[PATCH 0/2] Restructure va_high_addr_switch

[PATCH 0/2] Restructure va_high_addr_switch

[Dev Jain]

The va_high_addr_switch memory selftest tests out some corner cases
related to allocation and page/hugepage faulting around the switch
boundary. Currently, the page size and hugepage size have been statically
defined. Post FEAT_LPA2, the Aarch64 Linux kernel adds support for 4k and
16k translation granules on higher addresses; we restructure the test to
support the same. In addition, we avoid invocation of the binary twice,
in the shell script, to reduce test noise.

Dev Jain (2):
  selftests/mm: va_high_addr_switch: Reduce test noise
  selftests/mm: va_high_addr_switch: Dynamically initialize testcases to
    enable LPA2 testing

 .../selftests/mm/va_high_addr_switch.c        | 454 +++++++++---------
 .../selftests/mm/va_high_addr_switch.sh       |   4 -
 2 files changed, 232 insertions(+), 226 deletions(-)

-- 
2.34.1

[PATCH 1/2] selftests/mm: va_high_addr_switch: Reduce test noise

[Dev Jain]

When invoking the binary with "--run-hugetlb" flag, the testcases
involving the base page are anyways going to be run. Therefore, remove
duplication by invoking the binary only once.
 
Signed-off-by: Dev Jain <dev.jain@arm.com>
---
 tools/testing/selftests/mm/va_high_addr_switch.sh | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/tools/testing/selftests/mm/va_high_addr_switch.sh b/tools/testing/selftests/mm/va_high_addr_switch.sh
index a0a75f302904..2c725773cd79 100755
--- a/tools/testing/selftests/mm/va_high_addr_switch.sh
+++ b/tools/testing/selftests/mm/va_high_addr_switch.sh
@@ -57,8 +57,4 @@ check_test_requirements()
 }
 
 check_test_requirements
-./va_high_addr_switch
-
-# In order to run hugetlb testcases, "--run-hugetlb" must be appended
-# to the binary.
 ./va_high_addr_switch --run-hugetlb
-- 
2.34.1

[PATCH 2/2] selftests/mm: va_high_addr_switch: Dynamically initialize testcases to enable LPA2 testing

[Dev Jain]

Post FEAT_LPA2, the Aarch64 Linux kernel extends higher address support
to 4K and 16K translation granules. To support testing this out, we need
to do away with static initialization of page size, while still
maintaining the nice array of testcases; this can be achieved by
initializing and populating the array as a stack variable, and filling
in the page size and hugepage size at runtime.

Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dev Jain <dev.jain@arm.com>
---
 .../selftests/mm/va_high_addr_switch.c        | 454 +++++++++---------
 1 file changed, 232 insertions(+), 222 deletions(-)

diff --git a/tools/testing/selftests/mm/va_high_addr_switch.c b/tools/testing/selftests/mm/va_high_addr_switch.c
index cfbc501290d3..fa7eabfaf841 100644
--- a/tools/testing/selftests/mm/va_high_addr_switch.c
+++ b/tools/testing/selftests/mm/va_high_addr_switch.c
@@ -9,26 +9,9 @@
 #include <sys/mman.h>
 #include <string.h>
 
+#include "vm_util.h"
 #include "../kselftest.h"
 
-#ifdef __powerpc64__
-#define PAGE_SIZE	(64 << 10)
-/*
- * This will work with 16M and 2M hugepage size
- */
-#define HUGETLB_SIZE	(16 << 20)
-#elif __aarch64__
-/*
- * The default hugepage size for 64k base pagesize
- * is 512MB.
- */
-#define PAGE_SIZE	(64 << 10)
-#define HUGETLB_SIZE	(512 << 20)
-#else
-#define PAGE_SIZE	(4 << 10)
-#define HUGETLB_SIZE	(2 << 20)
-#endif
-
 /*
  * The hint addr value is used to allocate addresses
  * beyond the high address switch boundary.
@@ -37,18 +20,8 @@
 #define ADDR_MARK_128TB	(1UL << 47)
 #define ADDR_MARK_256TB	(1UL << 48)
 
