vfio: Add capability chain helpers

Allow sub-modules to easily reallocate a buffer for managing
capability chains for info ioctls.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 610a86a892b8..0ecae0b1cd34 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -92,6 +92,17 @@ extern int vfio_external_user_iommu_id(struct vfio_group *group);
 extern long vfio_external_check_extension(struct vfio_group *group,
 					  unsigned long arg);
 
+/*
+ * Sub-module helpers
+ */
+struct vfio_info_cap {
+	struct vfio_info_cap_header *buf;
+	size_t size;
+};
+extern struct vfio_info_cap_header *vfio_info_cap_add(
+		struct vfio_info_cap *caps, size_t size, u16 id, u16 version);
+extern void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset);
+
 struct pci_dev;
 #ifdef CONFIG_EEH
 extern void vfio_spapr_pci_eeh_open(struct pci_dev *pdev);