Non-server CPU compatibility - Ryzen and Intel

BlueBadger

I ordered a Ryzen 7900 last night and got it this morning. (Thanks Amazon).
I just replaced the 7950x with the 7900 and things seem to work better.

I can run now a AlmaLinux 8 VM without the nopv flag.
I can now run Xen Orchestra without the nopv flag.

I will do some more testing.

mgales

@BlueBadger - Thank you! Looking forward to see what else you learn.

BlueBadger

I was having issues (download stalls) with the onboard 2.5Gb NIC (RTL8125) on the ASUS Prime B650M-A II-CSM motherboard even after I switched from the Ryzen 7950x to the 7900.
My setup also includes a X540 10Gb NIC which seemed to be working well.

I swapped the motherboard back to the ASRock B650M PG Riptide and was still having issues with the onboard 2.5Gb NIC.

I disabled the onboard NIC and installed a second X540 and have not have any network issues so far.

I'm guessing there might be an issue with the r8125 driver.

Excluding the onboard 2.5Gb NIC, XCP-ng seems to run well on both motherboards.

The BIOS errors in dmesg don't seem to be causing any issues.
(The ASRock B650M PG Riptide seems like a nicer motherboard.)

olivierlambert

That's… interesting So the "X" series seems to have some issues in the end? It's weird since it should be very different than it's non-X counterpart.

andyhhp

So, we've had reports on xen-devel which look a little like this.

@BlueBadger are you able to switch back to your 7950x and try booting Xen with x2apic_phys=true ? It appears that the -X processors are missing a feature in their IOMMU and Xen was getting confused when setting up interrupt handling.

https://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=0d2686f6b66b4b1b3c72c3525083b0ce02830054 is at least part of the fix, but so far feedback on the mailing lists suggests it's not a complete fix.

BlueBadger

@andyhhp Thanks for the info.
I plan to leave my current machine (Ryzen 7900) as is since it seems to be running well.
I plan to build a new machine with the extra 7950x. The motherboard is on back order.
I will try the new setting once it is built.

BlueBadger

@andyhhp I built a new machine with my Ryzen 7950x.
Booting Xen with x2apic_phys=true did not seem to fix any issues.

olivierlambert

Interesting, thanks for the feedback. @andyhhp should we provide a Xen version with the initial fix and see if it's better? (maybe combined to the x2apic param)

Sam

I'm testing this combo:

AMD RYZEN 9 7900X
ASUS PRIME X670-P WIFI bios 1406
2x32GB KINGSTON 5600 CL40 (max QLV)
Boot drive NVME 250gb (chipset) and SN850X 4.0 1TB on CPU.

With setting: Local APIC Mode = X2APIC and UEFI set to Other OS. Installed 8.3 alpha and updated, got errors. Test installing XOA took too much time and booting was painfully slow using only 1 SSD on chipset NVME.

Tried disabling IOMMU, but the same issue.

olivierlambert

It's possible we got a fix, but we need sometime to generate the right build/RPM for you to test

Sam

@olivierlambert said in Non-server CPU compatibility - Ryzen and Intel:

It's possible we got a fix, but we need sometime to generate the right build/RPM for you to test

I have to identical setups for testing. With all the storage being pcie and interrupts. I also got a instlall with proxmox, but kind of same issues with IOMMU, trying to passtrough the 4.0 nvme. The disk was very slow, CPU wise performance on W11 machine was great.

olivierlambert

I'm almost sure the future patch will fix the slow CPU behavior Hang on!

peanutyost

@olivierlambert said in Non-server CPU compatibility - Ryzen and Intel:

I'm almost sure the future patch will fix the slow CPU behavior Hang on!

Any update on when this fix is available. I got a x series cpu and am having these same problems.

olivierlambert

We need to take a closer look, it's in our backlog but we also have other stuff pending (as you can imagine). Let me ping @stormi about this.

stormi

In theory we now have the relevant patches. We'll try to provide a patched build in the coming days, either this week or the next.

peanutyost

Awesome! I appreciate it.

Sam

@stormi Good news! if you need some testing to be done, I've a 7900X avaliable for testing.

stormi

Hi everyone!

So, @andSmv applied a few patches to Xen for you and built it.

As it's still only a temporary test build, you will find it in a special user repository at: https://koji.xcp-ng.org/repos/user/8/8.3/asemenov1/x86_64/

You may either add the repository (by creating a .repo file in /etc/yum.repos.d/) and then run yum update --enablerepo={nameofrepo}, or download the RPMs locally and then run yum update ./xen*.rpm.

Please let us know if it fixes issues with your CPUs.

BlueBadger

@stormi @andSmv
Thank you!
The patch seems to work.
My VMs seem to run without any issues on my Ryzen 7950x.

olivierlambert

Yay \o/