[PATCH v7 9/9] iommu/arm-smmu-v3: Add unit tests for arm_smmu_write_entry

[Jason Gunthorpe]

On Wed, Apr 17, 2024 at 01:09:40AM -0700, Nicolin Chen wrote:
> On Tue, Apr 16, 2024 at 04:28:20PM -0300, Jason Gunthorpe wrote:
> > Add tests for some of the more common STE update operations that we expect
> > to see, as well as some artificial STE updates to test the edges of
> > arm_smmu_write_entry. These also serve as a record of which common
> > operation is expected to be hitless, and how many syncs they require.
> > 
> > arm_smmu_write_entry implements a generic algorithm that updates an STE/CD
> > to any other abritrary STE/CD configuration. The update requires a
> > sequence of write+sync operations with some invariants that must be held
> > true after each sync. arm_smmu_write_entry lends itself well to
> > unit-testing since the function's interaction with the STE/CD is already
> > abstracted by input callbacks that we can hook to introspect into the
> > sequence of operations. We can use these hooks to guarantee that
> > invariants are held throughout the entire update operation.
> > 
> > Link: https://lore.kernel.org/r/20240106083617.1173871-3-mshavit@google.com
> > Signed-off-by: Michael Shavit <mshavit at google.com>
> > Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
> > ---
> >  drivers/iommu/Kconfig                         |  12 +-
> >  drivers/iommu/arm/arm-smmu-v3/Makefile        |   2 +
> >  .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c   |   6 +-
> >  .../iommu/arm/arm-smmu-v3/arm-smmu-v3-test.c  | 467 ++++++++++++++++++
> >  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   |  36 +-
> >  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   |  30 ++
>  
> > +config ARM_SMMU_V3_KUNIT_TEST
> > +	tristate "KUnit tests for arm-smmu-v3 driver"  if !KUNIT_ALL_TESTS
> > +	depends on KUNIT
> > +	default KUNIT_ALL_TESTS
> > +	help
> > +	  Enable this option to unit-test arm-smmu-v3 driver functions.
> > +
> > +	  If unsure, say N.
> 
> Forgot that my SVA sanity doesn't cover this patch. And it looks
> like some problems here when building it with "=m":
> 
> ERROR: modpost: missing MODULE_LICENSE() in drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-test.o
> ERROR: modpost: "arm_smmu_make_cdtable_ste" [drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-test.ko] undefined!
> ERROR: modpost: "arm_smmu_make_bypass_ste" [drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-test.ko] undefined!
> ERROR: modpost: "arm_smmu_make_abort_ste" [drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-test.ko] undefined!
> ERROR: modpost: "arm_smmu_make_s2_domain_ste" [drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-test.ko] undefined!
> ERROR: modpost: "arm_smmu_get_ste_used" [drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-test.ko] undefined!
> ERROR: modpost: "arm_smmu_write_entry" [drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-test.ko] undefined!
> 
> Likely needs MODULE_LICENSE and some EXPORT_SYMBOLs.

Oh! The kbuild never tested this kconfig combination...

I think just this? Michael?

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index d03c729c4142dc..7b6a4e244e99cf 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -411,7 +411,7 @@ config ARM_SMMU_V3_SVA
 	  and PRI.
 
 config ARM_SMMU_V3_KUNIT_TEST
-	tristate "KUnit tests for arm-smmu-v3 driver"  if !KUNIT_ALL_TESTS
+	bool "KUnit tests for arm-smmu-v3 driver"  if !KUNIT_ALL_TESTS
 	depends on KUNIT
 	default KUNIT_ALL_TESTS
 	help
diff --git a/drivers/iommu/arm/arm-smmu-v3/Makefile b/drivers/iommu/arm/arm-smmu-v3/Makefile
index 014a997753a8a2..0b97054b3929b7 100644
--- a/drivers/iommu/arm/arm-smmu-v3/Makefile
+++ b/drivers/iommu/arm/arm-smmu-v3/Makefile
@@ -2,6 +2,5 @@
 obj-$(CONFIG_ARM_SMMU_V3) += arm_smmu_v3.o
 arm_smmu_v3-objs-y += arm-smmu-v3.o
 arm_smmu_v3-objs-$(CONFIG_ARM_SMMU_V3_SVA) += arm-smmu-v3-sva.o
+arm_smmu_v3-objs-$(CONFIG_ARM_SMMU_V3_KUNIT_TEST) += arm-smmu-v3-test.o
 arm_smmu_v3-objs := $(arm_smmu_v3-objs-y)
-
-obj-$(CONFIG_ARM_SMMU_V3_KUNIT_TEST) += arm-smmu-v3-test.o


Jason