[Qemu-devel] [v6][PATCH 07/10] xen, gfx passthrough: register a isa bridge

[Tiejun Chen <tiejun.chen@intel.com>]

Currently IGD drivers always need to access PCH by 1f.0. But we
don't want to poke that directly to get ID, and although in real
world different GPU should have different PCH. But actually the
different PCH DIDs likely map to different PCH SKUs. We do the
same thing for the GPU. For PCH, the different SKUs are going to
be all the same silicon design and implementation, just different
features turn on and off with fuses. The SW interfaces should be
consistent across all SKUs in a given family (eg LPT). But just
same features may not be supported.

Most of these different PCH features probably don't matter to the
Gfx driver, but obviously any difference in display port connections
will so it should be fine with any PCH in case of passthrough.

So currently use one PCH version, 0x8c4e, to cover all HSW(Haswell)
scenarios, 0x9cc3 for BDW(Broadwell).

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
---
 hw/xen/xen_pt.c | 126 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 126 insertions(+)

diff --git a/hw/xen/xen_pt.c b/hw/xen/xen_pt.c
index fcc9f1c..5532d6f 100644
--- a/hw/xen/xen_pt.c
+++ b/hw/xen/xen_pt.c
@@ -632,6 +632,129 @@ static const MemoryListener xen_pt_io_listener = {
     .priority = 10,
 };
 
