From: Jan Kiszka <jan.kiszka@siemens.com>
Date: Fri, 17 Feb 2012 17:31:16 +0000 (+0100)
Subject: Allow to use pause_all_vcpus from VCPU context
X-Git-Tag: v1.1-rc0~289^2~7
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d798e97456658ea7605303b7c69b04ec7df95c10;p=thirdparty%2Fqemu.git

Allow to use pause_all_vcpus from VCPU context

In order to perform critical manipulations on the VM state in the
context of a VCPU, specifically code patching, stopping and resuming of
all VCPUs may be necessary. resume_all_vcpus is already compatible, now
enable pause_all_vcpus for this use case by stopping the calling context
before starting to wait for the whole gang.

CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
---

diff --git a/cpus.c b/cpus.c
index 4a10775cb61..17b055fba00 100644
--- a/cpus.c
+++ b/cpus.c
@@ -875,6 +875,18 @@ void pause_all_vcpus(void)
         penv = penv->next_cpu;
     }
 
+    if (!qemu_thread_is_self(&io_thread)) {
+        cpu_stop_current();
+        if (!kvm_enabled()) {
+            while (penv) {
+                penv->stop = 0;
+                penv->stopped = 1;
+                penv = penv->next_cpu;
+            }
+            return;
+        }
+    }
+
     while (!all_vcpus_paused()) {
         qemu_cond_wait(&qemu_pause_cond, &qemu_global_mutex);
         penv = first_cpu;