-#define HIGH_ADDR_128TB	((void *) (1UL << 48))
-#define HIGH_ADDR_256TB	((void *) (1UL << 49))
-
-#define LOW_ADDR	((void *) (1UL << 30))
-
-#ifdef __aarch64__
-#define ADDR_SWITCH_HINT ADDR_MARK_256TB
-#define HIGH_ADDR	 HIGH_ADDR_256TB
-#else
-#define ADDR_SWITCH_HINT ADDR_MARK_128TB
-#define HIGH_ADDR	 HIGH_ADDR_128TB
-#endif
+#define HIGH_ADDR_128TB	(1UL << 48)
+#define HIGH_ADDR_256TB	(1UL << 49)
 
 struct testcase {
 	void *addr;
@@ -59,195 +32,230 @@ struct testcase {
 	unsigned int keep_mapped:1;
 };
 
-static struct testcase testcases[] = {
-	{
-		/*
-		 * If stack is moved, we could possibly allocate
-		 * this at the requested address.
-		 */
-		.addr = ((void *)(ADDR_SWITCH_HINT - PAGE_SIZE)),
-		.size = PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE, PAGE_SIZE)",
-		.low_addr_required = 1,
-	},
-	{
-		/*
-		 * Unless MAP_FIXED is specified, allocation based on hint
-		 * addr is never at requested address or above it, which is
-		 * beyond high address switch boundary in this case. Instead,
-		 * a suitable allocation is found in lower address space.
-		 */
-		.addr = ((void *)(ADDR_SWITCH_HINT - PAGE_SIZE)),
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE, (2 * PAGE_SIZE))",
-		.low_addr_required = 1,
-	},
-	{
-		/*
-		 * Exact mapping at high address switch boundary, should
-		 * be obtained even without MAP_FIXED as area is free.
-		 */
-		.addr = ((void *)(ADDR_SWITCH_HINT)),
-		.size = PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(ADDR_SWITCH_HINT, PAGE_SIZE)",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = (void *)(ADDR_SWITCH_HINT),
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
-		.msg = "mmap(ADDR_SWITCH_HINT, 2 * PAGE_SIZE, MAP_FIXED)",
-	},
-	{
-		.addr = NULL,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(NULL)",
-		.low_addr_required = 1,
-	},
-	{
-		.addr = LOW_ADDR,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(LOW_ADDR)",
-		.low_addr_required = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(HIGH_ADDR)",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(HIGH_ADDR) again",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
-		.msg = "mmap(HIGH_ADDR, MAP_FIXED)",
-	},
-	{
-		.addr = (void *) -1,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(-1)",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = (void *) -1,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(-1) again",
-	},
-	{
-		.addr = ((void *)(ADDR_SWITCH_HINT - PAGE_SIZE)),
-		.size = PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE, PAGE_SIZE)",
-		.low_addr_required = 1,
-	},
-	{
-		.addr = (void *)(ADDR_SWITCH_HINT - PAGE_SIZE),
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE, 2 * PAGE_SIZE)",
-		.low_addr_required = 1,
-		.keep_mapped = 1,
-	},
-	{
-		.addr = (void *)(ADDR_SWITCH_HINT - PAGE_SIZE / 2),
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE/2 , 2 * PAGE_SIZE)",
-		.low_addr_required = 1,
-		.keep_mapped = 1,
-	},
-	{
-		.addr = ((void *)(ADDR_SWITCH_HINT)),
-		.size = PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(ADDR_SWITCH_HINT, PAGE_SIZE)",
-	},
-	{
-		.addr = (void *)(ADDR_SWITCH_HINT),
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
-		.msg = "mmap(ADDR_SWITCH_HINT, 2 * PAGE_SIZE, MAP_FIXED)",
-	},
-};
+static struct testcase *testcases;
+static struct testcase *hugetlb_testcases;
+static int sz_testcases, sz_hugetlb_testcases;
+static unsigned long switch_hint;
 
