linux/drivers/vfio/pci/vfio_pci_igd.c
Alex Williamson 5846ff54e8 vfio/pci: Intel IGD OpRegion support
This is the first consumer of vfio device specific resource support,
providing read-only access to the OpRegion for Intel graphics devices.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-22 16:10:09 -07:00

112 lines
2.7 KiB
C

/*
* VFIO PCI Intel Graphics support
*
* Copyright (C) 2016 Red Hat, Inc. All rights reserved.
* Author: Alex Williamson <alex.williamson@redhat.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.
*
* Register a device specific region through which to provide read-only
* access to the Intel IGD opregion. The register defining the opregion
* address is also virtualized to prevent user modification.
*/
#include <linux/io.h>
#include <linux/pci.h>
#include <linux/uaccess.h>
#include <linux/vfio.h>
#include "vfio_pci_private.h"
#define OPREGION_SIGNATURE "IntelGraphicsMem"
#define OPREGION_SIZE (8 * 1024)
#define OPREGION_PCI_ADDR 0xfc
static size_t vfio_pci_igd_rw(struct vfio_pci_device *vdev, char __user *buf,
size_t count, loff_t *ppos, bool iswrite)
{
unsigned int i = VFIO_PCI_OFFSET_TO_INDEX(*ppos) - VFIO_PCI_NUM_REGIONS;
void *base = vdev->region[i].data;
loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
if (pos >= vdev->region[i].size || iswrite)
return -EINVAL;
count = min(count, (size_t)(vdev->region[i].size - pos));
if (copy_to_user(buf, base + pos, count))
return -EFAULT;
*ppos += count;
return count;
}
static void vfio_pci_igd_release(struct vfio_pci_device *vdev,
struct vfio_pci_region *region)
{
memunmap(region->data);
}
static const struct vfio_pci_regops vfio_pci_igd_regops = {
.rw = vfio_pci_igd_rw,
.release = vfio_pci_igd_release,
};
int vfio_pci_igd_opregion_init(struct vfio_pci_device *vdev)
{
__le32 *dwordp = (__le32 *)(vdev->vconfig + OPREGION_PCI_ADDR);
u32 addr, size;
void *base;
int ret;
ret = pci_read_config_dword(vdev->pdev, OPREGION_PCI_ADDR, &addr);
if (ret)
return ret;
if (!addr || !(~addr))
return -ENODEV;
base = memremap(addr, OPREGION_SIZE, MEMREMAP_WB);
if (!base)
return -ENOMEM;
if (memcmp(base, OPREGION_SIGNATURE, 16)) {
memunmap(base);
return -EINVAL;
}
size = le32_to_cpu(*(__le32 *)(base + 16));
if (!size) {
memunmap(base);
return -EINVAL;
}
size *= 1024; /* In KB */
if (size != OPREGION_SIZE) {
memunmap(base);
base = memremap(addr, size, MEMREMAP_WB);
if (!base)
return -ENOMEM;
}
ret = vfio_pci_register_dev_region(vdev,
PCI_VENDOR_ID_INTEL | VFIO_REGION_TYPE_PCI_VENDOR_TYPE,
VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION,
&vfio_pci_igd_regops, size, VFIO_REGION_INFO_FLAG_READ, base);
if (ret) {
memunmap(base);
return ret;
}
/* Fill vconfig with the hw value and virtualize register */
*dwordp = cpu_to_le32(addr);
memset(vdev->pci_config_map + OPREGION_PCI_ADDR,
PCI_CAP_ID_INVALID_VIRT, 4);
return ret;
}