2016-01-21 05:33+0000, Wu, Feng:
From: linux-kernel-owner@xxxxxxxxxxxxxxx [mailto:linux-kernel-
owner@xxxxxxxxxxxxxxx] On Behalf Of Yang Zhang
On 2016/1/20 9:42, Feng Wu wrote:
+ /*that
+ * We may find a hardware disabled LAPIC here, if
+ * is the case, print out a error message once for eachinjection\n");
+ * guest and return.
+ */
+ if (!dst[idx-1] &&
+ (kvm->arch.disabled_lapic_found == 0)) {
+ kvm->arch.disabled_lapic_found = 1;
+ printk(KERN_ERR
+ "Disabled LAPIC found during irq
+ goto out;
What does "goto out" mean? Inject successfully or fail? According the
value of ret which is set to ture here, it means inject successfully but
(true actually means that fast path did the job and slow path isn't
needed.)
i = -1.
(I think there isn't a practical difference between *r=-1 and *r=0.)
Oh, I didn't notice 'ret' is initialized to true, I thought it was initialized
to false like another function, I should add a "ret = false' here. We should
failed to inject the interrupt since hardware disabled LAPIC is found.
'ret = true' is the better one. We know that the interrupt is not
deliverable [1], so there's no point in trying to deliver with the slow
path. We behave similarly when the interrupt targets a single disabled
APIC.
---
1: Well ... it's possible that slowpath would deliver it thanks to
different handling of disabled APICs, but it's undefined behavior,
so it doesn't matter matter if we don't try.