1:47 a.m.
On Fri, 8 Oct 2021, Laine Stump wrote:
On 10/5/21 1:51 AM, Ani Sinha wrote:
> This change introduces a new libvirt sub-element <pci> under <features>
that
> can be used to configure all pci related features.
> Currently the only sub-sub element supported by this sub-element is
> 'acpi-bridge-hotplug' as shown below:
>
> <features>
> <pci>
> <acpi-bridge-hotplug state='on|off'/>
> </pci>
> </features>
>
> The above option is only available for qemu driver and that too for x86
> guests
> only. It is a global option.
>
> 'acpi-bridge-hotplug' option enables or disables ACPI hotplug support for
> cold-plugged pci bridges. Examples of bridges include PCI-PCI bridge
> (pci-bridge controller) or PCIe-PCI bridges for pc machines and
> pcie-root-port controller for q35 machines. Being global option, no other
> bridge specific option are required. For pc machine type in x86, this option
> is available in qemu for a long time, from version 2.1.
> Please see the following changes in qemu repo:
>
> 9e047b982452c6 ("piix4: add acpi pci hotplug support")
> 133a2da488062e ("pc: acpi: generate AML only for PCI0 devices if PCI bridge
> hotplug is disabled")
>
> For q35 machine type, this was introduced in qemu 6.1 with the following
> changes in qemu repo:
>
> (a) c0e427d6eb5fef ("hw/acpi/ich9: Enable ACPI PCI hot-plug")
> (b) 17858a16950860 ("hw/acpi/ich9: Set ACPI PCI hot-plug as default on
Q35")
>
> The reasons for enabling ACPI based hotplug for PCIe (q35) based machines
> (as
> opposed to native hotplug) are outlined in (b). There are use cases where
> users
> would still want to use native hotplug. Therefore, this config option
> enables users to choose either ACPI based hotplug or native hotplug for
> bridges
> (for example for pcie root port controller in q35 machines).
>
> Qemu capability validation checks have also been added along with related
> unit
> tests to exercise the new conf option.
>
> Signed-off-by: Ani Sinha <ani(a)anisinha.ca>
> ---
> docs/formatdomain.rst | 11 +++
> docs/schemas/domaincommon.rng | 15 ++++
> src/conf/domain_conf.c | 89 ++++++++++++++++++-
> src/conf/domain_conf.h | 9 ++
> src/qemu/qemu_validate.c | 46 ++++++++++
> .../aarch64-acpi-hotplug-bridge-disable.xml | 33 +++++++
> .../pc-i440fx-acpi-hotplug-bridge-disable.xml | 33 +++++++
> .../pc-i440fx-acpi-hotplug-bridge-enable.xml | 33 +++++++
> .../q35-acpi-hotplug-bridge-disable.xml | 47 ++++++++++
> .../q35-acpi-hotplug-bridge-enable.xml | 47 ++++++++++
> .../pc-i440fx-acpi-hotplug-bridge-disable.xml | 1 +
> .../pc-i440fx-acpi-hotplug-bridge-enable.xml | 1 +
> .../q35-acpi-hotplug-bridge-disable.xml | 1 +
> .../q35-acpi-hotplug-bridge-enable.xml | 1 +
> tests/qemuxml2xmltest.c | 14 +++
> 15 files changed, 380 insertions(+), 1 deletion(-)
> create mode 100644
> tests/qemuxml2argvdata/aarch64-acpi-hotplug-bridge-disable.xml
> create mode 100644
> tests/qemuxml2argvdata/pc-i440fx-acpi-hotplug-bridge-disable.xml
> create mode 100644
> tests/qemuxml2argvdata/pc-i440fx-acpi-hotplug-bridge-enable.xml
> create mode 100644
> tests/qemuxml2argvdata/q35-acpi-hotplug-bridge-disable.xml
> create mode 100644
> tests/qemuxml2argvdata/q35-acpi-hotplug-bridge-enable.xml
> create mode 120000
> tests/qemuxml2xmloutdata/pc-i440fx-acpi-hotplug-bridge-disable.xml
> create mode 120000
> tests/qemuxml2xmloutdata/pc-i440fx-acpi-hotplug-bridge-enable.xml
> create mode 120000
> tests/qemuxml2xmloutdata/q35-acpi-hotplug-bridge-disable.xml
> create mode 120000
> tests/qemuxml2xmloutdata/q35-acpi-hotplug-bridge-enable.xml
>
> diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst
> index a02802a954..8d916eefa6 100644
> --- a/docs/formatdomain.rst
> +++ b/docs/formatdomain.rst
> @@ -1847,6 +1847,9 @@ Hypervisors may allow certain CPU / machine features
> to be toggled on/off.
