path: root/samples/vfio-mdev/mbochs.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Mediated virtual PCI display host device driver
 *
 * Emulate enough of qemu stdvga to make bochs-drm.ko happy.  That is
 * basically the vram memory bar and the bochs dispi interface vbe
 * registers in the mmio register bar.	Specifically it does *not*
 * include any legacy vga stuff.  Device looks a lot like "qemu -device
 * secondary-vga".
 *
 *   (c) Gerd Hoffmann <kraxel@redhat.com>
 *
 * based on mtty driver which is:
 *   Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
 *	 Author: Neo Jia <cjia@nvidia.com>
 *		 Kirti Wankhede <kwankhede@nvidia.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/cdev.h>
#include <linux/vfio.h>
#include <linux/iommu.h>
#include <linux/sysfs.h>
#include <linux/mdev.h>
#include <linux/pci.h>
#include <linux/dma-buf.h>
#include <linux/highmem.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_rect.h>
#include <drm/drm_modeset_lock.h>
#include <drm/drm_property.h>
#include <drm/drm_plane.h>


#define VBE_DISPI_INDEX_ID		0x0
#define VBE_DISPI_INDEX_XRES		0x1
#define VBE_DISPI_INDEX_YRES		0x2
#define VBE_DISPI_INDEX_BPP		0x3
#define VBE_DISPI_INDEX_ENABLE		0x4
#define VBE_DISPI_INDEX_BANK		0x5
#define VBE_DISPI_INDEX_VIRT_WIDTH	0x6
#define VBE_DISPI_INDEX_VIRT_HEIGHT	0x7
#define VBE_DISPI_INDEX_X_OFFSET	0x8
#define VBE_DISPI_INDEX_Y_OFFSET	0x9
#define VBE_DISPI_INDEX_VIDEO_MEMORY_64K 0xa
#define VBE_DISPI_INDEX_COUNT		0xb

#define VBE_DISPI_ID0			0xB0C0
#define VBE_DISPI_ID1			0xB0C1
#define VBE_DISPI_ID2			0xB0C2
#define VBE_DISPI_ID3			0xB0C3
#define VBE_DISPI_ID4			0xB0C4
#define VBE_DISPI_ID5			0xB0C5

#define VBE_DISPI_DISABLED		0x00
#define VBE_DISPI_ENABLED		0x01
#define VBE_DISPI_GETCAPS		0x02
#define VBE_DISPI_8BIT_DAC		0x20
#define VBE_DISPI_LFB_ENABLED		0x40
#define VBE_DISPI_NOCLEARMEM		0x80


#define MBOCHS_NAME		  "mbochs"
#define MBOCHS_CLASS_NAME	  "mbochs"

#define MBOCHS_EDID_REGION_INDEX  VFIO_PCI_NUM_REGIONS
#define MBOCHS_NUM_REGIONS        (MBOCHS_EDID_REGION_INDEX+1)

#define MBOCHS_CONFIG_SPACE_SIZE  0xff
#define MBOCHS_MMIO_BAR_OFFSET	  PAGE_SIZE
#define MBOCHS_MMIO_BAR_SIZE	  PAGE_SIZE
#define MBOCHS_EDID_OFFSET	  (MBOCHS_MMIO_BAR_OFFSET +	\
				   MBOCHS_MMIO_B