Commit 1dd4187f authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Joerg Roedel
Browse files

iommupt: Add a kunit test for Generic Page Table 



This intends to have high coverage of the page table format functions, it
uses the IOMMU implementation to create a tree which it then walks through
and directly calls the generic page table functions to test them.

It is a good starting point to test a new format header as it is often
able to find typos and inconsistencies much more directly, rather than
with an obscure failure in the iommu implementation.

The tests can be run with commands like:

tools/testing/kunit/kunit.py run --build_dir build_kunit_arm64 --arch arm64 --make_options LLVM=-19 --kunitconfig ./drivers/iommu/generic_pt/.kunitconfig
tools/testing/kunit/kunit.py run --build_dir build_kunit_uml --kunitconfig ./drivers/iommu/generic_pt/.kunitconfig --kconfig_add CONFIG_WERROR=n
tools/testing/kunit/kunit.py run --build_dir build_kunit_x86_64 --arch x86_64 --kunitconfig ./drivers/iommu/generic_pt/.kunitconfig
tools/testing/kunit/kunit.py run --build_dir build_kunit_i386 --arch i386 --kunitconfig ./drivers/iommu/generic_pt/.kunitconfig
tools/testing/kunit/kunit.py run --build_dir build_kunit_i386pae --arch i386 --kunitconfig ./drivers/iommu/generic_pt/.kunitconfig --kconfig_add CONFIG_X86_PAE=y

There are several interesting corner cases on the 32 bit platforms that
need checking.

The format can declare a list of configurations that generate different
configurations the initialize the page table, for instance with different
top levels or other parameters. The kunit will turn these into "params"
which cause each test to run multiple times.

The tests are repeated to run at every table level to check that all the
item encoding formats work.

The following are checked:
 - Basic init works for each configuration
 - The various log2 functions have the expected behavior at the limits
 - pt_compute_best_pgsize() works
 - pt_table_pa() reads back what pt_install_table() writes
 - range.max_vasz_lg2 works properly
 - pt_table_oa_lg2sz() and pt_table_item_lg2sz() use a contiguous
   non-overlapping set of bits from the VA up to the defined max_va
 - pt_possible_sizes() and pt_can_have_leaf() produces a sensible layout
 - pt_item_oa(), pt_entry_oa(), and pt_entry_num_contig_lg2() read back
   what pt_install_leaf_entry() writes
 - pt_clear_entry() works
 - pt_attr_from_entry() reads back what pt_iommu_set_prot() &
   pt_install_leaf_entry() writes
 - pt_entry_set_write_clean(), pt_entry_make_write_dirty(), and
   pt_entry_write_is_dirty() work

Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Tested-by: default avatarAlejandro Jimenez <alejandro.j.jimenez@oracle.com>
Tested-by: default avatarPasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent 4a00f943

drivers/iommu/generic_pt/.kunitconfig

0 → 100644
+12 −0
Original line number Diff line number Diff line 
CONFIG_KUNIT=y

CONFIG_GENERIC_PT=y

CONFIG_DEBUG_GENERIC_PT=y

CONFIG_IOMMU_PT=y

CONFIG_IOMMU_PT_AMDV1=y

CONFIG_IOMMU_PT_KUNIT_TEST=y



CONFIG_IOMMUFD=y

CONFIG_DEBUG_KERNEL=y

CONFIG_FAULT_INJECTION=y

CONFIG_RUNTIME_TESTING_MENU=y

CONFIG_IOMMUFD_TEST=y

drivers/iommu/generic_pt/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -41,5 +41,17 @@ config IOMMU_PT_AMDV1 
	  power of 2 and decodes an full 64-bit IOVA space.



	  Selected automatically by an IOMMU driver that uses this format.



config IOMMU_PT_KUNIT_TEST

	tristate "IOMMU Page Table KUnit Test" if !KUNIT_ALL_TESTS

	depends on KUNIT

	depends on IOMMU_PT_AMDV1 || !IOMMU_PT_AMDV1

	default KUNIT_ALL_TESTS

	help

	  Enable kunit tests for GENERIC_PT and IOMMU_PT that covers all the

	  enabled page table formats. The test covers most of the GENERIC_PT

	  functions provided by the page table format, as well as covering the

	  iommu_domain related functions.



endif

endif

drivers/iommu/generic_pt/fmt/Makefile

+12 −0
Original line number Diff line number Diff line
@@ -2,10 +2,22 @@ 


iommu_pt_fmt-$(CONFIG_IOMMU_PT_AMDV1) += amdv1



IOMMU_PT_KUNIT_TEST :=

define create_format

obj-$(2) += iommu_$(1).o

iommu_pt_kunit_test-y += kunit_iommu_$(1).o

CFLAGS_kunit_iommu_$(1).o += -DGENERIC_PT_KUNIT=1

IOMMU_PT_KUNIT_TEST := iommu_pt_kunit_test.o



endef



$(eval $(foreach fmt,$(iommu_pt_fmt-y),$(call create_format,$(fmt),y)))

$(eval $(foreach fmt,$(iommu_pt_fmt-m),$(call create_format,$(fmt),m)))



# The kunit objects are constructed by compiling the main source

# with -DGENERIC_PT_KUNIT

$(obj)/kunit_iommu_%.o: $(src)/iommu_%.c FORCE

	$(call rule_mkdir)

	$(call if_changed_dep,cc_o_c)



obj-$(CONFIG_IOMMU_PT_KUNIT_TEST) += $(IOMMU_PT_KUNIT_TEST)

drivers/iommu/generic_pt/fmt/amdv1.h

+10 −0
Original line number Diff line number Diff line
@@ -384,4 +384,14 @@ 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



#if defined(GENERIC_PT_KUNIT)

static const struct pt_iommu_amdv1_cfg amdv1_kunit_fmt_cfgs[] = {

	/* Matches what io_pgtable does */

	[0] = { .starting_level = 2 },

};

#define kunit_fmt_cfgs amdv1_kunit_fmt_cfgs

enum { KUNIT_FMT_FEATURES = 0 };

#endif



#endif

drivers/iommu/generic_pt/fmt/iommu_template.h

+8 −0
Original line number Diff line number Diff line
@@ -36,4 +36,12 @@ 
#include PT_FMT_H

#include "../pt_common.h"



#ifndef GENERIC_PT_KUNIT

#include "../iommu_pt.h"

#else

/*

 * The makefile will compile the .c file twice, once with GENERIC_PT_KUNIT set

 * which means we are building the kunit modle.

 */

#include "../kunit_generic_pt.h"

#endif