> <e820_host state='on'/>
> <passthrough state='on' mode='share_pt'/>
> </xen>
> + <pci>
> + <acpi-bridge-hotplug state="on"/>
> + </pci>
> <pvspinlock state='on'/>
> <gic version='2'/>
> <ioapic driver='qemu'/>
> @@ -1942,6 +1945,14 @@ are:
> passthrough Enable IOMMU mappings allowing PCI passthrough on, off;
> mode - optional string sync_pt or share_pt :since:`6.3.0`
> =========== ==============================================
> =================================================== ==============
> +``pci``
> + Various PCI bus related features of the hypervisor.
> + ====================
>
========================================================================================
> ======= ============================
> + Feature Description
> Value Since
> + ====================
>
========================================================================================
> ======= ============================
> + acpi-bridge-hotplug Enable ACPI based hotplug on the cold-plugged PCI
> bridges (pc) and pcie-root-ports (q35) on, off :since:`7.8.0 (QEMU 6.1.0)`
Weren't the qemu properties there in a much earlier version of QEMU? (Oh, and
also it needs to say 7.9.0 instead of 7.8.0)
That was for i440fx. I took the higher version.
Somewhere we need to put the extra info that on 440fx machinetypes ACPI is on
by default, and disabling it means that only SHPC hotplug is available, while
on q35 machinetypes, it is off by default until QEMU 6.1.0, and enabling it
has the side-effect of disabling native PCIe hotplug, while disabling (on qemu
6.1.0+) also has the side-effect of enabling native PCIe hotplug.
I have added a note in v7.
> + ====================
>
========================================================================================
> ======= ============================
> +
> ``pmu``
> Depending on the ``state`` attribute (values ``on``, ``off``, default
> ``on``)
> enable or disable the performance monitoring unit for the guest.
> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
> index ec5bd91740..6f33d1e774 100644
> --- a/docs/schemas/domaincommon.rng
> +++ b/docs/schemas/domaincommon.rng
> @@ -6169,6 +6169,9 @@
> <optional>
> <ref name="ioapic"/>
> </optional>
> + <optional>
> + <ref name="pci"/>
> + </optional>
> <optional>
> <ref name="hpt"/>
> </optional>
> @@ -6400,6 +6403,18 @@
> </element>
> </define>
> + <define name="pci">
> + <element name="pci">
> + <interleave>
> + <optional>
> + <element name="acpi-bridge-hotplug">
> + <ref name="featurestate"/>
> + </element>
> + </optional>
> + </interleave>
> + </element>
> + </define>
> +
> <define name="ioapic">
> <element name="ioapic">
> <attribute name="driver">
> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
> index b8370f6950..229b75fecc 100644
> --- a/src/conf/domain_conf.c
> +++ b/src/conf/domain_conf.c
> @@ -172,6 +172,7 @@ VIR_ENUM_IMPL(virDomainFeature,
> "cfpc",
> "sbbc",
> "ibs",
> + "pci",
