xen/pv-on-hvm kexec: rebind virqs to existing eventchannel ports

During a kexec boot some virqs such as timer and debugirq were already
registered by the old kernel.  The hypervisor will return -EEXISTS from
the new EVTCHNOP_bind_virq request and the BUG in bind_virq_to_irq()
triggers.  Catch the -EEXISTS error and loop through all possible ports to find
what port belongs to the virq/cpu combo.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
[v2:
  - use NR_EVENT_CHANNELS instead of private MAX_EVTCHNS]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Olaf Hering 2011-08-25 18:30:48 +02:00 committed by Konrad Rzeszutek Wilk
parent c4c303c7c5
commit 62cc5fc7b2

View file

@ -877,11 +877,32 @@ static int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
}
static int find_virq(unsigned int virq, unsigned int cpu)
{
struct evtchn_status status;
int port, rc = -ENOENT;
memset(&status, 0, sizeof(status));
for (port = 0; port <= NR_EVENT_CHANNELS; port++) {
status.dom = DOMID_SELF;
status.port = port;
rc = HYPERVISOR_event_channel_op(EVTCHNOP_status, &status);
if (rc < 0)
continue;
if (status.status != EVTCHNSTAT_virq)
continue;
if (status.u.virq == virq && status.vcpu == cpu) {
rc = port;
break;
}
}
return rc;
}
int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
{
struct evtchn_bind_virq bind_virq;
int evtchn, irq;
int evtchn, irq, ret;
spin_lock(&irq_mapping_update_lock);
@ -897,10 +918,16 @@ int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
bind_virq.virq = virq;
bind_virq.vcpu = cpu;
if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
&bind_virq) != 0)
BUG();
evtchn = bind_virq.port;
ret = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
&bind_virq);
if (ret == 0)
evtchn = bind_virq.port;
else {
if (ret == -EEXIST)
ret = find_virq(virq, cpu);
BUG_ON(ret < 0);
evtchn = ret;
}
xen_irq_info_virq_init(cpu, irq, evtchn, virq);