From 27dbf10245342d3547a969b9b69e95fee96932e0 Mon Sep 17 00:00:00 2001
Message-Id: <27dbf10245342d3547a969b9b69e95fee96932e0@dist-git>
From: Andrea Bolognani <abologna@redhat.com>
Date: Fri, 20 Nov 2015 13:29:13 +0100
Subject: [PATCH] qemu: Use qemuDomainRequiresMlock() when attaching PCI
 hostdev

The function is used everywhere else to check whether the locked
memory limit should be set / updated, and it should be used here
as well.

Moreover, qemuDomainGetMlockLimitBytes() expects the hostdev to
have already been added to the domain definition, but we only do
that at the end of qemuDomainAttachHostPCIDevice(). Work around
the issue by adding the hostdev before adjusting the locked memory
limit and removing it immediately afterwards.

(cherry picked from commit 79b8c97e995d2e8bc04fb9a3972e1875fad01e6d)

Bug: https://bugzilla.redhat.com/show_bug.cgi?id=1283924

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/qemu/qemu_hotplug.c | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index 785423a..003b614 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -1277,17 +1277,26 @@ qemuDomainAttachHostPCIDevice(virQEMUDriverPtr driver,
                              "supported by this version of qemu"));
             goto error;
         }
+        break;
 
-        /* setup memory locking limits, that are necessary for VFIO */
+    default:
+        break;
+    }
+
+    /* Temporarily add the hostdev to the domain definition. This is needed
+     * because qemuDomainRequiresMlock() and qemuDomainGetMlockLimitBytes()
+     * require the hostdev to be already part of the domain definition, but
+     * other functions like qemuAssignDeviceHostdevAlias() used below expect
+     * it *not* to be there. A better way to handle this would be nice */
+    vm->def->hostdevs[vm->def->nhostdevs++] = hostdev;
+    if (qemuDomainRequiresMlock(vm->def)) {
         if (virProcessSetMaxMemLock(vm->pid,
-                                    qemuDomainGetMlockLimitBytes(vm->def)) < 0)
+                                    qemuDomainGetMlockLimitBytes(vm->def)) < 0) {
+            vm->def->hostdevs[--(vm->def->nhostdevs)] = NULL;
             goto error;
-
-        break;
-
-    default:
-        break;
+        }
     }
+    vm->def->hostdevs[--(vm->def->nhostdevs)] = NULL;
 
     if (qemuSetupHostdevCGroup(vm, hostdev) < 0)
         goto error;
-- 
2.6.3