-14 17:25 ` Dave Hansen
2025-03-20 23:42 ` [PATCH RFC v2 8/9] x86/fpu/apx: Enable APX state support Chang S. Bae
2025-04-14 15:41 ` Sohil Mehta
2025-03-20 23:43 ` [PATCH RFC v2 9/9] selftests/x86/apx: Add APX test Chang S. Bae
2025-04-14 16:02 ` Sohil Mehta
2025-03-25 10:25 ` [PATCH RFC v2 0/9] x86: Support Intel Advanced Performance Extensions Ingo Molnar
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