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authorJoerg Roedel <jroedel@suse.de>2024-09-05 09:22:40 +0200
committerJoerg Roedel <jroedel@suse.de>2024-09-10 11:48:57 +0200
commitf0295913c4b4f377c454e06f50c1a04f2f80d9df (patch)
treeef3a288f6f08cdcc87dc87a515b59637774265a2 /mm
parent2910a7fa1be090fc7637cef0b2e70bcd15bf5469 (diff)
iommu/amd: Add kernel parameters to limit V1 page-sizes
Add two new kernel command line parameters to limit the page-sizes used for v1 page-tables: nohugepages - Limits page-sizes to 4KiB v2_pgsizes_only - Limits page-sizes to 4Kib/2Mib/1GiB; The same as the sizes used with v2 page-tables This is needed for multiple scenarios. When assigning devices to SEV-SNP guests the IOMMU page-sizes need to match the sizes in the RMP table, otherwise the device will not be able to access all shared memory. Also, some ATS devices do not work properly with arbitrary IO page-sizes as supported by AMD-Vi, so limiting the sizes used by the driver is a suitable workaround. All-in-all, these parameters are only workarounds until the IOMMU core and related APIs gather the ability to negotiate the page-sizes in a better way. Signed-off-by: Joerg Roedel <jroedel@suse.de> Reviewed-by: Vasant Hegde <vasant.hegde@amd.com> Link: https://lore.kernel.org/r/20240905072240.253313-1-joro@8bytes.org
Diffstat (limited to 'mm')
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