2017-06-16 21:37 GMT+08:00 Radim Krčmář <[email protected]>: > 2017-06-14 19:26-0700, Wanpeng Li: >> From: Wanpeng Li <[email protected]> >> >> Add an async_page_fault field to vcpu->arch.exception to identify an async >> page fault, and constructs the expected vm-exit information fields. Force >> a nested VM exit from nested_vmx_check_exception() if the injected #PF >> is async page fault. >> >> Cc: Paolo Bonzini <[email protected]> >> Cc: Radim Krčmář <[email protected]> >> Signed-off-by: Wanpeng Li <[email protected]> >> --- >> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >> @@ -452,7 +452,11 @@ EXPORT_SYMBOL_GPL(kvm_complete_insn_gp); >> void kvm_inject_page_fault(struct kvm_vcpu *vcpu, struct x86_exception >> *fault) >> { >> ++vcpu->stat.pf_guest; >> - vcpu->arch.cr2 = fault->address; >> + vcpu->arch.exception.async_page_fault = fault->async_page_fault; > > I think we need to act as if arch.exception.async_page_fault was not > pending in kvm_vcpu_ioctl_x86_get_vcpu_events(). Otherwise, if we > migrate with pending async_page_fault exception, we'd inject it as a > normal #PF, which could confuse/kill the nested guest. > > And kvm_vcpu_ioctl_x86_set_vcpu_events() should clean the flag for > sanity as well.
Do you mean we should add a field like async_page_fault to kvm_vcpu_events::exception, then saves arch.exception.async_page_fault to events->exception.async_page_fault through KVM_GET_VCPU_EVENTS and restores events->exception.async_page_fault to arch.exception.async_page_fault through KVM_SET_VCPU_EVENTS? Regards, Wanpeng Li
