[libvirt] [PATCH v2 1/2] conf: Fix backwards migration of pSeries guests
Recent commits made it so that pci-root controllers for
pSeries guests are automatically assigned the
spapr-pci-host-bridge model name; however, that prevents
guests to migrate to older versions of libvirt which don't
know about that model name at all, which at the moment is
all of them :)
To avoid the issue, just strip the model name from PHBs
when formatting the migratable XML; guests that use more
than one PHB are not going to be migratable anyway.
Signed-off-by: Andrea Bolognani <abologna(a)redhat.com>
---
src/conf/domain_conf.c | 25 ++++++++++++++++++++++++-
1 file changed, 24 insertions(+), 1 deletion(-)
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index d88a88e..b5ab97a 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -21813,7 +21813,30 @@ virDomainControllerDefFormat(virBufferPtr buf,
}
if (def->type == VIR_DOMAIN_CONTROLLER_TYPE_PCI) {
- if (def->opts.pciopts.modelName != VIR_DOMAIN_CONTROLLER_PCI_MODEL_NAME_NONE)
{
+ bool formatModelName = true;
+
+ if (def->opts.pciopts.modelName == VIR_DOMAIN_CONTROLLER_PCI_MODEL_NAME_NONE)
+ formatModelName = false;
+
+ /* Historically, libvirt didn't support specifying a model name for
+ * pci-root controllers; starting from 3.6.0, however, pSeries guests
+ * use pci-root controllers with model name spapr-pci-host-bridge to
+ * represent all PHBs, including the default one.
+ *
+ * In order to allow migration of pSeries guests from older libvirt
+ * versions and back, we don't format the model name in the migratable
+ * XML if it's spapr-pci-host-bridge, thus making "no model name"
and
+ * "spapr-pci-host-bridge model name" basically equivalent.
+ *
+ * The spapr-pci-host-bridge device is specific to pSeries.
+ */
+ if (def->model == VIR_DOMAIN_CONTROLLER_MODEL_PCI_ROOT &&
+ def->opts.pciopts.modelName ==
VIR_DOMAIN_CONTROLLER_PCI_MODEL_NAME_SPAPR_PCI_HOST_BRIDGE &&
+ flags & VIR_DOMAIN_DEF_FORMAT_MIGRATABLE) {
+ formatModelName = false;
+ }
+
+ if (formatModelName) {
modelName =
virDomainControllerPCIModelNameTypeToString(def->opts.pciopts.modelName);
if (!modelName) {
virReportError(VIR_ERR_INTERNAL_ERROR,
--
2.7.5