[PATCH 4.19 202/361] xen/balloon: Support xend-based toolstack

Greg Kroah-Hartman
2018-11-12T00:01:34Z

From: Boris Ostrovsky <boris.ostrovsky@oracle.com>

commit 3aa6c19d2f38be9c6e9a8ad5fa8e3c9d29ee3c35 upstream.

Xend-based toolstacks don't have static-max entry in xenstore. The
equivalent node for those toolstacks is memory_static_max.

Fixes: 5266b8e4445c (xen: fix booting ballooned down hvm guest)
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: <stable@vger.kernel.org> # 4.13
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/xen/xen-balloon.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

--- a/drivers/xen/xen-balloon.c
+++ b/drivers/xen/xen-balloon.c
@@ -76,12 +76,15 @@ static void watch_target(struct xenbus_w

if (!watch_fired) {
watch_fired = true;
- err = xenbus_scanf(XBT_NIL, "memory", "static-max", "%llu",
- &static_max);
- if (err != 1)
- static_max = new_target;
- else
+
+ if ((xenbus_scanf(XBT_NIL, "memory", "static-max",
+ "%llu", &static_max) == 1) ||
+ (xenbus_scanf(XBT_NIL, "memory", "memory_static_max",
+ "%llu", &static_max) == 1))
static_max >>= PAGE_SHIFT - 10;
+ else
+ static_max = new_target;
+
target_diff = (xen_pv_domain() || xen_initial_domain()) ? 0
: static_max - balloon_stats.target_pages;
}