[PATCH v4 4/4] nitro_enclaves: Add KUnit tests for contiguous physical memory regions merging

From: Longpeng(Mike)
Date: Wed Nov 03 2021 - 10:01:18 EST


From: Longpeng <longpeng2@xxxxxxxxxx>

Add KUnit tests for the contiguous physical memory regions merging
functionality from the Nitro Enclaves misc device logic.

We can build the test binary with the following configuration:
CONFIG_KUNIT=y
CONFIG_NITRO_ENCLAVES=m
CONFIG_NITRO_ENCLAVES_MISC_DEV_TEST=y
and install the nitro_enclaves module to run the testcases.

We'll see the following message using dmesg if everything goes well:

[...] # Subtest: ne_misc_dev_test
[...] 1..1
[...] (NULL device *): Physical mem region address is not 2 MiB aligned
[...] (NULL device *): Physical mem region size is not multiple of 2 MiB
[...] (NULL device *): Physical mem region address is not 2 MiB aligned
[...] ok 1 - ne_misc_dev_test_merge_phys_contig_memory_regions
[...] ok 1 - ne_misc_dev_test

Signed-off-by: Longpeng <longpeng2@xxxxxxxxxx>
---
Changes v3 -> v4:
- "int expect_num" -> "unsigned long expect_num" [Andra]
- rename several variables and structures [Andra]
- invoke "kunit_kfree" to free the "regions" [Andra]

Changes v2 -> v3:
- update the commit title and commit message. [Andra]
- align the fileds in 'struct phys_regions_test'. [Andra]
- rename 'phys_regions_testcases' to 'phys_regions_test_cases'. [Andra]
- add comments before each test cases. [Andra]
- initialize the variables in ne_misc_dev_test_merge_phys_contig_memory_regions. [Andra]
---
drivers/virt/nitro_enclaves/ne_misc_dev_test.c | 139 +++++++++++++++++++++++++
1 file changed, 139 insertions(+)

diff --git a/drivers/virt/nitro_enclaves/ne_misc_dev_test.c b/drivers/virt/nitro_enclaves/ne_misc_dev_test.c
index 6862e99..4648ec02 100644
--- a/drivers/virt/nitro_enclaves/ne_misc_dev_test.c
+++ b/drivers/virt/nitro_enclaves/ne_misc_dev_test.c
@@ -2,7 +2,146 @@

