[libvirt] [PATCH 2/2] qemu: ppc64: Align memory sizes to 256MiB

[Peter Krempa]

Since qemu upstream commit TBD [1] the memory size for numa nodes,
memory devices and the total size needs to be aligned to multiples of
256MiB. Otherwise qemu refuses to start with the following message:

qemu-kvm: Can't support memory configuration where RAM size 0x7d000000
or maxmem size 0x7d000000 isn't aligned to 256 MB

Change the alignment code to round sizes to 256 MiB multiples.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1249006

----

[1] Since qemu is in freeze, the commit that introduces the problem
doesn't have a valid upstream commit ID yet.

https://github.com/dgibson/qemu/commit/456156ea4974eeff761d3fe7addc279f297e2c17
---
 src/qemu/qemu_domain.c                                      | 9 ++++++++-
 tests/qemuxml2argvdata/qemuxml2argv-pseries-cpu-compat.args | 2 +-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index c1b3326..aad912a 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -3111,11 +3111,18 @@ qemuDomainAgentAvailable(virDomainObjPtr vm,


 static unsigned long long
-qemuDomainGetMemorySizeAlignment(virDomainDefPtr def ATTRIBUTE_UNUSED)
+qemuDomainGetMemorySizeAlignment(virDomainDefPtr def)
 {
     /* Align memory size. QEMU requires rounding to next 4KiB block.
      * We'll take the "traditional" path and round it to 1MiB*/

+    /* pseries aligns memory to 256MiB chunks */
+    if ((ARCH_IS_PPC64(def->os.arch) &&
+         def->os.machine &&
+         STRPREFIX(def->os.machine, "pseries"))) {
+        return 256 * 1024;
+    }
+
     return 1024;
 }

diff --git a/tests/qemuxml2argvdata/qemuxml2argv-pseries-cpu-compat.args b/tests/qemuxml2argvdata/qemuxml2argv-pseries-cpu-compat.args
index 64df406..305e924 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-pseries-cpu-compat.args
+++ b/tests/qemuxml2argvdata/qemuxml2argv-pseries-cpu-compat.args
@@ -1,7 +1,7 @@
 LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test \
 QEMU_AUDIO_DRV=none /usr/bin/qemu-system-ppc64 -S -M pseries \
 -cpu host,compat=power7 \
--m 214 -smp 4 -nographic -nodefconfig -nodefaults \
+-m 256 -smp 4 -nographic -nodefconfig -nodefaults \
 -chardev socket,id=charmonitor,path=/tmp/test-monitor,server,nowait \
 -mon chardev=charmonitor,id=monitor,mode=readline -no-acpi -boot c -usb \
 -chardev pty,id=charserial0 \
-- 
2.4.5