kvm_vcpu_check_block is called while not in TASK_RUNNING, and therefore cannot sleep. Writing to guest memory is therefore forbidden, but it can happen if kvm_check_nested_events causes a vmexit.
Fortunately, all events that are caught by kvm_check_nested_events are also handled by kvm_vcpu_has_events through vendor callbacks such as kvm_x86_interrupt_allowed or kvm_x86_ops.nested_ops->has_events, so remove the call.
Cc: stable@vger.kernel.org Reported-by: Maxim Levitsky mlevitsk@redhat.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com --- arch/x86/kvm/x86.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d563812ca229..90b4f50b9a84 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10341,9 +10341,6 @@ static inline int vcpu_block(struct kvm_vcpu *vcpu)
static inline bool kvm_vcpu_running(struct kvm_vcpu *vcpu) { - if (is_guest_mode(vcpu)) - kvm_check_nested_events(vcpu); - return (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE && !vcpu->arch.apf.halted); }