Re: [PATCH] drm/ttm: Print the memory decryption status just once

From: Christian König
Date: Thu Apr 18 2024 - 08:26:18 EST


Sorry haven't seen your reply. Feel free to add my rb to the patch.

Regards,
Christian.

Am 18.04.24 um 13:38 schrieb Zack Rusin:
Ping on this one. If we don't want the "_once" then I can quickly
prepare a patch that just removes the logging altogether, because
while useful it's polluting up the kernel logs too much right now so
getting a fix in for 6.9 for this would be great.

z

On Mon, Apr 8, 2024 at 1:46 PM Zack Rusin <zack.rusin@xxxxxxxxxxxx> wrote:
Sorry, apologies to everyone. By accident I replied off the list.
Redoing it now on the list. More below.

On Mon, Apr 8, 2024 at 12:10 PM Christian König
<christian.koenig@xxxxxxx> wrote:
Am 08.04.24 um 18:04 schrieb Zack Rusin:
On Mon, Apr 8, 2024 at 11:59 AM Christian König
<christian.koenig@xxxxxxx> wrote:
Am 08.04.24 um 17:56 schrieb Zack Rusin:
Stop printing the TT memory decryption status info each time tt is created
and instead print it just once.

Reduces the spam in the system logs when running guests with SEV enabled.
Do we then really need this in the first place?
Thomas asked for it just to have an indication when those paths are
being used because they could potentially break things pretty bad. I
think it is useful knowing that those paths are hit (but only once).
It makes it pretty easy for me to tell whether bug reports with people
who report black screen can be answered with "the kernel needs to be
upgraded" ;)
Sounds reasonable, but my expectation was rather that we would print
something on the device level.

If that's not feasible for whatever reason than printing it once works
as well of course.
TBH, I think it's pretty convenient to have the drm_info in the TT
just to make sure that when drivers request use_dma_alloc on SEV
systems TT turns decryption on correctly, i.e. it's a nice sanity
check when reading the logs. But if you'd prefer it in the driver I
can move this logic there as well.

z