Re: [PATCH v1 03/26] iommu/amd: Don't rely on external callers to enable IOMMU SNP support

Joerg Roedel
2024-01-04T10:58:33Z

On Sat, Dec 30, 2023 at 10:19:31AM -0600, Michael Roth wrote:
> From: Ashish Kalra <ashish.kalra@amd.com>
>
> Currently the expectation is that the kernel will call
> amd_iommu_snp_enable() to perform various checks and set the
> amd_iommu_snp_en flag that the IOMMU uses to adjust its setup routines
> to account for additional requirements on hosts where SNP is enabled.
>
> This is somewhat fragile as it relies on this call being done prior to
> IOMMU setup. It is more robust to just do this automatically as part of
> IOMMU initialization, so rework the code accordingly.
>
> There is still a need to export information about whether or not the
> IOMMU is configured in a manner compatible with SNP, so relocate the
> existing amd_iommu_snp_en flag so it can be used to convey that
> information in place of the return code that was previously provided by
> calls to amd_iommu_snp_enable().
>
> While here, also adjust the kernel messages related to IOMMU SNP
> enablement for consistency/grammar/clarity.
>
> Suggested-by: Borislav Petkov (AMD) <bp@alien8.de>
> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
> Co-developed-by: Michael Roth <michael.roth@amd.com>
> Signed-off-by: Michael Roth <michael.roth@amd.com>

Acked-by: Joerg Roedel <jroedel@suse.de>

--
Jörg Rödel
jroedel@suse.de

SUSE Software Solutions Germany GmbH
Frankenstraße 146
90461 Nürnberg
Germany

(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman