meson: add -Diommufd=[auto]|enabled|disabled

iommufd feature has been checked based on the kernel header file in
vfio.h in the current build system.  Even if iommufd is supported by the
current system, user might want to build and install libvfn with vfio
rather than iommufd.

This patch added -Diommufd option to meson to let user choose whether to
include or not.

Signed-off-by: Minwoo Im <minwoo.im@samsung.com>

Author: minwooim

meson.build

@@ -66,14 +66,31 @@ config_host = configuration_data()
 config_host.set('NVME_AQ_QSIZE', get_option('aq_qsize'),
   description: 'admin command queue size')
 
-config_host.set('HAVE_VFIO_DEVICE_BIND_IOMMUFD',
-  cc.has_header_symbol('linux/vfio.h', 'VFIO_DEVICE_BIND_IOMMUFD',
-    include_directories: linux_headers),
-  description: 'if VFIO_DEVICE_BIND_IOMMUFD is defined in linux/vfio.h')
-
-config_host.set('HAVE_IOMMU_FAULT_QUEUE_ALLOC',
-  cc.has_header_symbol('linux/iommufd.h', 'IOMMU_FAULT_QUEUE_ALLOC',
-    include_directories: linux_headers),
+# Check iommufd option
+iommufd_opt = get_option('iommufd')
+has_iommufd = false
+
+if not iommufd_opt.disabled()
+  has_vfio_bind = cc.has_header_symbol('linux/vfio.h', 'VFIO_DEVICE_BIND_IOMMUFD',
+    include_directories: linux_headers)
+
+  if has_vfio_bind
+    has_iommufd = true
+  elif iommufd_opt.enabled()
+    error('iommufd enabled but VFIO_DEVICE_BIND_IOMMUFD not found in linux/vfio.h')
+  endif
+endif
+
+config_host.set('HAVE_VFIO_DEVICE_BIND_IOMMUFD', has_iommufd,
+  description: 'if iommufd support is enabled')
+
+has_fault_queue = false
+if has_iommufd
+  has_fault_queue = cc.has_header_symbol('linux/iommufd.h', 'IOMMU_FAULT_QUEUE_ALLOC',
+    include_directories: linux_headers)
+endif
+
+config_host.set('HAVE_IOMMU_FAULT_QUEUE_ALLOC', has_fault_queue,
   description: 'if IOMMU_FAULT_QUEUE_ALLOC is defined in linux/iommufd.h')
 
 subdir('internal')
@@ -180,6 +197,6 @@ summary_info = {}
 summary_info += {'Debugging': get_option('debug')}
 summary_info += {'Documentation': build_docs}
 summary_info += {'Profiling': get_option('profiling')}
-summary_info += {'iommufd': config_host.get('HAVE_VFIO_DEVICE_BIND_IOMMUFD')}
-summary_info += {'iommufd fault queue': config_host.get('HAVE_IOMMU_FAULT_QUEUE_ALLOC')}
+summary_info += {'iommufd': has_iommufd}
+summary_info += {'iommufd fault queue': has_fault_queue}
 summary(summary_info, bool_yn: true, section: 'Features')

meson_options.txt

@@ -15,3 +15,6 @@ option('trace-events-file', type: 'string', value: 'config/trace-events-all',
 
 option('linux-headers', type: 'string', value: '',
   description: 'path to linux headers')
+
+option('iommufd', type: 'feature', value: 'auto',
+  description: 'enable/disable iommufd support')