diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/vfio/pci/vfio_pci_igd.c | 234 |
1 files changed, 175 insertions, 59 deletions
diff --git a/drivers/vfio/pci/vfio_pci_igd.c b/drivers/vfio/pci/vfio_pci_igd.c index 7ca4109bba48..56cd551e0e04 100644 --- a/drivers/vfio/pci/vfio_pci_igd.c +++ b/drivers/vfio/pci/vfio_pci_igd.c @@ -25,20 +25,121 @@ #define OPREGION_RVDS 0x3c2 #define OPREGION_VERSION 0x16 +struct igd_opregion_vbt { + void *opregion; + void *vbt_ex; +}; + +/** + * igd_opregion_shift_copy() - Copy OpRegion to user buffer and shift position. + * @dst: User buffer ptr to copy to. + * @off: Offset to user buffer ptr. Increased by bytes on return. + * @src: Source buffer to copy from. + * @pos: Increased by bytes on return. + * @remaining: Decreased by bytes on return. + * @bytes: Bytes to copy and adjust off, pos and remaining. + * + * Copy OpRegion to offset from specific source ptr and shift the offset. + * + * Return: 0 on success, -EFAULT otherwise. + * + */ +static inline unsigned long igd_opregion_shift_copy(char __user *dst, + loff_t *off, + void *src, + loff_t *pos, + size_t *remaining, + size_t bytes) +{ + if (copy_to_user(dst + (*off), src, bytes)) + return -EFAULT; + + *off += bytes; + *pos += bytes; + *remaining -= bytes; + + return 0; +} + static ssize_t vfio_pci_igd_rw(struct vfio_pci_core_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; + struct igd_opregion_vbt *opregionvbt = vdev->region[i].data; + loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK, off = 0; + size_t remaining; if (pos >= vdev->region[i].size || iswrite) return -EINVAL; - count = min(count, (size_t)(vdev->region[i].size - pos)); + count = min_t(size_t, count, vdev->region[i].size - pos); + remaining = count; + + /* Copy until OpRegion version */ + if (remaining && pos < OPREGION_VERSION) { + size_t bytes = min_t(size_t, remaining, OPREGION_VERSION - pos); + + if (igd_opregion_shift_copy(buf, &off, + opregionvbt->opregion + pos, &pos, + &remaining, bytes)) + return -EFAULT; + } + + /* Copy patched (if necessary) OpRegion version */ + if (remaining && pos < OPREGION_VERSION + sizeof(__le16)) { + size_t bytes = min_t(size_t, remaining, + OPREGION_VERSION + sizeof(__le16) - pos); + __le16 version = *(__le16 *)(opregionvbt->opregion + + OPREGION_VERSION); + + /* Patch to 2.1 if OpRegion 2.0 has extended VBT */ + if (le16_to_cpu(version) == 0x0200 && opregionvbt->vbt_ex) + version = cpu_to_le16(0x0201); + + if (igd_opregion_shift_copy(buf, &off, + &version + (pos - OPREGION_VERSION), + &pos, &remaining, bytes)) + return -EFAULT; + } + + /* Copy until RVDA */ + if (remaining && pos < OPREGION_RVDA) { + size_t bytes = min_t(size_t, remaining, OPREGION_RVDA - pos); - if (copy_to_user(buf, base + pos, count)) + if (igd_opregion_shift_copy(buf, &off, + opregionvbt->opregion + pos, &pos, + &remaining, bytes)) + return -EFAULT; + } + + /* Copy modified (if necessary) RVDA */ + if (remaining && pos < OPREGION_RVDA + sizeof(__le64)) { + size_t bytes = min_t(size_t, remaining, + OPREGION_RVDA + sizeof(__le64) - pos); + __le64 rvda = cpu_to_le64(opregionvbt->vbt_ex ? + OPREGION_SIZE : 0); + + if (igd_opregion_shift_copy(buf, &off, + &rvda + (pos - OPREGION_RVDA), + &pos, &remaining, bytes)) + return -EFAULT; + } + + /* Copy the rest of OpRegion */ + if (remaining && pos < OPREGION_SIZE) { + size_t bytes = min_t(size_t, remaining, OPREGION_SIZE - pos); + + if (igd_opregion_shift_copy(buf, &off, + opregionvbt->opregion + pos, &pos, + &remaining, bytes)) + return -EFAULT; + } + + /* Copy extended VBT if exists */ + if (remaining && + copy_to_user(buf + off, opregionvbt->vbt_ex + (pos - OPREGION_SIZE), + remaining)) return -EFAULT; *ppos += count; @@ -49,7 +150,13 @@ static ssize_t vfio_pci_igd_rw(struct vfio_pci_core_device *vdev, static void vfio_pci_igd_release(struct vfio_pci_core_device *vdev, struct vfio_pci_region *region) { - memunmap(region->data); + struct igd_opregion_vbt *opregionvbt = region->data; + + if (opregionvbt->vbt_ex) + memunmap(opregionvbt->vbt_ex); + + memunmap(opregionvbt->opregion); + kfree(opregionvbt); } static const struct vfio_pci_regops vfio_pci_igd_regops = { @@ -61,7 +168,7 @@ static int vfio_pci_igd_opregion_init(struct vfio_pci_core_device *vdev) { __le32 *dwordp = (__le32 *)(vdev->vconfig + OPREGION_PCI_ADDR); u32 addr, size; - void *base; + struct igd_opregion_vbt *opregionvbt; int ret; u16 version; @@ -72,84 +179,93 @@ static int vfio_pci_igd_opregion_init(struct vfio_pci_core_device *vdev) if (!addr || !