Hi,
Thank you Gabriel for the explanations, being able to set up IO_Driver via agent.properties is a good direction. I will try to check why it is not supported in CentOS8 SIG Virtualization. Regards, Piotr From: Gabriel Bräscher <gabrasc...@gmail.com> Sent: Wednesday, November 24, 2021 10:02 AM To: pi...@piszki.pl Cc: users <users@cloudstack.apache.org>; Дикевич Евгений Александрович <evgeniy.dikev...@becloud.by> Subject: Re: [!!Mass Mail]io uring is not supported by this QEMU binary Hi Piotr, Unfortunately, the current implementation does not allow to customize the driver via the agent.properties. Instead, it evaluates Libvirt and Qemu versions in order to assess if it is supported. I considered the libvirt & qemu documentation where address support for io_uring and release notes. According to release notes, io_urin is supported in: Qemu >= 5.0 [1], and Libvirt >= 6.3.0 [2]. (for reference) The kernel feature (io_uring itself) is described in this lwn.net <http://lwn.net> article [3]. However, I am not confident (anymore) that RedHat is supporting it [4,5]. It also might be that there has been a regression in the newer Qemu release. For the record, I've just re-checked a KVM host running 4.16.0.0 and I have indeed VMs running with io_uring configured in the "domain.xml". Host details: Ubuntu 20.04, Qemu 5.0.0, Libvirt 6.3.0. As a conclusion, considering that it is not as stable and widely supported as assumed before, I will propose a PR that would allow customizing the disk IO_Driver in the "agent.properties". Additionally, I will double-check documentation, release announcements, and bugs raised in qemu, libvirt, redhat, & ubuntu scopes. [1] https://wiki.qemu.org/ChangeLog/5.0 [2] https://libvirt.org/news.html#v6-3-0-2020-05-05 [3] https://lwn.net/Articles/776703/ [4] https://bugzilla.redhat.com/show_bug.cgi?id=1769597 [5] https://bugzilla.redhat.com/show_bug.cgi?id=1769598 Any feedback and tests with different OS and Libvurt/Qemu releases are very appreciated. Best Regards, Gabriel. Em qua., 24 de nov. de 2021 às 09:37, Piotr Pisz <pi...@piszki.pl <mailto:pi...@piszki.pl> > escreveu: Hi! Gabriel, could you suggest how to disable io_uring with agent.properties? In the second lab, I turned off advanced virtualization repo and downgrade qemu to native for CentOS 8 and everything works fine. Generally, I use a lot of nested virtualization and I need the latest version of qemu, hence the advanced virtualization repo. Regards, Piotr From: Gabriel Bräscher <gabrasc...@gmail.com <mailto:gabrasc...@gmail.com> > Sent: Wednesday, November 24, 2021 8:54 AM To: users <users@cloudstack.apache.org <mailto:users@cloudstack.apache.org> >; pi...@piszki.pl <mailto:pi...@piszki.pl> Cc: Дикевич Евгений Александрович <evgeniy.dikev...@becloud.by <mailto:evgeniy.dikev...@becloud.by> > Subject: Re: [!!Mass Mail]io uring is not supported by this QEMU binary It worked when I tested in Ubuntu with the following qemu/libvirt: ~# qemu-system-x86_64 --version QEMU emulator version 5.0.0 (Debian 1:5.0-5ubuntu6~ppa0) ~# libvirtd --version libvirtd (libvirt) 6.6.0 I will check if there has been any regressions in qemu. Maybe the best would be to extract that IO_URING configuration into an agent.properties variable. Just in case it is needed to be disabled, or changed to another disk IO Driver. Regards, Gabriel. On Mon, Nov 22, 2021, 13:59 Piotr Pisz <pi...@piszki.pl <mailto:pi...@piszki.pl> > wrote: Hi, I seem to meet these requirements: In one LAB I have a custom kernel: 5.4.129-1.el8.elrepo.x86_64 and libvirtd (libvirt) 7.6.0 with qemu 6.0.0 But in the second, it comes with the system: 4.18.0-240.22.1.el8_3.x86_64 and libvirtd (libvirt) 7.0.0 with qemu-kvm-5.2.0-16.el8 And I have the same error in both ☹ Colleagues who tested it can boast in what environments it was done? Regards, Piotr -----Original Message----- From: Дикевич Евгений Александрович <evgeniy.dikev...@becloud.by <mailto:evgeniy.dikev...@becloud.by> > Sent: Monday, November 22, 2021 1:37 PM To: users@cloudstack.apache.org <mailto:users@cloudstack.apache.org> ; pi...@piszki.pl <mailto:pi...@piszki.pl> Subject: RE: [!!Mass Mail]io uring is not supported by this QEMU binary Hi Mb this is answer for you) https://github.com/apache/cloudstack/pull/5012 -----Original Message----- From: Piotr Pisz [mailto:pi...@piszki.pl <mailto:pi...@piszki.pl> ] Sent: Monday, November 22, 2021 3:23 PM To: users@cloudstack.apache.org <mailto:users@cloudstack.apache.org> Subject: [!!Mass Mail]io uring is not supported by this QEMU binary Hi, I found the reason why the VM did not start in 4.16 after the upgrade. The following message appears during the start-up: libvirt.LibvirtException: unsupported configuration: io uring is not supported by this QEMU binary KVM Is CentOS 8.5 with advanced virtualization repo, now qemu has version: qemu-kvm-6.0.0-33.el8. This configuration works without any problem with CS 4.15, the question is, if anything has changed in the requirements or handling of kvm in 4.16? Regards, Piotr Внимание! Это электронное письмо и все прикрепленные к нему файлы являются конфиденциальными и предназначены исключительно для использования лицом (лицами), которому (которым) оно предназначено. Если Вы не являетесь лицом (лицами), которому (которым) предназначено это письмо, не копируйте и не разглашайте его содержимое и удалите это сообщение и все вложения из Вашей почтовой системы. 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