iommupt: Add a mock pagetable format for iommufd selftest to use

The iommufd self test uses an xarray to store the pfns and their orders to
emulate a page table. Slightly modify the amdv1 page table to create a
real page table that has similar properties:

 - 2k base granule to simulate something like a 4k page table on a 64K
   PAGE_SIZE ARM system
 - Contiguous page support for every PFN order
 - Dirty tracking

AMDv1 is the closest format, as it is the only one that already supports
every page size. Tweak it to have only 5 levels and an 11 bit base granule
and compile it separately as a format variant.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Samiullah Khawaja <skhawaja@google.com>
Tested-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
Tested-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

diff --git a/drivers/iommu/generic_pt/fmt/Makefile b/drivers/iommu/generic_pt/fmt/Makefile
index 32f3956c7509f8434c420267ac5a6642ebed5f5a..f0c22cf5f7bee6dab6644cef4cf0fb9d4e0e8e04 100644 (file)
--- a/drivers/iommu/generic_pt/fmt/Makefile
+++ b/drivers/iommu/generic_pt/fmt/Makefile
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
 iommu_pt_fmt-$(CONFIG_IOMMU_PT_AMDV1) += amdv1
+iommu_pt_fmt-$(CONFIG_IOMMUFD_TEST) += mock
 
 IOMMU_PT_KUNIT_TEST :=
 define create_format

diff --git a/drivers/iommu/generic_pt/fmt/amdv1.h b/drivers/iommu/generic_pt/fmt/amdv1.h
index aaf76bfd21dadc6f51a37e0b65daf8193785bf25..aa8e1a8ec95fdea36b7b62f299ff094b194d9c88 100644 (file)
--- a/drivers/iommu/generic_pt/fmt/amdv1.h
+++ b/drivers/iommu/generic_pt/fmt/amdv1.h
@@ -26,11 +26,23 @@
 #include <linux/string.h>
 
 enum {
-       PT_MAX_OUTPUT_ADDRESS_LG2 = 52,
-       PT_MAX_VA_ADDRESS_LG2 = 64,
        PT_ITEM_WORD_SIZE = sizeof(u64),
+       /*
+        * The IOMMUFD selftest uses the AMDv1 format with some alterations It
+        * uses a 2k page size to test cases where the CPU page size is not the
+        * same.
+        */
+#ifdef AMDV1_IOMMUFD_SELFTEST
+       PT_MAX_VA_ADDRESS_LG2 = 56,
+       PT_MAX_OUTPUT_ADDRESS_LG2 = 51,
+       PT_MAX_TOP_LEVEL = 4,
+       PT_GRANULE_LG2SZ = 11,
+#else
+       PT_MAX_VA_ADDRESS_LG2 = 64,
+       PT_MAX_OUTPUT_ADDRESS_LG2 = 52,
        PT_MAX_TOP_LEVEL = 5,
        PT_GRANULE_LG2SZ = 12,
+#endif
        PT_TABLEMEM_LG2SZ = 12,
 
        /* The DTE only has these bits for the top phyiscal address */
@@ -374,6 +386,7 @@ static inline int amdv1pt_iommu_fmt_init(struct pt_iommu_amdv1 *iommu_table,
 }
 #define pt_iommu_fmt_init amdv1pt_iommu_fmt_init
 
+#ifndef PT_FMT_VARIANT
 static inline void
 amdv1pt_iommu_fmt_hw_info(struct pt_iommu_amdv1 *table,
                          const struct pt_range *top_range,
@@ -384,6 +397,7 @@ amdv1pt_iommu_fmt_hw_info(struct pt_iommu_amdv1 *table,
        info->mode = top_range->top_level + 1;
 }
 #define pt_iommu_fmt_hw_info amdv1pt_iommu_fmt_hw_info
+#endif
 
 #if defined(GENERIC_PT_KUNIT)
 static const struct pt_iommu_amdv1_cfg amdv1_kunit_fmt_cfgs[] = {

diff --git a/drivers/iommu/generic_pt/fmt/iommu_mock.c b/drivers/iommu/generic_pt/fmt/iommu_mock.c
new file mode 100644 (file)
index 0000000..74e597c
--- /dev/null
+++ b/drivers/iommu/generic_pt/fmt/iommu_mock.c
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024-2025, NVIDIA CORPORATION & AFFILIATES
+ */
+#define AMDV1_IOMMUFD_SELFTEST 1
+#define PT_FMT amdv1
+#define PT_FMT_VARIANT mock
+#define PT_SUPPORTED_FEATURES 0
+
+#include "iommu_template.h"

diff --git a/include/linux/generic_pt/iommu.h b/include/linux/generic_pt/iommu.h
index 03a906fbe12a835a40bb90128ac368204ae7f051..848a5fb76272a9548f2fe427b36ec17091e259d6 100644 (file)
--- a/include/linux/generic_pt/iommu.h
+++ b/include/linux/generic_pt/iommu.h
@@ -237,6 +237,12 @@ struct pt_iommu_amdv1_hw_info {
 
 IOMMU_FORMAT(amdv1, amdpt);
 
+/* amdv1_mock is used by the iommufd selftest */
+#define pt_iommu_amdv1_mock pt_iommu_amdv1
+#define pt_iommu_amdv1_mock_cfg pt_iommu_amdv1_cfg
+struct pt_iommu_amdv1_mock_hw_info;
+IOMMU_PROTOTYPES(amdv1_mock);
+
 #undef IOMMU_PROTOTYPES
 #undef IOMMU_FORMAT
 #endif