From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0E44A30DEA6; Tue, 20 Jan 2026 06:57:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768892247; cv=none; b=MTkNENiouZtfkX5bLDl7q+YjPaw4qvaFaOaYfOeu5oV9hR9vXO5JTy0B2eZJDWBFkH3N6H7SOe4qxA85/7IQWXy/a3t1BB7QgqCJ9dR53NTy13Pk3fr2dj5X5dxvtaSWUdexHMQoHzCXPd83otVkRfth9Dl2eA+KoSDpwh9HFLM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768892247; c=relaxed/simple; bh=3Iut3vWBR4ORWGRTckLdfnkoVnRmJ3Ea3o7FsYVU4iE=; h=Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc: Message-Id:References:To; b=meKuD6o7pjuH4sOGJyH1pDTx4BKzMDryn8T0RyJBw7C1Ic7+s2IZcugo9lqIuqEjjCby1to9F9TcqYaJNL8uwgWaio1EhFOsYMXLU4nEL5GukTIx/vknPsvGdTowqJ99LJ2rQuat58vDkgdlnkvnE/1cnAGtu/C9MtuLupx9Mrw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=iAA5iIAx; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="iAA5iIAx" Received: from smtpclient.apple (c-24-130-165-117.hsd1.ca.comcast.net [24.130.165.117]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 60K6ueNx3503645 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 19 Jan 2026 22:56:40 -0800 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 60K6ueNx3503645 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2025122301; t=1768892202; bh=3Iut3vWBR4ORWGRTckLdfnkoVnRmJ3Ea3o7FsYVU4iE=; h=Subject:From:In-Reply-To:Date:Cc:References:To:From; b=iAA5iIAxtvT/7WYoWaMOSg5I7o+LVEwPByGsfL8bulkOSaAtMG2yi5nPFREBY029w 4fftLudPh61VpCTWWO8Ru/+ibyb2pXYyd/DO8osaE5/wh5IMQ5urGINei2LspA0rh5 jH7ROv3U6Fk1UYktKD/2OxbHScfC9gwEGtudWHM+yQ2VtCJvBp3ZFX7y11kc7pcqiS AZBMuTHoxwCZ7H6jaVhNRRFqACnuOfkqXrkGFTR83syxcnUd7nMj7jWiMA33Zx8jZK Kjz0AkzUU1giY63LIwcPYJ+R5hqpKhNdv27HFbtt8tLLwTBjgpLIvamObHNfRVdMI2 D150vjmt8+wVQ== Content-Type: text/plain; charset=utf-8 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3864.300.41.1.7\)) Subject: Re: [PATCH v9 17/22] KVM: x86: Advertise support for FRED From: Xin Li In-Reply-To: Date: Mon, 19 Jan 2026 22:56:29 -0800 Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, pbonzini@redhat.com, seanjc@google.com, corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, luto@kernel.org, peterz@infradead.org, andrew.cooper3@citrix.com, hch@infradead.org, sohil.mehta@intel.com Content-Transfer-Encoding: quoted-printable Message-Id: <71F2B269-4D29-4B23-9111-E43CDD09CF13@zytor.com> References: <20251026201911.505204-1-xin@zytor.com> <20251026201911.505204-18-xin@zytor.com> To: Chao Gao X-Mailer: Apple Mail (2.3864.300.41.1.7) > On Nov 11, 2025, at 11:30=E2=80=AFPM, Chao Gao = wrote: >=20 > I'm not sure if AMD CPUs support FRED, but just in case, we can clear = FRED > i.e., kvm_cpu_cap_clear(X86_FEATURE_FRED) in svm_set_cpu_caps(). AMD will support FRED, with ISA level compatibility: = https://www.amd.com/en/blogs/2025/amd-and-intel-celebrate-first-anniversar= y-of-x86-ecosys.html Thus we don=E2=80=99t need to clear the bit.