From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 248CA38D00A for ; Thu, 12 Mar 2026 16:33:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773333226; cv=none; b=V+41QnEQoNgvGW9H39nuQb+5XbyzqD8/lAJ1iNe5mYZwXtif5RFJpFEyiIB4+I8PUxEMAhUcddCajWZ2VDQjosKiwdre/mb/KMN+LjmotUIIG6GLTy8yjXA1go/ZaT2gZNUqqpmKfaHAz5rpSlPjnSCzNwGvhFzBtpDzetI//4Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773333226; c=relaxed/simple; bh=VWx/GkNL5qY83k/fHQxD0qBcYVCLhi3H3CO//Lkw7NQ=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Bdjatr/RWjt5ImU+pyFSnkaAdvEzu3Ea4bNV73wx2iZjCL203EFn4gPqWumai4Ku+nfvDlN9lOn4dzrgkOVQilX9OGTa1dyQkUtPONT/mHcEJ7PhlVmE5Bk2Sx0elC2T9DaV/IkmbpteaNDkfiEoi6cE/h4syZuqkcEnMy9Jue8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=APS+fFBI; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="APS+fFBI" Received: from localhost (unknown [52.148.140.42]) by linux.microsoft.com (Postfix) with ESMTPSA id 28BE420B710C; Thu, 12 Mar 2026 09:33:44 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 28BE420B710C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1773333224; bh=gFyhd1inkRGvHCHTJXBXEkAolUHlzFV8VtgF5KKhDx4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=APS+fFBIZ3aOpUUohO6ukWPlf2YktCsH5JtbKweAAf29ZpB/5tpelUyw68FRidGte 9VwhPQ01ZQ+CqnwiuUYUaeQecen4pE+v7HnSCYpKWVQObG6fh/CNZOJ4u1tCmlK+3X nw/Pb///xqzVCAvfsICSwzsXPpB+OSrWp2xkrPG8= Date: Thu, 12 Mar 2026 09:33:45 -0700 From: Jacob Pan To: Jason Gunthorpe Cc: kernel test robot , linux-kernel@vger.kernel.org, "iommu@lists.linux.dev" , Alex Williamson , Joerg Roedel , David Matlack , Nicolin Chen , "Tian, Kevin" , Yi Liu , Baolu Lu , oe-kbuild-all@lists.linux.dev, skhawaja@google.com, pasha.tatashin@soleen.com, Jean Philippe-Brucker , Robin Murphy Subject: Re: [PATCH 08/11] vfio: Enable cdev noiommu mode under iommufd Message-ID: <20260312093345.00007f60@linux.microsoft.com> In-Reply-To: <20260305233827.GA1651202@nvidia.com> References: <20260227175247.26103-9-jacob.pan@linux.microsoft.com> <202602280855.WxyIHCy5-lkp@intel.com> <20260228003540.GN5933@nvidia.com> <20260305152614.00001a0f@linux.microsoft.com> <20260305233827.GA1651202@nvidia.com> Organization: LSG X-Mailer: Claws Mail 3.21.0 (GTK+ 2.24.33; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Hi Jason, On Thu, 5 Mar 2026 19:38:27 -0400 Jason Gunthorpe wrote: > On Thu, Mar 05, 2026 at 03:26:14PM -0800, Jacob Pan wrote: > > Hi Jason, > > > > On Fri, 27 Feb 2026 20:35:40 -0400 > > Jason Gunthorpe wrote: > > > > > On Sat, Feb 28, 2026 at 08:18:41AM +0800, kernel test robot > > > wrote: > > > > Kconfig warnings: (for reference only) > > > > WARNING: unmet direct dependencies detected for > > > > IOMMU_PT_AMDV1 Depends on [n]: GENERIC_PT [=y] && IOMMU_PT [=y] > > > > && !GENERIC_ATOMIC64 [=y] Selected by [y]: > > > > - VFIO_NOIOMMU [=y] && VFIO [=y] && VFIO_GROUP [=y] > > > > > > Some kconfig stuff is missing, the iommufd IOMMU would only work > > > with GENERIC_ATOMIC64 > > I don't quite understand this dependency on GENERIC_ATOMIC64, or you > > mean the opposite? since we currently have: > > Oh, right the inverse. > > > config IOMMU_PT_AMDV1 > > tristate "IOMMU page table for 64-bit AMD IOMMU v1" > > depends on !GENERIC_ATOMIC64 # for cmpxchg64 > > > > And I already have noiommu depends on AMDV1 for mock page tables. > > I think it is kconfig not being really transitive with select > dependencies. So things like !GENERIC_ATOMIC64 have to be in the > parent that uses select too. > > You could also possibly use depends to avoid this, IIRC. I have tried to use "depends on" instead of select but it made VFIO_NOIOMMU impossible to enable if COMPILE_TEST is not set. I think it is because: menuconfig GENERIC_PT bool "Generic Radix Page Table" if COMPILE_TEST > > Anyway, this particular build issue can be fixed by adding > > IOMMU_SUPPORT. i.e. > > That feels indirect, but maybe it is needed too.. Yeah, it does feel a bit counterintuitive that noiommu depends on IOMMU support, but as noiommu mode is made to behave increasingly like full IOMMU support, this may be unavoidable. I just sent out v2. Thanks, Jacob