VisionFive2 Linux kernel

diff --git a/drivers/vfio/pci/vfio_pci_igd.c b/drivers/vfio/pci/vfio_pci_igd.c
index e66dfb0178ed..228df565e9bc 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 +88,54 @@ static int vfio_pci_igd_opregion_init(struct vfio_pci_device *vdev)
 
 	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 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.
+	 */
+	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) {
+			/* 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;
+			}
+
+			if (rvda != size) {
+				memunmap(base);
+				pci_err(vdev->pdev,
+					"Extended VBT does not follow opregion on version 0x%04x\n",
+					version);
+				return -EINVAL;
+			}
+
+			/* region size for opregion v2.0+: opregion and VBT size. */
+			size += rvds;
+		}
+	}
+
 	if (size != OPREGION_SIZE) {
 		memunmap(base);
 		base = memremap(addr, size, MEMREMAP_WB);