Can you clarify a few points:
It's just to get a better understanding of the setup.
On the guest tools and PV drivers side I'm not familiar with them myself on windows, maybe @dinhngtu could have some more insight?
Updated my machine at home, no issue so far.
We have 2 packages updated for the first 8.3 security update, a bit late to be part of the final ISO but they will be available at release time. For people willing to test them and provide feedback, see the announcement below.
A new XSA was published on September 24th 2024.
Intel published a microcode update on the September 10th 2024.
xen-*:intel-microcode:yum clean metadata --enablerepo=xcp-ng-candidates
yum update "xen-*" intel-microcode --enablerepo=xcp-ng-candidates
reboot
The usual update rules apply: pool coordinator first, etc.
xen: xen-4.17.5-3.xcpng8.3intel_microcode: intel-microcode-20240815-1.xcpng8.3Normal use and anything else you want to test.
Until 8.3 release.
Update published: https://xcp-ng.org/blog/2024/09/27/september-2024-security-updates/
Thank you for the tests!
So if the initrd has been regenerated, it's likely the second part that fails, otherwise it is dracut, which is more of an issue.
@Andrew If I understand correctly that is ran after regenerating the initrd, but to be sure, can you check the date of your /boot/initrd-4.19.0+1.img on this host?
A new XSA was published on September 24th 2024.
Intel published a microcode update on the September 10th 2024.
We also included an updated xcp-ng-release for testing, althrough not related to security.
xen-*:microcode_ctl:xcp-ng-release:yum clean metadata --enablerepo=xcp-ng-candidates
yum update "xen-*" microcode_ctl xcp-ng-release --enablerepo=xcp-ng-candidates
reboot
The usual update rules apply: pool coordinator first, etc.
xen: 4.13.5-9.44.1.xcpng8.2microcode_ctl: microcode_ctl-2.1-26.xs29.5.xcpng8.2xcp-ng-release: xcp-ng-release-8.2.1-13Normal use and anything else you want to test.
~ 1 day because of security updates.
Update published https://xcp-ng.org/blog/2024/08/16/august-security-update/
Thank you all for testing 
Thierry is on holidays for now
It is more likely due to the fact the ice driver is either coming from the intel-ice or intel-ice-alt which are both for the main kernel, the -alt one being a more up to date version, and not as the confusing name could imply, for the kernel-alt.
The kernel-alt is in any case a debugging and testing kernel and not meant for production, but your tests confirmed that this seems to fix the fan speed issue, now we can discuss internally about what to do.
A new XSA was published on August 14th 2024.
Intel published an updated microcode on August 13th 2024.
xen-*:
microcode_ctl: Security updates from Intel:
yum clean metadata --enablerepo=xcp-ng-candidates
yum update "xen-*" microcode_ctl --enablerepo=xcp-ng-candidates
reboot
The usual update rules apply: pool coordinator first, etc.
xen: 4.13.5-9.40.3.xcpng8.2microcode_ctl: 2.1-26.xs29.3.xcpng8.2Normal use and anything else you want to test. Feedback about PCI pass-through is also welcome.
~ 2 day because of security updates.
Olivier is currently on holidays, so I'll try to answer: it will mostly depend where the fix is implemented by XenServer, they do have some closed source parts, if that fix goes in such a part, we won't be able to get it back. If it is implemented in some of the open source part, we should be able to get it and integrate the change on our side.
Let's hope the fix ends up on the right side 
yes you're basically doing an RPU manually.
But it is indeed odd that the process is stuck at 0%, it should be fairly fast to do the install patches, no errors in the logs?
It actually depends if you chose "rolling pool update" or "Install all pool patches", as you're talking about evacuate I assume you went with the first one.
Rolling pool update (RPU) is documented here and Pool updates here.
But to sum it up, "Install all pool patches" button will indeed run the yum update on all server, so similar as doing it manually, while RPU will do hosts one by one, moving VM to other hosts in the pool, install updates and reboot host. Therefore it can take way longer to complete, time will vary based on the number of VMs that have to be migrated around, network speed between hosts, etc…
RPU is the recommanded way as it allows hosts to restart and therefore take hypervisor, microcode and dom0 kernel updates into account right away with no service interruption. But if you don't really mind shutting down some of the VMs to restart hosts, or if there are no low level updates that requires a reboot, you could get away with just the yum update manually. But if the RPU is started already, I would not advise trying to do things manually at the same time.
Update published https://xcp-ng.org/blog/2024/07/18/july-2024-security-updates/
Thank you everyone for your tests!
I indeed forgot to wait for mirrors to sync before posting, my bad, should be good soon 
Two new XSAs were published on 16th of July.
xen-*:
xapi, xsconsole:
yum clean metadata --enablerepo=xcp-ng-testing
yum update "xen-*" "xapi-*" xsconsole --enablerepo=xcp-ng-testing
reboot
The usual update rules apply: pool coordinator first, etc.
xen: xen-4.13.5-9.40.2.xcpng8.2xapi: xapi-1.249.36-1.2.xcpng8.2xsconsole: xsconsole-10.1.13-1.2.xcpng8.2Normal use and anything else you want to test.
~ 1 day because of security updates.
We're still actively working on it, we're still not a 100% sure what the root cause is unfortunately.
It does seem to affect all Zen generations, from what we could gather, sligthly differently: it seems to be a bit better on zen3 and 4, but still always leading to underwhelming network performance for such machines.
To provide some status/context to you guys: I worked on this internally for a while, then as I had to attend other tasks we hired external help, which gave us some insight but no solution, and now we have @andSmv working on it (but not this week as he's at the Xen Summit).
From the contractors we had, we found that grant table and event channels have more occurences than on an intel xeon, looking like we're having more packet processed at first, but then they took way more time.
What Andrei found most recently is that PV & PVH (which we do not support officially), are getting about twice the performance of HVM and PVHVM. Also, having both dom0 and a guest pinned to a single physical core is also having better results. It seems to indicate it may come from the handling of cache coherency and could be related to guest memory settings that differs between intel and amd. That's what is under investigation right now, but we're unsure there will be any possibilty to change that.
I hope this helps make things a bit clearer to you guys, and shows we do invest a lot of time and money digging into this.
Do you use wireguard on your OPNsense? We did have an issues with FreeBSD based systems and wireguard, but if I remember properly it is supposed to be fixed, still worth asking
My bad, we were a bit late and I tried to be quick and forgot to move it... Just did that, should be good soon, it needs some time to sync repos.
Three new XSAs were published on 9th of April.
Notes:
VULNERABLE SYSTEMS section for impacted systems.xen-*:
yum clean metadata --enablerepo=xcp-ng-testing
yum update "xen-*" --enablerepo=xcp-ng-testing
reboot
The usual update rules apply: pool coordinator first, etc.
xen: 4.13.5-9.40.1.xcpng8.2Normal use and anything else you want to test.
~1 days because of security updates.