[Xen-devel] [PATCH v2] libxc: fix PV vNUMA guest memory allocation

[Wei Liu <wei.liu2@xxxxxxxxxx>]

In 415b58c1 (tools/libxc: Batch memory allocations for PV guests) the
number of super pages is calculated with the number of total pages. That
is wrong. It breaks PV guest vNUMA. The correct number of super pages
should be derived from the number of pages within that virtual NUMA
node.

Also change the name and type of super page variable to match the naming
convention and type of normal page variable. Make the necessary
adjustment to make code compile.

Reported-by: Dario Faggioli <dario.faggioli@xxxxxxxxxx>
Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
Reviewed-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
---
v2: uint64_t for count variable for consistency, no functional changes wrt v1
    so I retain the Reviewed-by tag.
---
 tools/libxc/xc_dom_x86.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/tools/libxc/xc_dom_x86.c b/tools/libxc/xc_dom_x86.c
index acd7b3f..6a04399 100644
--- a/tools/libxc/xc_dom_x86.c
+++ b/tools/libxc/xc_dom_x86.c
@@ -879,9 +879,8 @@ int arch_setup_meminit(struct xc_dom_image *dom)
         for ( i = 0; i < nr_vmemranges; i++ )
         {
             unsigned int memflags;
-            uint64_t pages;
+            uint64_t pages, super_pages;
             unsigned int pnode = vnode_to_pnode[vmemranges[i].nid];
-            int nr_spages = dom->total_pages >> SUPERPAGE_PFN_SHIFT;
             xen_pfn_t extents[SUPERPAGE_BATCH_SIZE];
             xen_pfn_t pfn_base_idx;
 
@@ -891,15 +890,17 @@ int arch_setup_meminit(struct xc_dom_image *dom)
 
             pages = (vmemranges[i].end - vmemranges[i].start)
                 >> PAGE_SHIFT;
+            super_pages = pages >> SUPERPAGE_PFN_SHIFT;
             pfn_base = vmemranges[i].start >> PAGE_SHIFT;
 
             for ( pfn = pfn_base; pfn < pfn_base+pages; pfn++ )
                 dom->p2m_host[pfn] = pfn;
 
             pfn_base_idx = pfn_base;
-            while (nr_spages) {
-                int count = min(nr_spages, SUPERPAGE_BATCH_SIZE);
-                nr_spages -= count;
+            while (super_pages) {
+                uint64_t count =
+                    min_t(uint64_t, super_pages,SUPERPAGE_BATCH_SIZE);
+                super_pages -= count;
 
                 for ( pfn = pfn_base_idx, j = 0;
                       pfn < pfn_base_idx + (count << SUPERPAGE_PFN_SHIFT);
-- 
1.9.1


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