vfio: Move vfio_kvm_device_fd() into helpers.c

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>

5 files changed, 14 insertions, 13 deletions

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index f80c0ef..84a9a37 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -49,17 +49,6 @@
 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 7ddc979..48bd61d 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 31e4ddd..95ccbad 100644
--- a/hw/vfio/spapr.c
+++ b/hw/vfio/spapr.c
@@ -15,13 +15,13 @@
 #include "system/hostmem.h"
 #include "system/address-spaces.h"
 
-#include "hw/vfio/vfio-common.h"
 #include "hw/vfio/vfio-container.h"
 #include "hw/hw.h"
 #include "system/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;
diff --git a/hw/vfio/vfio-helpers.h b/hw/vfio/vfio-helpers.h
index dbcb68b..54a327f 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 2065c2f..06178cf 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,