Messages in this thread | | | Date | Tue, 26 Jul 2022 17:43:27 +0200 | Subject | Re: [PATCH] KVM: x86: enable TDP MMU by default | From | Paolo Bonzini <> |
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On 7/26/22 16:57, Stoiko Ivanov wrote: > Hi, > > Proxmox[0] recently switched to the 5.15 kernel series (based on the one > for Ubuntu 22.04), which includes this commit. > While it's working well on most installations, we have a few users who > reported that some of their guests shutdown with > `KVM: entry failed, hardware error 0x80000021` being logged under certain > conditions and environments[1]: > * The issue is not deterministically reproducible, and only happens > eventually with certain loads (e.g. we have only one system in our > office which exhibits the issue - and this only by repeatedly installing > Windows 2k22 ~ one out of 10 installs will cause the guest-crash) > * While most reports are referring to (newer) Windows guests, some users > run into the issue with Linux VMs as well > * The affected systems are from a quite wide range - our affected machine > is an old IvyBridge Xeon with outdated BIOS (an equivalent system with > the latest available BIOS is not affected), but we have > reports of all kind of Intel CPUs (up to an i5-12400). It seems AMD CPUs > are not affected. > > Disabling tdp_mmu seems to mitigate the issue, but I still thought you > might want to know that in some cases tdp_mmu causes problems, or that you > even might have an idea of how to fix the issue without explicitly > disabling tdp_mmu?
If you don't need secure boot, you can try disabling SMM. It should not be related to TDP MMU, but the logs (thanks!) point at an SMM entry (RIP = 0x8000, CS base=0x7ffc2000).
This is likely to be fixed by https://lore.kernel.org/kvm/20220621150902.46126-1-mlevitsk@redhat.com/.
Paolo
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