I get these messages on boot-up.
Sep 28 11:30:17 localhost /usr/sbin/irqbalance: WARNING: MSI interrupts found in /proc/interrupts
Sep 28 11:30:17 localhost /usr/sbin/irqbalance: But none found in sysfs, you need to update your kernel
Sep 28 11:30:17 localhost /usr/sbin/irqbalance: Until then, IRQs will be improperly classified
Description: Ubuntu quantal (development branch) (beta 2)
Release: 12.10
joey@warthog:~$ sudo lshw |grep msi
capabilities: pci msi pciexpress pm normal_decode bus_master cap_list
capabilities: pci msi pciexpress pm normal_decode bus_master cap_list
capabilities: pm msi pciexpress vga_controller bus_master cap_list rom
capabilities: pci msi pciexpress pm normal_decode bus_master cap_list
capabilities: pm msi pciexpress bus_master cap_list
capabilities: pci pciexpress msi pm normal_decode bus_master cap_list
capabilities: pm msi pciexpress msix vpd bus_master cap_list rom ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
capabilities: pci pciexpress msi pm normal_decode bus_master cap_list
capabilities: storage msi pm bus_master cap_list
Linux warthog 3.5.0-16-generic #24-Ubuntu SMP Thu Sep 27 23:57:26 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux