qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Jon Kohler <jon@nutanix.com>
To: pbonzini@redhat.com, zhao1.liu@intel.com, qemu-devel@nongnu.org,
	pawan.kumar.gupta@linux.intel.com
Cc: Jon Kohler <jon@nutanix.com>
Subject: [PATCH 0/5] target/i386: introduce ITS_NO to several models
Date: Thu,  6 Nov 2025 10:46:20 -0700	[thread overview]
Message-ID: <20251106174626.49930-1-jon@nutanix.com> (raw)

ITS_NO is a synthetic bit that indicates to a guest VM that it is
running on hardware that A) is not vulnerable to ITS vulnerability and
B) will not be migrated to a host that is vulnerable to ITS.

Guests will use ITS_NO to opt out of mitigating against ITS.

Intel Sapphire Rapids and higher are all invulnerable to ITS.

Note: for posterity, add MSR_ARCH_CAP_ITS_NO bit definition, such that
future CPU models can add ITS_NO without needing a sub version for
its-no.

Jon Kohler (5):
  target/i386: Add MSR_IA32_ARCH_CAPABILITIES ITS_NO
  target/i386: introduce SapphireRapids-v5 to expose ITS_NO
  target/i386: introduce GraniteRapids-v4 to expose ITS_NO
  target/i386: introduce SierraForest-v4 to expose ITS_NO
  target/i386: introduce ClearwaterForest-v2 to expose ITS_NO

 target/i386/cpu.c | 35 +++++++++++++++++++++++++++++++++++
 target/i386/cpu.h |  1 +
 2 files changed, 36 insertions(+)

-- 
2.43.0



             reply	other threads:[~2025-11-06 17:06 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-11-06 17:46 Jon Kohler [this message]
2025-11-06 17:46 ` [PATCH 1/5] target/i386: Add MSR_IA32_ARCH_CAPABILITIES ITS_NO Jon Kohler
2025-11-06 17:46 ` [PATCH 2/5] target/i386: introduce SapphireRapids-v5 to expose ITS_NO Jon Kohler
2025-11-06 17:46 ` [PATCH 3/5] target/i386: introduce GraniteRapids-v4 " Jon Kohler
2025-11-06 17:46 ` [PATCH 4/5] target/i386: introduce SierraForest-v4 " Jon Kohler
2025-11-06 17:46 ` [PATCH 5/5] target/i386: introduce ClearwaterForest-v2 " Jon Kohler

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=20251106174626.49930-1-jon@nutanix.com \
    --to=jon@nutanix.com \
    --cc=pawan.kumar.gupta@linux.intel.com \
    --cc=pbonzini@redhat.com \
    --cc=qemu-devel@nongnu.org \
    --cc=zhao1.liu@intel.com \
    /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;
as well as URLs for NNTP newsgroup(s).