Remove kasserts and move memset to central location

OK. I had that in because most (all?) calls to this function do a KASSERT(cmd != NULL) immediately afterwards. Should I delete those KASSERTs as well?

Address review feedback

You are correct. I had (mistakenly) convinced myself that pattern occurred in more places. I'll move as suggested and delete the occurrence in amdvi_inv_domain

Other functions call amdvi_get_cmd_tail() prior to calling the functions which would then format the command entry. Putting the memset() in amdvi_get_cmd_tail() would clear the command entry twice.

This patch worked for me as well and doesn't seem to bother Windows guest, but they don't seem to need it like the Linux ones do.

Address doc feedback

@mav beat me to the fix.

Testing with an unmodified Linux nvme-cli fails without the noted change masking cmd. Fix that, and this LGTM. Thanks for all the integration!

Testing with an unmodified Linux nvme-cli looks good using this patch rebased on top of my device alias changes.

LGTM

This looks good and helps explain (with examples) a common NVMe stumbling block.

Handful of nits, but overall, LGTM!

amazeballs!

LGTM

Not familiar with this driver, but the changes look OK to me.

LGTM, but I'll give other folks a chance to peek

Updated per review comments

When nda turns off reporting, how are pass-through commands treated? Will this change suppress errors from those commands as well?

If you are looking to add more flag values, I'd move this to after retries and change the type to uint32_t or uint16_t if you think more might be needed in the future.

I like @jhb 's table approach but would prefer the shorter string (i.e., RESERVATION REGISTER vs NVME_OPC_RESERVATION_REGISTER