xen: handled remapped IRQs when enabling a pcifront PCI device.
This happens to not be an issue currently because we take pains to try
to ensure that the GSI-IRQ mapping is 1-1 in a PV guest and that
regular event channels do not clash. However a subsequent patch is
going to break this 1-1 mapping.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index 25cd4a0..2a12f3d 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -226,21 +226,27 @@
{
int rc;
int share = 1;
+ u8 gsi;
- dev_info(&dev->dev, "Xen PCI enabling IRQ: %d\n", dev->irq);
-
- if (dev->irq < 0)
- return -EINVAL;
-
- if (dev->irq < NR_IRQS_LEGACY)
- share = 0;
-
- rc = xen_allocate_pirq(dev->irq, share, "pcifront");
+ rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);
if (rc < 0) {
- dev_warn(&dev->dev, "Xen PCI IRQ: %d, failed to register:%d\n",
- dev->irq, rc);
+ dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n",
+ rc);
return rc;
}
+
+ if (gsi < NR_IRQS_LEGACY)
+ share = 0;
+
+ rc = xen_allocate_pirq(gsi, share, "pcifront");
+ if (rc < 0) {
+ dev_warn(&dev->dev, "Xen PCI: failed to register GSI%d: %d\n",
+ gsi, rc);
+ return rc;
+ }
+
+ dev->irq = rc;
+ dev_info(&dev->dev, "Xen PCI mapped GSI%d to IRQ%d\n", gsi, dev->irq);
return 0;
}
