From: Dave Hansen <dave.hansen@intel.com>
To: Jim Mattson <jmattson@google.com>,
Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
x86@kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH 1/4] x86/fpu: Clear XSTATE_BV[i] in save state whenever XFD[i]=1
Date: Thu, 15 Jan 2026 08:07:16 -0800 [thread overview]
Message-ID: <9beb7ca4-7bcf-45f1-aefa-f8e6e8122ede@intel.com> (raw)
In-Reply-To: <CALMp9eToT-af8kntKK2TiFHHUcUQgU25GaaNqq49RZZt2Buffg@mail.gmail.com>
On 1/6/26 09:56, Jim Mattson wrote:
> Apologies. You're right. Though Intel is a bit coy, the only way to
> interpret that section of the SDM is to conclude that the AMX state in
> the CPU becomes undefined when XFD[18] is set.
I'll touch base with the folks that wrote that blurb. I'm a little
nervous to interpret that "software should not..." blurb as a full
architectural DANGER sign partly because it's in a "RECOMMENDATIONS FOR
SYSTEM SOFTWARE" section.
I'm _sure_ they discussed tying XFD[i] and XINUSE[i] together and there
was a good reason they did not.
next prev parent reply other threads:[~2026-01-15 16:07 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-01 9:05 [PATCH v2 0/4] x86, fpu/kvm: fix crash with AMX Paolo Bonzini
2026-01-01 9:05 ` [PATCH 1/4] x86/fpu: Clear XSTATE_BV[i] in save state whenever XFD[i]=1 Paolo Bonzini
2026-01-03 2:06 ` Yao Yuan
2026-01-05 17:31 ` Sean Christopherson
2026-01-06 5:25 ` Yao Yuan
2026-01-06 0:54 ` Jim Mattson
2026-01-06 1:17 ` Sean Christopherson
2026-01-06 17:56 ` Jim Mattson
2026-01-15 16:07 ` Dave Hansen [this message]
2026-01-15 16:12 ` Paolo Bonzini
2026-01-15 16:27 ` Dave Hansen
2026-01-07 0:28 ` Chang S. Bae
2026-01-07 22:33 ` Paolo Bonzini
2026-01-08 3:06 ` Binbin Wu
2026-01-08 16:26 ` Paolo Bonzini
2026-01-15 15:54 ` Dave Hansen
2026-01-15 16:22 ` Paolo Bonzini
2026-01-15 18:19 ` Dave Hansen
2026-01-15 18:26 ` Paolo Bonzini
2026-01-15 23:43 ` Chang S. Bae
2026-01-01 9:05 ` [PATCH 2/4] selftests: kvm: replace numbered sync points with actions Paolo Bonzini
2026-01-06 0:02 ` Sean Christopherson
2026-01-07 22:28 ` Paolo Bonzini
2026-01-08 20:26 ` Sean Christopherson
2026-01-01 9:05 ` [PATCH 3/4] selftests: kvm: try getting XFD and XSAVE state out of sync Paolo Bonzini
2026-01-01 9:05 ` [PATCH 4/4] selftests: kvm: Verify TILELOADD actually #NM faults when XFD[18]=1 Paolo Bonzini
2026-01-06 1:18 ` [PATCH v2 0/4] x86, fpu/kvm: fix crash with AMX Sean Christopherson
2026-01-15 12:22 ` Borislav Petkov
2026-01-15 13:49 ` Paolo Bonzini
2026-01-15 16:39 ` Sean Christopherson
2026-01-15 17:05 ` Borislav Petkov
2026-01-15 17:12 ` Sean Christopherson
2026-01-16 12:22 ` Borislav Petkov
2026-01-21 11:35 ` Paolo Bonzini
2026-01-22 11:12 ` Borislav Petkov
2026-01-22 12:00 ` Paolo Bonzini
2026-01-23 13:23 ` Borislav Petkov
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=9beb7ca4-7bcf-45f1-aefa-f8e6e8122ede@intel.com \
--to=dave.hansen@intel.com \
--cc=jmattson@google.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=seanjc@google.com \
--cc=stable@vger.kernel.org \
--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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®