From: Xiaoyao Li <xiaoyao.li@intel.com>
To: Zhao Liu <zhao1.liu@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Chao Gao <chao.gao@intel.com>, Xudong Hao <xudong.hao@intel.com>
Subject: Re: [PATCH 2/4] KVM: x86: Advertise AMX CPUIDs in subleaf 0x1E.0x1 to userspace
Date: Fri, 23 Jan 2026 14:02:42 +0800 [thread overview]
Message-ID: <cf20fff4-931a-4a07-83c1-a33de13fa230@intel.com> (raw)
In-Reply-To: <20251120050720.931449-3-zhao1.liu@intel.com>
On 11/20/2025 1:07 PM, Zhao Liu wrote:
> In addition to the new features, CPUID 0x1E.0x1.EAX[bits 0-3] are
> mirrored positions of existing AMX feature bits distributed across the
> 0x7 leaves. To avoid duplicate feature names, name these mirror bits
> with a *_MIRROR suffix, and define them in reverse_cpuid.h as KVM-only
> features as well.
It looks that KVM can emulate the mirroring CPUIDs regardless of whether
hardware supports subleaf 1. However, given such emulation provides no
real benefit but complicates KVM implementation, this patch looks good
to me.
next prev parent reply other threads:[~2026-01-23 6:02 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-20 5:07 [PATCH 0/4] KVM: x86: Advertise new instruction CPUIDs for Intel Diamond Rapids Zhao Liu
2025-11-20 5:07 ` [PATCH 1/4] KVM: x86: Advertise MOVRS CPUID to userspace Zhao Liu
2026-01-23 18:03 ` Sean Christopherson
2025-11-20 5:07 ` [PATCH 2/4] KVM: x86: Advertise AMX CPUIDs in subleaf 0x1E.0x1 " Zhao Liu
2026-01-23 6:02 ` Xiaoyao Li [this message]
2026-01-23 17:53 ` Sean Christopherson
2026-01-23 17:55 ` Sean Christopherson
2026-01-25 7:51 ` Zhao Liu
2026-07-15 23:08 ` Jim Mattson
2026-01-23 18:06 ` Sean Christopherson
2026-01-25 7:54 ` Zhao Liu
2025-11-20 5:07 ` [PATCH 3/4] KVM: x86: Advertise AVX10.2 CPUID " Zhao Liu
2025-11-20 5:07 ` [PATCH 4/4] KVM: x86: Advertise AVX10_VNNI_INT " Zhao Liu
2025-12-18 17:54 ` [PATCH 0/4] KVM: x86: Advertise new instruction CPUIDs for Intel Diamond Rapids Paolo Bonzini
2026-01-21 1:40 ` Zhao Liu
2026-01-23 6:03 ` Xiaoyao Li
2026-02-04 0:10 ` Sean Christopherson
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