[PATCH 02/16] libxc: introduce xc_dom_seg_to_ptr_pages

[Ian Jackson <ian.jackson@eu.citrix.com>]

Provide a version of xc_dom_seg_to_ptr which returns the number of
guest pages it has actually mapped.  This is useful for callers who
want to do range checking; we will use this later in this series.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 tools/libxc/xc_dom.h |   12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/tools/libxc/xc_dom.h b/tools/libxc/xc_dom.h
index ac36600..6c31440 100644
--- a/tools/libxc/xc_dom.h
+++ b/tools/libxc/xc_dom.h
@@ -294,16 +294,24 @@ void *xc_dom_pfn_to_ptr(struct xc_dom_image *dom, xen_pfn_t first,
 void xc_dom_unmap_one(struct xc_dom_image *dom, xen_pfn_t pfn);
 void xc_dom_unmap_all(struct xc_dom_image *dom);
 
-static inline void *xc_dom_seg_to_ptr(struct xc_dom_image *dom,
-                                      struct xc_dom_seg *seg)
+static inline void *xc_dom_seg_to_ptr_pages(struct xc_dom_image *dom,
+                                      struct xc_dom_seg *seg,
+                                      xen_pfn_t *pages_out)
 {
     xen_vaddr_t segsize = seg->vend - seg->vstart;
     unsigned int page_size = XC_DOM_PAGE_SIZE(dom);
     xen_pfn_t pages = (segsize + page_size - 1) / page_size;
+    if (pages_out) *pages_out = pages;
 
     return xc_dom_pfn_to_ptr(dom, seg->pfn, pages);
 }
 
+static inline void *xc_dom_seg_to_ptr(struct xc_dom_image *dom,
+                                      struct xc_dom_seg *seg)
+{
+    return xc_dom_seg_to_ptr_pages(dom, seg, NULL);
+}
+
 static inline void *xc_dom_vaddr_to_ptr(struct xc_dom_image *dom,
                                         xen_vaddr_t vaddr)
 {
-- 
1.7.2.5