Re: [PATCH v2 12/21] hw/vfio/igd: Check CONFIG_VFIO_IGD at runtime using vfio_igd_builtin()

[Cédric Le Goater]

On 3/9/25 00:09, Philippe Mathieu-Daudé wrote:

Convert the compile time check on the CONFIG_VFIO_IGD definition
by a runtime one by calling vfio_igd_builtin(), which check
whether VFIO_IGD is built in a qemu-system binary.

Add stubs to avoid when VFIO_IGD is not built in:

I thought we were trying to avoid stubs in QEMU build. Did that change ?


Thanks,

C.

   /usr/bin/ld: libqemu-x86_64-softmmu.a.p/hw_vfio_pci-quirks.c.o: in function 
`vfio_bar_quirk_setup':
   /usr/bin/ld: ../hw/vfio/pci-quirks.c:1216: undefined reference to 
`vfio_probe_igd_bar0_quirk'
   /usr/bin/ld: ../hw/vfio/pci-quirks.c:1217: undefined reference to 
`vfio_probe_igd_bar4_quirk'

Signed-off-by: Philippe Mathieu-Daudé <phi...@linaro.org>
---
  hw/vfio/pci-quirks.h |  6 ++++++
  hw/vfio/igd-stubs.c  | 20 ++++++++++++++++++++
  hw/vfio/pci-quirks.c |  9 ++++-----
  hw/vfio/meson.build  |  3 +++
  4 files changed, 33 insertions(+), 5 deletions(-)
  create mode 100644 hw/vfio/igd-stubs.c

diff --git a/hw/vfio/pci-quirks.h b/hw/vfio/pci-quirks.h
index fdaa81f00aa..dcdb1962600 100644
--- a/hw/vfio/pci-quirks.h
+++ b/hw/vfio/pci-quirks.h
@@ -13,6 +13,7 @@
  #define HW_VFIO_VFIO_PCI_QUIRKS_H

#include "qemu/osdep.h"

+#include "qom/object.h"
  #include "exec/memop.h"

/*

@@ -71,4 +72,9 @@ extern const MemoryRegionOps vfio_generic_mirror_quirk;

#define TYPE_VFIO_PCI_IGD_LPC_BRIDGE "vfio-pci-igd-lpc-bridge" +static inline bool vfio_igd_builtin(void)

+{
+    return type_is_registered(TYPE_VFIO_PCI_IGD_LPC_BRIDGE);
+}
+
  #endif /* HW_VFIO_VFIO_PCI_QUIRKS_H */
diff --git a/hw/vfio/igd-stubs.c b/hw/vfio/igd-stubs.c
new file mode 100644
index 00000000000..5d4e88aeb1b
--- /dev/null
+++ b/hw/vfio/igd-stubs.c
@@ -0,0 +1,20 @@
+/*
+ * IGD device quirk stubs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * Copyright (C) Linaro, Ltd.
+ */
+
+#include "qemu/osdep.h"
+#include "pci.h"
+
+void vfio_probe_igd_bar0_quirk(VFIOPCIDevice *vdev, int nr)
+{
+    g_assert_not_reached();
+}
+
+void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
+{
+    g_assert_not_reached();
+}
diff --git a/hw/vfio/pci-quirks.c b/hw/vfio/pci-quirks.c
index c53591fe2ba..22cb35af8cc 100644
--- a/hw/vfio/pci-quirks.c
+++ b/hw/vfio/pci-quirks.c
@@ -11,7 +11,6 @@
   */

#include "qemu/osdep.h"

-#include CONFIG_DEVICES
  #include "exec/memop.h"
  #include "qemu/units.h"
  #include "qemu/log.h"
@@ -1213,10 +1212,10 @@ 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_VFIO_IGD
-    vfio_probe_igd_bar0_quirk(vdev, nr);
-    vfio_probe_igd_bar4_quirk(vdev, nr);
-#endif
+    if (vfio_igd_builtin()) {
+        vfio_probe_igd_bar0_quirk(vdev, nr);
+        vfio_probe_igd_bar4_quirk(vdev, nr);
+    }
  }

void vfio_bar_quirk_exit(VFIOPCIDevice *vdev, int nr)

diff --git a/hw/vfio/meson.build b/hw/vfio/meson.build
index a8939c83865..6ab711d0539 100644
--- a/hw/vfio/meson.build
+++ b/hw/vfio/meson.build
@@ -17,6 +17,9 @@ specific_ss.add_all(when: 'CONFIG_VFIO', if_true: vfio_ss)

system_ss.add(when: 'CONFIG_VFIO_XGMAC', if_true: files('calxeda-xgmac.c'))

  system_ss.add(when: 'CONFIG_VFIO_AMD_XGBE', if_true: files('amd-xgbe.c'))
+system_ss.add(when: 'CONFIG_VFIO_IGD', if_false: files(
+  'igd-stubs.c',
+))
  system_ss.add(when: 'CONFIG_VFIO', if_true: files(
    'helpers.c',
    'container-base.c',