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

@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.

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.

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

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

@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.

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.)

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.

I built a system with a Ryzen 7950x on an ASRock B650M PG Riptide motherboard and was having similar issues as mgales. I switch to an ASUS Prime B650M-A II-CSM without any improvement.

With the ASUS Prime, there were no BIOS errors reported.
(I was able to get rid of 'ACPI BIOS Error (bug): Could not resolve [_SB.PCI0.GPP7.UP00.DP40.UP00.DP68], AE_NOT_FOUND (20180810/dswload2-160)' by enabling the onboard audio.)

I am able to run imported Windows VMs (Windows 10 and Server 2022) without any apparent issues.
I can run an imported AlmaLinux 8 VM with the nopv kernel option.
I can run the AlmaLinux 8 installer with the nopv option.
I can run Xen Orchestra with the nopv option.
I can also run an imported CentOS 6 VM without any additional options.

The main issue seems to be a stuck CPU on the Linux VMs when using PV drivers.

Could there be issues specific to Rzyen 7900x and 7950x?