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
next 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
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