From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932304AbdJXIK7 (ORCPT ); Tue, 24 Oct 2017 04:10:59 -0400 Received: from mx2.suse.de ([195.135.220.15]:54037 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932196AbdJXIKy (ORCPT ); Tue, 24 Oct 2017 04:10:54 -0400 From: Juergen Gross To: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org Cc: boris.ostrovsky@oracle.com, hw42@ipsumj.de, Juergen Gross , stable@vger.kernel.org Subject: [PATCH] xen: fix booting ballooned down hvm guest Date: Tue, 24 Oct 2017 10:10:50 +0200 Message-Id: <20171024081050.2441-1-jgross@suse.com> X-Mailer: git-send-email 2.12.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 96edd61dcf44362d3ef0bed1a5361e0ac7886a63 ("xen/balloon: don't online new memory initially") introduced a regression when booting a HVM domain with memory less than mem-max: instead of ballooning down immediately the system would try to use the memory up to mem-max resulting in Xen crashing the domain. For HVM domains the current size will be reflected in Xenstore node memory/static-max instead of memory/target. Additionally we have to trigger the ballooning process at once. Cc: # 4.13 Fixes: 96edd61dcf44362d3ef0bed1a5361e0ac7886a63 ("xen/balloon: don't online new memory initially") Suggested-by: Boris Ostrovsky Signed-off-by: Juergen Gross --- drivers/xen/xen-balloon.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/drivers/xen/xen-balloon.c b/drivers/xen/xen-balloon.c index e89136ab851e..3745748d9644 100644 --- a/drivers/xen/xen-balloon.c +++ b/drivers/xen/xen-balloon.c @@ -57,7 +57,7 @@ static int register_balloon(struct device *dev); static void watch_target(struct xenbus_watch *watch, const char *path, const char *token) { - unsigned long long new_target; + unsigned long long new_target, static_max; int err; static bool watch_fired; static long target_diff; @@ -72,13 +72,19 @@ static void watch_target(struct xenbus_watch *watch, * pages. PAGE_SHIFT converts bytes to pages, hence PAGE_SHIFT - 10. */ new_target >>= PAGE_SHIFT - 10; - if (watch_fired) { - balloon_set_new_target(new_target - target_diff); - return; + + if (!watch_fired) { + watch_fired = true; + err = xenbus_scanf(XBT_NIL, "memory", "static-max", "%llu", + &static_max); + if (err != 1) + static_max = new_target; + static_max >>= PAGE_SHIFT - 10; + target_diff = xen_pv_domain() ? 0 + : static_max - balloon_stats.target_pages; } - watch_fired = true; - target_diff = new_target - balloon_stats.target_pages; + balloon_set_new_target(new_target - target_diff); } static struct xenbus_watch target_watch = { .node = "memory/target", -- 2.12.3