On 6/23/2022 3:23 PM, Joerg Roedel wrote:
On Wed, Jun 22, 2022 at 12:11:31PM -0500, Suravee Suthikulpanit wrote:bool amd_iommu_v2_supported(void) { - return amd_iommu_v2_present; + /* + * Since DTE[Mode]=0 is prohibited on SNP-enabled system + * (i.e. EFR[SNPSup]=1), IOMMUv2 page table cannot be used without + * setting up IOMMUv1 page table. + */ + return amd_iommu_v2_present && !amd_iommu_snp_en;IOMMU_v2 APIs could actually be supported with GIOV and IOMMUv2 page-tables in-use, no?
We can support IOMMUv2 iff the v1 table is also setup (i.e. DTE[Mode] != 0). Currently w/ IOMMU_v2 APIs, the IOMMU sets the mode to zero. Therefore, we cannot support this use case. Best Regards, Suravee _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
