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Commit 62cc5fc7 authored by Olaf Hering's avatar Olaf Hering Committed by Konrad Rzeszutek Wilk
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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: default avatarOlaf Hering <olaf@aepfle.de>
[v2:
  - use NR_EVENT_CHANNELS instead of private MAX_EVTCHNS]
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent c4c303c7

drivers/xen/events.c

+32 −5
Original line number Diff line number Diff line
@@ -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();

		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);