nitro_enclaves: Add KUnit tests for contiguous physical memory regions merging

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

Reviewed-by: Andra Paraschiv <andraprs@amazon.com>
Signed-off-by: Longpeng <longpeng2@huawei.com>
Link: https://lore.kernel.org/r/20211107140918.2106-5-longpeng2@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 140 insertions, 0 deletions

diff --git a/drivers/virt/nitro_enclaves/ne_misc_dev_test.c b/drivers/virt/nitro_enclaves/ne_misc_dev_test.c
index 6862e990d2be..265797bed0ea 100644
--- a/drivers/virt/nitro_enclaves/ne_misc_dev_test.c
+++ b/drivers/virt/nitro_enclaves/ne_misc_dev_test.c
@@ -2,7 +2,147 @@
 
 #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);
+
+	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),
 	{}
 };