[Xen-changelog] [xen-unstable] x86 numa: Fix SRAT check for discontig memory

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1251208722 -3600
# Node ID 50a5950e6a243f10e0b9cd67b95518e1ef4efe87
# Parent  dc2aebb0e1d08b98a11d2e8a3bf7dc6435338e7f
x86 numa: Fix SRAT check for discontig memory

We currently compare the sum of the pages found in the SRAT table to
the address of the highest memory page found via the e820 table to
validate the SRAT.  This is completely bogus if there's any kind of
discontiguous memory, where the sum of the pages could be much smaller
than the address of the highest page.  I think all that's necessary is
to validate that each usable memory range in the e820 is covered by an
SRAT entry.  This might not be the most efficient way to do it, but
there are usually a relatively small number of entries on each side.

Signed-off-by: Alex Williamson <alex.williamson@xxxxxx>
---
 xen/arch/x86/srat.c |   43 ++++++++++++++++++++++++++-----------------
 1 files changed, 26 insertions(+), 17 deletions(-)

diff -r dc2aebb0e1d0 -r 50a5950e6a24 xen/arch/x86/srat.c
--- a/xen/arch/x86/srat.c       Tue Aug 25 14:58:07 2009 +0100
+++ b/xen/arch/x86/srat.c       Tue Aug 25 14:58:42 2009 +0100
@@ -17,6 +17,7 @@
 #include <xen/nodemask.h>
 #include <xen/acpi.h>
 #include <xen/numa.h>
+#include <asm/e820.h>
 #include <asm/page.h>
 
 static struct acpi_table_slit *acpi_slit;
@@ -236,23 +237,31 @@ static int nodes_cover_memory(void)
 static int nodes_cover_memory(void)
 {
        int i;
-       u64 pxmram, e820ram;
-
-       pxmram = 0;
-       for_each_node_mask(i, nodes_parsed) {
-               u64 s = nodes[i].start >> PAGE_SHIFT;
-               u64 e = nodes[i].end >> PAGE_SHIFT;
-               pxmram += e - s;
-       }
-
-       e820ram = max_page;
-       /* We seem to lose 3 pages somewhere. Allow a bit of slack. */
-       if ((long)(e820ram - pxmram) >= 1*1024*1024) {
-               printk(KERN_ERR "SRAT: PXMs only cover %"PRIu64"MB of your %"
-                       PRIu64"MB e820 RAM. Not used.\n",
-                       (pxmram << PAGE_SHIFT) >> 20,
-                       (e820ram << PAGE_SHIFT) >> 20);
-               return 0;
+
+       for (i = 0; i < e820.nr_map; i++) {
+               int j, found;
+               unsigned long long start, end;
+
+               if (e820.map[i].type != E820_RAM) {
+                       continue;
+               }
+
+               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) {
+                       printk(KERN_ERR "SRAT: No PXM for e820 range: "
+                               "%016Lx - %016Lx\n", start, end);
+                       return 0;
+               }
        }
        return 1;
 }

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