Xen dom0 "interrupt storm detected on "irq16:"; throttling interrupt source"

[Roger Pau Monné]

El 13/05/15 a les 15.48, Eggert, Lars ha escrit:
> isci0: <Intel(R) C600 Series Chipset SAS Controller (SATA mode)> port 0x6000-0x60ff mem 0xde07c000-0xde07ffff,0xddc00000-0xddffffff irq 16 at device 0.0 on pci10
> isci0: attempting to allocate 2 MSI-X vectors (2 supported)
> isci: 1:000089 ISCI bus_alloc_resource failed

This device is sharing the same IRQ#16 with ehci0, and I have a feeling 
it's not properly setting up it's interrupt sources. First, FreeBSD 
Dom0 still doesn't support MSI-X (only MSI), but isci doesn't check the 
errors returned by pci_alloc_msix. I have a patch for FreeBSD which 
might solve it, however I don't have any similar box I can use to test 
it, would you mind giving it a spin?

Thanks, Roger.

---
diff --git a/sys/x86/xen/xen_msi.c b/sys/x86/xen/xen_msi.c
index 0f678b1..181b956 100644
--- a/sys/x86/xen/xen_msi.c
+++ b/sys/x86/xen/xen_msi.c
@@ -114,6 +114,7 @@ int
 xen_msix_alloc(device_t dev, int *irq)
 {
 
+	*irq = -1;
 	return (ENXIO);
 }