Am 15.12.21 um 14:24 schrieb David Hildenbrand:
On 13.12.21 22:05, Eric Farman wrote:
With KVM_CAP_S390_USER_SIGP, there are only five Signal Processor
orders (CONDITIONAL EMERGENCY SIGNAL, EMERGENCY SIGNAL, EXTERNAL CALL,
SENSE, and SENSE RUNNING STATUS) which are intended for frequent use
and thus are processed in-kernel. The remainder are sent to userspace
with the KVM_CAP_S390_USER_SIGP capability. Of those, three orders
(RESTART, STOP, and STOP AND STORE STATUS) have the potential to
inject work back into the kernel, and thus are asynchronous.
Let's look for those pending IRQs when processing one of the in-kernel
SIGP orders, and return BUSY (CC2) if one is in process. This is in
agreement with the Principles of Operation, which states that only one
order can be "active" on a CPU at a time.
Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Eric Farman <farman@xxxxxxxxxxxxx>
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In general, LGTM. As raised, with SIGP RESTART there are other cases we
could fix in the kernel, but they are of very low priority IMHO.
Does that qualify as an RB, assuming that we can fix the other cases later on?
