xenoprof: adjust ordering of page sharing vs domain type setting

Buffer pages should be shared with "ignored" or "active" guests only
(besides, obviously, the primary profiling domain). Hence domain type
should be set to "ignored" before unsharing from the primary domain
(which implies even a previously "passive" domain may then access its
buffers, albeit that's not very useful unless it gets promoted to
"active" subsequently), i.e. such that no further writes of records to
the buffer would occur, and (at least for consistency) also before
sharing it (with the calling domain) from the XENOPROF_get_buffer path.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Wei Liu <wl@xen.org>

diff --git a/xen/common/xenoprof.c b/xen/common/xenoprof.c
index b04726cb495b3d0bbcbdf482772a603c989da8a5..3dad5dfb38c2ac0679368e0be5a094a07e346c67 100644 (file)
--- a/xen/common/xenoprof.c
+++ b/xen/common/xenoprof.c
@@ -372,8 +372,8 @@ static void reset_passive(struct domain *d)
     if ( x == NULL )
         return;
 
-    unshare_xenoprof_page_with_guest(x);
     x->domain_type = XENOPROF_DOMAIN_IGNORED;
+    unshare_xenoprof_page_with_guest(x);
 }
 
 static void reset_active_list(void)
@@ -654,6 +654,13 @@ static int xenoprof_op_get_buffer(XEN_GUEST_HANDLE_PARAM(void) arg)
         if ( ret < 0 )
             return ret;
     }
+    else
+    {
+        d->xenoprof->domain_ready = 0;
+        d->xenoprof->domain_type = XENOPROF_DOMAIN_IGNORED;
+    }
+
+    d->xenoprof->is_primary = (xenoprof_primary_profiler == d);
 
     ret = share_xenoprof_page_with_guest(
         d, virt_to_mfn(d->xenoprof->rawbuf), d->xenoprof->npages);
@@ -662,10 +669,6 @@ static int xenoprof_op_get_buffer(XEN_GUEST_HANDLE_PARAM(void) arg)
 
     xenoprof_reset_buf(d);
 
-    d->xenoprof->domain_type  = XENOPROF_DOMAIN_IGNORED;
-    d->xenoprof->domain_ready = 0;
-    d->xenoprof->is_primary   = (xenoprof_primary_profiler == current->domain);
-        
     xenoprof_get_buffer.nbuf = d->xenoprof->nbuf;
     xenoprof_get_buffer.bufsize = d->xenoprof->bufsize;
     if ( !paging_mode_translate(d) )