Re: swiotlb/caamjr regression (Was: [GIT PULL] (swiotlb) stable/for-linus-5.12)

From: Konrad Rzeszutek Wilk <konrad@darnok.org>
To: 'Dominique MARTINET' <dominique.martinet@atmark-techno.com>
Cc: "Chanho Park" <chanho61.park@samsung.com>,
	"'Jianxiong Gao'" <jxgao@google.com>,
	"'Christoph Hellwig'" <hch@lst.de>,
	"'Konrad Rzeszutek Wilk'" <konrad.wilk@oracle.com>,
	"'Linus Torvalds'" <torvalds@linux-foundation.org>,
	"'Horia Geantă'" <horia.geanta@nxp.com>,
	linux-kernel@vger.kernel.org,
	"'Lukas Hartmann'" <lukas@mntmn.com>,
	"'Aymen Sghaier'" <aymen.sghaier@nxp.com>,
	"'Herbert Xu'" <herbert@gondor.apana.org.au>,
	"'David S. Miller'" <davem@davemloft.net>,
	linux-crypto@vger.kernel.org, iommu@lists.linux-foundation.org,
	"'Marc Orr'" <marcorr@google.com>,
	"'Erdem Aktas'" <erdemaktas@google.com>,
	"'Peter Gonda'" <pgonda@google.com>,
	"'Bumyong Lee'" <bumyong.lee@samsung.com>
Subject: Re: swiotlb/caamjr regression (Was: [GIT PULL] (swiotlb) stable/for-linus-5.12)
Date: Tue, 22 Jun 2021 17:58:14 -0400	[thread overview]
Message-ID: <YNJc9qxeIjy6VuLt@fedora> (raw)
In-Reply-To: <YNGVyOyD+CAMmPos@atmark-techno.com>

On Tue, Jun 22, 2021 at 04:48:24PM +0900, 'Dominique MARTINET' wrote:
> Konrad Rzeszutek Wilk wrote on Mon, Jun 21, 2021 at 09:16:43AM -0400:
> > The beaty of 'devel' and 'linux-next' is that they can be reshuffled and
> > mangled. I pushed them original patch from Bumyong there and will let
> > it sit for a day and then create a stable branch and give it to Linus.
> 
> Thanks, that should be good.
> 
> Do you want me to send a follow-up patch with the two extra checks
> (tlb_addr & (IO_TLB_SIZE -1)) > swiotlb_align_offset(dev, orig_addr)
> tlb_offset < alloc_size
> 
> or are we certain this can't ever happen?

I would love more patches and I saw the previous one you posted.

But we only got two (or one) weeks before the next merge window opens
so I am sending to Linus the one that was tested with NVMe and crypto
(see above).

That is the
https://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb.git/commit/?h=stable/for-linus-5.14

And then after Linus releases the 5.14 - I would love to take your
cleanup on top of that and test it?

> (I didn't see any hit in dmesg when I ran with these, but my opinion is
> better safe than sorry...)
> 
> 
> > Then I need to expand the test-regression bucket so that this does not
> > happen again. Dominique, how easy would it be to purchase one of those
> > devices?
> 
> My company is making such a device, but it's not on the market yet
> (was planned for august, with some delay in approvisionning it'll
> probably be a bit late), and would mean buying from Japan so I'm not
> sure how convenient that would be...
> 
> These are originally NXP devices so I assume Horia would have better
> suggestions, if you would?
> 
> 
> > I was originally thinking to create a crypto device in QEMU to simulate
> > this but that may take longer to write than just getting the real thing.
> > 
> > Or I could create some fake devices with weird offsets and write a driver
> > for it to exercise this.. like this one I had done some time ago that
> > needs some brushing off.
> 
> Just a fake device with fake offsets as a test is probably good enough,
> ideally would need to exerce both failures we've seen (offset in
> dma_sync_single_for_device like caam does and in the original mapping (I
> assume?) like the NVMe driver does), but that sounds possible :)

Yup. Working on that now.
> 
> 
> Thanks again!
> -- 
> Dominique