From: Jan Beulich <jbeulich@suse.com>
Date: Mon, 19 Feb 2018 13:00:31 +0000 (+0100)
Subject: shut down domain when last vCPU goes down
X-Git-Tag: archive/raspbian/4.11.1-1+rpi1~1^2~66^2~560
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=d3b230fc46ee9853064e167f6cb4da8ea0a08112;p=xen.git

shut down domain when last vCPU goes down

I've just had to deal with an early boot crash of Linux which occurred
so early that even "earlyprintk=xen" did not produce any useful output.
Hence the domain appeared to hang, while in fact it had brought down its
only vCPU. By translating this to a shutdown, the situation will be
better recognizable.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
---

diff --git a/xen/common/domain.c b/xen/common/domain.c
index 4567773fe2..e1c003d71e 100644
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -1321,6 +1321,22 @@ long do_vcpu_op(int cmd, unsigned int vcpuid, XEN_GUEST_HANDLE_PARAM(void) arg)
         break;
 
     case VCPUOP_down:
+        for_each_vcpu ( d, v )
+            if ( v->vcpu_id != vcpuid && !test_bit(_VPF_down, &v->pause_flags) )
+            {
+               rc = 1;
+               break;
+            }
+
+        if ( !rc ) /* Last vcpu going down? */
+        {
+            domain_shutdown(d, SHUTDOWN_poweroff);
+            break;
+        }
+
+        rc = 0;
+        v = d->vcpu[vcpuid];
+
 #ifdef CONFIG_X86
         if ( pv_shim )
             rc = continue_hypercall_on_cpu(0, pv_shim_cpu_down, v);