On 21-02-11 12:00:11, Keith Busch wrote: > On Thu, Feb 11, 2021 at 04:52:52AM +0900, Minwoo Im wrote: > > nvme_inject_state command is to give a controller state to be. > > Human Monitor Interface(HMP) supports users to make controller to a > > specified state of: > > > > normal: Normal state (no injection) > > cmd-interrupted: Commands will be interrupted internally > > > > This patch is just a start to give dynamic command from the HMP to the > > QEMU NVMe device model. If "cmd-interrupted" state is given, then the > > controller will return all the CQ entries with Command Interrupts status > > code. > > > > Usage: > > -device nvme,id=nvme0,.... > > > > (qemu) nvme_inject_state nvme0 cmd-interrupted > > > > <All the commands will be interrupted internally> > > > > (qemu) nvme_inject_state nvme0 normal > > > > This feature is required to test Linux kernel NVMe driver for the > > command retry feature. > > Once the user sets the injected state, all commands return that status > until the user injects the normal state, so the CRD time is meaningless > here. If we're really going this route, the state needs to return to > normal on it's own.
That would also be fine to me. > But I would prefer to see advanced retry tied to real errors that can be > retried, like if we got an EBUSY or EAGAIN errno or something like that. I have seen a thread [1] about ACRE. Forgive me If I misunderstood this thread or missed something after this thread. It looks like CRD field in the CQE can be set for any NVMe error state which means it *may* depend on the device status. And this patch just introduced a internal temporarily error state of the controller by returning Command Intrrupted status. I think, in this stage, we can go with some errors in the middle of the AIO (nvme_aio_err()) for advanced retry. Shouldn't AIO errors are retry-able and supposed to be retried ? > The interface you found to implement this is very interesting though. Thanks, I just wanted to suggest a scheme to inject something to a running NVMe device model for various testing. [1] https://www.spinics.net/lists/dm-devel/msg42165.html