(~addr)) return -ENODEV; - base = memremap(addr, OPREGION_SIZE, MEMREMAP_WB); - if (!base) + opregionvbt = kzalloc(sizeof(*opregionvbt), GFP_KERNEL); + if (!opregionvbt) + return -ENOMEM; + + opregionvbt->opregion = memremap(addr, OPREGION_SIZE, MEMREMAP_WB); + if (!opregionvbt->opregion) { + kfree(opregionvbt); return -ENOMEM; + } - if (memcmp(base, OPREGION_SIGNATURE, 16)) { - memunmap(base); + if (memcmp(opregionvbt->opregion, OPREGION_SIGNATURE, 16)) { + memunmap(opregionvbt->opregion); + kfree(opregionvbt); return -EINVAL; } - size = le32_to_cpu(*(__le32 *)(base + 16)); + size = le32_to_cpu(*(__le32 *)(opregionvbt->opregion + 16)); if (!size) { - memunmap(base); + memunmap(opregionvbt->opregion); + kfree(opregionvbt); return -EINVAL; } size *= 1024; /* In KB */ /* - * Support opregion v2.1+ - * When VBT data exceeds 6KB size and cannot be within mailbox #4, then - * the Extended VBT region next to opregion is used to hold the VBT data. - * RVDA (Relative Address of VBT Data from Opregion Base) and RVDS - * (Raw VBT Data Size) from opregion structure member are used to hold the - * address from region base and size of VBT data. RVDA/RVDS are not - * defined before opregion 2.0. - * - * opregion 2.1+: RVDA is unsigned, relative offset from - * opregion base, and should point to the end of opregion. - * otherwise, exposing to userspace to allow read access to everything between - * the OpRegion and VBT is not safe. - * RVDS is defined as size in bytes. + * OpRegion and VBT: + * When VBT data doesn't exceed 6KB, it's stored in Mailbox #4. + * When VBT data exceeds 6KB size, Mailbox #4 is no longer large enough + * to hold the VBT data, the Extended VBT region is introduced since + * OpRegion 2.0 to hold the VBT data. Since OpRegion 2.0, RVDA/RVDS are + * introduced to define the extended VBT data location and size. + * OpRegion 2.0: RVDA defines the absolute physical address of the + * extended VBT data, RVDS defines the VBT data size. + * OpRegion 2.1 and above: RVDA defines the relative address of the + * extended VBT data to OpRegion base, RVDS defines the VBT data size. * - * opregion 2.0: rvda is the physical VBT address. - * Since rvda is HPA it cannot be directly used in guest. - * And it should not be practically available for end user,so it is not supported. + * Due to the RVDA definition diff in OpRegion VBT (also the only diff + * between 2.0 and 2.1), exposing OpRegion and VBT as a contiguous range + * for OpRegion 2.0 and above makes it possible to support the + * non-contiguous VBT through a single vfio region. From r/w ops view, + * only contiguous VBT after OpRegion with version 2.1+ is exposed, + * regardless the host OpRegion is 2.0 or non-contiguous 2.1+. The r/w + * ops will on-the-fly shift the actural offset into VBT so that data at + * correct position can be returned to the requester. */ - version = le16_to_cpu(*(__le16 *)(base + OPREGION_VERSION)); + version = le16_to_cpu(*(__le16 *)(opregionvbt->opregion + + OPREGION_VERSION)); if (version >= 0x0200) { - u64 rvda; - u32 rvds; + u64 rvda = le64_to_cpu(*(__le64 *)(opregionvbt->opregion + + OPREGION_RVDA)); + u32 rvds = le32_to_cpu(*(__le32 *)(opregionvbt->opregion + + OPREGION_RVDS)); - rvda = le64_to_cpu(*(__le64 *)(base + OPREGION_RVDA)); - rvds = le32_to_cpu(*(__le32 *)(base + OPREGION_RVDS)); + /* The extended VBT is valid only when RVDA/RVDS are non-zero */ if (rvda && rvds) { - /* no support for opregion v2.0 with physical VBT address */ - if (version == 0x0200) { - memunmap(base); - pci_err(vdev->pdev, - "IGD assignment does not support opregion v2.0 with an extended VBT region\n"); - return -EINVAL; - } + size += rvds; - if (rvda != size) { - memunmap(base); - pci_err(vdev->pdev, - "Extended VBT does not follow opregion on version 0x%04x\n", - version); - return -EINVAL; + /* + * Extended VBT location by RVDA: + * Absolute physical addr for 2.0. + * Relative addr to OpRegion header for 2.1+. + */ + if (version == 0x0200) + addr = rvda; + else + addr += rvda; + + opregionvbt->vbt_ex = memremap(addr, rvds, MEMREMAP_WB); + if (!opregionvbt->vbt_ex) { + memunmap(opregionvbt->opregion); + kfree(opregionvbt); + return -ENOMEM; } - - /* region size for opregion v2.0+: opregion and VBT size. */ - size += rvds; } } - 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); + VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION, &vfio_pci_igd_regops, + size, VFIO_REGION_INFO_FLAG_READ, opregionvbt); if (ret) { - memunmap(base); + if (opregionvbt->vbt_ex) + memunmap(opregionvbt->vbt_ex); + + memunmap(opregionvbt->opregion); + kfree(opregionvbt); return ret; } |