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| author | Juergen Gross <jgross@suse.com> | 2017-10-26 11:50:56 +0200 |
|---|---|---|
| committer | Boris Ostrovsky <boris.ostrovsky@oracle.com> | 2017-10-26 14:11:44 +0200 |
| commit | 5266b8e4445cc836c46689d80a9ff539fa3bfbda (patch) | |
| tree | be037f49bc59adf3a470d8807f34be4f3a4bbfc0 /drivers/xen | |
| parent | xen/gntdev: avoid out of bounds access in case of partial gntdev_mmap() (diff) | |
| download | linux-5266b8e4445cc836c46689d80a9ff539fa3bfbda.tar.xz linux-5266b8e4445cc836c46689d80a9ff539fa3bfbda.zip | |
xen: fix booting ballooned down hvm guest
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: <stable@vger.kernel.org> # 4.13
Fixes: 96edd61dcf44362d3ef0bed1a5361e0ac7886a63 ("xen/balloon: don't
online new memory initially")
Reported-by: Simon Gaiser <hw42@ipsumj.de>
Suggested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Diffstat (limited to 'drivers/xen')
| -rw-r--r-- | drivers/xen/xen-balloon.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/xen/xen-balloon.c b/drivers/xen/xen-balloon.c index e89136ab851e..b437fccd4e62 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 +72,20 @@ 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; + else + 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", |