> );
> VIR_ENUM_IMPL(virDomainCapabilitiesPolicy,
> @@ -212,6 +213,11 @@ VIR_ENUM_IMPL(virDomainXen,
> "passthrough",
> );
> +VIR_ENUM_IMPL(virDomainPCI,
> + VIR_DOMAIN_PCI_LAST,
> + "acpi-bridge-hotplug",
> +);
> +
> VIR_ENUM_IMPL(virDomainXenPassthroughMode,
> VIR_DOMAIN_XEN_PASSTHROUGH_MODE_LAST,
> "default",
> @@ -17536,6 +17542,36 @@ virDomainFeaturesKVMDefParse(virDomainDef *def,
> return 0;
> }
> +static int
> +virDomainFeaturesPCIDefParse(virDomainDef *def,
> + xmlNodePtr node)
> +{
> + def->features[VIR_DOMAIN_FEATURE_PCI] = VIR_TRISTATE_SWITCH_ON;
> +
> + node = xmlFirstElementChild(node);
> + while (node) {
> + int feature;
> + virTristateSwitch value;
> +
> + feature = virDomainPCITypeFromString((const char *)node->name);
> + if (feature < 0) {
> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> + _("unsupported PCI feature: %s"),
> + node->name);
> + return -1;
> + }
> +
> + if (virXMLPropTristateSwitch(node, "state",
VIR_XML_PROP_REQUIRED,
> + &value) < 0)
> + return -1;
> +
> + def->pci_features[feature] = value;
> +
> + node = xmlNextElementSibling(node);
> + }
> +
> + return 0;
> +}
> static int
> virDomainFeaturesXENDefParse(virDomainDef *def,
> @@ -17835,6 +17871,10 @@ virDomainFeaturesDefParse(virDomainDef *def,
> break;
> }
> + case VIR_DOMAIN_FEATURE_PCI:
> + if (virDomainFeaturesPCIDefParse(def, nodes[i]) < 0)
> + return -1;
> +
> case VIR_DOMAIN_FEATURE_LAST:
> break;
> }
> @@ -17843,7 +17883,6 @@ virDomainFeaturesDefParse(virDomainDef *def,
> return 0;
> }
> -
> static int
> virDomainDefMaybeAddHostdevSCSIcontroller(virDomainDef *def)
> {
> @@ -21521,6 +21560,7 @@ virDomainDefFeaturesCheckABIStability(virDomainDef
> *src,
> case VIR_DOMAIN_FEATURE_HTM:
> case VIR_DOMAIN_FEATURE_NESTED_HV:
> case VIR_DOMAIN_FEATURE_CCF_ASSIST:
> + case VIR_DOMAIN_FEATURE_PCI:
> if (src->features[i] != dst->features[i]) {
> virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> _("State of feature '%s' differs:
"
> @@ -21777,6 +21817,29 @@ virDomainDefFeaturesCheckABIStability(virDomainDef
> *src,
> }
> }
> + /* pci */
> + if (src->features[VIR_DOMAIN_FEATURE_PCI] == VIR_TRISTATE_SWITCH_ON) {
> + for (i = 0; i < VIR_DOMAIN_PCI_LAST; i++) {
> + switch ((virDomainPCI) i) {
> + case VIR_DOMAIN_PCI_ACPI_BRIDGE_HP:
> + if (src->pci_features[i] != dst->pci_features[i]) {
> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> + _("State of PCI feature '%s'
differs: "
> + "source: '%s', destination:
'%s'"),
> + virDomainPCITypeToString(i),
> +
> virTristateSwitchTypeToString(src->pci_features[i]),
> +
> virTristateSwitchTypeToString(dst->pci_features[i]));
> + return false;
> + }
> +
> + break;
> +
> + case VIR_DOMAIN_PCI_LAST:
> + break;
> + }
> + }
> + }
> +
> /* smm */
> if (src->features[VIR_DOMAIN_FEATURE_SMM] == VIR_TRISTATE_SWITCH_ON) {
> if (src->tseg_specified != dst->tseg_specified) {
> @@ -27932,6 +27995,30 @@ virDomainDefFormatFeatures(virBuffer *buf,
