/*
* This function is called to ensure that a vcpu "sees" a pending event
* as soon as possible:
* - If the vcpu thread is sleeping then it is woken up.
* - If the vcpu is running on a different host_cpu then an IPI will be directed
* to the host_cpu to cause the vcpu to trap into the hypervisor.
*/
void
vcpu_notify_event(struct vm *vm, int vcpuid, bool lapic_intr)
{
int hostcpu;
struct vcpu *vcpu;
vcpu = &vm->vcpu[vcpuid];
vcpu_lock(vcpu);
hostcpu = vcpu->hostcpu;
if (vcpu->state == VCPU_RUNNING) {
KASSERT(hostcpu != NOCPU, ("vcpu running on invalid hostcpu"));
if (hostcpu != curcpu) {
if (lapic_intr) {
vlapic_post_intr(vcpu->vlapic, hostcpu,
vmm_ipinum);
} else {
ipi_cpu(hostcpu, vmm_ipinum);
}
} else {
/*
* If the 'vcpu' is running on 'curcpu' then it must
* be sending a notification to itself (e.g. SELF_IPI).
* The pending event will be picked up when the vcpu
* transitions back to guest context.
*/
}
} else {
KASSERT(hostcpu == NOCPU, ("vcpu state %d not consistent "
"with hostcpu %d", vcpu->state, hostcpu));
if (vcpu->state == VCPU_SLEEPING)
wakeup_one(vcpu);
}
vcpu_unlock(vcpu);
}
void
forward_signal(struct thread *td)
{
int id;
/*
* signotify() has already set TDF_ASTPENDING and TDF_NEEDSIGCHECK on
* this thread, so all we need to do is poke it if it is currently
* executing so that it executes ast().
*/
THREAD_LOCK_ASSERT(td, MA_OWNED);
KASSERT(TD_IS_RUNNING(td),
("forward_signal: thread is not TDS_RUNNING"));
CTR1(KTR_SMP, "forward_signal(%p)", td->td_proc);
if (!smp_started || cold || panicstr)
return;
if (!forward_signal_enabled)
return;
/* No need to IPI ourself. */
if (td == curthread)
return;
id = td->td_oncpu;
if (id == NOCPU)
return;
ipi_cpu(id, IPI_AST);
}