#include <kunit/test.h>

+#define MAX_PHYS_REGIONS 16
+#define INVALID_VALUE (~0ull)
+
+struct ne_phys_regions_test {
+ u64 paddr;
+ u64 size;
+ int expect_rc;
+ unsigned long expect_num;
+ u64 expect_last_paddr;
+ u64 expect_last_size;
+} phys_regions_test_cases[] = {
+ /*
+ * Add the region from 0x1000 to (0x1000 + 0x200000 - 1):
+ * Expected result:
+ * Failed, start address is not 2M-aligned
+ *
+ * Now the instance of struct ne_phys_contig_mem_regions is:
+ * num = 0
+ * regions = {}
+ */
+ {0x1000, 0x200000, -EINVAL, 0, INVALID_VALUE, INVALID_VALUE},
+
+ /*
+ * Add the region from 0x200000 to (0x200000 + 0x1000 - 1):
+ * Expected result:
+ * Failed, size is not 2M-aligned
+ *
+ * Now the instance of struct ne_phys_contig_mem_regions is:
+ * num = 0
+ * regions = {}
+ */
+ {0x200000, 0x1000, -EINVAL, 0, INVALID_VALUE, INVALID_VALUE},
+
+ /*
+ * Add the region from 0x200000 to (0x200000 + 0x200000 - 1):
+ * Expected result:
+ * Successful
+ *
+ * Now the instance of struct ne_phys_contig_mem_regions is:
+ * num = 1
+ * regions = {
+ * {start=0x200000, end=0x3fffff}, // len=0x200000
+ * }
+ */
+ {0x200000, 0x200000, 0, 1, 0x200000, 0x200000},
+
+ /*
+ * Add the region from 0x0 to (0x0 + 0x200000 - 1):
+ * Expected result:
+ * Successful
+ *
+ * Now the instance of struct ne_phys_contig_mem_regions is:
+ * num = 2
+ * regions = {
+ * {start=0x200000, end=0x3fffff}, // len=0x200000
+ * {start=0x0, end=0x1fffff}, // len=0x200000
+ * }
+ */
+ {0x0, 0x200000, 0, 2, 0x0, 0x200000},
+
+ /*
+ * Add the region from 0x600000 to (0x600000 + 0x400000 - 1):
+ * Expected result:
+ * Successful
+ *
+ * Now the instance of struct ne_phys_contig_mem_regions is:
+ * num = 3
+ * regions = {
+ * {start=0x200000, end=0x3fffff}, // len=0x200000
+ * {start=0x0, end=0x1fffff}, // len=0x200000
+ * {start=0x600000, end=0x9fffff}, // len=0x400000
+ * }
+ */
+ {0x600000, 0x400000, 0, 3, 0x600000, 0x400000},
+
+ /*
+ * Add the region from 0xa00000 to (0xa00000 + 0x400000 - 1):
+ * Expected result:
+ * Successful, merging case!
+ *
+ * Now the instance of struct ne_phys_contig_mem_regions is:
+ * num = 3
+ * regions = {
+ * {start=0x200000, end=0x3fffff}, // len=0x200000
+ * {start=0x0, end=0x1fffff}, // len=0x200000
+ * {start=0x600000, end=0xdfffff}, // len=0x800000
+ * }
+ */
+ {0xa00000, 0x400000, 0, 3, 0x600000, 0x800000},
+
+ /*
+ * Add the region from 0x1000 to (0x1000 + 0x200000 - 1):
+ * Expected result:
+ * Failed, start address is not 2M-aligned
+ *
+ * Now the instance of struct ne_phys_contig_mem_regions is:
+ * num = 3
+ * regions = {
+ * {start=0x200000, end=0x3fffff}, // len=0x200000
+ * {start=0x0, end=0x1fffff}, // len=0x200000
+ * {start=0x600000, end=0xdfffff}, // len=0x800000
+ * }
+ */
+ {0x1000, 0x200000, -EINVAL, 3, 0x600000, 0x800000},
+};
+
+static void ne_misc_dev_test_merge_phys_contig_memory_regions(struct kunit *test)
+{
+ struct ne_phys_contig_mem_regions phys_contig_mem_regions = {};
+ int rc = 0;
+ int i = 0;
+
+ phys_contig_mem_regions.regions = kunit_kcalloc(test, MAX_PHYS_REGIONS,
+ sizeof(*phys_contig_mem_regions.regions), GFP_KERNEL);
+ KUNIT_ASSERT_TRUE(test, phys_contig_mem_regions.regions != NULL);
+
+ for (i = 0; i < ARRAY_SIZE(phys_regions_test_cases); i++) {
+ struct ne_phys_regions_test *test_case = &phys_regions_test_cases[i];
+ unsigned long num = 0;
+
+ rc = ne_merge_phys_contig_memory_regions(&phys_contig_mem_regions,
+ test_case->paddr, test_case->size);
+ KUNIT_EXPECT_EQ(test, rc, test_case->expect_rc);
+ KUNIT_EXPECT_EQ(test, phys_contig_mem_regions.num, test_case->expect_num);
+
+ if (test_case->expect_last_paddr == INVALID_VALUE)
+ continue;
+
+ num = phys_contig_mem_regions.num;
+ KUNIT_EXPECT_EQ(test, phys_contig_mem_regions.regions[num - 1].start,
+ test_case->expect_last_paddr);
+ KUNIT_EXPECT_EQ(test, range_len(&phys_contig_mem_regions.regions[num - 1]),
+ test_case->expect_last_size);
+ }
+
+ kunit_kfree(test, phys_contig_mem_regions.regions);
+}
+
static struct kunit_case ne_misc_dev_test_cases[] = {
+ KUNIT_CASE(ne_misc_dev_test_merge_phys_contig_memory_regions),
{}
};

--
1.8.3.1