On Tue, 2022-07-26 at 17:43 +0200, Paolo Bonzini wrote: > 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 is an old IvyBridge Xeon with outdated BIOS (an equivalent system with 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). No doubt about it. It is the issue. > > This is likely to be fixed by > https://lore.kernel.org/kvm/20220621150902.46126-1-mlevitsk@xxxxxxxxxx/. Speaking of my patch series, anything I should do to move that thing forward? My approach to preserve the interrupt shadow in SMRAM doesn't seem to be accepted, so what you think I should do? Best regards, Maxim Levitsky > > Paolo >
