xen/privcmd: add IOCTL_PRIVCMD_MMAP_RESOURCE

My recent Xen patch series introduces a new HYPERVISOR_memory_op to
support direct priv-mapping of certain guest resources (such as ioreq
pages, used by emulators) by a tools domain, rather than having to access
such resources via the guest P2M.

This patch adds the necessary infrastructure to the privcmd driver and
Xen MMU code to support direct resource mapping.

NOTE: The adjustment in the MMU code is partially cosmetic. Xen will now
      allow a PV tools domain to map guest pages either by GFN or MFN, thus
      the term 'mfn' has been swapped for 'pfn' in the lower layers of the
      remap code.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

1 files changed, 23 insertions, 1 deletions

diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
index fd23e42c6024..fd18c974a619 100644
--- a/include/xen/xen-ops.h
+++ b/include/xen/xen-ops.h
@@ -63,7 +63,7 @@ static inline void xen_destroy_contiguous_region(phys_addr_t pstart,
 struct vm_area_struct;
 
 /*
- * xen_remap_domain_gfn_array() - map an array of foreign frames
+ * xen_remap_domain_gfn_array() - map an array of foreign frames by gfn
  * @vma:     VMA to map the pages into
  * @addr:    Address at which to map the pages
  * @gfn:     Array of GFNs to map
@@ -86,6 +86,28 @@ int xen_remap_domain_gfn_array(struct vm_area_struct *vma,
 			       unsigned domid,
 			       struct page **pages);
 
+/*
+ * xen_remap_domain_mfn_array() - map an array of foreign frames by mfn
+ * @vma:     VMA to map the pages into
+ * @addr:    Address at which to map the pages
+ * @mfn:     Array of MFNs to map
+ * @nr:      Number entries in the MFN array
+ * @err_ptr: Returns per-MFN error status.
+ * @prot:    page protection mask
+ * @domid:   Domain owning the pages
+ * @pages:   Array of pages if this domain has an auto-translated physmap
+ *
+ * @mfn and @err_ptr may point to the same buffer, the MFNs will be
+ * overwritten by the error codes after they are mapped.
+ *
+ * Returns the number of successfully mapped frames, or a -ve error
+ * code.
+ */
+int xen_remap_domain_mfn_array(struct vm_area_struct *vma,
+			       unsigned long addr, xen_pfn_t *mfn, int nr,
+			       int *err_ptr, pgprot_t prot,
+			       unsigned int domid, struct page **pages);
+
 /* 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