On Mon, Dec 21, 2020, Zdenek Kaspar wrote: > [ 179.364305] WARNING: CPU: 0 PID: 369 at kvm_mmu_zap_oldest_mmu_pages+0xd1/0xe0 [kvm] > [ 179.365415] Call Trace: > [ 179.365443] paging64_page_fault+0x244/0x8e0 [kvm] This means the shadow page zapping is occuring because KVM is hitting the max number of allowed MMU shadow pages. Can you provide your QEMU command line? I can reproduce the performance degredation, but only by deliberately overriding the max number of MMU pages via `-machine kvm-shadow-mem` to be an absurdly low value. > [ 179.365596] kvm_mmu_page_fault+0x376/0x550 [kvm] > [ 179.365725] kvm_arch_vcpu_ioctl_run+0xbaf/0x18f0 [kvm] > [ 179.365772] kvm_vcpu_ioctl+0x203/0x520 [kvm] > [ 179.365938] __x64_sys_ioctl+0x338/0x720 > [ 179.365992] do_syscall_64+0x33/0x40 > [ 179.366013] entry_SYSCALL_64_after_hwframe+0x44/0xa9
