Re: [PATCH v5 2/4] conf: introduce option to enable/disable pci hotplug on pci-root controller

On a Monday in 2021, Ani Sinha wrote: > This change introduces libvirt xml support to enable/disable hotplug > on the > pci-root controller. It adds a 'target' subelement for the pci-root > controller > with a 'hotplug' property. This property can be used to enable or disable > hotplug for the pci-root controller. For example, in order to disable > hotplug > on the pci-root controller, one has to use set '<target > hotplug='off'>' as > shown below: > > <controller type='pci' model='pci-root'> >  <target hotplug='off'/> > </controller> > > '<target hotplug='on'>' option would enable hotplug for pci-root > controller. > This is also the default value. This option is only available for pc > machine > types and is applicable for qemu only/kvm accelerator onlt.This > feature was s/onlt./only. / > introduced from qemu version 5.2 with the following change in qemu > repository: > > 3d7e78aa7777f ("Introduce a new flag for i440fx to disable PCI hotplug > on the root bus") > > The above qemu commit describes some reasons why users might to > disable hotplug > on PCI root buses. > > Related unit tests to exercise the new conf option has also been added. > > Signed-off-by: Ani Sinha <ani(a)anisinha.ca&gt; > --- > docs/formatdomain.rst                         | 12 ++++---- > src/qemu/qemu_validate.c                      |  9 +++++- > .../pc-i440fx-acpi-root-hotplug-disable.xml   | 30 +++++++++++++++++++ > .../pc-i440fx-acpi-root-hotplug-enable.xml    | 30 +++++++++++++++++++ > .../pc-i440fx-acpi-root-hotplug-disable.xml   |  1 + > .../pc-i440fx-acpi-root-hotplug-enable.xml    |  1 + > tests/qemuxml2xmltest.c                       |  4 +++ > 7 files changed, 81 insertions(+), 6 deletions(-) > create mode 100644 > tests/qemuxml2argvdata/pc-i440fx-acpi-root-hotplug-disable.xml > create mode 100644 > tests/qemuxml2argvdata/pc-i440fx-acpi-root-hotplug-enable.xml > create mode 120000 > tests/qemuxml2xmloutdata/pc-i440fx-acpi-root-hotplug-disable.xml > create mode 120000 > tests/qemuxml2xmloutdata/pc-i440fx-acpi-root-hotplug-enable.xml > > @@ -3879,6 +3879,14 @@ qemuValidateDomainDeviceDefControllerPCI(const > virDomainControllerDef *cont, >     /* hotplug */ >     if (pciopts->hotplug != VIR_TRISTATE_SWITCH_ABSENT) { >         switch ((virDomainControllerModelPCI) cont->model) { > +        case VIR_DOMAIN_CONTROLLER_MODEL_PCI_ROOT: > +            if (!virQEMUCapsGet(qemuCaps, > QEMU_CAPS_PIIX_ACPI_ROOT_PCI_HOTPLUG)) { > +                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, > +                               _("setting the %s property on a > pci-root device is not supported by this QEMU binary"), > +                               "hotplug"); No need to create a new translatable string, the one used by the case below can be reused:                 virReportError(VIR_ERR_CONFIG_UNSUPPORTED,                                _("setting the hotplug property on a '%s' device is not supported by this QEMU binary"),