[PATCH v2] tools/libs/light: update xenstore entry when setting max domain memory

[Juergen Gross <jgross@xxxxxxxx>]

libxl_domain_setmaxmem() called during "xl mem-max" should update the
domain's memory/static-max Xenstore node, as otherwise "xl mem-set"
won't be able to set the memory size to the new maximum.

Adjust the related comments and documentation accordingly.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
V2:
- adjust comments and docs (Anthony Perard)
---
 tools/libs/light/libxl_mem.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/tools/libs/light/libxl_mem.c b/tools/libs/light/libxl_mem.c
index c739d00f39..92ec09f4cf 100644
--- a/tools/libs/light/libxl_mem.c
+++ b/tools/libs/light/libxl_mem.c
@@ -20,8 +20,7 @@
 /*
  * Set the maximum memory size of the domain in the hypervisor. There is no
  * change of the current memory size involved. The specified memory size can
- * even be above the configured maxmem size of the domain, but the related
- * Xenstore entry memory/static-max isn't modified!
+ * even be above the configured maxmem size of the domain.
  */
 int libxl_domain_setmaxmem(libxl_ctx *ctx, uint32_t domid, uint64_t max_memkb)
 {
@@ -82,6 +81,15 @@ int libxl_domain_setmaxmem(libxl_ctx *ctx, uint32_t domid, 
uint64_t max_memkb)
         goto out;
     }
 
+    rc = libxl__xs_printf(gc, XBT_NULL,
+                          GCSPRINTF("%s/memory/static-max", dompath),
+                          "%"PRIu64, max_memkb);
+    if (rc != 0) {
+        LOGED(ERROR, domid, "Couldn't set %s/memory/static-max, rc=%d\n",
+              dompath, rc);
+        goto out;
+    }
+
     rc = 0;
 out:
     libxl_domain_config_dispose(&d_config);
-- 
2.34.1