From: Jason Gunthorpe <jgg@ziepe.ca>
To: Zong Li <zong.li@sifive.com>
Cc: Baolu Lu <baolu.lu@linux.intel.com>,
Anup Patel <apatel@ventanamicro.com>,
Tomasz Jeznach <tjeznach@rivosinc.com>,
Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
Robin Murphy <robin.murphy@arm.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
Albert Ou <aou@eecs.berkeley.edu>,
linux@rivosinc.com, linux-kernel@vger.kernel.org,
Sebastien Boeuf <seb@rivosinc.com>,
iommu@lists.linux.dev, Palmer Dabbelt <palmer@dabbelt.com>,
Nick Kossifidis <mick@ics.forth.gr>,
linux-riscv@lists.infradead.org
Subject: Re: [PATCH 03/11] dt-bindings: Add RISC-V IOMMU bindings
Date: Wed, 9 Aug 2023 11:57:49 -0300 [thread overview]
Message-ID: <ZNOpbac4i5zfmHj4@ziepe.ca> (raw)
In-Reply-To: <CANXhq0qMWS_j0n_aUO8BVFSedYCjuMM=Z_tsnK05ZhG+Ob6pqw@mail.gmail.com>
On Thu, Jul 27, 2023 at 10:42:47AM +0800, Zong Li wrote:
> Perhaps this question could be related to the scenarios in which
> devices wish to be in bypass mode when the IOMMU is in translation
> mode, and why IOMMU defines/supports this case. Currently, I could
> envision a scenario where a device is already connected to the IOMMU
> in hardware, but it is not functioning correctly, or there are
> performance impacts. If modifying the hardware is not feasible, a
> default configuration that allows bypass mode could be provided as a
> solution. There might be other scenarios that I might have overlooked.
> It seems to me since IOMMU supports this configuration, it would be
> advantageous to have an approach to achieve it, and DT might be a
> flexible way.
So far we've taken the approach that broken hardware is quirked in the
kernel by matching OF compatible string pattners. This is HW that is
completely broken and the IOMMU doesn't work at all for it.
HW that is slow or whatever is not quirked and this is an admin policy
choice where the system should land on the security/performance
spectrum.
So I'm not sure adding DT makes sense here.
Jason
next prev parent reply other threads:[~2023-08-09 14:57 UTC|newest]
Thread overview: 86+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-19 19:33 [PATCH 00/13] Linux RISC-V IOMMU Support Tomasz Jeznach
2023-07-19 19:33 ` [PATCH 01/11] RISC-V: drivers/iommu: Add RISC-V IOMMU - Ziommu support Tomasz Jeznach
2023-07-19 20:49 ` Conor Dooley
2023-07-19 21:43 ` Tomasz Jeznach
2023-07-20 19:27 ` Conor Dooley
2023-07-21 9:44 ` Conor Dooley
2023-07-20 10:38 ` Baolu Lu
2023-07-20 12:31 ` Baolu Lu
2023-07-20 17:30 ` Tomasz Jeznach
2023-07-28 2:42 ` Zong Li
2023-08-02 20:15 ` Tomasz Jeznach
2023-08-02 20:25 ` Conor Dooley
2023-08-03 3:37 ` Zong Li
2023-08-03 0:18 ` Jason Gunthorpe
2023-08-03 8:27 ` Zong Li
2023-08-16 18:05 ` Robin Murphy
2024-04-13 10:15 ` Xingyou Chen
2023-07-19 19:33 ` [PATCH 02/11] RISC-V: arch/riscv/config: enable RISC-V IOMMU support Tomasz Jeznach
2023-07-19 20:22 ` Conor Dooley
2023-07-19 21:07 ` Tomasz Jeznach
