From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A5164C433F4 for ; Thu, 30 Aug 2018 15:17:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4F82120658 for ; Thu, 30 Aug 2018 15:17:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4F82120658 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727237AbeH3TUR (ORCPT ); Thu, 30 Aug 2018 15:20:17 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:37284 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725996AbeH3TUR (ORCPT ); Thu, 30 Aug 2018 15:20:17 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: tomeu) with ESMTPSA id 562F9263ABC Subject: Re: [PATCH v6] Add udmabuf misc device To: Gerd Hoffmann Cc: dri-devel@lists.freedesktop.org, David Airlie , Laurent Pinchart , Jonathan Corbet , Sumit Semwal , Shuah Khan , "open list:DOCUMENTATION" , open list , "open list:DMA BUFFER SHARING FRAMEWORK" , "moderated list:DMA BUFFER SHARING FRAMEWORK" , "open list:KERNEL SELFTEST FRAMEWORK" , Zach Reizner , Daniel Stone References: <20180703075359.30349-1-kraxel@redhat.com> <20180703083757.GG7880@phenom.ffwll.local> <20180704055338.n3b7oexltaejqmcd@sirius.home.kraxel.org> <9818b301-9c9d-c703-d4fe-7c2d4d43ed66@collabora.com> <20180704080005.juutrwri4kxm7yim@sirius.home.kraxel.org> From: Tomeu Vizoso Message-ID: <06d8aa8d-5eac-64e2-f21e-43fe7ca96cc2@collabora.com> Date: Thu, 30 Aug 2018 17:17:31 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180704080005.juutrwri4kxm7yim@sirius.home.kraxel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/04/2018 10:00 AM, Gerd Hoffmann wrote: > On Wed, Jul 04, 2018 at 09:26:39AM +0200, Tomeu Vizoso wrote: >> On 07/04/2018 07:53 AM, Gerd Hoffmann wrote: >>> On Tue, Jul 03, 2018 at 10:37:57AM +0200, Daniel Vetter wrote: >>>> On Tue, Jul 03, 2018 at 09:53:58AM +0200, Gerd Hoffmann wrote: >>>>> A driver to let userspace turn memfd regions into dma-bufs. >>>>> >>>>> Use case: Allows qemu create dmabufs for the vga framebuffer or >>>>> virtio-gpu ressources. Then they can be passed around to display >>>>> those guest things on the host. To spice client for classic full >>>>> framebuffer display, and hopefully some day to wayland server for >>>>> seamless guest window display. >>>>> >>>>> qemu test branch: >>>>> https://git.kraxel.org/cgit/qemu/log/?h=sirius/udmabuf >>>>> >>>>> Cc: David Airlie >>>>> Cc: Tomeu Vizoso >>>>> Cc: Laurent Pinchart >>>>> Cc: Daniel Vetter >>>>> Signed-off-by: Gerd Hoffmann >>>> >>>> I think some ack for a 2nd use-case, like virtio-wl or whatever would be >>>> really cool. To give us some assurance that this is generically useful. >>> >>> Tomeu? Laurent? >> >> Sorry, but I think I will need some help to understand how this could help >> in the virtio-wl case [adding Zach Reizner to CC]. >> >> Any graphics buffers that are allocated with memfd will be shared with the >> compositor via wl_shm, without need for dmabufs. > > Within one machine, yes. Once virtualization is added to the mix things > become more complicated ... > > When using virtio-gpu the guest will allocate graphics buffers from > normal (guest) ram, then register these buffers (which are allowed to be > scattered) with the host as resource. > > qemu can use memfd to allocate guest ram. Now, with the help of > udmabuf, qemu can create a *host* dma-buf for the *guest* graphics > buffer. Guess each physical address in the iovec in VIRTIO_GPU_CMD_RESOURCE_ATTACH_BACKING can be passed as the offset in the udmabuf_create_item struct? > That dma-buf can be used by qemu internally (mmap it to get a linear > mapping of the resource, to avoid copying). It can be passed on to > spice-client, to display the guest framebuffer. > > And I think