On 17/12/2015 08:17, Gonglei (Arei) wrote: >> On 16/12/2015 11:28, Gonglei (Arei) wrote: >>> I'll move the global nmi_disabled into RTCState, then I have to add a global >> RTCState >>> Variable so that other C files can use the rtc_state->external_nmi_disabled. >> >> Hmm, I think it should be done differently. This is a layering >> violation, the NMI_EN is essentially a pin (qemu_irq) between the ISA >> bridges and the RTC. The NMI "button" is also a component of the ISA > > So, you mean the NMI_EN can only control NMI injection came from ISA bridge? > What's this NMI "button" mean?
The NMI command in the monitor is a "virtual NMI button". >> bridge; you should not need to touch anything except the RTC and the ISA >> bridges, in particular not the APICs. >> > Currently, the qmp command "inject-nmi" doesn't pass ISA bridge. How > do we address this situation? That's step two below: make the ISA bridges implement NMIState. >> First, you need to add a qemu_irq argument to rtc_init. The RTC can >> raise/lower the IRQ on writes to port 0x70. >> >> Second, make the ISA bridges implement NMIState, where the >> implementation of NMIState is similar to inject_nmi in hw/core/nmi.c: >> >> CPU_FOREACH(cs) { >> X86CPU *cpu = X86_CPU(cs); >> >> if (!cpu->apic_state) { >> cpu_interrupt(cs, CPU_INTERRUPT_NMI); >> } else { >> apic_deliver_nmi(cpu->apic_state); >> } >> } >> >> Third, the ISA bridges (hw/isa/piix4.c and hw/isa/lpc_ich9.c) need to > > We don't use hw/isa/piix4.c but hw/pci-host/piix.c in x86 target. Right? Right, I said I had certainly messed up something. :) >> export a qemu_irq for nmi_en IRQ (e.g. using qdev_init_gpio_in_named), >> and you should modify the ISA bridge's implementation of NMIState to >> latch the NMI if you send one while NMIs are disabled. The nmi_en IRQ >> can also trigger an NMI when nmi_en is enabled and an NMI was latched. > > Sorry, I'm a bit confused. The nmi_en can trigger an NMI? Isn't a flag bit > which > can enable/disable the NMI switch? Suppose an NMI was injected with the monitor while nmi_en was disabled. The NMI is then latched, and triggered when you enable NMIs again with nmi_en. Thanks, Paolo