qemu: command: add support for acpi-bridge-hotplug feature

This change adds backend qemu command line support for new libvirt
global feature 'acpi-bridge-hotplug'. This option can be used as
following:

<feature>
  <pci>
    <acpi-bridge-hotplug state='off|on'/>
  </pci>
</feature>

The '<pci>' sub-element under '<feature>' is also newly introduced.

'acpi-bridge-hotplug' turns on the following command line option to
qemu for x86 guests:

(pc): -global PIIX4_PM.acpi-pci-hotplug-with-bridge-support=<off|on>

(q35): -global ICH9-LPC.acpi-pci-hotplug-with-bridge-support=<off|on>

This change also adds the required qemuxml2argv unit tests in order to
test correct qemu arguments. Unit tests have also been added to test
qemu capability validation checks as well as checks for using this
option with the right architecture.

Signed-off-by: Ani Sinha <ani@anisinha.ca>
Reviewed-by: Laine Stump <laine@redhat.com>

src/qemu/qemu_command.c

@@ -6102,6 +6102,7 @@ qemuBuildPMCommandLine(virCommand *cmd,
                        qemuDomainObjPrivate *priv)
 {
     virQEMUCaps *qemuCaps = priv->qemuCaps;
+    int acpihp_br = def->pci_features[VIR_DOMAIN_PCI_ACPI_BRIDGE_HOTPLUG];
 
     if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_SET_ACTION)) {
         /* with new qemu we always want '-no-shutdown' on startup and we set
@@ -6147,6 +6148,25 @@ qemuBuildPMCommandLine(virCommand *cmd,
                                pm_object, def->pm.s4 == VIR_TRISTATE_BOOL_NO);
     }
 
+    if (acpihp_br != VIR_TRISTATE_SWITCH_ABSENT) {
+        const char *pm_object = NULL;
+
+        if (!qemuDomainIsQ35(def) &&
+            virQEMUCapsGet(qemuCaps, QEMU_CAPS_PIIX4_ACPI_HOTPLUG_BRIDGE))
+            pm_object = "PIIX4_PM";
+
+        if (qemuDomainIsQ35(def) &&
+            virQEMUCapsGet(qemuCaps, QEMU_CAPS_ICH9_ACPI_HOTPLUG_BRIDGE))
+            pm_object = "ICH9-LPC";
+
+        if (pm_object != NULL) {
+            virCommandAddArg(cmd, "-global");
+            virCommandAddArgFormat(cmd, "%s.acpi-pci-hotplug-with-bridge-support=%s",
+                                   pm_object,
+                                   virTristateSwitchTypeToString(acpihp_br));
+        }
+    }
+
     return 0;
 }
 

tests/qemuxml2argvdata/aarch64-acpi-hotplug-bridge-disable.err

@@ -0,0 +1 @@
+unsupported configuration: acpi-bridge-hotplug is not available for architecture 'aarch64'

tests/qemuxml2argvdata/pc-i440fx-acpi-hotplug-bridge-disable.args

@@ -0,0 +1,31 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/tmp/lib/domain--1-i440fx \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/tmp/lib/domain--1-i440fx/.local/share \
+XDG_CACHE_HOME=/tmp/lib/domain--1-i440fx/.cache \
+XDG_CONFIG_HOME=/tmp/lib/domain--1-i440fx/.config \
+QEMU_AUDIO_DRV=none \
+/usr/bin/qemu-system-x86_64 \
+-name guest=i440fx,debug-threads=on \
+-S \
+-object secret,id=masterKey0,format=raw,file=/tmp/lib/domain--1-i440fx/master-key.aes \
+-machine pc-i440fx-2.5,accel=tcg,usb=off,dump-guest-core=off \
+-m 1024 \
+-realtime mlock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid 56f5055c-1b8d-490c-844a-ad646a1caaaa \
+-display none \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,path=/tmp/lib/domain--1-i440fx/monitor.sock,server=on,wait=off \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-no-acpi \
+-global PIIX4_PM.acpi-pci-hotplug-with-bridge-support=off \
+-boot strict=on \
+-usb \
+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x2 \
+-msg timestamp=on