it could also be quite useful to pass guest wayland windows > to the host compositor, without mapping host-allocated buffers into the > guest, so we don't have do deal with the "find some address space for > the mapping" issue in the first place. Sounds good to me if the answer to the above is "yes". > There are more things needed to > complete this of course, but it's a building block ... Are you thinking of anything else besides passing the winsrv protocol across the guest/host boundary? Just wondering if I'm missing something. Thanks, Tomeu From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from bhuna.collabora.co.uk ([46.235.227.227]:37284 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725996AbeH3TUR (ORCPT ); Thu, 30 Aug 2018 15:20:17 -0400 Subject: Re: [PATCH v6] Add udmabuf misc device To: Gerd Hoffmann Cc: dri-devel@lists.freedesktop.org, David Airlie , Laurent Pinchart , Jonathan Corbet , Sumit Semwal , Shuah Khan , "open list:DOCUMENTATION" , open list , "open list:DMA BUFFER SHARING FRAMEWORK" , "moderated list:DMA BUFFER SHARING FRAMEWORK" , "open list:KERNEL SELFTEST FRAMEWORK" , Zach Reizner , Daniel Stone References: <20180703075359.30349-1-kraxel@redhat.com> <20180703083757.GG7880@phenom.ffwll.local> <20180704055338.n3b7oexltaejqmcd@sirius.home.kraxel.org> <9818b301-9c9d-c703-d4fe-7c2d4d43ed66@collabora.com> <20180704080005.juutrwri4kxm7yim@sirius.home.kraxel.org> From: Tomeu Vizoso Message-ID: <06d8aa8d-5eac-64e2-f21e-43fe7ca96cc2@collabora.com> Date: Thu, 30 Aug 2018 17:17:31 +0200 MIME-Version: 1.0 In-Reply-To: <20180704080005.juutrwri4kxm7yim@sirius.home.kraxel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 07/04/2018 10:00 AM, Gerd Hoffmann wrote: > On Wed, Jul 04, 2018 at 09:26:39AM +0200, Tomeu Vizoso wrote: >> On 07/04/2018 07:53 AM, Gerd Hoffmann wrote: >>> On Tue, Jul 03, 2018 at 10:37:57AM +0200, Daniel Vetter wrote: >>>> On Tue, Jul 03, 2018 at 09:53:58AM +0200, Gerd Hoffmann wrote: >>>>> A driver to let userspace turn memfd regions into dma-bufs. >>>>> >>>>> Use case: Allows qemu create dmabufs for the vga framebuffer or >>>>> virtio-gpu ressources. Then they can be passed around to display >>>>> those guest things on the host. To spice client for classic full >>>>> framebuffer display, and hopefully some day to wayland server for >>>>> seamless guest window display. >>>>> >>>>> qemu test branch: >>>>> https://git.kraxel.org/cgit/qemu/log/?h=sirius/udmabuf >>>>> >>>>> Cc: David Airlie >>>>> Cc: Tomeu Vizoso >>>>> Cc: Laurent Pinchart >>>>> Cc: Daniel Vetter >>>>> Signed-off-by: Gerd Hoffmann >>>> >>>> I think some ack for a 2nd use-case, like virtio-wl or whatever would be >>>> really cool. To give us some assurance that this is generically useful. >>> >>> Tomeu? Laurent? >> >> Sorry, but I think I will need some help to understand how this could help >> in the virtio-wl case [adding Zach Reizner to CC]. >> >> Any graphics buffers that are allocated with memfd will be shared with the >> compositor via wl_shm, without need for dmabufs. > > Within one machine, yes. Once virtualization is added to the mix things > become more complicated ... > > When using virtio-gpu the guest will allocate graphics buffers from > normal (guest) ram, then register these buffers (which are allowed to be > scattered) with the host as resource. > > qemu can use memfd to allocate guest ram. Now, with the help of > udmabuf, qemu can create a *host* dma-buf for the *guest* graphics > buffer. Guess each physical address in the iovec in VIRTIO_GPU_CMD_RESOURCE_ATTACH_BACKING can be passed as the offset in the udmabuf_create_item struct? > That dma-buf can be used by qemu internally (mmap it