linux-stable/drivers/vfio/pci/vfio_pci_igd.c
Alex Williamson f572a960a1 vfio/pci: Intel IGD host and LCP bridge config space access
Provide read-only access to PCI config space of the PCI host bridge
and LPC bridge through device specific regions.  This may be used to
configure a VM with matching register contents to satisfy driver
requirements.  Providing this through the vfio file descriptor removes
an additional userspace requirement for access through pci-sysfs and
removes the CAP_SYS_ADMIN requirement that doesn't appear to apply to
the specific devices we're accessing.

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

280 lines
6.1 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,
};
static 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;
}
static size_t vfio_pci_igd_cfg_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;
struct pci_dev *pdev = vdev->region[i].data;
loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
size_t size;
int ret;
if (pos >= vdev->region[i].size || iswrite)
return -EINVAL;
size = count = min(count, (size_t)(vdev->region[i].size - pos));
if ((pos & 1) && size) {
u8 val;
ret = pci_user_read_config_byte(pdev, pos, &val);
if (ret)
return pcibios_err_to_errno(ret);
if (copy_to_user(buf + count - size, &val, 1))
return -EFAULT;
pos++;
size--;
}
if ((pos & 3) && size > 2) {
u16 val;
ret = pci_user_read_config_word(pdev, pos, &val);
if (ret)
return pcibios_err_to_errno(ret);
val = cpu_to_le16(val);
if (copy_to_user(buf + count - size, &val, 2))
return -EFAULT;
pos += 2;
size -= 2;
}
while (size > 3) {
u32 val;
ret = pci_user_read_config_dword(pdev, pos, &val);
if (ret)
return pcibios_err_to_errno(ret);
val = cpu_to_le32(val);
if (copy_to_user(buf + count - size, &val, 4))
return -EFAULT;
pos += 4;
size -= 4;
}
while (size >= 2) {
u16 val;
ret = pci_user_read_config_word(pdev, pos, &val);
if (ret)
return pcibios_err_to_errno(ret);
val = cpu_to_le16(val);
if (copy_to_user(buf + count - size, &val, 2))
return -EFAULT;
pos += 2;
size -= 2;
}
while (size) {
u8 val;
ret = pci_user_read_config_byte(pdev, pos, &val);
if (ret)
return pcibios_err_to_errno(ret);
if (copy_to_user(buf + count - size, &val, 1))
return -EFAULT;
pos++;
size--;
}
*ppos += count;
return count;
}
static void vfio_pci_igd_cfg_release(struct vfio_pci_device *vdev,
struct vfio_pci_region *region)
{
struct pci_dev *pdev = region->data;
pci_dev_put(pdev);
}
static const struct vfio_pci_regops vfio_pci_igd_cfg_regops = {
.rw = vfio_pci_igd_cfg_rw,
.release = vfio_pci_igd_cfg_release,
};
static int vfio_pci_igd_cfg_init(struct vfio_pci_device *vdev)
{
struct pci_dev *host_bridge, *lpc_bridge;
int ret;
host_bridge = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0, 0));
if (!host_bridge)
return -ENODEV;
if (host_bridge->vendor != PCI_VENDOR_ID_INTEL ||
host_bridge->class != (PCI_CLASS_BRIDGE_HOST << 8)) {
pci_dev_put(host_bridge);
return -EINVAL;
}
ret = vfio_pci_register_dev_region(vdev,
PCI_VENDOR_ID_INTEL | VFIO_REGION_TYPE_PCI_VENDOR_TYPE,
VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG,
&vfio_pci_igd_cfg_regops, host_bridge->cfg_size,
VFIO_REGION_INFO_FLAG_READ, host_bridge);
if (ret) {
pci_dev_put(host_bridge);
return ret;
}
lpc_bridge = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0x1f, 0));
if (!lpc_bridge)
return -ENODEV;
if (lpc_bridge->vendor != PCI_VENDOR_ID_INTEL ||
lpc_bridge->class != (PCI_CLASS_BRIDGE_ISA << 8)) {
pci_dev_put(lpc_bridge);
return -EINVAL;
}
ret = vfio_pci_register_dev_region(vdev,
PCI_VENDOR_ID_INTEL | VFIO_REGION_TYPE_PCI_VENDOR_TYPE,
VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG,
&vfio_pci_igd_cfg_regops, lpc_bridge->cfg_size,
VFIO_REGION_INFO_FLAG_READ, lpc_bridge);
if (ret) {
pci_dev_put(lpc_bridge);
return ret;
}
return 0;
}
int vfio_pci_igd_init(struct vfio_pci_device *vdev)
{
int ret;
ret = vfio_pci_igd_opregion_init(vdev);
if (ret)
return ret;
ret = vfio_pci_igd_cfg_init(vdev);
if (ret)
return ret;
return 0;
}