> virDomainIBSTypeToString(def->features[i]));
> break;
> + case VIR_DOMAIN_FEATURE_PCI:
> + if (def->features[i] != VIR_TRISTATE_SWITCH_ON)
> + break;
> +
> + virBufferAddLit(&childBuf, "<pci>\n");
> + virBufferAdjustIndent(&childBuf, 2);
> + for (j = 0; j < VIR_DOMAIN_PCI_LAST; j++) {
> + switch ((virDomainPCI) j) {
> + case VIR_DOMAIN_PCI_ACPI_BRIDGE_HP:
> + if (def->pci_features[j])
> + virBufferAsprintf(&childBuf, "<%s
state='%s'/>\n",
> + virDomainPCITypeToString(j),
> + virTristateSwitchTypeToString(
> + def->pci_features[j]));
> + break;
> +
> + case VIR_DOMAIN_PCI_LAST:
> + break;
> + }
> + }
> + virBufferAdjustIndent(&childBuf, -2);
> + virBufferAddLit(&childBuf, "</pci>\n");
> + break;
> +
> case VIR_DOMAIN_FEATURE_LAST:
> break;
> }
> diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
> index e054c1508e..e9902a473d 100644
> --- a/src/conf/domain_conf.h
> +++ b/src/conf/domain_conf.h
> @@ -2043,6 +2043,7 @@ typedef enum {
> VIR_DOMAIN_FEATURE_CFPC,
> VIR_DOMAIN_FEATURE_SBBC,
> VIR_DOMAIN_FEATURE_IBS,
> + VIR_DOMAIN_FEATURE_PCI,
> VIR_DOMAIN_FEATURE_LAST
> } virDomainFeature;
> @@ -2068,6 +2069,12 @@ typedef enum {
> VIR_DOMAIN_HYPERV_LAST
> } virDomainHyperv;
> +typedef enum {
> + VIR_DOMAIN_PCI_ACPI_BRIDGE_HP = 0,
> +
> + VIR_DOMAIN_PCI_LAST
> +} virDomainPCI;
> +
> typedef enum {
> VIR_DOMAIN_KVM_HIDDEN = 0,
> VIR_DOMAIN_KVM_DEDICATED,
> @@ -2800,6 +2807,7 @@ struct _virDomainDef {
> int features[VIR_DOMAIN_FEATURE_LAST];
> int caps_features[VIR_DOMAIN_PROCES_CAPS_FEATURE_LAST];
> int hyperv_features[VIR_DOMAIN_HYPERV_LAST];
> + int pci_features[VIR_DOMAIN_PCI_LAST];
> int kvm_features[VIR_DOMAIN_KVM_LAST];
> int msrs_features[VIR_DOMAIN_MSRS_LAST];
> int xen_features[VIR_DOMAIN_XEN_LAST];
> @@ -3923,6 +3931,7 @@ VIR_ENUM_DECL(virDomainGraphicsSpiceStreamingMode);
> VIR_ENUM_DECL(virDomainGraphicsSpiceMouseMode);
> VIR_ENUM_DECL(virDomainGraphicsVNCSharePolicy);
> VIR_ENUM_DECL(virDomainHyperv);
> +VIR_ENUM_DECL(virDomainPCI);
> VIR_ENUM_DECL(virDomainKVM);
> VIR_ENUM_DECL(virDomainXen);
> VIR_ENUM_DECL(virDomainXenPassthroughMode);
> diff --git a/src/qemu/qemu_validate.c b/src/qemu/qemu_validate.c
> index c84508cb64..e0e3ca0b10 100644
> --- a/src/qemu/qemu_validate.c
> +++ b/src/qemu/qemu_validate.c
> @@ -173,6 +173,48 @@ qemuValidateDomainDefPSeriesFeature(const virDomainDef
> *def,
> return 0;
> }
> +static int
> +qemuValidateDomainDefPCIFeature(const virDomainDef *def,
> + virQEMUCaps *qemuCaps,
> + int feature)
> +{
> + size_t i;
> + bool q35Dom = qemuDomainIsQ35(def);
> + bool q35cap = q35Dom && virQEMUCapsGet(qemuCaps,
> +
> QEMU_CAPS_ICH9_ACPI_HOTPLUG_BRIDGE);
> +
> + if (def->features[feature] == VIR_TRISTATE_SWITCH_ABSENT)
> + return 0;
> +
> + for (i = 0; i < VIR_DOMAIN_PCI_LAST; i++) {
> + if (def->pci_features[i] == VIR_TRISTATE_SWITCH_ABSENT)
> + continue;
> +
> + switch ((virDomainPCI) i) {
> + case VIR_DOMAIN_PCI_ACPI_BRIDGE_HP:
