[PATCH v2] tools/init-xenstore-domain: fix memory map for PVH stubdom

[Juergen Gross <jgross@xxxxxxxx>]

In case of maxmem != memsize the E820 map of the PVH stubdom is wrong,
as it is missing the RAM above memsize.

Additionally the memory map should only specify the Xen special pages
as reserved.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
V2:
- don't change mmio area settings (Anthony Perard)
---
 tools/helpers/init-xenstore-domain.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/tools/helpers/init-xenstore-domain.c 
b/tools/helpers/init-xenstore-domain.c
index b4f3c65a8a..2d9ab6f1c5 100644
--- a/tools/helpers/init-xenstore-domain.c
+++ b/tools/helpers/init-xenstore-domain.c
@@ -71,8 +71,9 @@ static int build(xc_interface *xch)
     char cmdline[512];
     int rv, xs_fd;
     struct xc_dom_image *dom = NULL;
-    int limit_kb = (maxmem ? : (memory + 1)) * 1024;
+    int limit_kb = (maxmem ? : memory) * 1024 + X86_HVM_NR_SPECIAL_PAGES * 4;
     uint64_t mem_size = MB(memory);
+    uint64_t max_size = MB(maxmem ? : memory);
     struct e820entry e820[3];
     struct xen_domctl_createdomain config = {
         .ssidref = SECINITSID_DOMU,
@@ -165,13 +166,16 @@ static int build(xc_interface *xch)
         dom->mmio_start = LAPIC_BASE_ADDRESS;
         dom->max_vcpus = 1;
         e820[0].addr = 0;
-        e820[0].size = dom->lowmem_end;
+        e820[0].size = (max_size > LAPIC_BASE_ADDRESS) ?
+                       LAPIC_BASE_ADDRESS : max_size;
         e820[0].type = E820_RAM;
-        e820[1].addr = LAPIC_BASE_ADDRESS;
-        e820[1].size = dom->mmio_size;
+        e820[1].addr = (X86_HVM_END_SPECIAL_REGION -
+                        X86_HVM_NR_SPECIAL_PAGES) << XC_PAGE_SHIFT;
+        e820[1].size = X86_HVM_NR_SPECIAL_PAGES << XC_PAGE_SHIFT;
         e820[1].type = E820_RESERVED;
         e820[2].addr = GB(4);
-        e820[2].size = dom->highmem_end - GB(4);
+        e820[2].size = (max_size > LAPIC_BASE_ADDRESS) ?
+                       max_size - LAPIC_BASE_ADDRESS : 0;
         e820[2].type = E820_RAM;
     }
 
-- 
2.35.3