2023-07-20 6:37 ` Krzysztof Kozlowski
2023-07-19 19:33 ` [PATCH 03/11] dt-bindings: Add RISC-V IOMMU bindings Tomasz Jeznach
2023-07-19 20:19 ` Conor Dooley
[not found] ` <CAH2o1u6CZSb7pXcaXmh7dJQmNZYh3uORk4x7vJPrb+uCwFdU5g@mail.gmail.com>
2023-07-19 20:57 ` Conor Dooley
2023-07-19 21:37 ` Rob Herring
2023-07-19 23:04 ` Tomasz Jeznach
2023-07-24 8:03 ` Zong Li
2023-07-24 10:02 ` Anup Patel
2023-07-24 11:31 ` Zong Li
2023-07-24 12:10 ` Anup Patel
2023-07-24 13:23 ` Zong Li
2023-07-26 3:21 ` Baolu Lu
2023-07-26 4:26 ` Zong Li
2023-07-26 12:17 ` Jason Gunthorpe
2023-07-27 2:42 ` Zong Li
2023-08-09 14:57 ` Jason Gunthorpe [this message]
2023-08-15 1:28 ` Zong Li
2023-08-15 18:38 ` Jason Gunthorpe
2023-08-16 2:16 ` Zong Li
2023-08-16 4:10 ` Baolu Lu
2023-07-19 19:33 ` [PATCH 04/11] MAINTAINERS: Add myself for RISC-V IOMMU driver Tomasz Jeznach
2023-07-20 12:42 ` Baolu Lu
2023-07-20 17:32 ` Tomasz Jeznach
2023-07-19 19:33 ` [PATCH 05/11] RISC-V: drivers/iommu/riscv: Add sysfs interface Tomasz Jeznach
2023-07-20 6:38 ` Krzysztof Kozlowski
2023-07-20 18:30 ` Tomasz Jeznach
2023-07-20 21:37 ` Krzysztof Kozlowski
2023-07-20 22:08 ` Conor Dooley
2023-07-21 3:49 ` Tomasz Jeznach
2023-07-20 12:50 ` Baolu Lu
2023-07-20 17:47 ` Tomasz Jeznach
2023-07-19 19:33 ` [PATCH 06/11] RISC-V: drivers/iommu/riscv: Add command, fault, page-req queues Tomasz Jeznach
2023-07-20 3:11 ` Nick Kossifidis
2023-07-20 18:00 ` Tomasz Jeznach
2023-07-20 18:43 ` Conor Dooley
2023-07-24 9:47 ` Zong Li
2023-07-28 5:18 ` Tomasz Jeznach
2023-07-28 8:48 ` Zong Li
2023-07-20 13:08 ` Baolu Lu
2023-07-20 17:49 ` Tomasz Jeznach
2023-07-29 12:58 ` Zong Li
2023-07-31 9:32 ` Nick Kossifidis
2023-07-31 13:15 ` Zong Li
2023-07-31 23:35 ` Nick Kossifidis
2023-08-01 0:37 ` Zong Li
2023-08-02 20:28 ` Tomasz Jeznach
2023-08-02 20:50 ` Tomasz Jeznach
2023-08-03 8:24 ` Zong Li
2023-08-16 18:49 ` Robin Murphy
2023-07-19 19:33 ` [PATCH 07/11] RISC-V: drivers/iommu/riscv: Add device context support Tomasz Jeznach
2023-08-16 19:08 ` Robin Murphy
2023-07-19 19:33 ` [PATCH 08/11] RISC-V: drivers/iommu/riscv: Add page table support Tomasz Jeznach
2023-07-25 13:13 ` Zong Li
2023-07-31 7:19 ` Zong Li
2023-08-16 21:04 ` Robin Murphy
2023-07-19 19:33 ` [PATCH 09/11] RISC-V: drivers/iommu/riscv: Add SVA with PASID/ATS/PRI support Tomasz Jeznach
2023-07-31 9:04 ` Zong Li
2023-07-19 19:33 ` [PATCH 10/11] RISC-V: drivers/iommu/riscv: Add MSI identity remapping Tomasz Jeznach
2023-07-31 8:02 ` Zong Li
2023-08-16 21:43 ` Robin Murphy
2023-07-19 19:33 ` [PATCH 11/11] RISC-V: drivers/iommu/riscv: Add G-Stage translation support Tomasz Jeznach
2023-07-31 8:12 ` Zong Li
2023-08-16 21:13 ` Robin Murphy
[not found] ` <CAHCEehJKYu3-GSX2L6L4_VVvYt1MagRgPJvYTbqekrjPw3ZSkA@mail.gmail.com>
2024-02-23 14:04 ` [PATCH 00/13] Linux RISC-V IOMMU Support Zong Li
2024-04-04 17:37 ` Tomasz Jeznach
2024-04-10 5:38 ` Zong Li
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