> + if (!ARCH_IS_X86(def->os.arch)) {
> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> + _("acpi-bridge-hotplug is not available
> "
> + "for architecture '%s'"),
> + virArchToString(def->os.arch));
> + return -1;
> + }
> + if (!q35cap &&
> + !virQEMUCapsGet(qemuCaps,
> + QEMU_CAPS_PIIX4_ACPI_HOTPLUG_BRIDGE)) {
> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> + _("acpi-bridge-hotplug is not available
> "
> + "with this QEMU binary"));
> + return -1;
> + }
> + break;
> +
> + case VIR_DOMAIN_PCI_LAST:
> + break;
> + }
> + }
> + return 0;
> +}
> static int
> qemuValidateDomainDefFeatures(const virDomainDef *def,
> @@ -294,6 +336,10 @@ qemuValidateDomainDefFeatures(const virDomainDef *def,
> }
> break;
> + case VIR_DOMAIN_FEATURE_PCI:
> + if (qemuValidateDomainDefPCIFeature(def, qemuCaps, i) < 0)
> + return -1;
> + break;
> case VIR_DOMAIN_FEATURE_SMM:
> case VIR_DOMAIN_FEATURE_KVM:
> case VIR_DOMAIN_FEATURE_XEN:
> diff --git a/tests/qemuxml2argvdata/aarch64-acpi-hotplug-bridge-disable.xml
> b/tests/qemuxml2argvdata/aarch64-acpi-hotplug-bridge-disable.xml
> new file mode 100644
> index 0000000000..0d5f945bd7
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/aarch64-acpi-hotplug-bridge-disable.xml
> @@ -0,0 +1,33 @@
> +<domain type='qemu'>
> + <name>i440fx</name>
> + <uuid>56f5055c-1b8d-490c-844a-ad646a1caaaa</uuid>
> + <memory unit='KiB'>1048576</memory>
> + <currentMemory unit='KiB'>1048576</currentMemory>
> + <vcpu placement='static'>1</vcpu>
> + <os>
> + <type arch='aarch64' machine='virt'>hvm</type>
> + <boot dev='network'/>
> + </os>
> + <features>
> + <pci>
> + <acpi-bridge-hotplug state='off'/>
> + </pci>
> + </features>
> + <clock offset='utc'/>
> + <on_poweroff>destroy</on_poweroff>
> + <on_reboot>restart</on_reboot>
> + <on_crash>destroy</on_crash>
> + <devices>
> + <emulator>/usr/bin/qemu-system-aarch64</emulator>
> + <controller type='usb' index='0'>
> + <address type='pci' domain='0x0000' bus='0x00'
slot='0x01'
> function='0x2'/>
> + </controller>
> + <controller type='pci' index='0'
model='pci-root'/>
> + <input type='mouse' bus='ps2'/>
> + <input type='keyboard' bus='ps2'/>
> + <audio id='1' type='none'/>
> + <memballoon model='virtio'>
> + <address type='pci' domain='0x0000' bus='0x00'
slot='0x02'
> function='0x0'/>
> + </memballoon>
> + </devices>
> +</domain>
> diff --git
> a/tests/qemuxml2argvdata/pc-i440fx-acpi-hotplug-bridge-disable.xml
> b/tests/qemuxml2argvdata/pc-i440fx-acpi-hotplug-bridge-disable.xml
> new file mode 100644
> index 0000000000..4482825858
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/pc-i440fx-acpi-hotplug-bridge-disable.xml
> @@ -0,0 +1,33 @@
> +<domain type='qemu'>
> + <name>i440fx</name>
> + <uuid>56f5055c-1b8d-490c-844a-ad646a1caaaa</uuid>
> + <memory unit='KiB'>1048576</memory>
> + <currentMemory unit='KiB'>1048576</currentMemory>
> + <vcpu placement='static'>1</vcpu>
> + <os>
> + <type arch='x86_64'
