x86: use 'dom0_mem' to limit the number of pages for dom0

Use the 'dom0_mem' command line option to set the maximum number of
pages for dom0.  dom0 can use then use the XENMEM_maximum_reservation
memory op to automatically find this limit and reduce the size of any
page tables etc.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/xen/arch/x86/domain_build.c b/xen/arch/x86/domain_build.c
index d7697e562b..f818f0b876 100644
--- a/xen/arch/x86/domain_build.c
+++ b/xen/arch/x86/domain_build.c
@@ -254,6 +254,8 @@ static unsigned long __init compute_dom0_nr_pages(
     }
 #endif
 
+    d->max_pages = min(max_pages, avail);
+
     return nr_pages;
 }