Re: vio12: cannot alloc q0 intr: 12 / couldn't establish msix interrupt

On 03/12/2025 16:02, Crystal Kolipe wrote:
> On Wed, Dec 03, 2025 at 03:17:07PM +0200, Kapetanakis Giannis wrote:
>> Is there a limit on number of vio devices?
> Not exactly a limit on vio devices - in this case you seem to be exceeding the
> number of available interrupt vectors.


Is this tunable (sysctl) or does it need a custom kernel?

probably something bigger...

the fail comes from intr.c: intr_allocate_slot()
which (to my reading is limited by MAX_INTR_SOURCES)

/*
 * Maximum # of interrupt sources per CPU. 64 to fit in one word.
 * ioapics can theoretically produce more, but it's not likely to
 * happen. For multiple ioapics, things can be routed to different
 * CPUs.
 */
#define MAX_INTR_SOURCES        64
#define NUM_LEGACY_IRQS         16

G