[PATCH v2 23/30] vfio/pci: re-introduce CONFIG_VFIO_PCI_ZDEV

[Matthew Rosato <mjrosato@linux.ibm.com>]

This was previously removed as unnecessary; while that was true, subsequent
changes will make KVM an additional required component for vfio-pci-zdev.
Let's re-introduce CONFIG_VFIO_PCI_ZDEV as now there is actually a reason
to say 'n' for it (when not planning to CONFIG_KVM).

Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
---
 drivers/vfio/pci/Kconfig      | 11 +++++++++++
 drivers/vfio/pci/Makefile     |  2 +-
 include/linux/vfio_pci_core.h |  2 +-
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig
index 860424ccda1b..fedd1d4cb592 100644
--- a/drivers/vfio/pci/Kconfig
+++ b/drivers/vfio/pci/Kconfig
@@ -42,5 +42,16 @@ config VFIO_PCI_IGD
 	  and LPC bridge config space.
 
 	  To enable Intel IGD assignment through vfio-pci, say Y.
+
+config VFIO_PCI_ZDEV
+	bool "VFIO PCI extensions for s390x KVM passthrough"
+	depends on S390 && KVM
+	default y
+	help
+	  Support s390x-specific extensions to enable support for enhancements
+	  to KVM passthrough capabilities, such as interpretive execution of
+	  zPCI instructions.
+
+	  To enable s390x KVM vfio-pci extensions, say Y.
 endif
 endif
diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile
index 349d68d242b4..01b1f83d83d7 100644
--- a/drivers/vfio/pci/Makefile
+++ b/drivers/vfio/pci/Makefile
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
 vfio-pci-core-y := vfio_pci_core.o vfio_pci_intrs.o vfio_pci_rdwr.o vfio_pci_config.o
-vfio-pci-core-$(CONFIG_S390) += vfio_pci_zdev.o
+vfio-pci-core-$(CONFIG_VFIO_PCI_ZDEV) += vfio_pci_zdev.o
 obj-$(CONFIG_VFIO_PCI_CORE) += vfio-pci-core.o
 
 vfio-pci-y := vfio_pci.o
diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h
index ef9a44b6cf5d..5e2bca3b89db 100644
--- a/include/linux/vfio_pci_core.h
+++ b/include/linux/vfio_pci_core.h
@@ -195,7 +195,7 @@ static inline int vfio_pci_igd_init(struct vfio_pci_core_device *vdev)
 }
 #endif
 
-#ifdef CONFIG_S390
+#ifdef CONFIG_VFIO_PCI_ZDEV
 extern int vfio_pci_info_zdev_add_caps(struct vfio_pci_core_device *vdev,
 				       struct vfio_info_cap *caps);
 #else
-- 
2.27.0