From 487610941b91468f80e6fd91ad9379cef4a77c60 Mon Sep 17 00:00:00 2001
Message-Id: <487610941b91468f80e6fd91ad9379cef4a77c60.1377873642.git.jdenemar@redhat.com>
From: Michal Privoznik <mprivozn@redhat.com>
Date: Mon, 26 Aug 2013 17:41:50 +0200
Subject: [PATCH] qemuDomainAttachHostPciDevice: Fall back to mem balloon if
 there's no hard_limit

https://bugzilla.redhat.com/show_bug.cgi?id=1001143

If there's no hard_limit set and domain uses VFIO we still must lock
the guest memory (prerequisite from qemu). Hence, we should compute
the amount to be locked from max_balloon.
(cherry picked from commit a45ec678e9bbe8a6157cb440f334b5d21e40f0b4)
---
 src/qemu/qemu_hotplug.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index 89df4ad..98b8ad1 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -1022,6 +1022,8 @@ int qemuDomainAttachHostPciDevice(virQEMUDriverPtr driver,
 
     if (hostdev->source.subsys.u.pci.backend
         == VIR_DOMAIN_HOSTDEV_PCI_BACKEND_VFIO) {
+        unsigned long long memKB;
+
         if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_DEVICE_VFIO_PCI)) {
             virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
                            _("VFIO PCI device assignment is not "
@@ -1034,8 +1036,9 @@ int qemuDomainAttachHostPciDevice(virQEMUDriverPtr driver,
          * doesn't hurt to "change" the limit to the same value.
          */
         vm->def->hostdevs[vm->def->nhostdevs++] = hostdev;
-        virProcessSetMaxMemLock(vm->pid,
-                                vm->def->mem.hard_limit * 1024);
+        memKB = vm->def->mem.hard_limit ?
+            vm->def->mem.hard_limit : vm->def->mem.max_balloon + 1024 * 1024;
+        virProcessSetMaxMemLock(vm->pid, memKB);
         vm->def->hostdevs[vm->def->nhostdevs--] = NULL;
     }
 
-- 
1.8.3.2