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authorJuergen Gross <jgross@suse.com>2019-02-14 11:42:40 +0100
committerJuergen Gross <jgross@suse.com>2019-02-18 06:52:51 +0100
commit1d988ed46543ca36c010634c97ac32114362ddb1 (patch)
treed135775178bd3a72aff42e7471dff7b8893cd487 /drivers/xen/xen-balloon.c
parent357b4da50a62e2fd70eacee21cdbd22d4c7a7b60 (diff)
x86/xen: dont add memory above max allowed allocation
Don't allow memory to be added above the allowed maximum allocation limit set by Xen. Trying to do so would result in cases like the following: [ 584.559652] ------------[ cut here ]------------ [ 584.564897] WARNING: CPU: 2 PID: 1 at ../arch/x86/xen/multicalls.c:129 xen_alloc_pte+0x1c7/0x390() [ 584.575151] Modules linked in: [ 584.578643] Supported: Yes [ 584.581750] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.4.120-92.70-default #1 [ 584.590000] Hardware name: Cisco Systems Inc UCSC-C460-M4/UCSC-C460-M4, BIOS C460M4.4.0.1b.0.0629181419 06/29/2018 [ 584.601862] 0000000000000000 ffffffff813175a0 0000000000000000 ffffffff8184777c [ 584.610200] ffffffff8107f4e1 ffff880487eb7000 ffff8801862b79c0 ffff88048608d290 [ 584.618537] 0000000000487eb7 ffffea0000000201 ffffffff81009de7 ffffffff81068561 [ 584.626876] Call Trace: [ 584.629699] [<ffffffff81019ad9>] dump_trace+0x59/0x340 [ 584.635645] [<ffffffff81019eaa>] show_stack_log_lvl+0xea/0x170 [ 584.642391] [<ffffffff8101ac51>] show_stack+0x21/0x40 [ 584.648238] [<ffffffff813175a0>] dump_stack+0x5c/0x7c [ 584.654085] [<ffffffff8107f4e1>] warn_slowpath_common+0x81/0xb0 [ 584.660932] [<ffffffff81009de7>] xen_alloc_pte+0x1c7/0x390 [ 584.667289] [<ffffffff810647f0>] pmd_populate_kernel.constprop.6+0x40/0x80 [ 584.675241] [<ffffffff815ecfe8>] phys_pmd_init+0x210/0x255 [ 584.681587] [<ffffffff815ed207>] phys_pud_init+0x1da/0x247 [ 584.687931] [<ffffffff815edb3b>] kernel_physical_mapping_init+0xf5/0x1d4 [ 584.695682] [<ffffffff815e9bdd>] init_memory_mapping+0x18d/0x380 [ 584.702631] [<ffffffff81064699>] arch_add_memory+0x59/0xf0 Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'drivers/xen/xen-balloon.c')
-rw-r--r--drivers/xen/xen-balloon.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/xen/xen-balloon.c b/drivers/xen/xen-balloon.c
index 2acbfe104e46..a67236b02452 100644
--- a/drivers/xen/xen-balloon.c
+++ b/drivers/xen/xen-balloon.c
@@ -37,6 +37,7 @@
#include <linux/mm_types.h>
#include <linux/init.h>
#include <linux/capability.h>
+#include <linux/memory_hotplug.h>
#include <xen/xen.h>
#include <xen/interface/xen.h>
@@ -50,6 +51,10 @@
#define BALLOON_CLASS_NAME "xen_memory"
+#ifdef CONFIG_MEMORY_HOTPLUG
+u64 xen_saved_max_mem_size = 0;
+#endif
+
static struct device balloon_dev;
static int register_balloon(struct device *dev);
@@ -63,6 +68,12 @@ static void watch_target(struct xenbus_watch *watch,
static bool watch_fired;
static long target_diff;
+#ifdef CONFIG_MEMORY_HOTPLUG
+ /* The balloon driver will take care of adding memory now. */
+ if (xen_saved_max_mem_size)
+ max_mem_size = xen_saved_max_mem_size;
+#endif
+
err = xenbus_scanf(XBT_NIL, "memory", "target", "%llu", &new_target);
if (err != 1) {
/* This is ok (for domain0 at least) - so just return */