x86/numa: fix c/s 20120 (Fix SRAT check for discontig memory)

That change converted the (wrong) assumption of contiguous nodes'
memory to a similarly wrong one of assuming discontiguous memory (i.e.
each node having separate E820 table entries). The code ought to be
able to deal with both, though, and I hope this change makes it so.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Alex Williamson <alex.williamson@hp.com>

diff --git a/xen/arch/x86/srat.c b/xen/arch/x86/srat.c
index b49654b78e9f578931d276cbe6cd878066eb6334..1a6d2a10fb5c9b1d62a1a0e520e6fa55a9776e05 100644 (file)
--- a/xen/arch/x86/srat.c
+++ b/xen/arch/x86/srat.c
@@ -249,15 +249,23 @@ static int nodes_cover_memory(void)
                start = e820.map[i].addr;
                end = e820.map[i].addr + e820.map[i].size - 1;
 
-               found = 0;
-               for_each_node_mask(j, nodes_parsed) {
-                       if (start >= nodes[j].start && end <= nodes[j].end) {
-                               found = 1;
-                               break;
-                       }
-               }
-
-               if (!found) {
+               do {
+                       found = 0;
+                       for_each_node_mask(j, nodes_parsed)
+                               if (start < nodes[j].end
+                                   && end > nodes[j].start) {
+                                       if (start >= nodes[j].start) {
+                                               start = nodes[j].end;
+                                               found = 1;
+                                       }
+                                       if (end <= nodes[j].end) {
+                                               end = nodes[j].start;
+                                               found = 1;
+                                       }
+                               }
+               } while (found && start < end);
+
+               if (start < end) {
                        printk(KERN_ERR "SRAT: No PXM for e820 range: "
                                "%016Lx - %016Lx\n", start, end);
                        return 0;