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xen: use PHYSDEVOP_get_free_pirq to implement find_unbound_pirq

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Use the new hypercall PHYSDEVOP_get_free_pirq to ask Xen to allocate a
pirq. Remove the unsupported PHYSDEVOP_get_nr_pirqs hypercall to get the
amount of pirq available.

This fixes find_unbound_pirq that otherwise would return a number
starting from nr_irqs that might very well be out of range in Xen.

The symptom of this bug is that when you passthrough an MSI capable pci
device to a PV on HVM guest, Linux would fail to enable MSIs on the
device.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
This commit is contained in:
Stefano Stabellini 2010-12-01 14:51:44 +00:00
parent e8a7e48bb2
commit e5fc734541
2 changed files with 30 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
drivers/xen/events.c
View File

@ -105,7 +105,6 @@ struct irq_info
static struct irq_info *irq_info;
static int *pirq_to_irq;
static int nr_pirqs;
static int *evtchn_to_irq;
struct cpu_evtchn_s {
@ -385,12 +384,17 @@ static int get_nr_hw_irqs(void)
return ret;
}
/* callers of this function should make sure that PHYSDEVOP_get_nr_pirqs
* succeeded otherwise nr_pirqs won't hold the right value */
static int find_unbound_pirq(void)
static int find_unbound_pirq(int type)
{
int i;
for (i = nr_pirqs-1; i >= 0; i--) {
int rc, i;
struct physdev_get_free_pirq op_get_free_pirq;
op_get_free_pirq.type = type;
rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
if (!rc)
return op_get_free_pirq.pirq;
for (i = 0; i < nr_irqs; i++) {
if (pirq_to_irq[i] < 0)
return i;
}
@ -611,10 +615,10 @@ int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int shareable, char *name)
spin_lock(&irq_mapping_update_lock);
if ((pirq > nr_pirqs) || (gsi > nr_irqs)) {
if ((pirq > nr_irqs) || (gsi > nr_irqs)) {
printk(KERN_WARNING "xen_map_pirq_gsi: %s %s is incorrect!\n",
pirq > nr_pirqs ? "nr_pirqs" :"",
gsi > nr_irqs ? "nr_irqs" : "");
pirq > nr_irqs ? "pirq" :"",
gsi > nr_irqs ? "gsi" : "");
goto out;
}
@ -672,7 +676,7 @@ void xen_allocate_pirq_msi(char *name, int *irq, int *pirq)
if (*irq == -1)
goto out;
*pirq = find_unbound_pirq();
*pirq = find_unbound_pirq(MAP_PIRQ_TYPE_MSI);
if (*pirq == -1)
goto out;
@ -1506,26 +1510,17 @@ void xen_callback_vector(void) {}
void __init xen_init_IRQ(void)
{
int i, rc;
struct physdev_nr_pirqs op_nr_pirqs;
int i;
cpu_evtchn_mask_p = kcalloc(nr_cpu_ids, sizeof(struct cpu_evtchn_s),
GFP_KERNEL);
irq_info = kcalloc(nr_irqs, sizeof(*irq_info), GFP_KERNEL);
rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_nr_pirqs, &op_nr_pirqs);
if (rc < 0) {
nr_pirqs = nr_irqs;
if (rc != -ENOSYS)
printk(KERN_WARNING "PHYSDEVOP_get_nr_pirqs returned rc=%d\n", rc);
} else {
if (xen_pv_domain() && !xen_initial_domain())
nr_pirqs = max((int)op_nr_pirqs.nr_pirqs, nr_irqs);
else
nr_pirqs = op_nr_pirqs.nr_pirqs;
}
pirq_to_irq = kcalloc(nr_pirqs, sizeof(*pirq_to_irq), GFP_KERNEL);
for (i = 0; i < nr_pirqs; i++)
/* We are using nr_irqs as the maximum number of pirq available but
* that number is actually chosen by Xen and we don't know exactly
* what it is. Be careful choosing high pirq numbers. */
pirq_to_irq = kcalloc(nr_irqs, sizeof(*pirq_to_irq), GFP_KERNEL);
for (i = 0; i < nr_irqs; i++)
pirq_to_irq[i] = -1;
evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),

10
include/xen/interface/physdev.h
View File

@ -188,6 +188,16 @@ struct physdev_nr_pirqs {
uint32_t nr_pirqs;
};
/* type is MAP_PIRQ_TYPE_GSI or MAP_PIRQ_TYPE_MSI
* the hypercall returns a free pirq */
#define PHYSDEVOP_get_free_pirq 23
struct physdev_get_free_pirq {
/* IN */
int type;
/* OUT */
uint32_t pirq;
};
/*
* Notify that some PIRQ-bound event channels have been unmasked.
* ** This command is obsolete since interface version 0x00030202 and is **