From nobody Sun Apr 19 09:18:49 2026 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 C2E59374E71; Tue, 3 Mar 2026 23:59:19 +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=1772582361; cv=none; b=YSP7K8qT0g7kjfdm+2UP6WCx1pdfScd0zQj6V3ui32b979zRJ7htnzWrIpuTB7HvvhJBWclqehCkeIkXP8Wko/+jHdhntXHrPHuqheb5zfQrP5mJc7A3HTWs8je/bDEgkMJahu2ikancnsJz4nV865oR6VYKQU2h4Yh2LZ+fDpE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772582361; c=relaxed/simple; bh=toZ7S88XMEjC8NPxeHVoJo35s2tl0+7VV3fLAQfPT/8=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=jCL6fHM3bjPQYgcoxBTuZdrlBXVWJIlwTK/Pg4DYGDMgdf/gfyfpOT1fdl7qeRqGCKnBhLq91EtF7Ks0hyC1UnxZCPN02AisRqBE3fzPUSANereOdC0p+6mmzPbqipPJ3SNPeeJFRQxQFgFAPo2NR5uQoPeL+pVaS/B+uWJIdMg= 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=mA6q3Hq0; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=0WFXNDvR; 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="mA6q3Hq0"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="0WFXNDvR" Date: Tue, 03 Mar 2026 23:59:14 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1772582355; 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=L9PPkUvRdZD4n0k9QpNMGhXyiOmnQ6qhzRpgbP9ZJfQ=; b=mA6q3Hq0apWmgVrU+nx+ts9Tr94hquSeiG8wNRhwJLMm8KOWLxVd3W98dvUEo0Na0fUiBb CJWxuXr9oXHqQ5IJ4xuKjHIj70rVBuwntR9nZwilphuHmIgm083P8nBv11boEHXU6Al+RH XzdgTxjAIv9isd7keWMzGPbdJbMPzq7VdMflAWx+1qawY8sImVy1EsFaVfoOL38lfoAc4B DZokfoJUmt68OPvEuMcBlqEDAxM7zIQ1LN5uq4FqSZ3F5EYtN5fVMQCa37oryCfRjH5Y4S 4PhiyjFmai8ooOKIN5VMwTLwPhlX7gCUBJNKFs71yNL3e/Jzq1O8gLEokD6L1A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1772582355; 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=L9PPkUvRdZD4n0k9QpNMGhXyiOmnQ6qhzRpgbP9ZJfQ=; b=0WFXNDvRzdq0qZGK0lo+DyIfQTW6HxVeu4HSgDN9zuyQNIGXqeC8B8QyKfuoif0KMJ+HyI +7zvnDhtkTtiQtDg== From: "tip-bot2 for Sohil Mehta" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/cpu] x86/cpu: Remove LASS restriction on EFI Cc: Sohil Mehta , Dave Hansen , Tony Luck , "Maciej Wieczor-Retman" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20260120234730.2215498-4-sohil.mehta@intel.com> References: <20260120234730.2215498-4-sohil.mehta@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <177258235440.1647592.17897502271877489630.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/cpu branch of tip: Commit-ID: 68400c1aaf02636a97c45ba198110b66feb270a9 Gitweb: https://git.kernel.org/tip/68400c1aaf02636a97c45ba198110b66f= eb270a9 Author: Sohil Mehta AuthorDate: Tue, 20 Jan 2026 15:47:30 -08:00 Committer: Dave Hansen CommitterDate: Tue, 03 Mar 2026 09:49:45 -08:00 x86/cpu: Remove LASS restriction on EFI The initial LASS enabling has been deferred to much later during boot, and EFI runtime services now run with LASS temporarily disabled. This removes LASS from the path of all EFI services. Remove the LASS restriction on EFI config, as the two can now coexist. Signed-off-by: Sohil Mehta Signed-off-by: Dave Hansen Tested-by: Tony Luck Tested-by: Maciej Wieczor-Retman Link: https://patch.msgid.link/20260120234730.2215498-4-sohil.mehta@intel.c= om --- arch/x86/kernel/cpu/common.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 8c56d59..3557f0e 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -415,14 +415,9 @@ static __always_inline void setup_lass(struct cpuinfo_= x86 *c) * Legacy vsyscall page access causes a #GP when LASS is active. * Disable LASS because the #GP handler doesn't support vsyscall * emulation. - * - * Also disable LASS when running under EFI, as some runtime and - * boot services rely on 1:1 mappings in the lower half. */ - if (IS_ENABLED(CONFIG_X86_VSYSCALL_EMULATION) || - IS_ENABLED(CONFIG_EFI)) { + if (IS_ENABLED(CONFIG_X86_VSYSCALL_EMULATION)) setup_clear_cpu_cap(X86_FEATURE_LASS); - } } =20 static int enable_lass(unsigned int cpu)