On Wed, Jan 06, 2021, Maxim Levitsky wrote: > If migration happens while L2 entry with an injected event to L2 is pending, > we weren't including the event in the migration state and it would be > lost leading to L2 hang.
But the injected event should still be in vmcs12 and KVM_STATE_NESTED_RUN_PENDING should be set in the migration state, i.e. it should naturally be copied to vmcs02 and thus (re)injected by vmx_set_nested_state(). Is nested_run_pending not set? Is the info in vmcs12 somehow lost? Or am I off in left field... > Fix this by queueing the injected event in similar manner to how we queue > interrupted injections. > > This can be reproduced by running an IO intense task in L2, > and repeatedly migrating the L1. > > Suggested-by: Paolo Bonzini <[email protected]> > Signed-off-by: Maxim Levitsky <[email protected]> > --- > arch/x86/kvm/vmx/nested.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c > index e2f26564a12de..2ea0bb14f385f 100644 > --- a/arch/x86/kvm/vmx/nested.c > +++ b/arch/x86/kvm/vmx/nested.c > @@ -2355,12 +2355,12 @@ static void prepare_vmcs02_early(struct vcpu_vmx > *vmx, struct vmcs12 *vmcs12) > * Interrupt/Exception Fields > */ > if (vmx->nested.nested_run_pending) { > - vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, > - vmcs12->vm_entry_intr_info_field); > - vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE, > - vmcs12->vm_entry_exception_error_code); > - vmcs_write32(VM_ENTRY_INSTRUCTION_LEN, > - vmcs12->vm_entry_instruction_len); > + if ((vmcs12->vm_entry_intr_info_field & > VECTORING_INFO_VALID_MASK)) > + vmx_process_injected_event(&vmx->vcpu, > + > vmcs12->vm_entry_intr_info_field, > + > vmcs12->vm_entry_instruction_len, > + > vmcs12->vm_entry_exception_error_code); > + > vmcs_write32(GUEST_INTERRUPTIBILITY_INFO, > vmcs12->guest_interruptibility_info); > vmx->loaded_vmcs->nmi_known_unmasked = > -- > 2.26.2 >
