libxc: Export xc_core_arch_map_p2m_writable()

This patch firstly change the xc_core_arch_map_p2m() to map the p2m to
be writable, then it export this function.
One notice for this patch is, caller should make sure change the p2m
in flight will not cause trouble.

Signed-off-by: Jiang, Yunhong <yunhong.jiang@intel.com>

1 files changed, 23 insertions, 5 deletions

diff --git a/tools/libxc/xc_core_x86.c b/tools/libxc/xc_core_x86.c
index 765c745cb6..fc2a7a1192 100644
--- a/tools/libxc/xc_core_x86.c
+++ b/tools/libxc/xc_core_x86.c
@@ -75,10 +75,10 @@ xc_core_arch_memory_map_get(int xc_handle, struct xc_core_arch_context *unused,
     return 0;
 }
 
-int
-xc_core_arch_map_p2m(int xc_handle, unsigned int guest_width, xc_dominfo_t *info,
-                     shared_info_any_t *live_shinfo, xen_pfn_t **live_p2m,
-                     unsigned long *pfnp)
+static int
+xc_core_arch_map_p2m_rw(int xc_handle, unsigned int guest_width, xc_dominfo_t *info,
+                        shared_info_any_t *live_shinfo, xen_pfn_t **live_p2m,
+                        unsigned long *pfnp, int rw)
 {
     /* Double and single indirect references to the live P2M table */
     xen_pfn_t *live_p2m_frame_list_list = NULL;
@@ -156,7 +156,8 @@ xc_core_arch_map_p2m(int xc_handle, unsigned int guest_width, xc_dominfo_t *info
         for ( i = P2M_FL_ENTRIES - 1; i >= 0; i-- )
             p2m_frame_list[i] = ((uint32_t *)p2m_frame_list)[i];
 
-    *live_p2m = xc_map_foreign_pages(xc_handle, dom, PROT_READ,
+    *live_p2m = xc_map_foreign_pages(xc_handle, dom,
+                                    rw ? (PROT_READ | PROT_WRITE) : PROT_READ,
                                     p2m_frame_list,
                                     P2M_FL_ENTRIES);
 
@@ -189,6 +190,23 @@ out:
     return ret;
 }
 
+int
+xc_core_arch_map_p2m(int xc_handle, unsigned int guest_width, xc_dominfo_t *info,
+                        shared_info_any_t *live_shinfo, xen_pfn_t **live_p2m,
+                        unsigned long *pfnp)
+{
+    return xc_core_arch_map_p2m_rw(xc_handle, guest_width, info,
+                                   live_shinfo, live_p2m, pfnp, 0);
+}
+
+int
+xc_core_arch_map_p2m_writable(int xc_handle, unsigned int guest_width, xc_dominfo_t *info,
+                              shared_info_any_t *live_shinfo, xen_pfn_t **live_p2m,
+                              unsigned long *pfnp)
+{
+    return xc_core_arch_map_p2m_rw(xc_handle, guest_width, info,
+                                   live_shinfo, live_p2m, pfnp, 1);
+}
 /*
  * Local variables:
  * mode: C