ENTRY(lg_irq_enable)
/*
* The reverse of irq_disable, this sets lguest_data.irq_enabled to
* X86_EFLAGS_IF (ie. "Interrupts enabled").
*/
movl $X86_EFLAGS_IF, lguest_data+LGUEST_DATA_irq_enabled
/*
* But now we need to check if the Host wants to know: there might have
* been interrupts waiting to be delivered, in which case it will have
* set lguest_data.irq_pending to X86_EFLAGS_IF. If it's not zero, we
* jump to send_interrupts, otherwise we're done.
*/
testl $0, lguest_data+LGUEST_DATA_irq_pending
^^^^^^^^^^^^^^^^^??????????
jnz send_interrupts
/*
* One cool thing about x86 is that you can do many things without using
* a register. In this case, the normal path hasn't needed to save or
* restore any registers at all!
*/
ret
send_interrupts:
TEST with zero will always set ZF. Thus, "jnz send_interrupts" never jumps.
--
vda
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