to get a linear > mapping of the resource, to avoid copying). It can be passed on to > spice-client, to display the guest framebuffer. > > And I think it could also be quite useful to pass guest wayland windows > to the host compositor, without mapping host-allocated buffers into the > guest, so we don't have do deal with the "find some address space for > the mapping" issue in the first place. Sounds good to me if the answer to the above is "yes". > There are more things needed to > complete this of course, but it's a building block ... Are you thinking of anything else besides passing the winsrv protocol across the guest/host boundary? Just wondering if I'm missing something. Thanks, Tomeu From mboxrd@z Thu Jan 1 00:00:00 1970 From: tomeu.vizoso at collabora.com (Tomeu Vizoso) Date: Thu, 30 Aug 2018 17:17:31 +0200 Subject: [PATCH v6] Add udmabuf misc device In-Reply-To: <20180704080005.juutrwri4kxm7yim@sirius.home.kraxel.org> References: <20180703075359.30349-1-kraxel@redhat.com> <20180703083757.GG7880@phenom.ffwll.local> <20180704055338.n3b7oexltaejqmcd@sirius.home.kraxel.org> <9818b301-9c9d-c703-d4fe-7c2d4d43ed66@collabora.com> <20180704080005.juutrwri4kxm7yim@sirius.home.kraxel.org> Message-ID: <06d8aa8d-5eac-64e2-f21e-43fe7ca96cc2@collabora.com> On 07/04/2018 10:00 AM, Gerd Hoffmann wrote: > On Wed, Jul 04, 2018 at 09:26:39AM +0200, Tomeu Vizoso wrote: >> On 07/04/2018 07:53 AM, Gerd Hoffmann wrote: >>> On Tue, Jul 03, 2018 at 10:37:57AM +0200, Daniel Vetter wrote: >>>> On Tue, Jul 03, 2018 at 09:53:58AM +0200, Gerd Hoffmann wrote: >>>>> A driver to let userspace turn memfd regions into dma-bufs. >>>>> >>>>> Use case: Allows qemu create dmabufs for the vga framebuffer or >>>>> virtio-gpu ressources. Then they can be passed around to display >>>>> those guest things on the host. To spice client for classic full >>>>> framebuffer display, and hopefully some day to wayland server for >>>>> seamless guest window display. >>>>> >>>>> qemu test branch: >>>>> https://git.kraxel.org/cgit/qemu/log/?h=sirius/udmabuf >>>>> >>>>> Cc: David Airlie >>>>> Cc: Tomeu Vizoso >>>>> Cc: Laurent Pinchart >>>>> Cc: Daniel Vetter >>>>> Signed-off-by: Gerd Hoffmann >>>> >>>> I think some ack for a 2nd use-case, like virtio-wl or whatever would be >>>> really cool. To give us some assurance that this is generically useful. >>> >>> Tomeu? Laurent? >> >> Sorry, but I think I will need some help to understand how this could help >> in the virtio-wl case [adding Zach Reizner to CC]. >> >> Any graphics buffers that are allocated with memfd will be shared with the >> compositor via wl_shm, without need for dmabufs. > > Within one machine, yes. Once virtualization is added to the mix things > become more complicated ... > > When using virtio-gpu the guest will allocate graphics buffers from > normal (guest) ram, then register these buffers (which are allowed to be > scattered) with the host as resource. > > qemu can use memfd to allocate guest ram. Now, with the help of > udmabuf, qemu can create a *host* dma-buf for the *guest* graphics > buffer. Guess each physical address in the iovec in VIRTIO_GPU_CMD_RESOURCE_ATTACH_BACKING can be passed as the offset in the udmabuf_create_item struct? > That dma-buf can be used by qemu internally (mmap it to get a linear > mapping of the resource, to avoid copying). It can be passed on to > spice-client, to display the guest framebuffer. > > And I think it could also be quite useful to pass guest wayland windows > to the host compositor, without mapping host-allocated buffers into the > guest, so we don't have do deal with the "find some address space for > the mapping" issue in the first place. Sounds