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>
This commit is contained in:
Alex Williamson 2016-02-22 16:02:45 -07:00
parent 5846ff54e8
commit f572a960a1
4 changed files with 186 additions and 7 deletions

View File

@ -111,6 +111,7 @@ static inline bool vfio_pci_is_vga(struct pci_dev *pdev)
}
static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev);
static void vfio_pci_disable(struct vfio_pci_device *vdev);
static int vfio_pci_enable(struct vfio_pci_device *vdev)
{
@ -170,10 +171,16 @@ static int vfio_pci_enable(struct vfio_pci_device *vdev)
vdev->has_vga = true;
if (vfio_pci_is_vga(pdev) && pdev->vendor == PCI_VENDOR_ID_INTEL) {
if (vfio_pci_igd_opregion_init(vdev) == 0)
dev_info(&pdev->dev,
"Intel IGD OpRegion support enabled\n");
if (vfio_pci_is_vga(pdev) &&
pdev->vendor == PCI_VENDOR_ID_INTEL &&
IS_ENABLED(CONFIG_VFIO_PCI_IGD)) {
ret = vfio_pci_igd_init(vdev);
if (ret) {
dev_warn(&vdev->pdev->dev,
"Failed to setup Intel IGD regions\n");
vfio_pci_disable(vdev);
return ret;
}
}
return 0;

View File

@ -55,7 +55,7 @@ static const struct vfio_pci_regops vfio_pci_igd_regops = {
.release = vfio_pci_igd_release,
};
int vfio_pci_igd_opregion_init(struct vfio_pci_device *vdev)
static int vfio_pci_igd_opregion_init(struct vfio_pci_device *vdev)
{
__le32 *dwordp = (__le32 *)(vdev->vconfig + OPREGION_PCI_ADDR);
u32 addr, size;
@ -109,3 +109,172 @@ int vfio_pci_igd_opregion_init(struct vfio_pci_device *vdev)
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;
}

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@ -123,9 +123,9 @@ extern int vfio_pci_register_dev_region(struct vfio_pci_device *vdev,
const struct vfio_pci_regops *ops,
size_t size, u32 flags, void *data);
#ifdef CONFIG_VFIO_PCI_IGD
extern int vfio_pci_igd_opregion_init(struct vfio_pci_device *vdev);
extern int vfio_pci_igd_init(struct vfio_pci_device *vdev);
#else
static inline int vfio_pci_igd_opregion_init(struct vfio_pci_device *vdev)
static inline int vfio_pci_igd_init(struct vfio_pci_device *vdev)
{
return -ENODEV;
}

View File

@ -283,7 +283,10 @@ struct vfio_region_info_cap_type {
#define VFIO_REGION_TYPE_PCI_VENDOR_TYPE (1 << 31)
#define VFIO_REGION_TYPE_PCI_VENDOR_MASK (0xffff)
/* 8086 Vendor sub-types */
#define VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION (1)
#define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG (2)
#define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG (3)
/**
* VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9,