1 files changed, 79 insertions, 0 deletions
diff --git a/hw/xen/xen_pt_graphics.c b/hw/xen/xen_pt_graphics.c
index 9b3df811b1..3232296bf8 100644
--- a/hw/xen/xen_pt_graphics.c
+++ b/hw/xen/xen_pt_graphics.c
@@ -109,3 +109,82 @@ int xen_pt_unregister_vga_regions(XenHostPCIDevice *dev)
 
     return 0;
 }
+
+static void *get_vgabios(XenPCIPassthroughState *s, int *size,
+                       XenHostPCIDevice *dev)
+{
+    return pci_assign_dev_load_option_rom(&s->dev, OBJECT(&s->dev), size,
+                                          dev->domain, dev->bus,
+                                          dev->dev, dev->func);
+}
+
+/* Refer to Seabios. */
+struct rom_header {
+    uint16_t signature;
+    uint8_t size;
+    uint8_t initVector[4];
+    uint8_t reserved[17];
+    uint16_t pcioffset;
+    uint16_t pnpoffset;
+} __attribute__((packed));
+
+struct pci_data {
+    uint32_t signature;
+    uint16_t vendor;
+    uint16_t device;
+    uint16_t vitaldata;
+    uint16_t dlen;
+    uint8_t drevision;
+    uint8_t class_lo;
+    uint16_t class_hi;
+    uint16_t ilen;
+    uint16_t irevision;
+    uint8_t type;
+    uint8_t indicator;
+    uint16_t reserved;
+} __attribute__((packed));
+
+int xen_pt_setup_vga(XenPCIPassthroughState *s, XenHostPCIDevice *dev)
+{
+    unsigned char *bios = NULL;
+    struct rom_header *rom;
+    int bios_size;
+    char *c = NULL;
+    char checksum = 0;
+    uint32_t len = 0;
+    struct pci_data *pd = NULL;
+
+    if (!is_igd_vga_passthrough(dev)) {
+        return -1;
+    }
+
+    bios = get_vgabios(s, &bios_size, dev);
+    if (!bios) {
+        XEN_PT_ERR(&s->dev, "VGA: Can't getting VBIOS!\n");
+        return -1;
+    }
+
+    /* Currently we fixed this address as a primary. */
+    rom = (struct rom_header *)bios;
+    pd = (void *)(bios + (unsigned char)rom->pcioffset);
+
+    /* We may need to fixup Device Identification. */
+    if (pd->device != s->real_device.device_id) {
+        pd->device = s->real_device.device_id;
+
+        len = rom->size * 512;
+        /* Then adjust the bios checksum */
+        for (c = (char *)bios; c < ((char *)bios + len); c++) {
+            checksum += *c;
+        }
+        if (checksum) {
+            bios[len - 1] -= checksum;
+            XEN_PT_LOG(&s->dev, "vga bios checksum is adjusted %x!\n",
+                       checksum);
+        }
+    }
+
+    /* Currently we fixed this address as a primary for legacy BIOS. */
+    cpu_physical_memory_rw(0xc0000, bios, bios_size, 1);
+    return 0;
+}