Bug 1995807

Summary:	RFE: Remove SGA, deprecate cirrus, and set defaults for QEMU machine-types in RHEL9
Product:	Red Hat Enterprise Linux 9	Reporter:	Klaus Heinrich Kiwi <kkiwi>
Component:	qemu-kvm	Assignee:	Gerd Hoffmann <kraxel>
qemu-kvm sub component:	Graphics	QA Contact:	Guo, Zhiyi <zhguo>
Status:	CLOSED CURRENTRELEASE	Docs Contact:	Jiri Herrmann <jherrman>
Severity:	medium
Priority:	urgent	CC:	berrange, coli, gfialova, jherrman, jinzhao, juzhang, kraxel, mrezanin, pvlasin, rjones, virt-maint, xuwei, ymankad, zhguo
Version:	9.0	Keywords:	FutureFeature, Triaged
Target Milestone:	beta	Flags:	zhguo: needinfo-
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	qemu-kvm-6.0.0-13.el9_b.1	Doc Type:	Removed functionality
Doc Text:		Story Points:	---
Clone Of:
Clones:	2000845 2003040 (view as bug list)		Environment:
Last Closed:	2021-12-07 21:20:54 UTC	Type:	Feature Request
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2002326, 2002993
Bug Blocks:	2000845, 2003040

Description Klaus Heinrich Kiwi 2021-08-19 19:31:05 UTC

Description of problem:
According to the thread in virt-devel, we need to re-arrange the graphic drivers in QEMU for RHEL9.0 machine-types

The plan, as far as I understand it, is:

1) Remove sga support from Qemu builds (no evidence that it's being used)
2) Deprecate cirrus on Documentation + Add warning logging whenever it's used (OPS mentions this was the default, so there are still users for it on eventual live-migration)
3) Set the default graphics for the the bios machine-types to stdvga
4) set the default graphics for the UEFI machine-types to bochs-display
5) Build and Package virtio-gpu, but not virtio-vga (for which virtio-gpu's functionality essentially overlaps)

Comment 5 Klaus Heinrich Kiwi 2021-08-19 20:11:42 UTC

Another point to note here: currently, sgabios-bin and sgabios are dependencies for the qemu-kvm package. It is my understanding that once we don't build the sga device any longer, that dependency will no longer be true, and we can safely remove that package from RHEL9 as well.

Feel free to correct me if I'm wrong.

Comment 8 Klaus Heinrich Kiwi 2021-08-25 12:36:41 UTC

Discussed with Gerd, seems like this is already MODIFIED in CentOS Stream, so perhaps we should move this to ON_QA? I think we don't need exception+ for bugs ON_QA.

Comment 9 Miroslav Rezanina 2021-08-25 13:07:10 UTC

(In reply to Klaus Heinrich Kiwi from comment #8)
> Discussed with Gerd, seems like this is already MODIFIED in CentOS Stream,
> so perhaps we should move this to ON_QA? I think we don't need exception+
> for bugs ON_QA.

Nope, we've got MR for this filed against CentOS (we try to get it committed in next build).

Comment 10 Guo, Zhiyi 2021-08-26 01:38:31 UTC

(In reply to Miroslav Rezanina from comment #9)
> (In reply to Klaus Heinrich Kiwi from comment #8)
> > Discussed with Gerd, seems like this is already MODIFIED in CentOS Stream,
> > so perhaps we should move this to ON_QA? I think we don't need exception+
> > for bugs ON_QA.
> 
> Nope, we've got MR for this filed against CentOS (we try to get it committed
> in next build).

Move to ITM 27 based on this comment

Comment 17 Guo, Zhiyi 2021-09-06 06:07:00 UTC

Giving the patch only has the content for disabling sga device and the rest(deprecate cirrus, and set defaults for QEMU machine-types in RHEL9) are not covered by the patch, so just test sga device disabling:

Test against qemu-kvm-6.0.0-12.el9.x86_64

1)Test sga device is functional:
# /usr/libexec/qemu-kvm -device sga -serial stdio
VNC server running on ::1:5900

