[libvirt PATCH 15/17] qemu: Add external_limit_manager config knob

[Michal Privoznik]

On 3/8/21 11:52 AM, Daniel P. Berrangé wrote:
> On Fri, Mar 05, 2021 at 08:14:02PM +0100, Andrea Bolognani wrote:
>> This will be useful when libvirtd is running in a containerized
>> environment with limited capabilities, and in order to make
>> things like VFIO device assignment still work an external
>> privileged process changes the limits from outside of the
>> container. KubeVirt is an example of this setup.
>>
>> Signed-off-by: Andrea Bolognani <abologna at redhat.com>
>> ---
>>   src/qemu/libvirtd_qemu.aug         |  1 +
>>   src/qemu/qemu.conf                 | 12 ++++++++++++
>>   src/qemu/qemu_conf.c               |  4 ++++
>>   src/qemu/qemu_conf.h               |  1 +
>>   src/qemu/test_libvirtd_qemu.aug.in |  1 +
>>   5 files changed, 19 insertions(+)
>>
>> diff --git a/src/qemu/libvirtd_qemu.aug b/src/qemu/libvirtd_qemu.aug
>> index 3c1045858b..f1b024a37f 100644
>> --- a/src/qemu/libvirtd_qemu.aug
>> +++ b/src/qemu/libvirtd_qemu.aug
>> @@ -104,6 +104,7 @@ module Libvirtd_qemu =
>>                    | str_entry "slirp_helper"
>>                    | str_entry "dbus_daemon"
>>                    | bool_entry "set_process_name"
>> +                 | bool_entry "external_limit_manager"
>>                    | int_entry "max_processes"
>>                    | int_entry "max_files"
>>                    | limits_entry "max_core"
>> diff --git a/src/qemu/qemu.conf b/src/qemu/qemu.conf
>> index 0c1054f198..15cbc3ba38 100644
>> --- a/src/qemu/qemu.conf
>> +++ b/src/qemu/qemu.conf
>> @@ -662,6 +662,18 @@
>>   #
>>   #set_process_name = 1
>>   
>> +# If enabled, libvirt will not attempt to change process limits (as
>> +# configured with the max_processes, max_files and max_core settings
>> +# below) itself but will instead expect an external entity to perform
>> +# this task.
> 
> Can't users simply not set max_core, max_files, etc already ?

These two yes, mem lock no.

Michal