Re: [PATCH v5 04/15] iommupt: Add the AMD IOMMU v1 page table format

Jason Gunthorpe
2025-10-08T13:08:22Z

On Wed, Oct 08, 2025 at 03:13:32PM +0530, Vasant Hegde wrote:
> Jason,
>
> On 9/3/2025 11:16 PM, Jason Gunthorpe wrote:
> > AMD IOMMU v1 is unique in supporting contiguous pages with a variable size
> > and it can decode the full 64 bit VA space. Unlike other x86 page tables
> > this explicitly does not do sign extension as part of allowing the entire
> > 64 bit VA space to be supported.
>
> I am still catching up w/ entire series.. But here is few fixes needed to boot
> this series w/ SME.

I got them all, like this - thanks a lot!

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 92095fd17b3899..0b97db94c8c4e0 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -2054,7 +2054,7 @@ static void set_dte_entry(struct amd_iommu *iommu,
&pt_info);
}

- new.data[0] |= pt_info.host_pt_root |
+ new.data[0] |= __sme_set(pt_info.host_pt_root) |
(pt_info.mode & DEV_ENTRY_MODE_MASK)
<< DEV_ENTRY_MODE_SHIFT;
}
@@ -2166,7 +2166,7 @@ static int init_gcr3_table(struct iommu_dev_data *dev_data,
return ret;

pt_iommu_x86_64_hw_info(&pdom->amdv2, &pt_info);
- ret = update_gcr3(dev_data, 0, pt_info.gcr3_pt, true);
+ ret = update_gcr3(dev_data, 0, __sme_set(pt_info.gcr3_pt), true);
if (ret)
free_gcr3_table(&dev_data->gcr3_info);

diff --git a/drivers/iommu/generic_pt/fmt/amdv1.h b/drivers/iommu/generic_pt/fmt/amdv1.h
index d7660d4170ef78..26e29b08a9b4ae 100644
--- a/drivers/iommu/generic_pt/fmt/amdv1.h
+++ b/drivers/iommu/generic_pt/fmt/amdv1.h
@@ -73,22 +73,29 @@ enum {

static inline pt_oaddr_t amdv1pt_table_pa(const struct pt_state *pts)
{
- return oalog2_mul(FIELD_GET(AMDV1PT_FMT_OA, pts->entry),
- PT_GRANULE_LG2SZ);
+ u64 entry = pts->entry;
+
+ if (pts_feature(pts, PT_FEAT_AMDV1_ENCRYPT_TABLES))
+ entry = __sme_clr(entry);
+ return oalog2_mul(FIELD_GET(AMDV1PT_FMT_OA, entry), PT_GRANULE_LG2SZ);
}
#define pt_table_pa amdv1pt_table_pa

/* Returns the oa for the start of the contiguous entry */
static inline pt_oaddr_t amdv1pt_entry_oa(const struct pt_state *pts)
{
- pt_oaddr_t oa = FIELD_GET(AMDV1PT_FMT_OA, pts->entry);
+ u64 entry = pts->entry;
+ pt_oaddr_t oa;

- if (FIELD_GET(AMDV1PT_FMT_NEXT_LEVEL, pts->entry) ==
- AMDV1PT_FMT_NL_SIZE) {
+ if (pts_feature(pts, PT_FEAT_AMDV1_ENCRYPT_TABLES))
+ entry = __sme_clr(entry);
+ oa = FIELD_GET(AMDV1PT_FMT_OA, entry);
+
+ if (FIELD_GET(AMDV1PT_FMT_NEXT_LEVEL, entry) == AMDV1PT_FMT_NL_SIZE) {
unsigned int sz_bits = oaffz(oa);

oa = oalog2_set_mod(oa, 0, sz_bits);
- } else if (PT_WARN_ON(FIELD_GET(AMDV1PT_FMT_NEXT_LEVEL, pts->entry) !=
+ } else if (PT_WARN_ON(FIELD_GET(AMDV1PT_FMT_NEXT_LEVEL, entry) !=
AMDV1PT_FMT_NL_DEFAULT))
return 0;
return oalog2_mul(oa, PT_GRANULE_LG2SZ);
diff --git a/drivers/iommu/generic_pt/fmt/x86_64.h b/drivers/iommu/generic_pt/fmt/x86_64.h
index be2a0a770f903f..d33b2fcd865b84 100644
--- a/drivers/iommu/generic_pt/fmt/x86_64.h
+++ b/drivers/iommu/generic_pt/fmt/x86_64.h
@@ -79,14 +79,22 @@ enum {

static inline pt_oaddr_t x86_64_pt_table_pa(const struct pt_state *pts)
{
- return oalog2_mul(FIELD_GET(X86_64_FMT_OA, pts->entry),
+ u64 entry = pts->entry;
+
+ if (pts_feature(pts, PT_FEAT_X86_64_AMD_ENCRYPT_TABLES))
+ entry = __sme_clr(entry);
+ return oalog2_mul(FIELD_GET(X86_64_FMT_OA, entry),
PT_TABLEMEM_LG2SZ);
}
#define pt_table_pa x86_64_pt_table_pa

static inline pt_oaddr_t x86_64_pt_entry_oa(const struct pt_state *pts)
{
- return oalog2_mul(FIELD_GET(X86_64_FMT_OA, pts->entry),
+ u64 entry = pts->entry;
+
+ if (pts_feature(pts, PT_FEAT_X86_64_AMD_ENCRYPT_TABLES))
+ entry = __sme_clr(entry);
+ return oalog2_mul(FIELD_GET(X86_64_FMT_OA, entry),
PT_GRANULE_LG2SZ);
}
#define pt_entry_oa x86_64_pt_entry_oa