https://bugzilla.kernel.org/show_bug.cgi?id=215459 Sean Christopherson (seanjc@xxxxxxxxxx) changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |seanjc@xxxxxxxxxx --- Comment #4 from Sean Christopherson (seanjc@xxxxxxxxxx) --- The fix Maxim is referring to is commit fdba608f15e2 ("KVM: VMX: Wake vCPU when delivering posted IRQ even if vCPU == this vCPU"). But the buggy commit was introduced back in v5.8, so it's unlikely that's the issue, or at least that it's the only issue. And assuming the VM in question has multiple vCPUs (which I'm pretty sure is true based on the config), that bug is unlikely to cause the entire VM to freeze; the expected symptom is that a vCPU isn't awakened when it should be, and while it's possible multiple vCPUs could get unlucky, taking down the entire VM is highly improbable. That said, it's worth trying that fix, I'm just not very optimistic :-) Assuming this is something different, the biggest relevant changes in v5.15 are that the TDP MMU is enabled by default, and that the APIC access page memslot is not deleted when APICv is inhibited. Can you try disabling the TDP MMU with APICv still enabled? KVM allows that to be toggled without unloading, e.g. "echo N | sudo tee /sys/module/kvm/parameters/tdp_mmu", the VM just needs to be started after the param is toggled. Running v5.16 (or v5.16-rc8, as there are no KVM changes expected between rc8 ad the final release) would also be very helpful. If we get lucky and the issue is resolved in v5.16, then it would be nice to "reverse" bisect to understand exactly what fixed the problem. > Assuming I really do have APICv: is there anything I need to change in my XML > to really make use of this feature or does it work "out of the box"? APICv works out of the box, though lack of IOMMU support does mean that your system can't post interrupts from devices, which is usually the biggest performance benefit to APICv on Intel. -- You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.
