1. 12 Jul, 2017 38 commits
  2. 05 Jul, 2017 2 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.9.36 · 9f86f302
      Greg Kroah-Hartman authored
      9f86f302
    • Wanpeng Li's avatar
      KVM: nVMX: Fix exception injection · a29fd27c
      Wanpeng Li authored
      commit d4912215 upstream.
      
       WARNING: CPU: 3 PID: 2840 at arch/x86/kvm/vmx.c:10966 nested_vmx_vmexit+0xdcd/0xde0 [kvm_intel]
       CPU: 3 PID: 2840 Comm: qemu-system-x86 Tainted: G           OE   4.12.0-rc3+ #23
       RIP: 0010:nested_vmx_vmexit+0xdcd/0xde0 [kvm_intel]
       Call Trace:
        ? kvm_check_async_pf_completion+0xef/0x120 [kvm]
        ? rcu_read_lock_sched_held+0x79/0x80
        vmx_queue_exception+0x104/0x160 [kvm_intel]
        ? vmx_queue_exception+0x104/0x160 [kvm_intel]
        kvm_arch_vcpu_ioctl_run+0x1171/0x1ce0 [kvm]
        ? kvm_arch_vcpu_load+0x47/0x240 [kvm]
        ? kvm_arch_vcpu_load+0x62/0x240 [kvm]
        kvm_vcpu_ioctl+0x384/0x7b0 [kvm]
        ? kvm_vcpu_ioctl+0x384/0x7b0 [kvm]
        ? __fget+0xf3/0x210
        do_vfs_ioctl+0xa4/0x700
        ? __fget+0x114/0x210
        SyS_ioctl+0x79/0x90
        do_syscall_64+0x81/0x220
        entry_SYSCALL64_slow_path+0x25/0x25
      
      This is triggered occasionally by running both win7 and win2016 in L2, in
      addition, EPT is disabled on both L1 and L2. It can't be reproduced easily.
      
      Commit 0b6ac343 (KVM: nVMX: Correct handling of exception injection) mentioned
      that "KVM wants to inject page-faults which it got to the guest. This function
      assumes it is called with the exit reason in vmcs02 being a #PF exception".
      Commit e011c663 (KVM: nVMX: Check all exceptions for intercept during delivery to
      L2) allows to check all exceptions for intercept during delivery to L2. However,
      there is no guarantee the exit reason is exception currently, when there is an
      external interrupt occurred on host, maybe a time interrupt for host which should
      not be injected to guest, and somewhere queues an exception, then the function
      nested_vmx_check_exception() will be called and the vmexit emulation codes will
      try to emulate the "Acknowledge interrupt on exit" behavior, the warning is
      triggered.
      
      Reusing the exit reason from the L2->L0 vmexit is wrong in this case,
      the reason must always be EXCEPTION_NMI when injecting an exception into
      L1 as a nested vmexit.
      
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Signed-off-by: default avatarWanpeng Li <wanpeng.li@hotmail.com>
      Fixes: e011c663 ("KVM: nVMX: Check all exceptions for intercept during delivery to L2")
      Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a29fd27c