On Tue, Nov 07, 2023 at 08:19:31PM +0100, Borislav Petkov wrote:
> Arch code does not call drivers - arch code sets up the arch and
> provides facilities which the drivers use.
IOW (just an example diff):
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 1c9924de607a..00cdbc844961 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -3290,6 +3290,7 @@ static int __init state_next(void)
break;
case IOMMU_ENABLED:
register_syscore_ops(&amd_iommu_syscore_ops);
+ amd_iommu_snp_enable();
ret = amd_iommu_init_pci();
init_state = ret ? IOMMU_INIT_ERROR : IOMMU_PCI_INIT;
break;
@@ -3814,16 +3815,6 @@ int amd_iommu_snp_enable(void)
return -EINVAL;
}
- /*
- * Prevent enabling SNP after IOMMU_ENABLED state because this process
- * affect how IOMMU driver sets up data structures and configures
- * IOMMU hardware.
- */
- if (init_state > IOMMU_ENABLED) {
- pr_err("SNP: Too late to enable SNP for IOMMU.\n");
- return -EINVAL;
- }
-
amd_iommu_snp_en = check_feature_on_all_iommus(FEATURE_SNP);
if (!amd_iommu_snp_en)
return -EINVAL;
and now you only need to line up snp_rmptable_init() after IOMMU init
instead of having it be a fs_initcall which happens right after
pci_subsys_init() so that PCI is there but at the right time when iommu
init state is at IOMMU_ENABLED but no later because then it is too late.
And there you need to test amd_iommu_snp_en which is already exported
anyway.
Ok?
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
