[PATCH] qdev-monitor: Forbid repeated device_del

From: Julia Suvorova <jusual@redhat.com>
To: qemu-devel@nongnu.org
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
	"Daniel P. Berrangé" <berrange@redhat.com>,
	"Eduardo Habkost" <ehabkost@redhat.com>,
	"Julia Suvorova" <jusual@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>
Subject: [PATCH] qdev-monitor: Forbid repeated device_del
Date: Thu, 20 Feb 2020 17:55:56 +0100	[thread overview]
Message-ID: <20200220165556.39388-1-jusual@redhat.com> (raw)

Device unplug can be done asynchronously. Thus, sending the second
device_del before the previous unplug is complete may lead to
unexpected results. On PCIe devices, this cancels the hot-unplug
process.

Signed-off-by: Julia Suvorova <jusual@redhat.com>
---
 qdev-monitor.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/qdev-monitor.c b/qdev-monitor.c
index 8ce71a206b..8a2a9538cd 100644
--- a/qdev-monitor.c
+++ b/qdev-monitor.c
@@ -887,6 +887,12 @@ void qmp_device_del(const char *id, Error **errp)
 {
     DeviceState *dev = find_device_state(id, errp);
     if (dev != NULL) {
+        if (dev->pending_deleted_event) {
+            error_setg(errp, "Device %s is already in the "
+                             "process of unplug", id);
+            return;
+        }
+
         qdev_unplug(dev, errp);
     }
 }
-- 
2.24.1


