Paolo Bonzini <pbonzini@xxxxxxxxxx> 于2019年7月29日周一 上午11:10写道： > > On 29/07/19 10:58, Jack Wang wrote: > > Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> 于2019年7月25日周四 下午3:29写道： > >> > >> From: Paolo Bonzini <pbonzini@xxxxxxxxxx> > >> > >> [ Upstream commit 88dddc11a8d6b09201b4db9d255b3394d9bc9e57 ] > >> > >> If a KVM guest is reset while running a nested guest, free_nested will > >> disable the shadow VMCS execution control in the vmcs01. However, > >> on the next KVM_RUN vmx_vcpu_run would nevertheless try to sync > >> the VMCS12 to the shadow VMCS which has since been freed. > >> > >> This causes a vmptrld of a NULL pointer on my machime, but Jan reports > >> the host to hang altogether. Let's see how much this trivial patch fixes. > >> > >> Reported-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> > >> Cc: Liran Alon <liran.alon@xxxxxxxxxx> > >> Cc: stable@xxxxxxxxxxxxxxx > >> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> > > > > Hi all, > > > > Do we need to backport the fix also to stable 4.14? It applies > > cleanly and compiles fine. > > The reproducer required newer kernels that support KVM_GET_NESTED_STATE > and KVM_SET_NESTED_STATE, so it would be hard to test it. However, the > patch itself should be safe. > > Paolo Thanks Paolo for confirmation. I'm asking because we had one incident in our production with 4.14.129 kernel, System is Skylake Gold cpu, first kvm errors, host hung afterwards kernel: [1186161.091160] kvm: vmptrld (null)/6bfc00000000 failed kernel: [1186161.091537] kvm: vmclear fail: (null)/6bfc00000000 kernel: [1186186.490300] watchdog: BUG: soft lockup - CPU#54 stuck for 23s! [qemu:16639] Hi Sasha, hi Greg, Would be great if you can pick this patch also to 4.14 kernel. Best regards, Jack Wang
