> On 30 Sep 2019, at 11:43, Jinpu Wang <jinpu.wang@xxxxxxxxxxxxxxx> wrote: > > Dear KVM experts, > > We have a Broadwell server reboot itself recently, before the reboot, > there were error messages from KVM in netconsole: > [5599380.317055] kvm [9046]: vcpu1, guest rIP: 0xffffffff816ad716 vmx: > unexpected exit reason 0x3 > [5599380.317060] kvm [49626]: vcpu0, guest rIP: 0xffffffff81060fe6 > vmx: unexpected exit reason 0x3 > [5599380.317062] kvm [36632]: vcpu0, guest rIP: 0xffffffff8103970d > vmx: unexpected exit reason 0x3 > [5599380.317064] kvm [9620]: vcpu1, guest rIP: 0xffffffffb6c1b08e vmx: > unexpected exit reason 0x3 > [5599380.317067] kvm [49925]: vcpu5, guest rIP: 0xffffffff9b406ea2 > vmx: unexpected exit reason 0x3 > [5599380.317068] kvm [49925]: vcpu3, guest rIP: 0xffffffff9b406ea2 > vmx: unexpected exit reason 0x3 > [5599380.317070] kvm [33871]: vcpu2, guest rIP: 0xffffffff81060fe6 > vmx: unexpected exit reason 0x3 > [5599380.317072] kvm [49925]: vcpu4, guest rIP: 0xffffffff9b406ea2 > vmx: unexpected exit reason 0x3 > [5599380.317074] kvm [48505]: vcpu1, guest rIP: 0xffffffffaf36bf9b > vmx: unexpected exit reason 0x3 > [5599380.317076] kvm [21880]: vcpu1, guest rIP: 0xffffffff8103970d > vmx: unexpected exit reason 0x3 The only way a CPU will raise this exit-reason (3 == EXIT_REASON_INIT_SIGNAL) is if CPU is in VMX non-root mode while it has a pending INIT signal in LAPIC. In simple terms, it means that one CPU was running inside guest while another CPU have sent it a signal to reset itself. I see in code that kvm_init() does register_reboot_notifier(&kvm_reboot_notifier). kvm_reboot() runs hardware_disable_nolock() on each CPU before reboot. Which should result on every CPU running VMX’s hardware_disable() which should exit VMX operation (VMXOFF) and disable VMX (Clear CR4.VMXE). Therefore, I’m quite puzzled on how a server reboot triggers the scenario you present here. Can you send your full kernel log? > > Kernel version is: 4.14.129 > CPU is Intel(R) Xeon(R) CPU E5-2680 v4 @ 2.40GHz > There is no crashdump generated, only above message right before server reboot. > > Anyone has an idea, what could cause the reboot? is there a known > problem in this regards? > > I notice EXIT_REASON_INIT_SIGNAL(3) is introduced recently, is it related? > https://urldefense.proofpoint.com/v2/url?u=https-3A__git.kernel.org_pub_scm_linux_kernel_git_torvalds_linux.git_commit_arch_x86_kvm-3Fid-3D4b9852f4f38909a9ca74e71afb35aafba0871aa1&d=DwIBaQ&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=Jk6Q8nNzkQ6LJ6g42qARkg6ryIDGQr-yKXPNGZbpTx0&m=3JMSVEOhF1eCpny7VowcBwzScGDxjUkUZpipoP8Hlqw&s=war3Qw8cey9BewvAWmnGQdx3TY7EnL6O5aUkrg3FQUg&e= As the author of this commit, this shouldn’t be related. i.e. It won’t help you to apply this commit to your kernel. That commit changes the handling of *virtual* INIT signals inside guest. What you are seeing here are exits which results from a *physical* INIT signal while CPU was in guest. -Liran > > Regards, > Jinpu
