From: Leon Romanovsky <leon@kernel.org>
To: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Pirko <jiri@resnulli.us>,
dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org,
iommu@lists.linux.dev, linux-media@vger.kernel.org,
sumit.semwal@linaro.org, benjamin.gaignard@collabora.com,
Brian.Starkey@arm.com, jstultz@google.com, tjmercier@google.com,
christian.koenig@amd.com, m.szyprowski@samsung.com,
robin.murphy@arm.com, sean.anderson@linux.dev, ptesarik@suse.com,
catalin.marinas@arm.com, aneesh.kumar@kernel.org,
suzuki.poulose@arm.com, steven.price@arm.com,
thomas.lendacky@amd.com, john.allen@amd.com,
ashish.kalra@amd.com, suravee.suthikulpanit@amd.com,
linux-coco@lists.linux.dev
Subject: Re: [PATCH net-next v3 1/2] dma-mapping: introduce DMA_ATTR_CC_DECRYPTED for pre-decrypted memory
Date: Mon, 9 Mar 2026 16:02:33 +0200 [thread overview]
Message-ID: <20260309140233.GW12611@unreal> (raw)
In-Reply-To: <20260309131530.GJ1687929@ziepe.ca>
On Mon, Mar 09, 2026 at 10:15:30AM -0300, Jason Gunthorpe wrote:
> On Sun, Mar 08, 2026 at 12:19:48PM +0200, Leon Romanovsky wrote:
>
> > > +/*
> > > + * DMA_ATTR_CC_DECRYPTED: Indicates memory that has been explicitly decrypted
> > > + * (shared) for confidential computing guests. The caller must have
> > > + * called set_memory_decrypted(). A struct page is required.
> > > + */
> > > +#define DMA_ATTR_CC_DECRYPTED (1UL << 12)
> >
> > While adding the new attribute is fine, I would expect additional checks in
> > dma_map_phys() to ensure the attribute cannot be misused. For example,
> > WARN_ON(attrs & (DMA_ATTR_CC_DECRYPTED | DMA_ATTR_MMIO)), along with a check
> > that we are taking the direct path only.
>
> DECRYPYED and MMIO is something that needs to work, VFIO (inside a
> TVM) should be using that combination.
So this sentence "A struct page is required" from the comment above is
not accurate.
Thanks
>
> Jason
next prev parent reply other threads:[~2026-03-09 14:02 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-05 12:36 [PATCH net-next v3 0/2] dma-buf: heaps: system: add an option to allocate explicitly decrypted memory Jiri Pirko
2026-03-05 12:36 ` [PATCH net-next v3 1/2] dma-mapping: introduce DMA_ATTR_CC_DECRYPTED for pre-decrypted memory Jiri Pirko
2026-03-08 10:19 ` Leon Romanovsky
2026-03-09 8:57 ` Jiri Pirko
2026-03-09 13:15 ` Jason Gunthorpe
2026-03-09 14:02 ` Leon Romanovsky [this message]
2026-03-09 15:18 ` Jason Gunthorpe
2026-03-09 17:51 ` Jiri Pirko
2026-03-12 0:34 ` Jason Gunthorpe
2026-03-12 9:03 ` Jiri Pirko
2026-03-12 12:06 ` Jason Gunthorpe
2026-03-12 13:27 ` Jiri Pirko
2026-03-09 12:56 ` Petr Tesarik
2026-03-09 13:01 ` Jiri Pirko
2026-03-09 13:17 ` Jason Gunthorpe
2026-03-11 14:19 ` Jiri Pirko
2026-03-05 12:36 ` [PATCH net-next v3 2/2] dma-buf: heaps: system: add system_cc_decrypted heap for explicitly decrypted memory Jiri Pirko
2026-03-09 15:39 ` Peter Gonda
2026-03-09 15:50 ` Jason Gunthorpe
2026-03-05 12:40 ` [PATCH net-next v3 0/2] dma-buf: heaps: system: add an option to allocate " Jiri Pirko
2026-03-17 13:24 ` Mostafa Saleh
2026-03-17 13:37 ` Jiri Pirko
2026-03-17 15:40 ` Mostafa Saleh
2026-03-24 12:00 ` Jason Gunthorpe
2026-03-24 12:14 ` Mostafa Saleh
2026-03-24 12:24 ` Jason Gunthorpe
2026-03-24 17:36 ` Mostafa Saleh
2026-03-24 17:57 ` Jason Gunthorpe
2026-03-24 18:32 ` Mostafa Saleh
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