machine='pc-i440fx-2.5'>hvm</type>
> + <boot dev='network'/>
> + </os>
> + <features>
> + <pci>
> + <acpi-bridge-hotplug state='off'/>
> + </pci>
> + </features>
> + <clock offset='utc'/>
> + <on_poweroff>destroy</on_poweroff>
> + <on_reboot>restart</on_reboot>
> + <on_crash>destroy</on_crash>
> + <devices>
> + <emulator>/usr/bin/qemu-system-x86_64</emulator>
> + <controller type='usb' index='0'>
> + <address type='pci' domain='0x0000' bus='0x00'
slot='0x01'
> function='0x2'/>
> + </controller>
> + <controller type='pci' index='0'
model='pci-root'/>
> + <input type='mouse' bus='ps2'/>
> + <input type='keyboard' bus='ps2'/>
> + <audio id='1' type='none'/>
> + <memballoon model='virtio'>
> + <address type='pci' domain='0x0000' bus='0x00'
slot='0x02'
> function='0x0'/>
> + </memballoon>
> + </devices>
> +</domain>
> diff --git a/tests/qemuxml2argvdata/pc-i440fx-acpi-hotplug-bridge-enable.xml
> b/tests/qemuxml2argvdata/pc-i440fx-acpi-hotplug-bridge-enable.xml
> new file mode 100644
> index 0000000000..8215ee0d50
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/pc-i440fx-acpi-hotplug-bridge-enable.xml
> @@ -0,0 +1,33 @@
> +<domain type='qemu'>
> + <name>i440fx</name>
> + <uuid>56f5055c-1b8d-490c-844a-ad646a1caaaa</uuid>
> + <memory unit='KiB'>1048576</memory>
> + <currentMemory unit='KiB'>1048576</currentMemory>
> + <vcpu placement='static'>1</vcpu>
> + <os>
> + <type arch='x86_64'
machine='pc-i440fx-2.5'>hvm</type>
> + <boot dev='network'/>
> + </os>
> + <features>
> + <pci>
> + <acpi-bridge-hotplug state='on'/>
> + </pci>
> + </features>
> + <clock offset='utc'/>
> + <on_poweroff>destroy</on_poweroff>
> + <on_reboot>restart</on_reboot>
> + <on_crash>destroy</on_crash>
> + <devices>
> + <emulator>/usr/bin/qemu-system-x86_64</emulator>
> + <controller type='usb' index='0'>
> + <address type='pci' domain='0x0000' bus='0x00'
slot='0x01'
> function='0x2'/>
> + </controller>
> + <controller type='pci' index='0'
model='pci-root'/>
> + <input type='mouse' bus='ps2'/>
> + <input type='keyboard' bus='ps2'/>
> + <audio id='1' type='none'/>
> + <memballoon model='virtio'>
> + <address type='pci' domain='0x0000' bus='0x00'
slot='0x02'
> function='0x0'/>
> + </memballoon>
> + </devices>
> +</domain>
> diff --git a/tests/qemuxml2argvdata/q35-acpi-hotplug-bridge-disable.xml
> b/tests/qemuxml2argvdata/q35-acpi-hotplug-bridge-disable.xml
> new file mode 100644
> index 0000000000..2ef3a7231f
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/q35-acpi-hotplug-bridge-disable.xml
> @@ -0,0 +1,47 @@
> +<domain type='qemu'>
> + <name>q35</name>
> + <uuid>56f5055c-1b8d-490c-844a-ad646a1caaaa</uuid>
> + <memory unit='KiB'>1048576</memory>
> + <currentMemory unit='KiB'>1048576</currentMemory>
> + <vcpu placement='static'>1</vcpu>
> + <os>
> + <type arch='x86_64'
machine='pc-q35-2.5'>hvm</type>
> + <boot dev='network'/>
> + </os>
> + <features>
> + <pci>
> + <acpi-bridge-hotplug state='off'/>
