Merge tag 'stable/for-linus-3.16-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull Xen fixes from Konrad Rzeszutek Wilk:
 "Two fixes found during migration of PV guests.  David would be the one
  doing this pull but he is on vacation.

  Fixes:
   - fix console deadlock when resuming PV guests
   - fix regression hit when ballooning and resuming PV guests"

* tag 'stable/for-linus-3.16-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/balloon: set ballooned out pages as invalid in p2m
  xen/manage: fix potential deadlock when resuming the console

2 files changed, 9 insertions, 8 deletions

diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index b7a506f2bb14..5c660c77f03b 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -426,20 +426,18 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
                  * p2m are consistent.
                  */
                 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
-                        unsigned long p;
-                        struct page   *scratch_page = get_balloon_scratch_page();
-
                         if (!PageHighMem(page)) {
+                                struct page *scratch_page = get_balloon_scratch_page();
+
                                 ret = HYPERVISOR_update_va_mapping(
                                                 (unsigned long)__va(pfn << PAGE_SHIFT),
                                                 pfn_pte(page_to_pfn(scratch_page),
                                                         PAGE_KERNEL_RO), 0);
                                 BUG_ON(ret);
-                        }
-                        p = page_to_pfn(scratch_page);
-                        __set_phys_to_machine(pfn, pfn_to_mfn(p));
 
-                        put_balloon_scratch_page();
+                                put_balloon_scratch_page();
+                        }
+                        __set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
                 }
 #endif
 
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index c3667b202f2f..5f1e1f3cd186 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -88,7 +88,6 @@ static int xen_suspend(void *data)
 
         if (!si->cancelled) {
                 xen_irq_resume();
-                xen_console_resume();
                 xen_timer_resume();
         }
 
@@ -135,6 +134,10 @@ static void do_suspend(void)
 
         err = stop_machine(xen_suspend, &si, cpumask_of(0));
 
+        /* Resume console as early as possible. */
+        if (!si.cancelled)
+                xen_console_resume();
+
         raw_notifier_call_chain(&xen_resume_notifier, 0, NULL);
 
         dpm_resume_start(si.cancelled ? PMSG_THAW : PMSG_RESTORE);