Mailing List Archive

CentOS 8.x: if your virt stack does not start with Xen you did it wrong
Hello xen-users,

It is one year now after the C8 was released, what is the state of Xen
dom0 and the Xen based Virt stack?

Of course there is no official support from RH for Xen anymore, but
there is a rumbling of Xen dom0 support coming from the Virt SIG.

Once its done, it would appear in this tree:
http://mirrors.oit.uci.edu/centos/8/virt/x86_64/

Here is a short writeup about the xen virt stack I did in April:
http://lists.ghettoforge.org/pipermail/users/2020-April/000013.html

What are some major changes from Xen builds in C7?
To build/link EFI in C7 needed a build-requires (BR) on mingw64-binutils.
However, C8 now includes EFI linking support in the native GNU (ld)
loader in the
binutils package - thus one less BR.

C7 had a python package with python2 default. C8 has no such python
package, only python2 or python3. It is possible to build and run any
Xen from xen-4.12+ with python3.

New in C8 is modularity, including the `virt module`, which is
equivalent to a wrench in the fan, bringing all virt builds based on
Xen to a screeching halt. As discussed in the GF-Users post this
obstacle can be overcome.

There is a reason that the Centos Virt SIG has stalled their Xen
release. As shown there is a limited build in koji without any
libvirt+ support. I know the whole Xen based stack is possible and how
it can be done.

cheers,
PryMar55
Re: CentOS 8.x: if your virt stack does not start with Xen you did it wrong [ In reply to ]
Hello,

Significant news has happened since I started this.
https://blog.centos.org/2020/12/future-is-centos-stream/

as stated in the Centos blog, the new EOL for C8 is less than 1 year out.
Nevertheless I pushed through and got a Copr build for xen-4.13.2 with
qemu-4.1 and libvirt-5.6.

Copr now alllows disabling modules in the buildroot, so there is a way
to disable the `virt module`, which makes building a xen based virt8
stack impossible.

After doing the Copr build I added the Copr repo into my dom0
repolist, did the install. The dom0 is running as expected.

Copr result packages:
https://copr-be.cloud.fedoraproject.org/results/prymar56/virt8-xen4d/epel-8-x86_64/

Copr repo link:
https://copr.fedorainfracloud.org/coprs/prymar56/virt8-xen4d/repo/epel-8/prymar56-virt8-xen4d-epel-8.repo

The big letdown with libvirt is there is no support for a pv install.
The desired kernel is from elrepo kernel-ml.

cheers,
Prymar56


On 12/2/20, Pry Mar <pryorm09@gmail.com> wrote:
> Hello xen-users,
>
> It is one year now after the C8 was released, what is the state of Xen
> dom0 and the Xen based Virt stack?
>
> Of course there is no official support from RH for Xen anymore, but
> there is a rumbling of Xen dom0 support coming from the Virt SIG.
>
> Once its done, it would appear in this tree:
> http://mirrors.oit.uci.edu/centos/8/virt/x86_64/
>
> Here is a short writeup about the xen virt stack I did in April:
> http://lists.ghettoforge.org/pipermail/users/2020-April/000013.html
>
> What are some major changes from Xen builds in C7?
> To build/link EFI in C7 needed a build-requires (BR) on mingw64-binutils.
> However, C8 now includes EFI linking support in the native GNU (ld)
> loader in the
> binutils package - thus one less BR.
>
> C7 had a python package with python2 default. C8 has no such python
> package, only python2 or python3. It is possible to build and run any
> Xen from xen-4.12+ with python3.
>
> New in C8 is modularity, including the `virt module`, which is
> equivalent to a wrench in the fan, bringing all virt builds based on
> Xen to a screeching halt. As discussed in the GF-Users post this
> obstacle can be overcome.
>
> There is a reason that the Centos Virt SIG has stalled their Xen
> release. As shown there is a limited build in koji without any
> libvirt+ support. I know the whole Xen based stack is possible and how
> it can be done.
>
> cheers,
> PryMar55
>
Re: CentOS 8.x: if your virt stack does not start with Xen you did it wrong [ In reply to ]
Hi,

nice work. But why not version 4.14? Have it here since it is released
and it works very stable. I've build my own rpm's based on "xen made
easy" project.

Second question: It is possible to integrate patches in your releases,
for example:
https://github.com/JordanBoulan/Xen-4.12-NvidiaVGApassthrough-patch
it works with 4.13/4.14 to...

---
------
Greetz

Am 23.01.2021 06:05, schrieb Pry Mar:
> Hello,
>
> Significant news has happened since I started this.
> https://blog.centos.org/2020/12/future-is-centos-stream/
>
> as stated in the Centos blog, the new EOL for C8 is less than 1 year
> out.
> Nevertheless I pushed through and got a Copr build for xen-4.13.2 with
> qemu-4.1 and libvirt-5.6.
>
> Copr now alllows disabling modules in the buildroot, so there is a way
> to disable the `virt module`, which makes building a xen based virt8
> stack impossible.
>
> After doing the Copr build I added the Copr repo into my dom0
> repolist, did the install. The dom0 is running as expected.
>
> Copr result packages:
> https://copr-be.cloud.fedoraproject.org/results/prymar56/virt8-xen4d/epel-8-x86_64/
>
> Copr repo link:
> https://copr.fedorainfracloud.org/coprs/prymar56/virt8-xen4d/repo/epel-8/prymar56-virt8-xen4d-epel-8.repo
>
> The big letdown with libvirt is there is no support for a pv install.
> The desired kernel is from elrepo kernel-ml.
>
> cheers,
> Prymar56
>
>
> On 12/2/20, Pry Mar <pryorm09@gmail.com> wrote:
>> Hello xen-users,
>>
>> It is one year now after the C8 was released, what is the state of Xen
>> dom0 and the Xen based Virt stack?
>>
>> Of course there is no official support from RH for Xen anymore, but
>> there is a rumbling of Xen dom0 support coming from the Virt SIG.
>>
>> Once its done, it would appear in this tree:
>> http://mirrors.oit.uci.edu/centos/8/virt/x86_64/
>>
>> Here is a short writeup about the xen virt stack I did in April:
>> http://lists.ghettoforge.org/pipermail/users/2020-April/000013.html
>>
>> What are some major changes from Xen builds in C7?
>> To build/link EFI in C7 needed a build-requires (BR) on
>> mingw64-binutils.
>> However, C8 now includes EFI linking support in the native GNU (ld)
>> loader in the
>> binutils package - thus one less BR.
>>
>> C7 had a python package with python2 default. C8 has no such python
>> package, only python2 or python3. It is possible to build and run any
>> Xen from xen-4.12+ with python3.
>>
>> New in C8 is modularity, including the `virt module`, which is
>> equivalent to a wrench in the fan, bringing all virt builds based on
>> Xen to a screeching halt. As discussed in the GF-Users post this
>> obstacle can be overcome.
>>
>> There is a reason that the Centos Virt SIG has stalled their Xen
>> release. As shown there is a limited build in koji without any
>> libvirt+ support. I know the whole Xen based stack is possible and how
>> it can be done.
>>
>> cheers,
>> PryMar55
>>