From: Rik van Riel <riel@redhat.com>
Subject: [PATCH][RHEL5 Xen] make ballooning work right
Date: Mon, 11 Dec 2006 21:13:35 -0500
Bugzilla: 212069
Message-Id: <457E104F.3030600@redhat.com>
Changelog: Xen: make ballooning work right


These patches (kernel and hypervisor) make the memory sizing of Xen
domains work right, by letting the Xen guest kernel know at boot time
how much memory it could get in the future.

This allows one to boot up a Xen guest with (eg.) 200MB and later
grow it to 500MB, by specifying the "maxmem=500" in the domain config
file.

The accompanying tools patch (for the xen RPM) will be posted just
to virtualist.

Fixes bug 212069

-- 
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the best in the world, and those who believe it already is.  Each group
calls the other unpatriotic.

diff -r 8beecb8c5ae2 -r df5fa63490f4 linux/include/xen/interface/memory.h
--- linux/include/xen/interface/memory.h	Fri Dec 08 11:08:26 2006 +0000
+++ linux/include/xen/interface/memory.h	Fri Dec 08 11:30:30 2006 +0000
@@ -222,7 +222,8 @@ DEFINE_XEN_GUEST_HANDLE(xen_translate_gp
 
 /*
  * Returns the pseudo-physical memory map as it was when the domain
- * was started.
+ * was started (specified by XENMEM_set_memory_map).
+ * arg == addr of xen_memory_map_t.
  */
 #define XENMEM_memory_map           9
 struct xen_memory_map {
@@ -245,8 +246,22 @@ DEFINE_XEN_GUEST_HANDLE(xen_memory_map_t
 /*
  * Returns the real physical memory map. Passes the same structure as
  * XENMEM_memory_map.
+ * arg == addr of xen_memory_map_t.
  */
 #define XENMEM_machine_memory_map	10
+
+/*
+ * Set the pseudo-physical memory map of a domain, as returned by
+ * XENMEM_memory_map.
+ * arg == addr of xen_foreign_memory_map_t.
+ */
+#define XENMEM_set_memory_map       13
+struct xen_foreign_memory_map {
+    domid_t domid;
+    struct xen_memory_map map;
+};
+typedef struct xen_foreign_memory_map xen_foreign_memory_map_t;
+DEFINE_XEN_GUEST_HANDLE(xen_foreign_memory_map_t);
 
 #endif /* __XEN_PUBLIC_MEMORY_H__ */