On Tue, 2022-05-03 at 12:12 +0300, Maxim Levitsky wrote: > On Mon, 2022-05-02 at 16:51 +0000, Sean Christopherson wrote: > > On Mon, May 02, 2022, Maxim Levitsky wrote: > > > On Mon, 2022-05-02 at 10:59 +0300, Maxim Levitsky wrote: > > > > > > Also I can reproduce it all the way to 5.14 kernel (last kernel I have installed in this VM). > > > > > > > > > > > > I tested kvm/queue as of today, sadly I still see the warning. > > > > > > > > > > Due to a race, the above statements are out of order ;-) > > > > > > > > So futher investigation shows that the trigger for this *is* cpu_pm=on :( > > > > > > > > So this is enough to trigger the warning when run in the guest: > > > > > > > > qemu-system-x86_64 -nodefaults -vnc none -serial stdio -machine accel=kvm > > > > -kernel x86/dummy.flat -machine kernel-irqchip=on -smp 8 -m 1g -cpu host > > > > -overcommit cpu-pm=on > > > > > > > > > > > > '-smp 8' is needed, and the more vCPUs the more often the warning appears. > > > > > > > > > > > > Due to non atomic memslot update bug, I use patched qemu version, with an > > > > attached hack, to pause/resume vcpus around the memslot update it does, but > > > > even without this hack, you can just ctrl+c the test after it gets the KVM > > > > internal error, and then tdp mmu memory leak warning shows up (not always > > > > but very often). > > > > > > > > > > > > Oh, and if I run the above command on the bare metal, it never terminates. > > > > Must be due to preemption, qemu shows beeing stuck in kvm_vcpu_block. AVIC > > > > disabled, kvm/queue. Bugs, bugs, and features :) > > > > > > All right, at least that was because I removed the '-device isa-debug-exit,iobase=0xf4,iosize=0x4', > > > which is apparently used by KVM unit tests to signal exit from the VM. > > > > Can you provide your QEMU command line for running your L1 VM? And your L0 and L1 > > Kconfigs too? I've tried both the dummy and ipi_stress tests on a variety of hardware, > > kernels, QEMUs, etc..., with no luck. > > > > So now both L0 and L1 run almost pure kvm/queue) > (commit 2764011106d0436cb44702cfb0981339d68c3509) > > I have some local patches but they are not relevant to KVM at all, more > like various tweaks to sensors, a sad hack for yet another regression > in AMDGPU, etc. > > The config and qemu command line attached. > > AVIC disabled in L0, L0 qemu is from master upstream. > Bug reproduces too well IMHO, almost always. > > For reference the warning is printed in L1's dmesg. Tested this without any preemption in L0 and L1 - bug still reproduces just fine. (kvm/queue) Best regards, Maxim Levitsky > > > > Best regards, > Maxim Levitsky
