Re: PCI passthrough w/ shared IRQ in xen/master

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Fri, Feb 19, 2010 at 10:56:08AM -0500, Michael D Labriola wrote:
> I cannot pass a PCI card w/ a shared IRQ to a domU.
> 
> If my PCI card is in a different slot, and gets a different IRQ, it works. 
>  But in this one particular slot, it gets an IRQ that's shared with a 
> bunch of other bits of gear (USB, firewire, and ATA controller).  With the 
> shared IRQ, not only can I not pass the card to my domU, my dom0 freaks 
> and dies as well...
> 
> Both my dom0 and domU are using the latest xen/master pv_ops kernel and 
> I'm using Xen 3.4.2 (for now).  My domU is a pv domain.

There is a missing patch that I haven't pushed in the pcifront branch:

diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index e138053..923de2e 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -25,7 +25,7 @@ static int xen_pcifront_enable_irq(struct pci_dev *dev)
 	if (dev->irq < 0)
 		return -EINVAL;
 
-	rc = xen_allocate_pirq(dev->irq, 0, "pcifront");
+	rc = xen_allocate_pirq(dev->irq, 1 /* share */, "pcifront");
 	if (rc < 0) {
 		dev_warn(&dev->dev, "Xen PCI IRQ: %d, failed to register:%d\n",
 			 dev->irq, rc);