Re: [PATCH kernel 2/2] crypto/ccp: Allow multiple streams on the same root bridge
From: Alexey Kardashevskiy
Date: Thu Jan 29 2026 - 17:30:14 EST
On 27/1/26 17:59, dan.j.williams@xxxxxxxxx wrote:
Alexey Kardashevskiy wrote:
On 24/1/26 09:59, dan.j.williams@xxxxxxxxx wrote:
Alexey Kardashevskiy wrote:
IDE stream IDs are responsibility of a platform and in some cases
TSM allocates the numbers. AMD SEV TIO though leaves it to the host
OS. Mistakenly stream ID is hard coded to be the same as a traffic
class.
I scratched my head at this comment, but now realize that you are
saying the existing code used the local @tc, not that the hardware
stream ID is in any way related to traffic class, right?
When I did that in the first place, I also wanted to try different
traffic classes so I just took a shortcut here.
It would help to detail what the end user visible effects of this
bug are. The TSM framework does not allow for multiple streams per
PF, so I wonder what scenario is being fixed?
There is no way in the current upstream code to specify this TC so the
only visible effect is that 2 devices under the same bridge can work
now, previously the second device would fail to allocate a stream.
Lastly, are you expecting tsm.git#fixes to pick this up? I am
assuming that this goes through crypto.git and tsm.git can just stay
focused on core fixes.
I was kinda hoping that Tom acks these (as he did) and you could take
them. Thanks,
Ok, so can you refresh the changelog to call out the user visible
effects? Something like:
---
With SEV-TIO the low-level TSM driver is responsible for allocating a
Stream ID. The Stream ID needs to be unique within each IDE partner
port. Fix the Stream ID selection to reuse the host bridge stream
resource id which is a pool of 256 ids per host bridge on AMD platforms.
Otherwise, only one device per-host bridge can establish Selective
Stream IDE.
---
Send a v2, and I will pick it up.
Please squash it in the v1, if possible.
Acked-by: Alexey Kardashevskiy <aik@xxxxxxx>
thanks!
ps sorry missed that on time, I do suck at multitasking :(
--
Alexey