[PATCH v9 01/11] xen: introduce SHUTDOWN_soft_reset shutdown reason

[Vitaly Kuznetsov <vkuznets@redhat.com>]

This special type of shutdown is supposed to be used by PVHVM guests when
they want to perform some sort of kexec/kdump.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
Changes since v8:
- describe the expected behavior for 'soft reset' [Ian Jackson]
---
 xen/common/shutdown.c      |  6 ++++++
 xen/include/public/sched.h | 11 ++++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/xen/common/shutdown.c b/xen/common/shutdown.c
index 9cfbf7a..03a8641 100644
--- a/xen/common/shutdown.c
+++ b/xen/common/shutdown.c
@@ -66,6 +66,12 @@ void hwdom_shutdown(u8 reason)
         machine_restart(0);
         break; /* not reached */
 
+    case SHUTDOWN_soft_reset:
+        printk("Hardware domain %d did unsupported soft reset, rebooting.\n",
+               hardware_domain->domain_id);
+        machine_restart(0);
+        break; /* not reached */
+
     default:
         printk("Hardware Dom%u shutdown (unknown reason %u): ",
                hardware_domain->domain_id, reason);
diff --git a/xen/include/public/sched.h b/xen/include/public/sched.h
index 4000ac9..b91bb9b 100644
--- a/xen/include/public/sched.h
+++ b/xen/include/public/sched.h
@@ -159,7 +159,16 @@ DEFINE_XEN_GUEST_HANDLE(sched_watchdog_t);
 #define SHUTDOWN_suspend    2  /* Clean up, save suspend info, kill.         */
 #define SHUTDOWN_crash      3  /* Tell controller we've crashed.             */
 #define SHUTDOWN_watchdog   4  /* Restart because watchdog time expired.     */
-#define SHUTDOWN_MAX        4  /* Maximum valid shutdown reason.             */
+
+/*
+ * Domain asked to perform 'soft reset' for it. The expected behavior is to
+ * reset internal Xen state for the domain returning it to the point where it
+ * was created but leaving the domain's memory and vCPU contexts intact. This
+ * will allow the domain to start over and set up all Xen specific interfaces
+ * again.
+ */
+#define SHUTDOWN_soft_reset 5
+#define SHUTDOWN_MAX        5  /* Maximum valid shutdown reason.             */
 /* ` } */
 
 #endif /* __XEN_PUBLIC_SCHED_H__ */
-- 
2.4.3