[RFC] CAM pass(4) patch for NVMe

[Warner Losh]

On Tue, Apr 4, 2017 at 2:48 PM, Chuck Tuffli <chuck at tuffli.net> wrote:
> On Tue, Apr 4, 2017 at 11:13 AM, Warner Losh <imp at bsdimp.com> wrote:
> ...
>> Fair Enough. I'd thought 0xffff was the magic number :). However, you
>> raise a good point.
>>
>> Grep tells me all the xflags are actually unused. So we could use it,
>> but after chatting with Scott Long, I'm not sure that we should.
>>
>> However, I think Jim's idea of having a separate command for commands
>> for the I/O queue and commands for the admin queue might be the better
>> part of valor here. I'd initially read Jim's mail as use #defines for
>> the xflags values, but that's not at all what he was saying.
>>
>> The code change would be a bit bigger, but not by a lot. It's super
>> easy to add new XPT_ function code.
>
> OK, I'll head down that path and add a new XPT opcode XPT_NVME_ADMIN
> and helper macro cam_fill_nvmeadmin() which would be used for Admin
> commands. The existing XPT_NVME_IO would be used for NVM/IO commands.
> Both opcodes would use the ccb_nvmeio structure unless there are
> objections .... ?

Seems reasonable to me.

Warner