From: Jason Gunthorpe <jgg@ziepe.ca>
To: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>
Cc: Mostafa Saleh <smostafa@google.com>,
iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev,
Robin Murphy <robin.murphy@arm.com>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
Steven Price <steven.price@arm.com>,
Suzuki K Poulose <Suzuki.Poulose@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Jiri Pirko <jiri@resnulli.us>, Petr Tesarik <ptesarik@suse.com>,
Alexey Kardashevskiy <aik@amd.com>,
Dan Williams <dan.j.williams@intel.com>,
Xu Yilun <yilun.xu@linux.intel.com>,
linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org,
Madhavan Srinivasan <maddy@linux.ibm.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Nicholas Piggin <npiggin@gmail.com>,
"Christophe Leroy (CS GROUP)" <chleroy@kernel.org>,
Alexander Gordeev <agordeev@linux.ibm.com>,
Gerald Schaefer <gerald.schaefer@linux.ibm.com>,
Heiko Carstens <hca@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Christian Borntraeger <borntraeger@linux.ibm.com>,
Sven Schnelle <svens@linux.ibm.com>,
x86@kernel.org
Subject: Re: [PATCH v4 04/13] dma: swiotlb: track pool encryption state and honor DMA_ATTR_CC_SHARED
Date: Thu, 14 May 2026 11:37:33 -0300 [thread overview]
Message-ID: <20260514143733.GB7702@ziepe.ca> (raw)
In-Reply-To: <yq5apl2y5f96.fsf@kernel.org>
On Thu, May 14, 2026 at 06:18:05PM +0530, Aneesh Kumar K.V wrote:
> > There is no problem with non-protected guests as they don't use memory
> > encryption, my initial thought was that th encrpyted/decrypted is
> > per-pool property which is decided by FW (device-tree).
>
> What I meant was that we need a generic way to identify a pKVM guest, so
> that we can use it in the conditional above.
If I understood Mostafa's remarks I think different devices in the
guest need shared/decrypted and some don't? Ie a virtio hypervisor
device needs shared while a real PCI device doesn't? Is that right?
In CC terms that would be a mixture of T=0 and T=1 devices hardwired
and signaled by firwmare..
Ideally we'd have a flow where if the arch precreates a swiotlb pool
with special parameters this overrides all other decision making. Then
this series is about making CC NOT use that flow... ??
Jason
next prev parent reply other threads:[~2026-05-14 14:37 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-12 9:03 [PATCH v4 00/13] dma-mapping: Use DMA_ATTR_CC_SHARED through direct, pool and swiotlb paths Aneesh Kumar K.V (Arm)
2026-05-12 9:03 ` [PATCH v4 01/13] dma-direct: swiotlb: handle swiotlb alloc/free outside __dma_direct_alloc_pages Aneesh Kumar K.V (Arm)
2026-05-13 13:57 ` Mostafa Saleh
2026-05-14 4:54 ` Aneesh Kumar K.V
2026-05-12 9:03 ` [PATCH v4 02/13] dma-direct: use DMA_ATTR_CC_SHARED in alloc/free paths Aneesh Kumar K.V (Arm)
2026-05-13 13:58 ` Mostafa Saleh
2026-05-14 5:01 ` Aneesh Kumar K.V
2026-05-12 9:03 ` [PATCH v4 03/13] dma-pool: track decrypted atomic pools and select them via attrs Aneesh Kumar K.V (Arm)
2026-05-13 14:00 ` Mostafa Saleh
2026-05-14 7:00 ` Aneesh Kumar K.V
2026-05-14 8:06 ` Mostafa Saleh
2026-05-12 9:03 ` [PATCH v4 04/13] dma: swiotlb: track pool encryption state and honor DMA_ATTR_CC_SHARED Aneesh Kumar K.V (Arm)
2026-05-13 14:27 ` Mostafa Saleh
2026-05-13 17:24 ` Jason Gunthorpe
2026-05-14 6:24 ` Aneesh Kumar K.V
2026-05-14 11:48 ` Mostafa Saleh
2026-05-14 12:35 ` Jason Gunthorpe
2026-05-14 14:43 ` Mostafa Saleh
2026-05-14 5:54 ` Aneesh Kumar K.V
2026-05-14 12:02 ` Mostafa Saleh
2026-05-14 12:48 ` Aneesh Kumar K.V
2026-05-14 14:21 ` Mostafa Saleh
2026-05-14 14:43 ` Aneesh Kumar K.V
2026-05-14 14:37 ` Jason Gunthorpe [this message]
2026-05-14 15:43 ` Mostafa Saleh
2026-05-12 9:04 ` [PATCH v4 05/13] dma-mapping: make dma_pgprot() " Aneesh Kumar K.V (Arm)
2026-05-12 9:04 ` [PATCH v4 06/13] dma-direct: pass attrs to dma_capable() for DMA_ATTR_CC_SHARED checks Aneesh Kumar K.V (Arm)
2026-05-12 9:04 ` [PATCH v4 07/13] dma-direct: make dma_direct_map_phys() honor DMA_ATTR_CC_SHARED Aneesh Kumar K.V (Arm)
2026-05-12 9:04 ` [PATCH v4 08/13] dma-direct: set decrypted flag for remapped DMA allocations Aneesh Kumar K.V (Arm)
2026-05-12 9:04 ` [PATCH v4 09/13] dma-direct: select DMA address encoding from DMA_ATTR_CC_SHARED Aneesh Kumar K.V (Arm)
2026-05-12 9:04 ` [PATCH v4 10/13] dma-pool: fix page leak in atomic_pool_expand() cleanup Aneesh Kumar K.V (Arm)
2026-05-12 9:04 ` [PATCH v4 11/13] dma-direct: rename ret to cpu_addr in alloc helpers Aneesh Kumar K.V (Arm)
2026-05-12 9:04 ` [PATCH v4 12/13] dma-direct: return struct page from dma_direct_alloc_from_pool() Aneesh Kumar K.V (Arm)
2026-05-12 9:04 ` [PATCH v4 13/13] x86/amd-gart: preserve the direct DMA address until GART mapping succeeds Aneesh Kumar K.V (Arm)
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