From f572a960a15e8bb56599f6d2358a9c18f0808e91 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Mon, 22 Feb 2016 16:02:45 -0700 Subject: 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 --- drivers/vfio/pci/vfio_pci.c | 15 +++- drivers/vfio/pci/vfio_pci_igd.c | 171 +++++++++++++++++++++++++++++++++++- drivers/vfio/pci/vfio_pci_private.h | 4 +- 3 files changed, 183 insertions(+), 7 deletions(-) (limited to 'drivers/vfio') diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index cb2624db37d8..74a375297494 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -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; diff --git a/drivers/vfio/pci/vfio_pci_igd.c b/drivers/vfio/pci/vfio_pci_igd.c index 3b6a6f7b367b..6394b168ef29 100644 --- a/drivers/vfio/pci/vfio_pci_igd.c +++ b/drivers/vfio/pci/vfio_pci_igd.c @@ -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; +} diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h index 19f7699ac699..8a7d546d18a0 100644 --- a/drivers/vfio/pci/vfio_pci_private.h +++ b/drivers/vfio/pci/vfio_pci_private.h @@ -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; } -- cgit v1.2.3