[libvirt] [PATCH v3 18/26] qemu: Use multiple PHBs for pSeries guests

[Andrea Bolognani]

Additional PHBs (pci-root controllers) will be created for
the guest using the spapr-pci-host-bridge QEMU device, if
available; the implicit default PHB, while present in the
guest configuration, will be skipped.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1431193

Signed-off-by: Andrea Bolognani <abologna at redhat.com>
---
 src/qemu/qemu_command.c | 47 ++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 44 insertions(+), 3 deletions(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index dba2519..fb0beed 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -3164,6 +3164,40 @@ qemuBuildControllerDevStr(const virDomainDef *domainDef,
                                  def->opts.pciopts.numaNode);
             break;
         case VIR_DOMAIN_CONTROLLER_MODEL_PCI_ROOT:
+            if (def->opts.pciopts.modelName == VIR_DOMAIN_CONTROLLER_PCI_MODEL_NAME_NONE ||
+                def->opts.pciopts.idx == -1) {
+                virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                               _("autogenerated pci-root options not set"));
+                goto error;
+            }
+
+            /* Skip the implicit one */
+            if (def->opts.pciopts.idx == 0)
+                goto done;
+
+            modelName = virDomainControllerPCIModelNameTypeToString(def->opts.pciopts.modelName);
+            if (!modelName) {
+                virReportError(VIR_ERR_INTERNAL_ERROR,
+                               _("unknown pci-root model name value %d"),
+                               def->opts.pciopts.modelName);
+                goto error;
+            }
+            if (def->opts.pciopts.modelName != VIR_DOMAIN_CONTROLLER_PCI_MODEL_NAME_SPAPR_PCI_HOST_BRIDGE) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                               _("PCI controller model name '%s' is not valid for a pci-root"),
+                               modelName);
+                goto error;
+            }
+            if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_SPAPR_PCI_HOST_BRIDGE)) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                               _("the spapr-pci-host-bridge controller "
+                                 "is not supported in this QEMU binary"));
+                goto error;
+            }
+            virBufferAsprintf(&buf, "%s,index=%d,id=%s",
+                              modelName, def->opts.pciopts.idx,
+                              def->info.alias);
+            break;
         case VIR_DOMAIN_CONTROLLER_MODEL_PCIE_ROOT:
         case VIR_DOMAIN_CONTROLLER_MODEL_PCI_LAST:
             virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
@@ -3213,6 +3247,7 @@ qemuBuildControllerDevStr(const virDomainDef *domainDef,
     if (virBufferCheckError(&buf) < 0)
         goto error;
 
+ done:
     *devstr = virBufferContentAndReset(&buf);
     return 0;
 
@@ -3270,10 +3305,16 @@ qemuBuildControllerDevCommandLine(virCommandPtr cmd,
                 continue;
             }
 
-            /* skip pci-root/pcie-root */
+            /* skip pcie-root */
             if (cont->type == VIR_DOMAIN_CONTROLLER_TYPE_PCI &&
-                (cont->model == VIR_DOMAIN_CONTROLLER_MODEL_PCI_ROOT ||
-                 cont->model == VIR_DOMAIN_CONTROLLER_MODEL_PCIE_ROOT))
+                cont->model == VIR_DOMAIN_CONTROLLER_MODEL_PCIE_ROOT)
+                continue;
+
+            /* Skip pci-root, except for pSeries guests (which actually
+             * support more than one PCI Host Bridge per guest) */
+            if (!qemuDomainIsPSeries(def) &&
+                cont->type == VIR_DOMAIN_CONTROLLER_TYPE_PCI &&
+                cont->model == VIR_DOMAIN_CONTROLLER_MODEL_PCI_ROOT)
                 continue;
 
             /* first SATA controller on Q35 machines is implicit */
-- 
2.7.5