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7d953a0624
When a device performs DMA to a shared buffer using physical addresses,
(without Stage1 translation), the device must use the "{I}PA address" with the
top bit set in Realm. This is to make sure that a trusted device will be able
to write to shared buffers as well as the protected buffers. Thus, a Realm must
always program the full address including the "protection" bit, like AMD SME
encryption bits.
Enable this by providing arm64 specific dma_addr_{encrypted, canonical}
helpers for Realms. Please note that the VMM needs to similarly make sure that
the SMMU Stage2 in the Non-secure world is setup accordingly to map IPA at the
unprotected alias.
Cc: Will Deacon <will@kernel.org>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Fixes: 42be24a417 ("arm64: Enable memory encrypt for Realms")
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250227144150.1667735-4-suzuki.poulose@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.