From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E3D9F1DF987; Wed, 21 Jan 2026 07:26:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768980400; cv=none; b=H4kNoDwCqXXpbptHS2+POZlABOw6zOWoXNur8hT61H/K5s4FobCeC3hSSp26EDxDVrfzL2JgcCjeRnB07RHrRhXA2+cGskAtnyR0E27eNPNx4JFvm7sDRgZCCMktgl7LIepoPeEkB9HqySsFfP3fKMZ+ekP06pC+EBtYMAuQwos= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768980400; c=relaxed/simple; bh=yEy8ny2OHjOtoQ2ahukebTc7/PIRqGKPRC4eM81ckRg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Pontqo1T4LHLA9iUchLbrgqH2xTkTZcaW1fDxxgygWBT+jM6i3Ta8eIWq5dp/LIGIA9ygsl9tbYTZaQXLrBpR8hj0mSrF+MjSEdF11cl9NaGTd+N6H4GklVruGHOAbE+1wUh5VALNeT/u5kwrS06XzB86lASuZhh3sRbCBZklMU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=GvfZ23L2; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="GvfZ23L2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C5DBAC116D0; Wed, 21 Jan 2026 07:26:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1768980399; bh=yEy8ny2OHjOtoQ2ahukebTc7/PIRqGKPRC4eM81ckRg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=GvfZ23L2UM5yHQfLC62glIikpstrcLJ2GYd9DbdSLzKHXYZsANEikxg7d9zeeDZYB 1pULdccyQ+ciRwBYKAZITQvI3Dhb4k7UPria7PIWAUV7zxNydQsu1c3NktSaZ90xYh ewjxJfI/lPeA1cRIMrJftasv1CK4235VRkyrVg+A= Date: Wed, 21 Jan 2026 08:26:36 +0100 From: Greg KH To: Baolu Lu Cc: Mario Limonciello , Mario Limonciello , regressions , stable@vger.kernel.org, iommu@lists.linux.dev, "Hegde, Vasant" , "Hou, Lizhi" Subject: Re: IOMMU regression in linux-6.18.y Message-ID: <2026012112-phantom-music-f6e8@gregkh> References: <870872aa-28e9-412a-bac6-8020bf560e4f@amd.com> <3fccd233-c5cf-4252-98ea-61f240f82695@linux.intel.com> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <3fccd233-c5cf-4252-98ea-61f240f82695@linux.intel.com> On Wed, Jan 21, 2026 at 03:14:42PM +0800, Baolu Lu wrote: > On 1/21/26 13:26, Mario Limonciello wrote: > > > > > > On 1/20/26 8:08 PM, Mario Limonciello wrote: > > > Hi, > > > > > > Recently I found out that amdxdna stopped working in linux-6.18.4. > > > This is because of this commit in linux-6.18.y: > > > > > > commit c341dee80b5d ("iommu: disable SVA when CONFIG_X86 is set") > > > > > > That was originally backported from upstream: > > > > > > commit 72f98ef9a4be ("iommu: disable SVA when CONFIG_X86 is set") > > > > > > --- > > > > > > SVA support is a requirement for amdxdna. > > > > > > The series that this commit came from was part of a larger 8 patch > > > series, but this was the only commit that was CC'ed to stable. > > > > > > As a result this is not broken in 6.19-rc, but it is broken in > > > linux-6.18.y (and presumably any older stable kernels still around > > > that picked it up). > > > > > > So there are two options I see: > > > > > > 1) Revert c341dee80b5d in linux-6.18.y (and any other stable kernel > > > that picked it up but has amdxdna) > > > > > > 2) Bring the entire 8 patch series to linux-6.18.y. > > > > > > This is the entire series (I didn't look up the hashes from > > > mainline, but they should have all landed): > > > https://lore.kernel.org/linux-iommu/20251022082635.2462433-1- > > > baolu.lu@linux.intel.com/ > > > > > > What should we do? > > > > > > > If the decision is to take the remaining commits to 6.18.y to fix this I > > did confirm they cleanly cherry pick and build.  Here are the hashes. > > > > commit 27bfafac65d8 ("mm: add a ptdesc flag to mark kernel page tables") > > commit 977870522af3 ("mm: actually mark kernel page table pages") > > commit 412d000346ea ("x86/mm: use 'ptdesc' when freeing PMD pages") > > commit 018942956723 ("mm: introduce pure page table freeing function") > > commit bf9e4e30f353 ("x86/mm: use pagetable_free()") > > commit 5ba2f0a15564 ("mm: introduce deferred freeing for kernel page > > tables") > > commit e37d5a2d60a3 ("iommu/sva: invalidate stale IOTLB entries for > > kernel address space") > > > > Yes. These patches fix a security issue in iommu/sva on x86 and restore > the SVA functionality. So all should be backported? If so, great, but why were they not tagged as such? thanks, greg k-h