From: Jim Mattson <jmattson@google.com>
To: seanjc@google.com, pbonzini@redhat.com, tglx@kernel.org,
mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com,
x86@kernel.org, hpa@zytor.com, shuah@kernel.org,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-kselftest@vger.kernel.org, ctpence@google.com
Cc: Jim Mattson <jmattson@google.com>
Subject: [PATCH v3 0/4] KVM: x86: Virtualize AMD's "disable CPUID in usermode"
Date: Wed, 13 May 2026 15:46:03 -0700 [thread overview]
Message-ID: <20260513224608.1859737-1-jmattson@google.com> (raw)
AMD's "disable CPUID in usermode" feature is analogous to Intel's "CPUID
faulting" feature, but it is advertised and activated differently. The AMD
feature is advertised via CPUID.80000021H:EAX.CpuidUserDis[bit 17] and
activated by setting HWCR.CpuidUserDis[bit 35].
Add virtualization support for the AMD feature.
v2 -> v3:
* Logic consolidation between emulator and CPUID VM-exit handler [Sean]
* Define MSR_K7_HWCR_CPUID_USER_DIS
* Keep u64 in the selftest (oops)
* Fixe the selftest failre on Intel hosts
v1: https://lore.kernel.org/kvm/20260402223108.650572-1-jmattson@google.com/
v2: https://lore.kernel.org/kvm/20260508170714.489136-1-jmattson@google.com/
Jim Mattson (3):
KVM: x86: Remove supports_cpuid_fault() helper
KVM: x86: Virtualize AMD CPUID faulting
KVM: selftests: Update hwcr_msr_test for CPUID faulting bit
Sean Christopherson (1):
KVM: x86: Consolidate CPUID fault handling for emulator and
interception logic
arch/x86/include/asm/kvm_host.h | 1 -
arch/x86/include/asm/msr-index.h | 1 +
arch/x86/kvm/cpuid.c | 7 ++--
arch/x86/kvm/cpuid.h | 14 ++++---
arch/x86/kvm/emulate.c | 6 +--
arch/x86/kvm/kvm_emulate.h | 1 +
arch/x86/kvm/x86.c | 38 +++++++++----------
.../selftests/kvm/include/x86/processor.h | 1 +
.../testing/selftests/kvm/x86/hwcr_msr_test.c | 9 ++++-
9 files changed, 43 insertions(+), 35 deletions(-)
base-commit: 85f871f6ba46f20d7fbc0b016b4db648c33220dd
--
2.54.0.631.ge1b05301d1-goog
next reply other threads:[~2026-05-13 22:46 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-13 22:46 Jim Mattson [this message]
2026-05-13 22:46 ` [PATCH v3 1/4] KVM: x86: Consolidate CPUID fault handling for emulator and interception logic Jim Mattson
2026-05-14 8:41 ` Binbin Wu
2026-05-13 22:46 ` [PATCH v3 2/4] KVM: x86: Remove supports_cpuid_fault() helper Jim Mattson
2026-05-14 8:51 ` Binbin Wu
2026-05-13 22:46 ` [PATCH v3 3/4] KVM: x86: Virtualize AMD CPUID faulting Jim Mattson
2026-05-14 13:19 ` Jim Mattson
2026-05-14 14:28 ` Sean Christopherson
2026-05-14 14:45 ` Jim Mattson
2026-05-13 22:46 ` [PATCH v3 4/4] KVM: selftests: Update hwcr_msr_test for CPUID faulting bit Jim Mattson
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