[PULL 08/29] igd gfx passthrough: create a isa bridge

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

From: 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>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/i386/pc_piix.c    |  112 ++++++++++++++++++++++++++++++++++++++++++++++++++
 include/hw/i386/pc.h |    1 +
 2 files changed, 113 insertions(+)

diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 626a19f..301a675 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -882,6 +882,118 @@ static void pc_i440fx_0_10_machine_options(MachineClass *m)
 DEFINE_I440FX_MACHINE(v0_10, "pc-0.10", pc_compat_0_13,
                       pc_i440fx_0_10_machine_options);
 
+typedef struct {
+    uint16_t gpu_device_id;
+    uint16_t pch_device_id;
+    uint8_t pch_revision_id;
+} IGDDeviceIDInfo;
+
+/* 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 IGDDeviceIDInfo 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          = "igd-passthrough-isa-bridge",
+    .parent        = TYPE_PCI_DEVICE,
+    .instance_size = sizeof(PCIDevice),
+    .class_init = isa_bridge_class_init,
+};
+
+static void pt_graphics_register_types(void)
+{
+    type_register_static(&isa_bridge_info);
+}
+type_init(pt_graphics_register_types)
+
+void igd_passthrough_isa_bridge_create(PCIBus *bus, uint16_t gpu_dev_id)
+{
+    struct PCIDevice *bridge_dev;
+    int i, num;
+    uint16_t pch_dev_id = 0xffff;
+    uint8_t pch_rev_id;
+
+    num = ARRAY_SIZE(igd_combo_id_infos);
+    for (i = 0; i < num; i++) {
+        if (gpu_dev_id == igd_combo_id_infos[i].gpu_device_id) {
+            pch_dev_id = igd_combo_id_infos[i].pch_device_id;
+            pch_rev_id = igd_combo_id_infos[i].pch_revision_id;
+        }
+    }
+
+    if (pch_dev_id == 0xffff) {
+        return;
+    }
+
+    /* Currently IGD drivers always need to access PCH by 1f.0. */
+    bridge_dev = pci_create_simple(bus, PCI_DEVFN(0x1f, 0),
+                                   "igd-passthrough-isa-bridge");
+
+    /*
+     * Note that vendor id is always PCI_VENDOR_ID_INTEL.
+     */
+    if (!bridge_dev) {
+        fprintf(stderr, "set igd-passthrough-isa-bridge failed!\n");
+        return;
+    }
+    pci_config_set_device_id(bridge_dev->config, pch_dev_id);
+    pci_config_set_revision(bridge_dev->config, pch_rev_id);
+}
 
 static void isapc_machine_options(MachineClass *m)
 {
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 5cda2a3..0639e46 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -726,4 +726,5 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *);
     (m)->compat_props = props; \
 } while (0)
 
+extern void igd_passthrough_isa_bridge_create(PCIBus *bus, uint16_t gpu_dev_id);
 #endif
-- 
1.7.10.4