[RFC PATCH-for-5.0] hw/pci-host: Add Kconfig selector for IGD PCIe pass-through

[Philippe Mathieu-Daudé]

Introduce a kconfig selector to allow builds without Intel
Integrated Graphics Device GPU PCIe passthrough.
We keep the default as enabled.

Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com>
---
RFC because to be able to use the Kconfig-generated
"config-devices.h" header we have to move this device
out of $common-obj and build i440fx.o on a per-target
basis, which is not optimal...
---
 hw/pci-host/i440fx.c      | 9 ++++++++-
 hw/vfio/pci-quirks.c      | 6 ++++++
 hw/pci-host/Kconfig       | 5 +++++
 hw/pci-host/Makefile.objs | 2 +-
 4 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/hw/pci-host/i440fx.c b/hw/pci-host/i440fx.c
index f27131102d..41e93581f4 100644
--- a/hw/pci-host/i440fx.c
+++ b/hw/pci-host/i440fx.c
@@ -34,6 +34,7 @@
 #include "hw/pci-host/pam.h"
 #include "qapi/visitor.h"
 #include "qemu/error-report.h"
+#include "config-devices.h"
 
 /*
  * I440FX chipset data sheet.
@@ -386,6 +387,8 @@ static const TypeInfo i440fx_info = {
     },
 };
 
+#ifdef CONFIG_INTEL_IGD_PASSTHROUGH
+
 /* IGD Passthrough Host Bridge. */
 typedef struct {
     uint8_t offset;
@@ -470,6 +473,8 @@ static const TypeInfo igd_passthrough_i440fx_info = {
     .class_init    = igd_passthrough_i440fx_class_init,
 };
 
+#endif /* CONFIG_INTEL_IGD_PASSTHROUGH */
+
 static const char *i440fx_pcihost_root_bus_path(PCIHostState *host_bridge,
                                                 PCIBus *rootbus)
 {
@@ -514,8 +519,10 @@ static const TypeInfo i440fx_pcihost_info = {
 static void i440fx_register_types(void)
 {
     type_register_static(&i440fx_info);
-    type_register_static(&igd_passthrough_i440fx_info);
     type_register_static(&i440fx_pcihost_info);
+#ifdef CONFIG_INTEL_IGD_PASSTHROUGH
+    type_register_static(&igd_passthrough_i440fx_info);
+#endif /* CONFIG_INTEL_IGD_PASSTHROUGH */
 }
 
 type_init(i440fx_register_types)
diff --git a/hw/vfio/pci-quirks.c b/hw/vfio/pci-quirks.c
index 136f3a9ad6..858148fa39 100644
--- a/hw/vfio/pci-quirks.c
+++ b/hw/vfio/pci-quirks.c
@@ -1166,6 +1166,8 @@ static void vfio_probe_rtl8168_bar2_quirk(VFIOPCIDevice 
*vdev, int nr)
     trace_vfio_quirk_rtl8168_probe(vdev->vbasedev.name);
 }
 
+#ifdef CONFIG_INTEL_IGD_PASSTHROUGH
+
 /*
  * Intel IGD support
  *
@@ -1811,6 +1813,8 @@ out:
     g_free(lpc);
 }
 
+#endif /* CONFIG_INTEL_IGD_PASSTHROUGH */
+
 /*
  * Common quirk probe entry points.
  */
@@ -1860,7 +1864,9 @@ void vfio_bar_quirk_setup(VFIOPCIDevice *vdev, int nr)
     vfio_probe_nvidia_bar5_quirk(vdev, nr);
     vfio_probe_nvidia_bar0_quirk(vdev, nr);
     vfio_probe_rtl8168_bar2_quirk(vdev, nr);
+#ifdef CONFIG_INTEL_IGD_PASSTHROUGH
     vfio_probe_igd_bar4_quirk(vdev, nr);
+#endif /* CONFIG_INTEL_IGD_PASSTHROUGH */
 }
 
 void vfio_bar_quirk_exit(VFIOPCIDevice *vdev, int nr)
diff --git a/hw/pci-host/Kconfig b/hw/pci-host/Kconfig
index b0aa8351c4..0b7539765a 100644
--- a/hw/pci-host/Kconfig
+++ b/hw/pci-host/Kconfig
@@ -1,6 +1,10 @@
 config PAM
     bool
 
+config INTEL_IGD_PASSTHROUGH
+    default y
+    bool
+
 config PREP_PCI
     bool
     select PCI
@@ -32,6 +36,7 @@ config PCI_I440FX
     bool
     select PCI
     select PAM
+    imply INTEL_IGD_PASSTHROUGH
 
 config PCI_EXPRESS_Q35
     bool
diff --git a/hw/pci-host/Makefile.objs b/hw/pci-host/Makefile.objs
index efd752b766..3c925192dd 100644
--- a/hw/pci-host/Makefile.objs
+++ b/hw/pci-host/Makefile.objs
@@ -13,7 +13,7 @@ common-obj-$(CONFIG_VERSATILE_PCI) += versatile.o
 
 common-obj-$(CONFIG_PCI_SABRE) += sabre.o
 common-obj-$(CONFIG_FULONG) += bonito.o
-common-obj-$(CONFIG_PCI_I440FX) += i440fx.o
+obj-$(CONFIG_PCI_I440FX) += i440fx.o
 common-obj-$(CONFIG_PCI_EXPRESS_Q35) += q35.o
 common-obj-$(CONFIG_PCI_EXPRESS_GENERIC_BRIDGE) += gpex.o
 common-obj-$(CONFIG_PCI_EXPRESS_XILINX) += xilinx-pcie.o
-- 
2.21.0