[PATCH 0/2] Unprivileged sgl-only passthrough

[Jens Axboe]

On 10/18/23 12:30 PM, Kanchan Joshi wrote:
> Patch 1: Prep. Adds the meta-transfer ability in nvme-pci
> Patch 2: Enables fine-granular passthrough with the change that i/o
> commands can transfer the data only via SGL.
> 
> Requirement:
> - Prepared against block 6.6 tree.
> - The patch in uring-passthrough failure handling is required to see the
>   submission failure (if any)
>   https://lore.kernel.org/linux-nvme/20231018135718.28820-1-joshi.k@samsung.com/

I didn't have time to follow the previous discussion, but what's the
reasoning behind allowing it for SGL only? IIRC, we do have an inline
vec for a small number of vecs, so presumably this would not hit
alloc+free for each IO? But even so, I would imagine that SGL is slower
than PRP? Do we know how much?

-- 
Jens Axboe