[PATCH v3 22/37] vfio: Move vfio_kvm_device_fd() into helpers.c

["Cédric Le Goater" <clg@redhat.com>]

The vfio_kvm_device_add/del_fd() routines opening the VFIO pseudo
device are defined in "helpers.c". Move 'vfio_kvm_device_fd'
definition there and its declaration into "vfio-helpers.h" to reduce
exposure of VFIO internals in "hw/vfio/vfio-common.h".

Reviewed-by: John Levon <john.levon@nutanix.com>
Link: https://lore.kernel.org/qemu-devel/20250318095415.670319-22-clg@redhat.com
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Link: https://lore.kernel.org/qemu-devel/20250326075122.1299361-23-clg@redhat.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
 hw/vfio/vfio-helpers.h        |  2 ++
 include/hw/vfio/vfio-common.h |  1 -
 hw/vfio/common.c              | 11 -----------
 hw/vfio/helpers.c             | 11 +++++++++++
 hw/vfio/spapr.c               |  2 +-
 5 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/hw/vfio/vfio-helpers.h b/hw/vfio/vfio-helpers.h
index dbcb68bbb0e12607f5ccf15f114530966c2cbcb2..54a327ffbc04a2df364fdd78bd97fe7e2065b38c 100644
--- a/hw/vfio/vfio-helpers.h
+++ b/hw/vfio/vfio-helpers.h
@@ -12,6 +12,8 @@
 #ifdef CONFIG_LINUX
 #include <linux/vfio.h>
 
+extern int vfio_kvm_device_fd;
+
 struct vfio_info_cap_header *
 vfio_get_cap(void *ptr, uint32_t cap_offset, uint16_t id);
 struct vfio_info_cap_header *
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index c587ed08feabd0c4845d824960dd0799e9ace69b..8b300e7768fb61af881f6a8b7eeb75dc84c98ac3 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -132,7 +132,6 @@ VFIODevice *vfio_get_vfio_device(Object *obj);
 typedef QLIST_HEAD(VFIODeviceList, VFIODevice) VFIODeviceList;
 extern VFIODeviceList vfio_device_list;
 extern const MemoryListener vfio_memory_listener;
-extern int vfio_kvm_device_fd;
 
 #ifdef CONFIG_LINUX
 int vfio_get_region_info(VFIODevice *vbasedev, int index,
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 2dcf70c66e81dddffb35a152da5a18d27a05c6f1..91ffc5e1a37a3ba7ab50cb5f14cbe5d56f78949d 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -50,17 +50,6 @@
 VFIODeviceList vfio_device_list =
     QLIST_HEAD_INITIALIZER(vfio_device_list);
 
-#ifdef CONFIG_KVM
-/*
- * We have a single VFIO pseudo device per KVM VM.  Once created it lives
- * for the life of the VM.  Closing the file descriptor only drops our
- * reference to it and the device's reference to kvm.  Therefore once
- * initialized, this file descriptor is only released on QEMU exit and
- * we'll re-use it should another vfio device be attached before then.
- */
-int vfio_kvm_device_fd = -1;
-#endif
-
 /*
  * Device state interfaces
  */
diff --git a/hw/vfio/helpers.c b/hw/vfio/helpers.c
index 7ddc9797ef7659035d927e40a3b99a8f74dca2de..48bd61d5280967dffa509dcbaeeee7a1ba01335a 100644
--- a/hw/vfio/helpers.c
+++ b/hw/vfio/helpers.c
@@ -106,6 +106,17 @@ bool vfio_get_info_dma_avail(struct vfio_iommu_type1_info *info,
     return true;
 }
 
+#ifdef CONFIG_KVM
+/*
+ * We have a single VFIO pseudo device per KVM VM.  Once created it lives
+ * for the life of the VM.  Closing the file descriptor only drops our
+ * reference to it and the device's reference to kvm.  Therefore once
+ * initialized, this file descriptor is only released on QEMU exit and
+ * we'll re-use it should another vfio device be attached before then.
+ */
+int vfio_kvm_device_fd = -1;
+#endif
+
 int vfio_kvm_device_add_fd(int fd, Error **errp)
 {
 #ifdef CONFIG_KVM
diff --git a/hw/vfio/spapr.c b/hw/vfio/spapr.c
index 522314fec7fb6e0a5951472031be840daf2af8d1..8ac11c39a83b3c54378b747ebdabc4c95d03b7c2 100644
--- a/hw/vfio/spapr.c
+++ b/hw/vfio/spapr.c
@@ -15,13 +15,13 @@
 #include "system/hostmem.h"
 #include "exec/address-spaces.h"
 
-#include "hw/vfio/vfio-common.h"
 #include "hw/vfio/vfio-container.h"
 #include "hw/hw.h"
 #include "exec/ram_addr.h"
 #include "qemu/error-report.h"
 #include "qapi/error.h"
 #include "trace.h"
+#include "vfio-helpers.h"
 
 typedef struct VFIOHostDMAWindow {
     hwaddr min_iova;
-- 
2.49.0