[libvirt] [PATCH v2 16/24] qemu: Deal with PHB naming convention

[Andrea Bolognani]

Usually, a controller with alias 'x' will create a bus with the
same name; however, the bus created by a PHBs with alias 'x' will
be named 'x.0' instead, so we need to account for that.

As an exception to the exception, the implicit PHB that's added
automatically to every pSeries guest creates the 'pci.0' bus.

Signed-off-by: Andrea Bolognani <abologna at redhat.com>
---
 src/qemu/qemu_command.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 8123276..372f5ca 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -302,6 +302,9 @@ qemuBuildDeviceAddressStr(virBufferPtr buf,
     int ret = -1;
     char *devStr = NULL;
     const char *contAlias = NULL;
+    virDomainControllerModelPCI contModel;
+    virDomainControllerPCIModelName contModelName;
+    int contIndex;
 
     if (info->type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI) {
         size_t i;
@@ -314,6 +317,9 @@ qemuBuildDeviceAddressStr(virBufferPtr buf,
             if (cont->type == VIR_DOMAIN_CONTROLLER_TYPE_PCI &&
                 cont->idx == info->addr.pci.bus) {
                 contAlias = cont->info.alias;
+                contModel = cont->model;
+                contModelName = cont->opts.pciopts.modelName;
+                contIndex = cont->opts.pciopts.idx;
                 if (!contAlias) {
                     virReportError(VIR_ERR_INTERNAL_ERROR,
                                    _("Device alias was not set for PCI "
@@ -349,7 +355,19 @@ qemuBuildDeviceAddressStr(virBufferPtr buf,
             }
         }
 
-        virBufferAsprintf(buf, ",bus=%s", contAlias);
+        if (contModel == VIR_DOMAIN_CONTROLLER_MODEL_PCI_ROOT &&
+            contModelName == VIR_DOMAIN_CONTROLLER_PCI_MODEL_NAME_SPAPR_PCI_HOST_BRIDGE &&
+            contIndex > 0) {
+            /* The PCI bus created by a spapr-pci-host-bridge device with
+             * alias 'x' will be called 'x.0' rather than 'x'; however,
+             * this does not apply to the implicit PHB in a pSeries guest,
+             * which always has the hardcoded name 'pci.0' */
+            virBufferAsprintf(buf, ",bus=%s.0", contAlias);
+        } else {
+            /* For all other controllers, the bus name matches the alias
+             * of the corresponding controller */
+            virBufferAsprintf(buf, ",bus=%s", contAlias);
+        }
 
         if (info->addr.pci.multi == VIR_TRISTATE_SWITCH_ON)
             virBufferAddLit(buf, ",multifunction=on");
-- 
2.7.5