[Qemu-devel] [PATCH] increase maxmem before calling xc_domain_populate_physmap

[Stefano Stabellini]

Increase maxmem before calling xc_domain_populate_physmap_exact to avoid
the risk of running out of guest memory. This way we can also avoid
complex memory calculations in libxl at domain construction time.

This patch fixes an abort() when assigning more than 4 NICs to a VM.

Signed-off-by: Stefano Stabellini <address@hidden>

diff --git a/xen-hvm.c b/xen-hvm.c
index 5c69a8d..38e08c3 100644
--- a/xen-hvm.c
+++ b/xen-hvm.c
@@ -218,6 +218,7 @@ void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, 
MemoryRegion *mr)
     unsigned long nr_pfn;
     xen_pfn_t *pfn_list;
     int i;
+    xc_dominfo_t info;
 
     if (runstate_check(RUN_STATE_INMIGRATE)) {
         /* RAM already populated in Xen */
@@ -240,6 +241,13 @@ void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, 
MemoryRegion *mr)
         pfn_list[i] = (ram_addr >> TARGET_PAGE_BITS) + i;
     }
 
+    if (xc_domain_getinfo(xen_xc, xen_domid, 1, &info) < 0) {
+        hw_error("xc_domain_getinfo failed");
+    }
+    if (xc_domain_setmaxmem(xen_xc, xen_domid, info.max_memkb +
+                            (nr_pfn * XC_PAGE_SIZE / 1024)) < 0) {
+        hw_error("xc_domain_setmaxmem failed");
+    }
     if (xc_domain_populate_physmap_exact(xen_xc, xen_domid, nr_pfn, 0, 0, 
pfn_list)) {
         hw_error("xen: failed to populate ram at " RAM_ADDR_FMT, ram_addr);
     }