conf: new pcie-controller model "pcie-switch-downstream-port"

This controller can be connected only to a port on a
pcie-switch-upstream-port. It provides a single hotpluggable port that
will accept any PCI or PCIe device, as well as any device requiring a
pcie-*-port (the only current example of such a device is the
pcie-switch-upstream-port).

docs/formatdomain.html.in

@@ -3032,11 +3032,12 @@
       PCI controllers have an optional <code>model</code> attribute with
       possible values <code>pci-root</code>, <code>pcie-root</code>,
       <code>pcie-root-port</code>, <code>pci-bridge</code>,
-      <code>dmi-to-pci-bridge</code>, or <code>pcie-switch-upstream-port</code>.
+      <code>dmi-to-pci-bridge</code>, <code>pcie-switch-upstream-port</code>, or
+      <code>pcie-switch-downstream-port</code>.
       (pci-root and pci-bridge <span class="since">since 1.0.5</span>,
       pcie-root and dmi-to-pci-bridge <span class="since">since
-      1.1.2</span>, pcie-root-port and
+      1.1.2</span>, pcie-root-port, pcie-switch-upstream-port, and
-      pcie-switch-upstream-port <span class="since">since 1.2.19</span>)
+      pcie-switch-downstream-port <span class="since">since 1.2.19</span>)
       The root controllers (<code>pci-root</code> and <code>pcie-root</code>)
       have an optional <code>pcihole64</code> element specifying how big
       (in kilobytes, or in the unit specified by <code>pcihole64</code>'s
@@ -3083,8 +3084,8 @@
       </dd>
       <dt><code>chassis</code></dt>
       <dd>
-        pcie-root-port controllers can also have
+        pcie-root-port and pcie-switch-downstream-port controllers can
-        a <code>chassis</code> attribute in
+        also have a <code>chassis</code> attribute in
         the <code>&lt;target&gt;</code> subelement, which is used to
         set the controller's "chassis" configuration value, which is
         visible to the virtual machine. If set, chassis must be
@@ -3092,8 +3093,9 @@
       </dd>
       <dt><code>port</code></dt>
       <dd>
-        pcie-root-port controllers can also have a <code>port</code>
+        pcie-root-port and pcie-switch-downstream-port controllers can
-        attribute in the <code>&lt;target&gt;</code> subelement, which
+        also have a <code>port</code> attribute in
+        the <code>&lt;target&gt;</code> subelement, which
         is used to set the controller's "port" configuration value,
         which is visible to the virtual machine. If set, port must be
         between 0 and 255.
@@ -3146,14 +3148,32 @@
     </p>
     <p>
       Domains with an implicit pcie-root can also add controllers
-      with <code>model='pcie-root-port'</code>. This is a simple type of
+      with <code>model='pcie-root-port'</code>,
-      bridge device that can connect only to one of the 31 slots on
+      <code>model='pcie-switch-upstream-port'</code>,
-      the pcie-root bus on the upstream side, and makes a single
+      and <code>model='pcie-switch-downstream-port'</code>. pcie-root-port
-      (PCIe, hotpluggable) port (at slot='0') available on the
+      is a simple type of bridge device that can connect only to one
-      downstream side. This controller can be used to provide a single
+      of the 31 slots on the pcie-root bus on its upstream side, and
-      slot to later hotplug a PCIe device (but is not itself
+      makes a single (PCIe, hotpluggable) port available on the
-      hotpluggable - it must be in the configuration when the domain
+      downstream side (at slot='0'). pcie-root-port can be used to
-      is started). (<span class="since">since 1.2.19</span>)
+      provide a single slot to later hotplug a PCIe device (but is not
+      itself hotpluggable - it must be in the configuration when the
+      domain is started).
+      (<span class="since">since 1.2.19</span>)
+    </p>
+    <p>
+      pcie-switch-upstream-port is a more flexible (but also more
+      complex) device that can only plug into a pcie-root-port or
+      pcie-switch-downstream-port on the upstream side (and only
+      before the domain is started - it is not hot-pluggable), and
+      provides 32 ports on the downstream side (slot='0' - slot='31')
+      that accept only pcie-switch-downstream-port devices; each
+      pcie-switch-downstream-port device can only plug into a
+      pcie-switch-upstream-port on its upstream side (again, not
+      hot-pluggable), and on its downstream side provides a single
+      hotpluggable pcie port that can accept any standard pci or pcie
+      device (or another pcie-switch-upstream-port), i.e. identical in
+      function to a pcie-root-port.  (<span class="since">since
+      1.2.19</span>)
     </p>
 <pre>
   ...

docs/schemas/domaincommon.rng

@@ -1743,6 +1743,8 @@
                     <value>ioh3420</value>
                     <!-- implementations of 'pcie-switch-upstream-port' -->
                     <value>x3130-upstream</value>
+                    <!-- implementations of 'pcie-switch-downstream-port' -->
+                    <value>xio3130-downstream</value>
                   </choice>
                 </attribute>
                 <empty/>
@@ -1790,6 +1792,7 @@
                     <value>dmi-to-pci-bridge</value>
                     <value>pcie-root-port</value>
                     <value>pcie-switch-upstream-port</value>
+                    <value>pcie-switch-downstream-port</value>
                   </choice>
                 </attribute>
               </group>

src/conf/domain_addr.c

@@ -197,6 +197,7 @@ virDomainPCIAddressBusSetModel(virDomainPCIAddressBusPtr bus,
         bus->maxSlot = VIR_PCI_ADDRESS_SLOT_LAST;
         break;
     case VIR_DOMAIN_CONTROLLER_MODEL_PCIE_ROOT_PORT:
+    case VIR_DOMAIN_CONTROLLER_MODEL_PCIE_SWITCH_DOWNSTREAM_PORT:
         /* provides one slot which is pcie, can be used by devices
          * that must connect to some type of "pcie-*-port", and
          * is hotpluggable

src/conf/domain_conf.c

@@ -326,7 +326,8 @@ VIR_ENUM_IMPL(virDomainControllerModelPCI, VIR_DOMAIN_CONTROLLER_MODEL_PCI_LAST,
               "pci-bridge",
               "dmi-to-pci-bridge",
               "pcie-root-port",
-              "pcie-switch-upstream-port")
+              "pcie-switch-upstream-port",
+              "pcie-switch-downstream-port")
 
