[PATCH] hw/ppc: Improve build for PPC VFIO

[Zhenzhong Duan <zhenzhong.duan@intel.com>]

VFIO is not a required subsystem for the pseries machine but it's
force enabled currently. When --without-default-devices is used
to drop some default devices including vfio-pci, vfio core code
is still kept which is unnecessary.

Introduce a stub file to hold stub functions of VFIO EEH hooks,
then vfio core could be compiled out.

Suggested-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
Based on vfio-next/vfio-8.2

 hw/ppc/spapr_pci_vfio_stub.c | 33 +++++++++++++++++++++++++++++++++
 hw/ppc/Kconfig               |  2 +-
 hw/ppc/meson.build           |  6 +++---
 3 files changed, 37 insertions(+), 4 deletions(-)
 create mode 100644 hw/ppc/spapr_pci_vfio_stub.c

diff --git a/hw/ppc/spapr_pci_vfio_stub.c b/hw/ppc/spapr_pci_vfio_stub.c
new file mode 100644
index 0000000000..adb3fb5e35
--- /dev/null
+++ b/hw/ppc/spapr_pci_vfio_stub.c
@@ -0,0 +1,33 @@
+#include "qemu/osdep.h"
+#include "hw/pci-host/spapr.h"
+
+bool spapr_phb_eeh_available(SpaprPhbState *sphb)
+{
+    return false;
+}
+
+void spapr_phb_vfio_reset(DeviceState *qdev)
+{
+}
+
+int spapr_phb_vfio_eeh_set_option(SpaprPhbState *sphb,
+                                  unsigned int addr, int option)
+{
+    return RTAS_OUT_NOT_SUPPORTED;
+}
+
+int spapr_phb_vfio_eeh_get_state(SpaprPhbState *sphb, int *state)
+{
+    return RTAS_OUT_NOT_SUPPORTED;
+}
+
+int spapr_phb_vfio_eeh_reset(SpaprPhbState *sphb, int option)
+{
+    return RTAS_OUT_NOT_SUPPORTED;
+}
+
+int spapr_phb_vfio_eeh_configure(SpaprPhbState *sphb)
+{
+    return RTAS_OUT_NOT_SUPPORTED;
+}
+
diff --git a/hw/ppc/Kconfig b/hw/ppc/Kconfig
index edc6d2d139..b8dabdbfbe 100644
--- a/hw/ppc/Kconfig
+++ b/hw/ppc/Kconfig
@@ -3,11 +3,11 @@ config PSERIES
     imply PCI_DEVICES
     imply TEST_DEVICES
     imply VIRTIO_VGA
+    imply VFIO if LINUX   # needed by spapr_pci_vfio.c
     select NVDIMM
     select DIMM
     select PCI
     select SPAPR_VSCSI
-    select VFIO_PCI if LINUX   # needed by spapr_pci_vfio.c
     select XICS
     select XIVE
     select MSI_NONBROKEN
diff --git a/hw/ppc/meson.build b/hw/ppc/meson.build
index ea44856d43..2df5db2eef 100644
--- a/hw/ppc/meson.build
+++ b/hw/ppc/meson.build
@@ -34,9 +34,9 @@ ppc_ss.add(when: ['CONFIG_PSERIES', 'CONFIG_TCG'], if_true: files(
   'spapr_softmmu.c',
 ))
 ppc_ss.add(when: 'CONFIG_SPAPR_RNG', if_true: files('spapr_rng.c'))
-ppc_ss.add(when: ['CONFIG_PSERIES', 'CONFIG_LINUX'], if_true: files(
-  'spapr_pci_vfio.c',
-))
+ppc_ss.add(when: [ 'CONFIG_VFIO_PCI', 'CONFIG_PSERIES', 'CONFIG_LINUX'],
+           if_true: files('spapr_pci_vfio.c'),
+           if_false: files('spapr_pci_vfio_stub.c'))
 
 # IBM PowerNV
 ppc_ss.add(when: 'CONFIG_POWERNV', if_true: files(
-- 
2.34.1