From nobody Tue Oct 7 08:35:50 2025 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 E09182EF9A8; Fri, 11 Jul 2025 16:09:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752250177; cv=none; b=bhqLYNm8PNhSd0aQA7S8iLHGFkks7HPRgTfObVjmOs5U2B/So4Hw64uDAM1WGVXoiVAyTP+a3Pqe1bm46V6YxfD4brnzmOxMusu0vRjlwjca3tGOi/TQPUA1SAOar1RzO6fgp7D8Nvatm5/dx/QefKA5VjhuGk340frVsXLv4cU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752250177; c=relaxed/simple; bh=UHMDUuvX/Zgxq4GEzRPOukhTpOjQGHAhlSTNu/YvqGc=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=OKLkK5s9tYqdZ0RUGGTS51fMBgEJ0kihbz21NUxE93nItCwlaHXdeBy9ZeCfTTKGTvpi01Kcd9A+xoiNY+Fn+aM6LWwxMFUCR4x7PbcNS//e0l2/m7S/KdKly1fp1petxRSpFi5kFvNNCtR0p59m6gLD17y/w+v5UmIlsKSQk2g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=3m2Ul64K; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=ko5+EzQN; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="3m2Ul64K"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="ko5+EzQN" Date: Fri, 11 Jul 2025 16:09:33 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1752250174; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=EcmL/QijISVOJjarxU4Isonm5yZshn3xmlijAJS/zEY=; b=3m2Ul64K3k/T8qsM1eGqVVPI78heffn5H7f2KFMzWJM2oFwzQ2bUCGvVur9h68NgpoBayn dSvjFMqbsBh9U3aUSK3BpJHV5CefDOGKi9EqrAdoaHCQOnwndoPFT7XO5llgOOAT+3StSZ AVA4r8j7PjM1jK2g6tVykJ+0Dz3KtVFUXmbFaiyXRkEpSItoKp3KpPv0lYGOgX68a3tfmm /h+I5IV9YiQdPFs/rVvmvfUj8Ck70bfxILJuHZ2K1AkyfFsGXvxE2Ce03xJnWT40KY1zc6 ygZSqxjEHbeCfS730k+pebOXeLsc+D1kFkuBC3DNne8byhhlvgM3S9mVVNl/PA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1752250174; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=EcmL/QijISVOJjarxU4Isonm5yZshn3xmlijAJS/zEY=; b=ko5+EzQNRrr2u9pemOTYSvX8Tao9ixgQmM0udpX+N/r21h/4JHjJ1A6HLu0h4VtvGLy92q SeTwOU8ZEDp4P4DA== From: "tip-bot2 for David Kaplan" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/bugs] x86/bugs: Add attack vector controls for L1TF Cc: David Kaplan , "Borislav Petkov (AMD)" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20250707183316.1349127-17-david.kaplan@amd.com> References: <20250707183316.1349127-17-david.kaplan@amd.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <175225017305.406.13997731550461668881.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the x86/bugs branch of tip: Commit-ID: 2f970a526975f4437bdc9a4ba550ecc7e66d861d Gitweb: https://git.kernel.org/tip/2f970a526975f4437bdc9a4ba550ecc7e= 66d861d Author: David Kaplan AuthorDate: Mon, 07 Jul 2025 13:33:11 -05:00 Committer: Borislav Petkov (AMD) CommitterDate: Fri, 11 Jul 2025 17:56:41 +02:00 x86/bugs: Add attack vector controls for L1TF Use attack vector controls to determine if L1TF mitigation is required. Disable SMT if cross-thread protection is desired. Signed-off-by: David Kaplan Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/20250707183316.1349127-17-david.kaplan@amd.com --- arch/x86/kernel/cpu/bugs.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 94c72f4..2128623 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -2995,17 +2995,23 @@ static void override_cache_bits(struct cpuinfo_x86 = *c) =20 static void __init l1tf_select_mitigation(void) { - if (!boot_cpu_has_bug(X86_BUG_L1TF) || cpu_mitigations_off()) { + if (!boot_cpu_has_bug(X86_BUG_L1TF)) { l1tf_mitigation =3D L1TF_MITIGATION_OFF; return; } =20 - if (l1tf_mitigation =3D=3D L1TF_MITIGATION_AUTO) { - if (cpu_mitigations_auto_nosmt()) - l1tf_mitigation =3D L1TF_MITIGATION_FLUSH_NOSMT; - else - l1tf_mitigation =3D L1TF_MITIGATION_FLUSH; + if (l1tf_mitigation !=3D L1TF_MITIGATION_AUTO) + return; + + if (!should_mitigate_vuln(X86_BUG_L1TF)) { + l1tf_mitigation =3D L1TF_MITIGATION_OFF; + return; } + + if (smt_mitigations =3D=3D SMT_MITIGATIONS_ON) + l1tf_mitigation =3D L1TF_MITIGATION_FLUSH_NOSMT; + else + l1tf_mitigation =3D L1TF_MITIGATION_FLUSH; } =20 static void __init l1tf_apply_mitigation(void)