Comment 18 for bug 1921880

I have retested with kernel 5.4.0-72 and qemu 1:4.2-3ubuntu6.15

With 5.4.0-72 on the host and 5.4.0-70 the MSR error (WRMSR to 0x48) is consistently there. After updating the instance to 5.4.0-72 the MSR error is gone without the need for the ibrs flag.
Booting mainline 5.11.14-051114-generic still has the other error (RDMSR from 0xda0).

So right now, I am using our build with the ibrs flag to get rid of the MSR 0x48 error on all distros, even though it's gone with 5.4.0-72 in the guest (and host).

The missing "erms" on my 7713 seems to stem from a buggy BIOS, I will recheck once I have an update from the vendor. The 7763 are on a different platform and the ones we have in production. Those work just fine and don't have any "scary" ECC errors ;-)

I am more than happy to do further testing with/for you.