 VIR_ENUM_IMPL(virDomainControllerPCIModelName,
               VIR_DOMAIN_CONTROLLER_PCI_MODEL_NAME_LAST,
@@ -334,7 +335,8 @@ VIR_ENUM_IMPL(virDomainControllerPCIModelName,
               "pci-bridge",
               "i82801b11-bridge",
               "ioh3420",
-              "x3130-upstream")
+              "x3130-upstream",
+              "xio3130-downstream")
 
 VIR_ENUM_IMPL(virDomainControllerModelSCSI, VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LAST,
               "auto",

src/conf/domain_conf.h

@@ -754,6 +754,7 @@ typedef enum {
     VIR_DOMAIN_CONTROLLER_MODEL_DMI_TO_PCI_BRIDGE,
     VIR_DOMAIN_CONTROLLER_MODEL_PCIE_ROOT_PORT,
     VIR_DOMAIN_CONTROLLER_MODEL_PCIE_SWITCH_UPSTREAM_PORT,
+    VIR_DOMAIN_CONTROLLER_MODEL_PCIE_SWITCH_DOWNSTREAM_PORT,
 
     VIR_DOMAIN_CONTROLLER_MODEL_PCI_LAST
 } virDomainControllerModelPCI;
@@ -764,6 +765,7 @@ typedef enum {
     VIR_DOMAIN_CONTROLLER_PCI_MODEL_NAME_I82801B11_BRIDGE,
     VIR_DOMAIN_CONTROLLER_PCI_MODEL_NAME_IOH3420,
     VIR_DOMAIN_CONTROLLER_PCI_MODEL_NAME_X3130_UPSTREAM,
+    VIR_DOMAIN_CONTROLLER_PCI_MODEL_NAME_XIO3130_DOWNSTREAM,
 
     VIR_DOMAIN_CONTROLLER_PCI_MODEL_NAME_LAST
 } virDomainControllerPCIModelName;

src/qemu/qemu_command.c

@@ -2307,6 +2307,7 @@ qemuDomainAssignPCIAddresses(virDomainDefPtr def,
                     if (options->modelName == VIR_DOMAIN_CONTROLLER_PCI_MODEL_NAME_NONE)
                         options->modelName = VIR_DOMAIN_CONTROLLER_PCI_MODEL_NAME_X3130_UPSTREAM;
                     break;
+                case VIR_DOMAIN_CONTROLLER_MODEL_PCIE_SWITCH_DOWNSTREAM_PORT:
                 case VIR_DOMAIN_CONTROLLER_MODEL_PCI_ROOT:
                 case VIR_DOMAIN_CONTROLLER_MODEL_PCIE_ROOT:
                 case VIR_DOMAIN_CONTROLLER_MODEL_PCI_LAST:

tests/qemuxml2argvdata/qemuxml2argv-pcie-switch-downstream-port.xml

@@ -0,0 +1,44 @@
+<domain type='qemu'>
+  <name>q35-test</name>
+  <uuid>11dbdcdd-4c3b-482b-8903-9bdb8c0a2774</uuid>
+  <memory unit='KiB'>2097152</memory>
+  <currentMemory unit='KiB'>2097152</currentMemory>
+  <vcpu placement='static' cpuset='0-1'>2</vcpu>
+  <os>
+    <type arch='x86_64' machine='q35'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/libexec/qemu-kvm</emulator>
+    <disk type='block' device='disk'>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='sda' bus='sata'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <controller type='pci' index='0' model='pcie-root'/>
+    <controller type='pci' index='1' model='dmi-to-pci-bridge'/>
+    <controller type='pci' index='2' model='pci-bridge'/>
+    <controller type='pci' index='3' model='pcie-root-port'/>
+    <controller type='pci' index='4' model='pcie-switch-upstream-port'/>
+    <controller type='pci' index='5' model='pcie-switch-downstream-port'/>
+    <controller type='pci' index='6' model='pcie-switch-downstream-port'/>
+    <controller type='pci' index='7' model='pcie-switch-downstream-port'/>
+    <controller type='pci' index='8' model='pcie-switch-downstream-port'>
+      <model name='xio3130-downstream'/>
+      <target chassis='30' port='0x27'/>
+    </controller>
+    <controller type='pci' index='9' model='pcie-switch-upstream-port'/>
+    <controller type='pci' index='10' model='pcie-switch-downstream-port'/>
+    <controller type='pci' index='11' model='pcie-switch-downstream-port'/>
+    <controller type='pci' index='12' model='pcie-switch-downstream-port'/>
+    <controller type='sata' index='0'/>
+    <video>
+      <model type='qxl' ram='65536' vram='32768' vgamem='8192' heads='1'/>
+    </video>
+    <memballoon model='none'/>
+  </devices>
+</domain>

tests/qemuxml2xmltest.c

@@ -570,6 +570,7 @@ mymain(void)
     DO_TEST("pcie-root-port");
     DO_TEST("pcie-root-port-too-many");
     DO_TEST("pcie-switch-upstream-port");
+    DO_TEST("pcie-switch-downstream-port");
 
     DO_TEST("hostdev-scsi-lsi");
     DO_TEST("hostdev-scsi-virtio-scsi");