+typedef struct {
+    uint16_t gpu_device_id;
+    uint16_t pch_device_id;
+    uint8_t pch_revision_id;
+} XenIGDDeviceIDInfo;
+
+/* In real world different GPU should have different PCH. But actually
+ * the different PCH DIDs likely map to different PCH SKUs. We do the
+ * same thing for the GPU. For PCH, the different SKUs are going to be
+ * all the same silicon design and implementation, just different
+ * features turn on and off with fuses. The SW interfaces should be
+ * consistent across all SKUs in a given family (eg LPT). But just same
+ * features may not be supported.
+ *
+ * Most of these different PCH features probably don't matter to the
+ * Gfx driver, but obviously any difference in display port connections
+ * will so it should be fine with any PCH in case of passthrough.
+ *
+ * So currently use one PCH version, 0x8c4e, to cover all HSW(Haswell)
+ * scenarios, 0x9cc3 for BDW(Broadwell).
+ */
+static const XenIGDDeviceIDInfo xen_igd_combo_id_infos[] = {
+    /* HSW Classic */
+    {0x0402, 0x8c4e, 0x04}, /* HSWGT1D, HSWD_w7 */
+    {0x0406, 0x8c4e, 0x04}, /* HSWGT1M, HSWM_w7 */
+    {0x0412, 0x8c4e, 0x04}, /* HSWGT2D, HSWD_w7 */
+    {0x0416, 0x8c4e, 0x04}, /* HSWGT2M, HSWM_w7 */
+    {0x041E, 0x8c4e, 0x04}, /* HSWGT15D, HSWD_w7 */
+    /* HSW ULT */
+    {0x0A06, 0x8c4e, 0x04}, /* HSWGT1UT, HSWM_w7 */
+    {0x0A16, 0x8c4e, 0x04}, /* HSWGT2UT, HSWM_w7 */
+    {0x0A26, 0x8c4e, 0x06}, /* HSWGT3UT, HSWM_w7 */
+    {0x0A2E, 0x8c4e, 0x04}, /* HSWGT3UT28W, HSWM_w7 */
+    {0x0A1E, 0x8c4e, 0x04}, /* HSWGT2UX, HSWM_w7 */
+    {0x0A0E, 0x8c4e, 0x04}, /* HSWGT1ULX, HSWM_w7 */
+    /* HSW CRW */
+    {0x0D26, 0x8c4e, 0x04}, /* HSWGT3CW, HSWM_w7 */
+    {0x0D22, 0x8c4e, 0x04}, /* HSWGT3CWDT, HSWD_w7 */
+    /* HSW Server */
+    {0x041A, 0x8c4e, 0x04}, /* HSWSVGT2, HSWD_w7 */
+    /* HSW SRVR */
+    {0x040A, 0x8c4e, 0x04}, /* HSWSVGT1, HSWD_w7 */
+    /* BSW */
+    {0x1606, 0x9cc3, 0x03}, /* BDWULTGT1, BDWM_w7 */
+    {0x1616, 0x9cc3, 0x03}, /* BDWULTGT2, BDWM_w7 */
+    {0x1626, 0x9cc3, 0x03}, /* BDWULTGT3, BDWM_w7 */
+    {0x160E, 0x9cc3, 0x03}, /* BDWULXGT1, BDWM_w7 */
+    {0x161E, 0x9cc3, 0x03}, /* BDWULXGT2, BDWM_w7 */
+    {0x1602, 0x9cc3, 0x03}, /* BDWHALOGT1, BDWM_w7 */
+    {0x1612, 0x9cc3, 0x03}, /* BDWHALOGT2, BDWM_w7 */
+    {0x1622, 0x9cc3, 0x03}, /* BDWHALOGT3, BDWM_w7 */
+    {0x162B, 0x9cc3, 0x03}, /* BDWHALO28W, BDWM_w7 */
+    {0x162A, 0x9cc3, 0x03}, /* BDWGT3WRKS, BDWM_w7 */
+    {0x162D, 0x9cc3, 0x03}, /* BDWGT3SRVR, BDWM_w7 */
+};
+
+static void isa_bridge_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
+
+    dc->desc        = "ISA bridge faked to support IGD PT";
+    k->vendor_id    = PCI_VENDOR_ID_INTEL;
+    k->class_id     = PCI_CLASS_BRIDGE_ISA;
+};
+
+static TypeInfo isa_bridge_info = {
+    .name          = "xen-igd-passthrough-isa-bridge",
+    .parent        = TYPE_PCI_DEVICE,
+    .instance_size = sizeof(PCIDevice),
+    .class_init = isa_bridge_class_init,
+};
+
+static void xen_pt_graphics_register_types(void)
+{
+    type_register_static(&isa_bridge_info);
+}
+type_init(xen_pt_graphics_register_types)
+
+static void
+xen_igd_passthrough_isa_bridge_create(XenPCIPassthroughState *s,
+                                      XenHostPCIDevice *dev)
+{
+    struct PCIDevice *pci_dev;
+    int i, num;
+    uint16_t gpu_dev_id, pch_dev_id = 0xffff;
+    uint8_t pch_rev_id;
+    PCIDevice *d = &s->dev;
+
+    if (!is_igd_vga_passthrough(dev)) {
+        return;
+    }
+
+    gpu_dev_id = dev->device_id;
+    num = ARRAY_SIZE(xen_igd_combo_id_infos);
+    for (i = 0; i < num; i++) {
+        if (gpu_dev_id == xen_igd_combo_id_infos[i].gpu_device_id) {
+            pch_dev_id = xen_igd_combo_id_infos[i].pch_device_id;
+            pch_rev_id = xen_igd_combo_id_infos[i].pch_revision_id;
+        }
+    }
+
+    if (pch_dev_id == 0xffff) {
+        fprintf(stderr, "unsupported PCH!\n");
+        return;
+    }
+
+    /* Currently IGD drivers always need to access PCH by 1f.0. */
+    pci_dev = pci_create_simple(d->bus, PCI_DEVFN(0x1f, 0),
+                                "xen-igd-passthrough-isa-bridge");
+
+    /*
+     * Identify PCH card with its own real vendor/device ids.
+     * Note that vendor id is always PCI_VENDOR_ID_INTEL.
+     */
+    if (!pci_dev) {
+        fprintf(stderr, "xen set xen-igd-passthrough-isa-bridge failed!\n");
+        return;
+    }
+    pci_config_set_device_id(pci_dev->config, pch_dev_id);
+    pci_config_set_revision(pci_dev->config, pch_rev_id);
+}
+
 /* init */
 
 static int xen_pt_initfn(PCIDevice *d)
@@ -680,6 +803,9 @@ static int xen_pt_initfn(PCIDevice *d)
             xen_host_pci_device_put(&s->real_device);
             return -1;
         }
+
+        /* Register ISA bridge for passthrough GFX. */
+        xen_igd_passthrough_isa_bridge_create(s, &s->real_device);
     }
 
     /* Handle real device's MMIO/PIO BARs */
-- 
1.9.1