Fwd: Re: [PATCH] Add irqdevice interface + userint implementation

Gregory Haskins
2007-04-10T15:53:58Z

>>> On Tue, Apr 10, 2007 at 11:39 AM, in message <461B7755.BA47.005A.0-Et1tbQHTxzrQT0dZR+AlfA@public.gmane.org>,
Gregory Haskins wrote:
> We could change the API to handle the pending condition as a tri-level

I just thought of a better way. Leave the return value as a boolean, but use the concept of the mask_reasons. It simplifies the logic, and allows the irqdevice to register for additional VMEXITs regardless of whether its currently injecting something or not. So we have:

spin_lock(vcpu- >irq_lock)
vcpu->exit_reasons = 0;
nmi = !irq_window_open(vcpu)
if (vcpu- >irq- >pending(nmi, &mask_reasons))
inject(vcpu, vcpu- >irq- >read_vector(nmi))
if (mask_reasons) {
if (mask_reasons & MASKREASON_TPR)
vcpu->exit_reasons &= TPR;
/* etc */
}
spin_unlock(vcpu- >irq_lock)