13 Oct
2023
13 Oct
'23
10:14 a.m.
On 10/13/2023 10:56 AM, Christoph Hellwig wrote:
On Fri, Oct 13, 2023 at 10:44:58AM +0530, Kanchan Joshi wrote:
Changes since v3:
- Block only unprivileged user
That's not really what at least I had in mind. I'd much rather completely disable unprivileged passthrough for now as an easy backportable patch. And then only re-enable it later in a way where it does require using SGLs for all data transfers.
I did not get how forcing SGLs can solve the issue at hand. The problem happened because (i) user specified short buffer/len, and (ii) kernel allocated buffer. Whether the buffer is fed to device using PRP or SGL does not seem to solve the large DMA problem.