Commit 15ebbb82 authored by Konrad Rzeszutek Wilk's avatar Konrad Rzeszutek Wilk
Browse files

xen: fix shared irq device passthrough 



In driver/xen/events.c, whether bind_pirq is shareable or not is
determined by desc->action is NULL or not. But in __setup_irq,
startup(irq) is invoked before desc->action is assigned with
new action. So desc->action in startup_irq is always NULL, and
bind_pirq is always not shareable. This results in pt_irq_create_bind
failure when passthrough a device which shares irq to other devices.

This patch doesn't use probing_irq to determine if pirq is shareable
or not, instead set shareable flag in irq_info according to trigger
mode in xen_allocate_pirq. Set level triggered interrupts shareable.
Thus use this flag to set bind_pirq flag accordingly.

[v2: arch/x86/xen/pci.c no more, so file skipped]

Signed-off-by: default avatarWeidong Han <weidong.han@intel.com>
Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent d9a8814f

drivers/xen/events.c

+8 −3
Original line number Diff line number Diff line
@@ -97,6 +97,7 @@ struct irq_info 
	} u;

};

#define PIRQ_NEEDS_EOI	(1 << 0)

#define PIRQ_SHAREABLE	(1 << 1)



static struct irq_info *irq_info;
@@ -445,6 +446,7 @@ static unsigned int startup_pirq(unsigned int irq) 
	struct evtchn_bind_pirq bind_pirq;

	struct irq_info *info = info_for_irq(irq);

	int evtchn = evtchn_from_irq(irq);

	int rc;



	BUG_ON(info->type != IRQT_PIRQ);
@@ -453,8 +455,10 @@ static unsigned int startup_pirq(unsigned int irq) 


	bind_pirq.pirq = irq;

	/* NB. We are happy to share unless we are probing. */

	bind_pirq.flags = probing_irq(irq) ? 0 : BIND_PIRQ__WILL_SHARE;

	if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq) != 0) {

	bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?

					BIND_PIRQ__WILL_SHARE : 0;

	rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);

	if (rc != 0) {

		if (!probing_irq(irq))

			printk(KERN_INFO "Failed to obtain physical IRQ %d\n",

			       irq);
@@ -564,7 +568,7 @@ static int find_irq_by_gsi(unsigned gsi) 
 * event channel until the irq actually started up.  Return an

 * existing irq if we've already got one for the gsi.

 */

int xen_allocate_pirq(unsigned gsi, char *name)

int xen_allocate_pirq(unsigned gsi, int shareable, char *name)

{

	int irq;

	struct physdev_irq irq_op;
@@ -596,6 +600,7 @@ int xen_allocate_pirq(unsigned gsi, char *name) 
	}



	irq_info[irq] = mk_pirq_info(0, gsi, irq_op.vector);

	irq_info[irq].u.pirq.flags |= shareable ? PIRQ_SHAREABLE : 0;



out:

	spin_unlock(&irq_mapping_update_lock);

include/xen/events.h

+1 −1
Original line number Diff line number Diff line
@@ -70,7 +70,7 @@ void xen_hvm_evtchn_do_upcall(void); 
/* Allocate an irq for a physical interrupt, given a gsi.  "Legacy"

 * GSIs are identity mapped; others are dynamically allocated as

 * usual. */

int xen_allocate_pirq(unsigned gsi, char *name);

int xen_allocate_pirq(unsigned gsi, int shareable, char *name);



/* Return vector allocated to pirq */

int xen_vector_from_irq(unsigned pirq);

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