Before opregion version 2.0 VBT data is stored in opregion mailbox #4,
However, When VBT data exceeds 6KB size and cannot be within mailbox #4
starting from opregion v2.0+, Extended VBT region, next to opregion, is
used to hold the VBT data, so the total size will be opregion size plus
extended VBT region size.
Cc: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx>
Signed-off-by: Swee Yee Fonn <swee.yee.fonn@xxxxxxxxx>
Signed-off-by: Fred Gao <fred.gao@xxxxxxxxx>
---
drivers/vfio/pci/vfio_pci_igd.c | 59 +++++++++++++++++++++++++++++++++
1 file changed, 59 insertions(+)
diff --git a/drivers/vfio/pci/vfio_pci_igd.c b/drivers/vfio/pci/vfio_pci_igd.c
index 53d97f459252..fc470278a492 100644
--- a/drivers/vfio/pci/vfio_pci_igd.c
+++ b/drivers/vfio/pci/vfio_pci_igd.c
@@ -21,6 +21,10 @@
#define OPREGION_SIZE (8 * 1024)
#define OPREGION_PCI_ADDR 0xfc
+#define OPREGION_RVDA 0x3ba
+#define OPREGION_RVDS 0x3c2
+#define OPREGION_VERSION 0x16
+
static size_t vfio_pci_igd_rw(struct vfio_pci_device *vdev, char __user *buf,
size_t count, loff_t *ppos, bool iswrite)
{
@@ -58,6 +62,7 @@ static int vfio_pci_igd_opregion_init(struct vfio_pci_device *vdev)
u32 addr, size;
void *base;
int ret;
+ u16 version;
ret = pci_read_config_dword(vdev->pdev, OPREGION_PCI_ADDR, &addr);
if (ret)
@@ -83,6 +88,60 @@ static int vfio_pci_igd_opregion_init(struct vfio_pci_device *vdev)
size *= 1024; /* In KB */
+ /*
+ * Support opregion v2.0+
+ * When VBT data exceeds 6KB size and cannot be within mailbox #4
+ * Extended VBT region, next to opregion, is used to hold the VBT data.
+ * RVDA (Relative Address of VBT Data from Opregion Base) and RVDS
+ * (VBT Data Size) from opregion structure member are used to hold the
+ * address from region base and size of VBT data while RVDA/RVDS
+ * are not defined before opregion 2.0.
+ *
+ * opregion 2.0: rvda is the physical VBT address.
+ *
+ * opregion 2.1+: rvda is unsigned, relative offset from
+ * opregion base, and should never point within opregion.
+ */
+ version = le16_to_cpu(*(__le16 *)(base + OPREGION_VERSION));
+ if (version >= 0x0200) {
+ u64 rvda;
+ u32 rvds;
+
+ rvda = le64_to_cpu(*(__le64 *)(base + OPREGION_RVDA));
+ rvds = le32_to_cpu(*(__le32 *)(base + OPREGION_RVDS));
+ if (rvda && rvds) {
+ u32 offset;
+
+ if (version == 0x0200)
+ offset = rvda - (u64)addr;
+ else
+ offset = rvda;
+
+ if (offset != size) {
+ pci_err(vdev->pdev,
+ "Extended VBT does not follow opregion !\n"
+ "opregion version 0x%x:offset 0x%x\n", version, offset);
+ return -EINVAL;
+ }
+
+ /*
+ * the only difference between opregion 2.0 and 2.1 is
+ * rvda addressing mode. since rvda is physical host
+ * VBT address and cannot be directly used in guest,
+ * faked into opregion 2.1's relative offset.
+ */
+ if (version == 0x0200) {
+ *(__le16 *)(base + OPREGION_VERSION) =
+ cpu_to_le16(0x0201);
+ (*(__le64 *)(base + OPREGION_RVDA)) =
+ cpu_to_le64((rvda - (u64)addr));
+ }
+
+ /* region size for opregion v2.0+: opregion and VBT size */
+ size = offset + rvds;
+ }
+ }
+
if (size != OPREGION_SIZE) {
memunmap(base);
base = memremap(addr, size, MEMREMAP_WB);
--
2.24.1.1.gb6d4d82bd5
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