From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751656AbeBUIrq (ORCPT ); Wed, 21 Feb 2018 03:47:46 -0500 Received: from mail-lf0-f68.google.com ([209.85.215.68]:41008 "EHLO mail-lf0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750831AbeBUIrp (ORCPT ); Wed, 21 Feb 2018 03:47:45 -0500 X-Google-Smtp-Source: AH8x226uoXTv6/qzJpa4ZB7yfueL7L9q9mzTGY8lxWpZpzxQs04bF3pMz+I4+mPxoJnKkts6OOZrGw== Subject: Re: [PATCH 1/9] drm/xen-front: Introduce Xen para-virtualized frontend driver To: Juergen Gross , xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, airlied@linux.ie, daniel.vetter@intel.com, seanpaul@chromium.org, gustavo@padovan.org, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com Cc: Oleksandr Andrushchenko References: <1519200222-20623-1-git-send-email-andr2000@gmail.com> <1519200222-20623-2-git-send-email-andr2000@gmail.com> From: Oleksandr Andrushchenko Message-ID: <91386840-c34a-31a4-2bb3-14a27ececa9c@gmail.com> Date: Wed, 21 Feb 2018 10:47:40 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/21/2018 10:19 AM, Juergen Gross wrote: > On 21/02/18 09:03, Oleksandr Andrushchenko wrote: >> From: Oleksandr Andrushchenko >> >> Introduce skeleton of the para-virtualized Xen display >> frontend driver. This patch only adds required >> essential stubs. >> >> Signed-off-by: Oleksandr Andrushchenko >> --- >> drivers/gpu/drm/Kconfig | 2 + >> drivers/gpu/drm/Makefile | 1 + >> drivers/gpu/drm/xen/Kconfig | 17 ++++++++ >> drivers/gpu/drm/xen/Makefile | 5 +++ >> drivers/gpu/drm/xen/xen_drm_front.c | 83 +++++++++++++++++++++++++++++++++++++ >> 5 files changed, 108 insertions(+) >> create mode 100644 drivers/gpu/drm/xen/Kconfig >> create mode 100644 drivers/gpu/drm/xen/Makefile >> create mode 100644 drivers/gpu/drm/xen/xen_drm_front.c >> >> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig >> index deeefa7a1773..757825ac60df 100644 >> --- a/drivers/gpu/drm/Kconfig >> +++ b/drivers/gpu/drm/Kconfig >> @@ -289,6 +289,8 @@ source "drivers/gpu/drm/pl111/Kconfig" >> >> source "drivers/gpu/drm/tve200/Kconfig" >> >> +source "drivers/gpu/drm/xen/Kconfig" >> + >> # Keep legacy drivers last >> >> menuconfig DRM_LEGACY >> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile >> index 50093ff4479b..9d66657ea117 100644 >> --- a/drivers/gpu/drm/Makefile >> +++ b/drivers/gpu/drm/Makefile >> @@ -103,3 +103,4 @@ obj-$(CONFIG_DRM_MXSFB) += mxsfb/ >> obj-$(CONFIG_DRM_TINYDRM) += tinydrm/ >> obj-$(CONFIG_DRM_PL111) += pl111/ >> obj-$(CONFIG_DRM_TVE200) += tve200/ >> +obj-$(CONFIG_DRM_XEN) += xen/ >> diff --git a/drivers/gpu/drm/xen/Kconfig b/drivers/gpu/drm/xen/Kconfig >> new file mode 100644 >> index 000000000000..4cca160782ab >> --- /dev/null >> +++ b/drivers/gpu/drm/xen/Kconfig >> @@ -0,0 +1,17 @@ >> +config DRM_XEN >> + bool "DRM Support for Xen guest OS" >> + depends on XEN >> + help >> + Choose this option if you want to enable DRM support >> + for Xen. >> + >> +config DRM_XEN_FRONTEND >> + tristate "Para-virtualized frontend driver for Xen guest OS" >> + depends on DRM_XEN >> + depends on DRM >> + select DRM_KMS_HELPER >> + select VIDEOMODE_HELPERS >> + select XEN_XENBUS_FRONTEND >> + help >> + Choose this option if you want to enable a para-virtualized >> + frontend DRM/KMS driver for Xen guest OSes. >> diff --git a/drivers/gpu/drm/xen/Makefile b/drivers/gpu/drm/xen/Makefile >> new file mode 100644 >> index 000000000000..967074d348f6 >> --- /dev/null >> +++ b/drivers/gpu/drm/xen/Makefile >> @@ -0,0 +1,5 @@ >> +# SPDX-License-Identifier: GPL-2.0 >> + >> +drm_xen_front-objs := xen_drm_front.o >> + >> +obj-$(CONFIG_DRM_XEN_FRONTEND) += drm_xen_front.o >> diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c >> new file mode 100644 >> index 000000000000..fd372fb464a1 >> --- /dev/null >> +++ b/drivers/gpu/drm/xen/xen_drm_front.c >> @@ -0,0 +1,83 @@ >> +/* >> + * Xen para-virtual DRM device >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License as published by >> + * the Free Software Foundation; either version 2 of the License, or >> + * (at your option) any later version. >> + * >> + * This program is distributed in the hope that it will be useful, >> + * but WITHOUT ANY WARRANTY; without even the implied warranty of >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the >> + * GNU General Public License for more details. > Use SPDX identifier instead (same applies for all other new > sources): > > // SPDX-License-Identifier: GPL-2.0 Will update, thank you >> + * >> + * Copyright (C) 2016-2018 EPAM Systems Inc. >> + * >> + * Author: Oleksandr Andrushchenko >> + */ >> + >> +#include >> + >> +#include >> +#include >> +#include >> + >> +#include >> + >> +static void backend_on_changed(struct xenbus_device *xb_dev, >> + enum xenbus_state backend_state) >> +{ >> +} >> + >> +static int xen_drv_probe(struct xenbus_device *xb_dev, >> + const struct xenbus_device_id *id) >> +{ >> + return 0; >> +} >> + >> +static int xen_drv_remove(struct xenbus_device *dev) >> +{ >> + return 0; >> +} >> + >> +static const struct xenbus_device_id xen_drv_ids[] = { >> + { XENDISPL_DRIVER_NAME }, >> + { "" } >> +}; >> + >> +static struct xenbus_driver xen_driver = { >> + .ids = xen_drv_ids, >> + .probe = xen_drv_probe, >> + .remove = xen_drv_remove, >> + .otherend_changed = backend_on_changed, >> +}; >> + >> +static int __init xen_drv_init(void) >> +{ >> + if (!xen_domain()) >> + return -ENODEV; >> + >> + if (xen_initial_domain()) { >> + DRM_ERROR(XENDISPL_DRIVER_NAME " cannot run in initial domain\n"); >> + return -ENODEV; >> + } > Why not? Wouldn't that be possible in case of the backend living in a > driver domain? It is possible (and in my use-case backend indeed runs in a driver domain). I was just not sure if it is really a good idea to allow that. If you think this is ok, then I'll remove this check > > Juergen Thank you, Oleksandr