From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.8]) (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 7816A8248C for ; Thu, 17 Apr 2025 02:50:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.8 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744858235; cv=none; b=gToa++xu+jHUyuTAzzXnnP70G7mRC9rLzmKpPJyOCgN9W6WEel5ASYbqSZO6qa+YdZ0O/NBqwOrp2Urt/jl9xoqokI7v9uUuEFI387K/ark7vqJOduAlrHrDxHJWbpQ3qKb/ruYhqCCz3HBk812idOB6Tk6N3xh0Pk2qulfld30= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744858235; c=relaxed/simple; bh=eUYT3dpebgx2Vo1FupbAiZMiDngB2nyBleDr/EMzWtY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=aJrCKF1JmQfYFdeqVZNFAqq/UsqL6KAYOgzkZnx5Bix+RUrtoz3MgBGKNGQR2Ngc3A+MFcUkRGqpOYcUuln+uiOrofJTOIIxqKYIde5RLdA0HF8xU5u6HSi1oeJ5/68jL4MxTqWn7RLfsHLsmeoZER4LkGIMkjfJqr4jQVhEXYQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=APOFH1mX; arc=none smtp.client-ip=192.198.163.8 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="APOFH1mX" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1744858234; x=1776394234; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=eUYT3dpebgx2Vo1FupbAiZMiDngB2nyBleDr/EMzWtY=; b=APOFH1mXleCNn7SlbN19fPEEieq4U6B4l2YU/2AZNtxdUueYjTLrd+ZF +H5I36y+TjpNVvX0/OQ/1b3o90PrGhwvKmBX4FDgO6xhZ48PTO2bh0zh5 081NmtS7CtOK2BOSs8TtymzptEVxgND1VbGN0+pN5DWbJCjihTvsVjduv sZhGMjrn3rtMHPhEVHI0waHsNYwoZc0UbBH2AJWv7MN7yEGoaXHg02Hdl dnJ5+NbL8zyXRYPlEyycnOLhh7Z/Rvc0PCH5KgA3O3sI1mTgtS4fJC5bc Y79EaP/DaXXVd4MbxdqKSRxIzT66yCiU0XApD+7r2UthMc28s1RGCKXIk g==; X-CSE-ConnectionGUID: 7B/tHwR+TvKvApBW5gpAng== X-CSE-MsgGUID: ToCOKMuQTpmru6JsGksjDw== X-IronPort-AV: E=McAfee;i="6700,10204,11405"; a="63966262" X-IronPort-AV: E=Sophos;i="6.15,217,1739865600"; d="scan'208";a="63966262" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by fmvoesa102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Apr 2025 19:50:34 -0700 X-CSE-ConnectionGUID: O4OaXdwwQCyMWGJ/4a5kOg== X-CSE-MsgGUID: gHkg0ZW/R5WheBCX3AGC6g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.15,217,1739865600"; d="scan'208";a="130634454" Received: from allen-sbox.sh.intel.com (HELO [10.239.159.30]) ([10.239.159.30]) by orviesa006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Apr 2025 19:50:32 -0700 Message-ID: Date: Thu, 17 Apr 2025 10:46:28 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/1] iommu/vt-d: Revert ATS timing change to fix boot failure To: "Tian, Kevin" , Joerg Roedel , Will Deacon , Robin Murphy , Jarkko Nikula Cc: "iommu@lists.linux.dev" , "linux-kernel@vger.kernel.org" References: <20250416073608.1799578-1-baolu.lu@linux.intel.com> Content-Language: en-US From: Baolu Lu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 4/17/25 10:23, Tian, Kevin wrote: >> From: Lu Baolu >> Sent: Wednesday, April 16, 2025 3:36 PM >> >> Commit <5518f239aff1> ("iommu/vt-d: Move scalable mode ATS enablement >> to >> probe path") changed the PCI ATS enablement logic to run earlier, >> specifically before the default domain attachment. >> >> On some client platforms, this change resulted in boot failures, causing >> the kernel to panic with the following message and call trace: >> >> Kernel panic - not syncing: DMAR hardware is malfunctioning >> CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.14.0-rc3+ #175 >> Call Trace: >> >> dump_stack_lvl+0x6f/0xb0 >> dump_stack+0x10/0x16 >> panic+0x10a/0x2b7 >> iommu_enable_translation.cold+0xc/0xc >> intel_iommu_init+0xe39/0xec0 >> ? trace_hardirqs_on+0x1e/0xd0 >> ? __pfx_pci_iommu_init+0x10/0x10 >> pci_iommu_init+0xd/0x40 >> do_one_initcall+0x5b/0x390 >> kernel_init_freeable+0x26d/0x2b0 >> ? __pfx_kernel_init+0x10/0x10 >> kernel_init+0x15/0x120 >> ret_from_fork+0x35/0x60 >> ? __pfx_kernel_init+0x10/0x10 >> ret_from_fork_asm+0x1a/0x30 >> RIP: 1f0f:0x0 >> Code: Unable to access opcode bytes at 0xffffffffffffffd6. >> RSP: 0000:0000000000000000 EFLAGS: 841f0f2e66 ORIG_RAX: >> 1f0f2e6600000000 >> RAX: 0000000000000000 RBX: 1f0f2e6600000000 RCX: >> 2e66000000000084 >> RDX: 0000000000841f0f RSI: 000000841f0f2e66 RDI: >> 00841f0f2e660000 >> RBP: 00841f0f2e660000 R08: 00841f0f2e660000 R09: >> 000000841f0f2e66 >> R10: 0000000000841f0f R11: 2e66000000000084 R12: >> 000000841f0f2e66 >> R13: 0000000000841f0f R14: 2e66000000000084 R15: >> 1f0f2e6600000000 >> >> ---[ end Kernel panic - not syncing: DMAR hardware is malfunctioning ]--- >> >> Fix this by reverting the timing change for ATS enablement introduced by >> the offending commit and restoring the previous behavior. >> > > it's unclear how this timing is related to the dumped stack. Is there > more detail how they are related? > I'm not sure, but I'm trying to find a machine and get more information. Anyway, let's revert the change and remove the boot regression first. Thanks, baolu