diff options
| author | Vasant Hegde <vasant.hegde@amd.com> | 2023-02-07 12:17:52 +0300 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2023-02-16 12:45:33 +0300 |
| commit | 18792e99ea2fea27c72eb1ecca1879e5e6be304d (patch) | |
| tree | 1677e048540e1e13fef669bf5d25979453efae99 /drivers/iommu | |
| parent | b6b26d86c61c441144c72f842f7469bb686e1211 (diff) | |
| download | linux-18792e99ea2fea27c72eb1ecca1879e5e6be304d.tar.xz | |
iommu/amd: Do not identity map v2 capable device when snp is enabled
Flow:
- Booted system with SNP enabled, memory encryption off and
IOMMU DMA translation mode
- AMD driver detects v2 capable device and amd_iommu_def_domain_type()
returns identity mode
- amd_iommu_domain_alloc() returns NULL an SNP is enabled
- System will fail to register device
On SNP enabled system, passthrough mode is not supported. IOMMU default
domain is set to translation mode. We need to return zero from
amd_iommu_def_domain_type() so that it allocates translation domain.
Fixes: fb2accadaa94 ("iommu/amd: Introduce function to check and enable SNP")
CC: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20230207091752.7656-1-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/amd/iommu.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 33c134a2b581..80749b99472f 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -2403,12 +2403,17 @@ static int amd_iommu_def_domain_type(struct device *dev) return 0; /* - * Do not identity map IOMMUv2 capable devices when memory encryption is - * active, because some of those devices (AMD GPUs) don't have the - * encryption bit in their DMA-mask and require remapping. + * Do not identity map IOMMUv2 capable devices when: + * - memory encryption is active, because some of those devices + * (AMD GPUs) don't have the encryption bit in their DMA-mask + * and require remapping. + * - SNP is enabled, because it prohibits DTE[Mode]=0. */ - if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT) && dev_data->iommu_v2) + if (dev_data->iommu_v2 && + !cc_platform_has(CC_ATTR_MEM_ENCRYPT) && + !amd_iommu_snp_en) { return IOMMU_DOMAIN_IDENTITY; + } return 0; } |