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 7D421339B30; Wed, 21 Jan 2026 14:55:29 +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=1769007329; cv=none; b=lWVciuywU2+hMOWizSEepmF2CIdBEew+lEy9NvWA94Ma9jMgnBSF6BJUmvUCVmUuAeEz+OethDYEtzsL5DdvMQWtPLsEX3BBNv1xVK4RIAHROEXMjczYGLEL1gOEEszUFLczx8VHGMeJnMz32sM1XYDADfOBgZkBYhNdabUQ2V8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769007329; c=relaxed/simple; bh=CXwnx1t8wyz3VfpGOXzehAEuCOrJbBBjpxzQID/HcVA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Qr+O2b2jDLEx6LRDxmIXix+jrGLQWQqTO4OBam/84XGG9rR4wKHrCBMvto/gZdttRMcO/cVSzW9QDwz68jVineXNHWWaxKYdzYsJ80nFsezG6pKHh4TQ2MG1QX97RfvCsF9a4PlMjchsErlgPpU6eXYa50arjbchoOiHcJkDuhA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=NtqfizRY; 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="NtqfizRY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6F6B7C19421; Wed, 21 Jan 2026 14:55:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1769007329; bh=CXwnx1t8wyz3VfpGOXzehAEuCOrJbBBjpxzQID/HcVA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NtqfizRYBdSsyCyq9fi6KoYVYQMyPZLrKZluAjqj/oIPVsw06CnuH+XQRrofRAyGR ZtkCJxMdBJYjIYMENQNp+kHVl+bdFtL007y604SMZaFrRiqdeXlFSK75La1HD7YTz6 zyMFNz3Ctzk9TwF7PUAP8HsPaBECSKi972VxDhbE= Date: Wed, 21 Jan 2026 15:55:25 +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: <2026012113-multiple-stunned-0f64@gregkh> References: <870872aa-28e9-412a-bac6-8020bf560e4f@amd.com> <3fccd233-c5cf-4252-98ea-61f240f82695@linux.intel.com> <2026012112-phantom-music-f6e8@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org 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: On Wed, Jan 21, 2026 at 03:32:42PM +0800, Baolu Lu wrote: > On 1/21/26 15:26, Greg KH wrote: > > 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? > > Yes, they should be backported. I am sorry; we should have tagged them > at the time we upstreamed them. Ok, all now queued up, thanks. greg k-h