good to me if the answer to the above is "yes". > There are more things needed to > complete this of course, but it's a building block ... Are you thinking of anything else besides passing the winsrv protocol across the guest/host boundary? Just wondering if I'm missing something. Thanks, Tomeu From mboxrd@z Thu Jan 1 00:00:00 1970 From: tomeu.vizoso@collabora.com (Tomeu Vizoso) Date: Thu, 30 Aug 2018 17:17:31 +0200 Subject: [PATCH v6] Add udmabuf misc device In-Reply-To: <20180704080005.juutrwri4kxm7yim@sirius.home.kraxel.org> References: <20180703075359.30349-1-kraxel@redhat.com> <20180703083757.GG7880@phenom.ffwll.local> <20180704055338.n3b7oexltaejqmcd@sirius.home.kraxel.org> <9818b301-9c9d-c703-d4fe-7c2d4d43ed66@collabora.com> <20180704080005.juutrwri4kxm7yim@sirius.home.kraxel.org> Message-ID: <06d8aa8d-5eac-64e2-f21e-43fe7ca96cc2@collabora.com> Content-Type: text/plain; charset="UTF-8" Message-ID: <20180830151731.aDj_ERlFyyn-9pe7UzRezKixlZV4o1KU0l-wXa4fhPc@z> On 07/04/2018 10:00 AM, Gerd Hoffmann wrote: > On Wed, Jul 04, 2018@09:26:39AM +0200, Tomeu Vizoso wrote: >> On 07/04/2018 07:53 AM, Gerd Hoffmann wrote: >>> On Tue, Jul 03, 2018@10:37:57AM +0200, Daniel Vetter wrote: >>>> On Tue, Jul 03, 2018@09:53:58AM +0200, Gerd Hoffmann wrote: >>>>> A driver to let userspace turn memfd regions into dma-bufs. >>>>> >>>>> Use case: Allows qemu create dmabufs for the vga framebuffer or >>>>> virtio-gpu ressources. Then they can be passed around to display >>>>> those guest things on the host. To spice client for classic full >>>>> framebuffer display, and hopefully some day to wayland server for >>>>> seamless guest window display. >>>>> >>>>> qemu test branch: >>>>> https://git.kraxel.org/cgit/qemu/log/?h=sirius/udmabuf >>>>> >>>>> Cc: David Airlie >>>>> Cc: Tomeu Vizoso >>>>> Cc: Laurent Pinchart >>>>> Cc: Daniel Vetter >>>>> Signed-off-by: Gerd Hoffmann >>>> >>>> I think some ack for a 2nd use-case, like virtio-wl or whatever would be >>>> really cool. To give us some assurance that this is generically useful. >>> >>> Tomeu? Laurent? >> >> Sorry, but I think I will need some help to understand how this could help >> in the virtio-wl case [adding Zach Reizner to CC]. >> >> Any graphics buffers that are allocated with memfd will be shared with the >> compositor via wl_shm, without need for dmabufs. > > Within one machine, yes. Once virtualization is added to the mix things > become more complicated ... > > When using virtio-gpu the guest will allocate graphics buffers from > normal (guest) ram, then register these buffers (which are allowed to be > scattered) with the host as resource. > > qemu can use memfd to allocate guest ram. Now, with the help of > udmabuf, qemu can create a *host* dma-buf for the *guest* graphics > buffer. Guess each physical address in the iovec in VIRTIO_GPU_CMD_RESOURCE_ATTACH_BACKING can be passed as the offset in the udmabuf_create_item struct? > That dma-buf can be used by qemu internally (mmap it to get a linear > mapping of the resource, to avoid copying). It can be passed on to > spice-client, to display the guest framebuffer. > > And I think it could also be quite useful to pass guest wayland windows > to the host compositor, without mapping host-allocated buffers into the > guest, so we don't have do deal with the "find some address space for > the mapping" issue in the first place. Sounds good to me if the answer to the above is "yes". > There are more things needed to > complete this of course, but it's a building block ... Are you thinking of anything else besides passing the winsrv protocol across the guest/host boundary? Just wondering if I'm missing something. Thanks, Tomeu