Messages in this thread | | | Subject | Re: [PATCH v2] nvme: allow 64-bit results in passthru commands | From | James Smart <> | Date | Mon, 19 Aug 2019 08:57:01 -0700 |
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On 8/19/2019 7:49 AM, Keith Busch wrote: > On Mon, Aug 19, 2019 at 12:06:23AM -0700, Marta Rybczynska wrote: >> ----- On 16 Aug, 2019, at 15:16, Christoph Hellwig hch@lst.de wrote: >>> Sorry for not replying to the earlier version, and thanks for doing >>> this work. >>> >>> I wonder if instead of using our own structure we'd just use >>> a full nvme SQE for the input and CQE for that output. Even if we >>> reserve a few fields that means we are ready for any newly used >>> field (at least until the SQE/CQE sizes are expanded..). >> We could do that, nvme_command and nvme_completion are already UAPI. >> On the other hand that would mean not filling out certain fields like >> command_id. Can do an approach like this. > Well, we need to pass user space addresses and lengths, which isn't > captured in struct nvme_command. > This is going to be fun. It's going to have to be a cooperative effort between app and transport. There will always need to be some parts of the SQE filled out by the transport like SGL, command type/subtype bits, as well as dealing with buffers as Keith states. Command ID is another of those fields.
-- james
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