From: Jan Beulich <jbeulich@suse.com>
Date: Thu, 27 Feb 2020 14:45:31 +0000 (+0100)
Subject: libxl/PCI: align reserved device memory boundary for HAP guests
X-Git-Tag: archive/raspbian/4.14.0+80-gd101b417b7-1+rpi1^2~63^2~611
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/%22/%22http:/www.example.com/cgi/%22?a=commitdiff_plain;h=5f29f349818be5b4e06caae57727405a7ea1a978;p=xen.git

libxl/PCI: align reserved device memory boundary for HAP guests

As the code comment says, this will allow use of a 2Mb super page
mapping at the end of "low" memory.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wl@xen.org>
---

diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index e0c3aa4998..f4007bbe50 100644
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -562,6 +562,13 @@ int libxl__domain_device_construct_rdm(libxl__gc *gc,
 
         /* Just check if RDM > our memory boundary. */
         if (rdm_start > rdm_mem_boundary) {
+            /*
+             * For HAP guests round down to a 2Mb boundary to allow use
+             * of large page mappings.
+             */
+            if (libxl_defbool_val(d_config->c_info.hap)
+                && rdm_start > MB(2))
+                rdm_start &= ~(MB(2) - 1);
             /*
              * We will move downwards lowmem_end so we have to expand
              * highmem_end.