From: Jason Gunthorpe <jgg@ziepe.ca>
To: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
Robin Murphy <robin.murphy@arm.com>,
Kevin Tian <kevin.tian@intel.com>,
iommu@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 2/7] iommu/vt-d: Remove identity mappings from si_domain
Date: Tue, 6 Aug 2024 14:05:29 -0300 [thread overview]
Message-ID: <20240806170529.GK676757@ziepe.ca> (raw)
In-Reply-To: <20240806023941.93454-3-baolu.lu@linux.intel.com>
On Tue, Aug 06, 2024 at 10:39:36AM +0800, Lu Baolu wrote:
> As the driver has enforced DMA domains for devices managed by an IOMMU
> hardware that doesn't support passthrough translation mode, there is no
> need for static identity mappings in the si_domain. Remove the identity
> mapping code to avoid dead code.
>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
> drivers/iommu/intel/iommu.c | 122 ++----------------------------------
> 1 file changed, 4 insertions(+), 118 deletions(-)
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
I always wondered why this was so fine grained, I would have expected
it to work on blocks of 512 x 1G, once you allocate a memory for the
1G table level you may as well fill it with identity IOPTEs. The only
optimization point is how many blocks of 512x1G are needed..
Jason
next prev parent reply other threads:[~2024-08-06 17:05 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-06 2:39 [PATCH v3 0/7] iommu/vt-d: Convert to use static identity domain Lu Baolu
2024-08-06 2:39 ` [PATCH v3 1/7] iommu/vt-d: Require DMA domain if hardware not support passthrough Lu Baolu
2024-08-06 16:54 ` Jason Gunthorpe
2024-08-14 16:13 ` Jerry Snitselaar
2024-08-06 2:39 ` [PATCH v3 2/7] iommu/vt-d: Remove identity mappings from si_domain Lu Baolu
2024-08-06 17:05 ` Jason Gunthorpe [this message]
2024-08-07 6:14 ` Baolu Lu
2024-08-06 2:39 ` [PATCH v3 3/7] iommu/vt-d: Always reserve a domain ID for identity setup Lu Baolu
2024-08-06 17:06 ` Jason Gunthorpe
2024-08-07 6:19 ` Baolu Lu
2024-08-07 12:09 ` Jason Gunthorpe
2024-08-07 13:38 ` Baolu Lu
2024-08-14 16:31 ` Jerry Snitselaar
2024-08-06 2:39 ` [PATCH v3 4/7] iommu/vt-d: Prepare for global static identity domain Lu Baolu
2024-08-06 17:12 ` Jason Gunthorpe
2024-08-07 6:41 ` Baolu Lu
2024-08-07 12:17 ` Jason Gunthorpe
2024-08-07 13:44 ` Baolu Lu
2024-08-06 2:39 ` [PATCH v3 5/7] iommu/vt-d: Factor out helpers from domain_context_mapping_one() Lu Baolu
2024-08-06 17:13 ` Jason Gunthorpe
2024-08-14 16:19 ` Jerry Snitselaar
2024-08-06 2:39 ` [PATCH v3 6/7] iommu/vt-d: Add support for static identity domain Lu Baolu
2024-08-06 17:18 ` Jason Gunthorpe
2024-08-06 2:39 ` [PATCH v3 7/7] iommu/vt-d: Cleanup si_domain Lu Baolu
2024-08-06 17:19 ` Jason Gunthorpe
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