From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx.denx.de (mx.denx.de [89.58.32.78]) (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 252AE215792; Fri, 18 Apr 2025 16:54:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=89.58.32.78 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744995285; cv=none; b=SrbtII8PX2dm6R8SpSMPQFxWOqRrTDPiYMQdlzanII2MvVgULv9G1UN/EczaI2a6pRN/lULuAkBKA06/jHrqWIM5efyQDvoO5SQLZhjZchTashH8jbuGAmKcL5inkQ/texE5wBLhCHpasdEBcIRZdzqgZd8mfXLgLmy1mcUb7QQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744995285; c=relaxed/simple; bh=j7fNl3tHVUdXIBqTvyHtLGQvCjLhT0OY1thb0ltxEyo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kLVBPc+MJfhMVnaQgkBZO96Oj27m44NxjOTD1IrMs+SttTYgmRueTTnvpXHwPbhjdOkZolLdOFDLtqpmVF4rcs2bWtbcMmMnozo8uDpv6CAAmC+be6c7Zqw7x0B3gafnLGsPdywSvdszDl3kpXH/VHYDLLcqSPvC+qjQ6uDaL68= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=denx.de; spf=pass smtp.mailfrom=denx.de; dkim=pass (2048-bit key) header.d=denx.de header.i=@denx.de header.b=Kb/7DIgt; arc=none smtp.client-ip=89.58.32.78 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=denx.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=denx.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=denx.de header.i=@denx.de header.b="Kb/7DIgt" Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 71E451026E029; Fri, 18 Apr 2025 18:54:34 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=mx-20241105; t=1744995280; h=from:subject:date:message-id:to:cc:mime-version:content-type: in-reply-to:references; bh=TAqX++6Pz/ZYQQAXoqXwuM4rSIQviXyqdaPFZ7+tlKo=; b=Kb/7DIgtRcM41ZsxZkrECY9DLkPpFfYpIUGIo+o031MdcoVIPPj7zWKbmntUdnptQ4u78d ALl5SJSjmXnigieQ6oDUD8hCI13qjnKp83KLwag4xicWOZw11CD5ishAMs2Yc3aTV+zYs+ xAWzZe5qJTReQ8rAe5IAZ/iVmoezsHDTlsDS1zy/B0nC2mtqWc9DIGnXHx6E+Z47KEGGzn oE8ZdoH6ro+Vlze+bCPwEysByjyMGXsOjzG72KCRHOSb1yZN0FGObsNPjFqgYVB+NW1CdH ah5EA2UcM463UfMXEay2ZIgBr2pxecWQxTjn9joG6NRi3qDzEl0KZD2mnXqGUQ== Date: Fri, 18 Apr 2025 18:54:32 +0200 From: Pavel Machek To: Sasha Levin Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Max Grobecker , Ingo Molnar , Borislav Petkov , tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com, x86@kernel.org, thomas.lendacky@amd.com, perry.yuan@amd.com, mario.limonciello@amd.com, riel@surriel.com, mjguzik@gmail.com, seanjc@google.com, darwi@linutronix.de Subject: Re: [PATCH AUTOSEL 5.10 2/6] x86/cpu: Don't clear X86_FEATURE_LAHF_LM flag in init_amd_k8() on AMD when running in a virtual machine Message-ID: References: <20250331143710.1686600-1-sashal@kernel.org> <20250331143710.1686600-2-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="+9WIDzG7gKAFMWwy" Content-Disposition: inline In-Reply-To: <20250331143710.1686600-2-sashal@kernel.org> X-Last-TLS-Session-Version: TLSv1.3 --+9WIDzG7gKAFMWwy Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > From: Max Grobecker >=20 > [ Upstream commit a4248ee16f411ac1ea7dfab228a6659b111e3d65 ] > This can prevent some docker containers from starting or build scripts to= create > unoptimized binaries. >=20 > Admittably, this is more a small inconvenience than a severe bug in the k= ernel > and the shoddy scripts that rely on parsing /proc/cpuinfo > should be fixed instead. I'd say this is not good stable candidate. Best regards, Pavel > +++ b/arch/x86/kernel/cpu/amd.c > @@ -839,7 +839,7 @@ static void init_amd_k8(struct cpuinfo_x86 *c) > * (model =3D 0x14) and later actually support it. > * (AMD Erratum #110, docId: 25759). > */ > - if (c->x86_model < 0x14 && cpu_has(c, X86_FEATURE_LAHF_LM)) { > + if (c->x86_model < 0x14 && cpu_has(c, X86_FEATURE_LAHF_LM) && !cpu_has(= c, X86_FEATURE_HYPERVISOR)) { > clear_cpu_cap(c, X86_FEATURE_LAHF_LM); > if (!rdmsrl_amd_safe(0xc001100d, &value)) { > value &=3D ~BIT_64(32); --=20 DENX Software Engineering GmbH, Managing Director: Erika Unter HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany --+9WIDzG7gKAFMWwy Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABECAB0WIQRPfPO7r0eAhk010v0w5/Bqldv68gUCaAKDyAAKCRAw5/Bqldv6 8pngAJ903ri4tAqDyAQ87mK58oN4vwjsvACghbk/ai+TZYVEE7l+NIcp0w76jF4= =N72X -----END PGP SIGNATURE----- --+9WIDzG7gKAFMWwy--