On 6/9/2022 10:01 AM, Paolo Bonzini wrote:
On 5/31/22 19:00, mike tancsa wrote:
On Ubuntu 22 LTS, with the original kernel from release day, I can
migrate VMs back and forth between a 3700x and a 5800x without issue
On Ubuntu 22 LTS with everything up to date as of mid May 2022, I can
migrate from the 3700X to the 5800x without issue. But going from the
5800x to the 3700x results in a migrated VM that either crashes
inside the VM or has the CPU pegged at 100% spinning its wheels with
the guest frozen and needing a hard reset. This is with --live or
without and with --unsafe or without. The crash / hang happens once
the VM is fully migrated with the sender thinking it was successfully
sent and the receiver thinking it successfully arrived in.
On stock Ubuntu 22 (5.15.0-33-generic) I can migrate back and forth
to Ubuntu 20 as long as the hardware / cpu is identical (in this
case, 3700x)
On Ubuntu 22 LTS with everything up to date as of mid May 2022 with
5.18.0-051800-generic #202205222030 SMP PREEMPT_DYNAMIC Sun May 22. I
can migrate VMs back and forth that have as its CPU def EPYC or
EPYC-IBPB. If the def (in my one test case anyways) is Nehalem then I
get a frozen VM on migration back to the 3700X.
Hi, this is probably related to the patch at
https://www.spinics.net/lists/stable/msg538630.html, which needs a
backport to 5.15 however.
Note that using Intel definitions on AMD or vice versa is not going to
always work, though in this case it seems to be a regression.
Thanks for the followup. Forgive the naive question, but I am new to
linux. Do patches like this typically get picked up by distributions
like Ubuntu, or would I need open a bug report to flag this for them so
its included in their updates ?
---Mike
Paolo
