File libvirt-qemuBuildCommandLine-Fall-back-to-mem-balloon-if-there-s-no-hard_limit.patch of Package libvirt

From 54cc7a53a4e8ae2101b1e971841aa57a4184a5d2 Mon Sep 17 00:00:00 2001
Message-Id: <54cc7a53a4e8ae2101b1e971841aa57a4184a5d2.1380730269.git.jdenemar@redhat.com>
From: Michal Privoznik <mprivozn@redhat.com>
Date: Mon, 30 Sep 2013 20:14:57 +0200
Subject: [PATCH] qemuBuildCommandLine: Fall back to mem balloon if there's no
 hard_limit

https://bugzilla.redhat.com/show_bug.cgi?id=1013758

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 a7f94a40bb2554c56d0c6bea98a5843690dc3933)

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/qemu/qemu_command.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 628f8d4..763a265 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -6957,8 +6957,19 @@ qemuBuildCommandLine(virConnectPtr conn,
         goto error;
     }
 
-    if (mlock)
-        virCommandSetMaxMemLock(cmd, def->mem.hard_limit * 1024);
+    if (mlock) {
+        unsigned long long memKB;
+
+        /* VFIO requires all of the guest's memory to be
+         * locked resident, plus some amount for IO
+         * space. Alex Williamson suggested adding 1GiB for IO
+         * space just to be safe (some finer tuning might be
+         * nice, though).
+         */
+        memKB = def->mem.hard_limit ?
+            def->mem.hard_limit : def->mem.max_balloon + 1024 * 1024;
+        virCommandSetMaxMemLock(cmd, memKB * 1024);
+    }
 
     return cmd;
 
-- 
1.8.3.2