> + </pci>
> + </features>
> + <clock offset='utc'/>
> + <on_poweroff>destroy</on_poweroff>
> + <on_reboot>restart</on_reboot>
> + <on_crash>destroy</on_crash>
> + <devices>
> + <emulator>/usr/bin/qemu-system-x86_64</emulator>
> + <controller type='sata' index='0'>
> + <address type='pci' domain='0x0000' bus='0x00'
slot='0x1f'
> function='0x2'/>
> + </controller>
> + <controller type='pci' index='0'
model='pcie-root'/>
> + <controller type='pci' index='1'
model='dmi-to-pci-bridge'>
> + <model name='i82801b11-bridge'/>
> + <address type='pci' domain='0x0000' bus='0x00'
slot='0x1e'
> function='0x0'/>
> + </controller>
> + <controller type='pci' index='2'
model='pci-bridge'>
> + <model name='pci-bridge'/>
> + <target chassisNr='2'/>
> + <address type='pci' domain='0x0000' bus='0x01'
slot='0x00'
> function='0x0'/>
> + </controller>
> + <controller type='pci' index='3'
model='pcie-root-port'>
> + <model name='ioh3420'/>
> + <target chassis='3' port='0x8'/>
> + <address type='pci' domain='0x0000' bus='0x00'
slot='0x01'
> function='0x0'/>
> + </controller>
> + <input type='mouse' bus='ps2'/>
> + <input type='keyboard' bus='ps2'/>
> + <audio id='1' type='none'/>
> + <memballoon model='virtio'>
> + <address type='pci' domain='0x0000' bus='0x02'
slot='0x01'
> function='0x0'/>
> + </memballoon>
> + </devices>
> +</domain>
> diff --git a/tests/qemuxml2argvdata/q35-acpi-hotplug-bridge-enable.xml
> b/tests/qemuxml2argvdata/q35-acpi-hotplug-bridge-enable.xml
> new file mode 100644
> index 0000000000..2e1b31b0f8
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/q35-acpi-hotplug-bridge-enable.xml
> @@ -0,0 +1,47 @@
> +<domain type='qemu'>
> + <name>q35</name>
> + <uuid>56f5055c-1b8d-490c-844a-ad646a1caaaa</uuid>
> + <memory unit='KiB'>1048576</memory>
> + <currentMemory unit='KiB'>1048576</currentMemory>
> + <vcpu placement='static'>1</vcpu>
> + <os>
> + <type arch='x86_64'
machine='pc-q35-2.5'>hvm</type>
> + <boot dev='network'/>
> + </os>
> + <features>
> + <pci>
> + <acpi-bridge-hotplug state='on'/>
> + </pci>
> + </features>
> + <clock offset='utc'/>
> + <on_poweroff>destroy</on_poweroff>
> + <on_reboot>restart</on_reboot>
> + <on_crash>destroy</on_crash>
> + <devices>
> + <emulator>/usr/bin/qemu-system-x86_64</emulator>
> + <controller type='sata' index='0'>
> + <address type='pci' domain='0x0000' bus='0x00'
slot='0x1f'
> function='0x2'/>
> + </controller>
> + <controller type='pci' index='0'
model='pcie-root'/>
> + <controller type='pci' index='1'
model='dmi-to-pci-bridge'>
> + <model name='i82801b11-bridge'/>
> + <address type='pci' domain='0x0000' bus='0x00'
slot='0x1e'
> function='0x0'/>
> + </controller>
> + <controller type='pci' index='2'
model='pci-bridge'>
> + <model name='pci-bridge'/>
> + <target chassisNr='2'/>
> + <address type='pci' domain='0x0000' bus='0x01'
slot='0x00'
> function='0x0'/>
> + </controller>
> + <controller type='pci' index='3'
