Re: [Qemu-block] [PATCH 2/2] nvme: Check PSDT flag for admin and rw command

[Andrew Meir]

Hi Qu Wenruo,

On 06/06/2017 09:38 AM, Qu Wenruo wrote:
> Check PRP or SGL for Data Transfer(PSDT) flag for admin and read/write
> commands.
>
> For NVMe-over-PCIE, admin sq entry should not set SGL bits.
> and rw sq entry PSDT flag should not be set beyond controller support.
>
> Although currently either linux kernel NVMe-over-PCIE host driver uses
> SGL nor qemu nvme controller supports it, it's never a bad idea to
> enhance the check.

Interesting work! By some coincidence, I have a similar need to exercise 
SGL data transfers in NVMe-over-PCIe using a patched host driver and to 
(somehow) test it. I have a forked NVMe driver from the 4.10 kernel, 
supporting SGL data transfers, based partly on this patch:

http://lists.infradead.org/pipermail/linux-nvme/2013-December/000596.html

If you're making some progress, perhaps we can test this forked driver's 
SGL data transfers against QEMU. Drop me a mail if you're interested in 
working together.

Thanks and regards,
Andrew