Improve the handling of cpuset with interrupts.

- For x86, change the interrupt source method to assign an interrupt source
  to a specific CPU to return an error value instead of void, thus allowing
  it to fail.
- If moving an interrupt to a CPU fails due to a lack of IDT vectors in the
  destination CPU, fail the request with ENOSPC rather than panicing.
- For MSI interrupts on x86 (but not MSI-X), only allow cpuset to be used
  on the first interrupt in a group.  Moving the first interrupt in a group
  moves the entire group.
- Use the icu_lock to protect intr_next_cpu() on x86 instead of the
  intr_table_lock to fix a LOR introduced in the last set of MSI changes.
- Add a new privilege PRIV_SCHED_CPUSET_INTR for using cpuset with
  interrupts.  Previously, binding an interrupt to a CPU only performed a
  privilege check if the interrupt had an interrupt thread.  Interrupts
  without a thread could be bound by non-root users as a result.
- If an interrupt event's assign_cpu method fails, then restore the original
  cpuset mask for the associated interrupt thread.

Approved by:	re (kib)

0 files changed, 0 insertions, 0 deletions