On 21/02/18 09:47, Oleksandr Andrushchenko wrote:
On 02/21/2018 10:19 AM, Juergen Gross wrote:
On 21/02/18 09:03, Oleksandr Andrushchenko wrote:
From: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com
Introduce skeleton of the para-virtualized Xen display frontend driver. This patch only adds required essential stubs.
Signed-off-by: Oleksandr Andrushchenko
oleksandr_andrushchenko@epam.com
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 oleksandr_andrushchenko@epam.com
- */
+#include <drm/drmP.h>
+#include <xen/platform_pci.h> +#include <xen/xen.h> +#include <xen/xenbus.h>
+#include <xen/interface/io/displif.h>
+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
I don't think the driver should decide that. This would be the job of Xen tools IMO.
Juergen