 SeaBIOS (version 1.14.0-6.el9)


iPXE (http://ipxe.org) 00:03.0 CB00 PCI2.10 PnP PMM+07F8C6B0+07ECC6B0 CB00
                                                                               


Booting from Hard Disk...
Boot failed: could not read the boot disk

Booting from Floppy...
Boot failed: could not read the boot disk

Booting from DVD/CD...
Boot failed: Could not read from CDROM (code 0003)
Booting from ROM...
iPXE (PCI 00:03.0) starting execution...ok
iPXE initialising devices...ok
...
2)Qemu help show sga device is enabled:
# /usr/libexec/qemu-kvm -device ? | grep -i sga
name "sga", bus ISA, desc "Serial Graphics Adapter"

3)sgabios-bin is a dependency of qemu-kvm-common:
# rpm -qR qemu-kvm-common | grep sgabios
sgabios-bin

Now test against qemu-kvm-6.0.0-13.el9_b.1.x86_64

1)sga device is completely disabled:
# /usr/libexec/qemu-kvm -device sga -serial stdio
qemu-kvm: -device sga: 'sga' is not a valid device model name
# /usr/libexec/qemu-kvm -device ? | grep -I sga
(empty output)

2)sgabios-bin is removed from qemu-kvm-common dependency list:
# rpm -qR qemu-kvm-common | grep sgabios
(empty output)

So sga device is disabled without problems on qemu-kvm-6.0.0-13.el9_b.1.x86_64

Comment 19 Yanan Fu 2021-09-06 10:59:29 UTC

QE bot(pre verify): Set 'Verified:Tested,SanityOnly' as gating/tier1 test pass.

Comment 22 Guo, Zhiyi 2021-09-06 13:34:20 UTC

Verified per comment 17

Comment 23 Richard W.M. Jones 2021-09-08 14:38:17 UTC

> 1) Remove sga support from Qemu builds (no evidence that it's being used)

libguestfs uses it, please do not remove it

Comment 24 Richard W.M. Jones 2021-09-09 12:29:04 UTC

Gerd,

Does this affect RHEL AV 8.5?

How about RHEL 8.6.0 (unified with RHEL 9, perhaps)?

I think we need to revert the SGA change for RHEL 9 Beta, but we're
fine with the change in RHEL 9 GA.

Comment 26 Klaus Heinrich Kiwi 2021-09-09 18:00:04 UTC

(In reply to Richard W.M. Jones from comment #24)
> Gerd,
> 
> Does this affect RHEL AV 8.5?
>
Doesn't look like so: https://gitlab.com/redhat/rhel/src/qemu-kvm/qemu-kvm/-/blob/rhel-av-8.5.0/redhat/qemu-kvm.spec.template (apologies, couldn't find a public references)
 
> How about RHEL 8.6.0 (unified with RHEL 9, perhaps)?
The same seems to be true for 8.6.0: https://gitlab.com/redhat/rhel/src/qemu-kvm/qemu-kvm/-/blob/rhel-8.6.0/redhat/qemu-kvm.spec.template

> 
> I think we need to revert the SGA change for RHEL 9 Beta, but we're
Since this bug was essentially verified, I think we need a new bug filled against beta to undo the damage.

> fine with the change in RHEL 9 GA.
And looks like we need this same change applied to RHEL9 GA... https://gitlab.com/redhat/centos-stream/src/qemu-kvm/-/tree/c9s/

Comment 27 Gerd Hoffmann 2021-09-10 05:57:08 UTC

> Does this affect RHEL AV 8.5?
> How about RHEL 8.6.0 (unified with RHEL 9, perhaps)?

I have no plans to drop sga in 8.x.

Comment 28 Gerd Hoffmann 2021-09-10 05:59:29 UTC

> I have no plans to drop sga in 8.x.

Which means both "-machine graphics=off" and "-device sga" will work and you can choose.

Comment 32 Gerd Hoffmann 2022-05-06 08:09:28 UTC

Default display device on qemu level is 'stdvga'.  For UEFI guests the recommended variant is indeed bochs-display, that is implemented higher up in the management stack though and not handled by qemu.

On sga: "<bios useserial='yes'/>" isn't new.  On rhel-8 and older it activates sga.  On rhel-9 it activates the serial console support in seabios.  So when using libvirt there isn't much of a change.  The implementation under the hood changes, but existing libvirt domain configs should continue to work just fine without manual updates.