tests/qemuxml2argvdata/pc-i440fx-acpi-hotplug-bridge-disable.err

@@ -0,0 +1 @@
+unsupported configuration: acpi-bridge-hotplug is not available with this QEMU binary

tests/qemuxml2argvdata/q35-acpi-hotplug-bridge-disable.args

@@ -0,0 +1,33 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/tmp/lib/domain--1-q35 \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/tmp/lib/domain--1-q35/.local/share \
+XDG_CACHE_HOME=/tmp/lib/domain--1-q35/.cache \
+XDG_CONFIG_HOME=/tmp/lib/domain--1-q35/.config \
+QEMU_AUDIO_DRV=none \
+/usr/bin/qemu-system-x86_64 \
+-name guest=q35,debug-threads=on \
+-S \
+-object secret,id=masterKey0,format=raw,file=/tmp/lib/domain--1-q35/master-key.aes \
+-machine pc-q35-2.5,accel=tcg,usb=off,dump-guest-core=off \
+-m 1024 \
+-realtime mlock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid 56f5055c-1b8d-490c-844a-ad646a1caaaa \
+-display none \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,path=/tmp/lib/domain--1-q35/monitor.sock,server=on,wait=off \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-no-acpi \
+-global ICH9-LPC.acpi-pci-hotplug-with-bridge-support=off \
+-boot strict=on \
+-device i82801b11-bridge,id=pci.1,bus=pcie.0,addr=0x1e \
+-device pci-bridge,chassis_nr=2,id=pci.2,bus=pci.1,addr=0x0 \
+-device ioh3420,port=0x8,chassis=3,id=pci.3,bus=pcie.0,addr=0x1 \
+-device virtio-balloon-pci,id=balloon0,bus=pci.2,addr=0x1 \
+-msg timestamp=on

tests/qemuxml2argvdata/q35-acpi-hotplug-bridge-disable.err

@@ -0,0 +1 @@
+unsupported configuration: acpi-bridge-hotplug is not available with this QEMU binary

tests/qemuxml2argvtest.c

@@ -2562,6 +2562,22 @@ mymain(void)
     DO_TEST("pc-i440fx-acpi-root-hotplug-disable",
             QEMU_CAPS_PIIX4_ACPI_ROOT_PCI_HOTPLUG);
     DO_TEST_PARSE_ERROR_NOCAPS("pc-i440fx-acpi-root-hotplug-disable");
+    DO_TEST("q35-acpi-hotplug-bridge-disable",
+            QEMU_CAPS_DEVICE_PCI_BRIDGE,
+            QEMU_CAPS_DEVICE_IOH3420,
+            QEMU_CAPS_DEVICE_DMI_TO_PCI_BRIDGE, QEMU_CAPS_ICH9_AHCI,
+            QEMU_CAPS_ICH9_ACPI_HOTPLUG_BRIDGE);
+    DO_TEST("pc-i440fx-acpi-hotplug-bridge-disable",
+            QEMU_CAPS_DEVICE_PCI_BRIDGE,
+            QEMU_CAPS_DEVICE_IOH3420,
+            QEMU_CAPS_DEVICE_DMI_TO_PCI_BRIDGE,
+            QEMU_CAPS_PIIX4_ACPI_HOTPLUG_BRIDGE);
+    DO_TEST_PARSE_ERROR_NOCAPS("q35-acpi-hotplug-bridge-disable");
+    DO_TEST_PARSE_ERROR_NOCAPS("pc-i440fx-acpi-hotplug-bridge-disable");
+    /* verify that we fail when acpi-bridge-hotplug option is specified for
+     * archs other than x86
+     */
+    DO_TEST_PARSE_ERROR_NOCAPS("aarch64-acpi-hotplug-bridge-disable");
     DO_TEST("q35-usb2",
             QEMU_CAPS_DEVICE_PCI_BRIDGE,
             QEMU_CAPS_DEVICE_DMI_TO_PCI_BRIDGE,