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

[Laine Stump]

On 9/27/21 4:05 AM, Ján Tomko wrote:
> 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 at anisinha.ca>
>> ---
>> 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"),

Wouldn't it be better if "hotplug" was also put in the arg list rather 
than inline in the function? That would avoid some overzealous 
translator attempting to translate that word. (Or maybe just use the 
function virReportControllerInvalidOption() for both of these error 
cases, thus removing both strings)