xen/privcmd: Further s/MFN/GFN/ clean-up

The privcmd code is mixing the usage of GFN and MFN within the same
functions which make the code difficult to understand when you only work
with auto-translated guests.

The privcmd driver is only dealing with GFN so replace all the mention
of MFN into GFN.

The ioctl structure used to map foreign change has been left unchanged
given that the userspace is using it. Nonetheless, add a comment to
explain the expected value within the "mfn" field.

Signed-off-by: Julien Grall <julien.grall@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

2 files changed, 9 insertions, 5 deletions

diff --git a/include/uapi/xen/privcmd.h b/include/uapi/xen/privcmd.h
index a85316811d79..7ddeeda93809 100644
--- a/include/uapi/xen/privcmd.h
+++ b/include/uapi/xen/privcmd.h
@@ -44,6 +44,10 @@ struct privcmd_hypercall {
 
 struct privcmd_mmap_entry {
         __u64 va;
+        /*
+         * This should be a GFN. It's not possible to change the name because
+         * it's exposed to the user-space.
+         */
         __u64 mfn;
         __u64 npages;
 };
diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
index 0ce4f32017ea..e4e214a5abd5 100644
--- a/include/xen/xen-ops.h
+++ b/include/xen/xen-ops.h
@@ -30,7 +30,7 @@ void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order);
 struct vm_area_struct;
 
 /*
- * xen_remap_domain_mfn_array() - map an array of foreign frames
+ * xen_remap_domain_gfn_array() - map an array of foreign frames
  * @vma:     VMA to map the pages into
  * @addr:    Address at which to map the pages
  * @gfn:     Array of GFNs to map
@@ -46,14 +46,14 @@ struct vm_area_struct;
  * Returns the number of successfully mapped frames, or a -ve error
  * code.
  */
-int xen_remap_domain_mfn_array(struct vm_area_struct *vma,
+int xen_remap_domain_gfn_array(struct vm_area_struct *vma,
                                unsigned long addr,
                                xen_pfn_t *gfn, int nr,
                                int *err_ptr, pgprot_t prot,
                                unsigned domid,
                                struct page **pages);
 
-/* xen_remap_domain_mfn_range() - map a range of foreign frames
+/* xen_remap_domain_gfn_range() - map a range of foreign frames
  * @vma:     VMA to map the pages into
  * @addr:    Address at which to map the pages
  * @gfn:     First GFN to map.
@@ -65,12 +65,12 @@ int xen_remap_domain_mfn_array(struct vm_area_struct *vma,
  * Returns the number of successfully mapped frames, or a -ve error
  * code.
  */
-int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
+int xen_remap_domain_gfn_range(struct vm_area_struct *vma,
                                unsigned long addr,
                                xen_pfn_t gfn, int nr,
                                pgprot_t prot, unsigned domid,
                                struct page **pages);
-int xen_unmap_domain_mfn_range(struct vm_area_struct *vma,
+int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
                                int numpgs, struct page **pages);
 int xen_xlate_remap_gfn_array(struct vm_area_struct *vma,
                               unsigned long addr,