model='pcie-root-port'>
> + <model name='ioh3420'/>
> + <target chassis='3' port='0x8'/>
> + <address type='pci' domain='0x0000' bus='0x00'
slot='0x01'
> function='0x0'/>
> + </controller>
> + <input type='mouse' bus='ps2'/>
> + <input type='keyboard' bus='ps2'/>
> + <audio id='1' type='none'/>
> + <memballoon model='virtio'>
> + <address type='pci' domain='0x0000' bus='0x02'
slot='0x01'
> function='0x0'/>
> + </memballoon>
> + </devices>
> +</domain>
> diff --git
> a/tests/qemuxml2xmloutdata/pc-i440fx-acpi-hotplug-bridge-disable.xml
> b/tests/qemuxml2xmloutdata/pc-i440fx-acpi-hotplug-bridge-disable.xml
> new file mode 120000
> index 0000000000..8154897401
> --- /dev/null
> +++ b/tests/qemuxml2xmloutdata/pc-i440fx-acpi-hotplug-bridge-disable.xml
> @@ -0,0 +1 @@
> +../qemuxml2argvdata/pc-i440fx-acpi-hotplug-bridge-disable.xml
> \ No newline at end of file
> diff --git
> a/tests/qemuxml2xmloutdata/pc-i440fx-acpi-hotplug-bridge-enable.xml
> b/tests/qemuxml2xmloutdata/pc-i440fx-acpi-hotplug-bridge-enable.xml
> new file mode 120000
> index 0000000000..6b9e5492f8
> --- /dev/null
> +++ b/tests/qemuxml2xmloutdata/pc-i440fx-acpi-hotplug-bridge-enable.xml
> @@ -0,0 +1 @@
> +../qemuxml2argvdata/pc-i440fx-acpi-hotplug-bridge-enable.xml
> \ No newline at end of file
> diff --git a/tests/qemuxml2xmloutdata/q35-acpi-hotplug-bridge-disable.xml
> b/tests/qemuxml2xmloutdata/q35-acpi-hotplug-bridge-disable.xml
> new file mode 120000
> index 0000000000..77719b1325
> --- /dev/null
> +++ b/tests/qemuxml2xmloutdata/q35-acpi-hotplug-bridge-disable.xml
> @@ -0,0 +1 @@
> +../qemuxml2argvdata/q35-acpi-hotplug-bridge-disable.xml
> \ No newline at end of file
> diff --git a/tests/qemuxml2xmloutdata/q35-acpi-hotplug-bridge-enable.xml
> b/tests/qemuxml2xmloutdata/q35-acpi-hotplug-bridge-enable.xml
> new file mode 120000
> index 0000000000..3cd8ee569e
> --- /dev/null
> +++ b/tests/qemuxml2xmloutdata/q35-acpi-hotplug-bridge-enable.xml
> @@ -0,0 +1 @@
> +../qemuxml2argvdata/q35-acpi-hotplug-bridge-enable.xml
> \ No newline at end of file
> diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c
> index 69363ef85c..2e622c002f 100644
> --- a/tests/qemuxml2xmltest.c
> +++ b/tests/qemuxml2xmltest.c
> @@ -428,6 +428,20 @@ mymain(void)
> QEMU_CAPS_PIIX4_ACPI_ROOT_PCI_HOTPLUG);
> DO_TEST("pc-i440fx-acpi-root-hotplug-enable",
> QEMU_CAPS_PIIX4_ACPI_ROOT_PCI_HOTPLUG);
> + DO_TEST("pc-i440fx-acpi-hotplug-bridge-disable",
> + QEMU_CAPS_PIIX4_ACPI_HOTPLUG_BRIDGE);
> + DO_TEST("pc-i440fx-acpi-hotplug-bridge-enable",
> + QEMU_CAPS_PIIX4_ACPI_HOTPLUG_BRIDGE);
> + 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_ACPI_HOTPLUG_BRIDGE);
> + DO_TEST("q35-acpi-hotplug-bridge-enable",
> + QEMU_CAPS_DEVICE_PCI_BRIDGE,
> + QEMU_CAPS_DEVICE_IOH3420,
> + QEMU_CAPS_DEVICE_DMI_TO_PCI_BRIDGE,
> + QEMU_CAPS_ICH9_ACPI_HOTPLUG_BRIDGE);
> DO_TEST("misc-disable-suspends",
> QEMU_CAPS_PIIX_DISABLE_S3,
> QEMU_CAPS_PIIX_DISABLE_S4);
>