From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-dm6nam12on2063.outbound.protection.outlook.com ([40.107.243.63] helo=NAM12-DM6-obe.outbound.protection.outlook.com) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mLiWd-00917R-7W for linux-um@lists.infradead.org; Thu, 02 Sep 2021 08:56:51 +0000 Subject: Re: [PATCH] drm/ttm: provide default page protection for UML References: <20210902020129.25952-1-rdunlap@infradead.org> <9faacbc8-3346-8033-5b4d-60543eae959e@cambridgegreys.com> <0887903c-483d-49c7-0d35-f59be2f85bac@cambridgegreys.com> <288a2d4dbcb1e6b0fbeff6da86569aa92df09202.camel@sipsolutions.net> From: =?UTF-8?Q?Christian_K=c3=b6nig?= Message-ID: Date: Thu, 2 Sep 2021 10:56:36 +0200 In-Reply-To: <288a2d4dbcb1e6b0fbeff6da86569aa92df09202.camel@sipsolutions.net> Content-Language: en-US MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-um" Errors-To: linux-um-bounces+geert=linux-m68k.org@lists.infradead.org To: Johannes Berg , Anton Ivanov , Randy Dunlap , linux-kernel@vger.kernel.org Cc: =?UTF-8?Q?Thomas_Hellstr=c3=b6m?= , Huang Rui , dri-devel@lists.freedesktop.org, Jeff Dike , Richard Weinberger , linux-um@lists.infradead.org, David Airlie , Daniel Vetter Am 02.09.21 um 09:43 schrieb Johannes Berg: > On Thu, 2021-09-02 at 07:19 +0100, Anton Ivanov wrote: >>>> I have a question though - why all of DRM is not !UML in config. Not >>>> like we can use them. >>> I have no idea about that. >>> Hopefully one of the (other) UML maintainers can answer you. >> Touche. >> >> We will discuss that and possibly push a patch to !UML that part of the >> tree. IMHO it is not applicable. > As I just said on the other patch, all of this is fallout from my commit > 68f5d3f3b654 ("um: add PCI over virtio emulation driver") which is the > first time that you could have PCI on UML. > > Without having checked, in this particular case it's probably something > like > > depends on PCI && X86_64 > > as we've seen in other drivers (idxd, ioat). > > The biggest problem is probably that UML internally uses X86_64 > (arch/x86/um/Kconfig), which is ... unexpected ... since CONFIG_X86_64 > is typically considered the ARCH, and now the ARCH is actually um. Yeah, as TTM maintainer I was about to NAK that approach here. Basically you are claiming to be X86_64, but then you don't use the X86_64 architecture and are surprised that it things break somewhere else. This is not something you can blame on subsystems or even drivers, but rather just a broken architectural design and so needs to be fixed there. Regards, Christian. > > I think we can just fix that and get rid of this entire class of > problems? Something like > > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fp.sipsolutions.net%2Ffbac19d86637e286.txt&data=04%7C01%7Cchristian.koenig%40amd.com%7Cd773b1e8b66643874d1308d96de56a86%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637661654674393046%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=xBT%2Fj%2FbEgltQfvE%2B7%2FGRV7IctGn3sDvy8ycmBvTTSXU%3D&reserved=0 > > johannes > > _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um