-static struct testcase hugetlb_testcases[] = {
-	{
-		.addr = NULL,
-		.size = HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(NULL, MAP_HUGETLB)",
-		.low_addr_required = 1,
-	},
-	{
-		.addr = LOW_ADDR,
-		.size = HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(LOW_ADDR, MAP_HUGETLB)",
-		.low_addr_required = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(HIGH_ADDR, MAP_HUGETLB)",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(HIGH_ADDR, MAP_HUGETLB) again",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
-		.msg = "mmap(HIGH_ADDR, MAP_FIXED | MAP_HUGETLB)",
-	},
-	{
-		.addr = (void *) -1,
-		.size = HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(-1, MAP_HUGETLB)",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = (void *) -1,
-		.size = HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(-1, MAP_HUGETLB) again",
-	},
-	{
-		.addr = (void *)(ADDR_SWITCH_HINT - PAGE_SIZE),
-		.size = 2 * HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE, 2*HUGETLB_SIZE, MAP_HUGETLB)",
-		.low_addr_required = 1,
-		.keep_mapped = 1,
-	},
-	{
-		.addr = (void *)(ADDR_SWITCH_HINT),
-		.size = 2 * HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
-		.msg = "mmap(ADDR_SWITCH_HINT , 2*HUGETLB_SIZE, MAP_FIXED | MAP_HUGETLB)",
-	},
-};
+/* Initialize testcases inside a function to compute parameters at runtime */
+void testcases_init(void)
+{
+	unsigned long pagesize = getpagesize();
+	unsigned long hugepagesize = default_huge_page_size();
+	unsigned long low_addr = (1UL << 30);
+	unsigned long addr_switch_hint = ADDR_MARK_128TB;
+	unsigned long high_addr = HIGH_ADDR_128TB;
+
+#ifdef __aarch64__
+
+	/* Post LPA2, the lower userspace VA on a 16K pagesize is 47 bits. */
+	if (pagesize != (16UL << 10)) {
+		addr_switch_hint = ADDR_MARK_256TB;
+		high_addr = HIGH_ADDR_256TB;
+	}
+#endif
+
+	struct testcase t[] = {
+		{
+			/*
+			 * If stack is moved, we could possibly allocate
+			 * this at the requested address.
+			 */
+			.addr = ((void *)(addr_switch_hint - pagesize)),
+			.size = pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(addr_switch_hint - pagesize, pagesize)",
+			.low_addr_required = 1,
+		},
+		{
+			/*
+			 * Unless MAP_FIXED is specified, allocation based on hint
+			 * addr is never at requested address or above it, which is
+			 * beyond high address switch boundary in this case. Instead,
+			 * a suitable allocation is found in lower address space.
+			 */
+			.addr = ((void *)(addr_switch_hint - pagesize)),
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(addr_switch_hint - pagesize, (2 * pagesize))",
+			.low_addr_required = 1,
+		},
+		{
+			/*
+			 * Exact mapping at high address switch boundary, should
+			 * be obtained even without MAP_FIXED as area is free.
+			 */
+			.addr = ((void *)(addr_switch_hint)),
+			.size = pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(addr_switch_hint, pagesize)",
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *)(addr_switch_hint),
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
+			.msg = "mmap(addr_switch_hint, 2 * pagesize, MAP_FIXED)",
+		},
+		{
+			.addr = NULL,
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(NULL)",
+			.low_addr_required = 1,
+		},
+		{
+			.addr = (void *)low_addr,
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(low_addr)",
+			.low_addr_required = 1,
+		},
+		{
+			.addr = (void *)high_addr,
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(high_addr)",
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *)high_addr,
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(high_addr) again",
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *)high_addr,
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
+			.msg = "mmap(high_addr, MAP_FIXED)",
+		},
+		{
+			.addr = (void *) -1,
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(-1)",
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *) -1,
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(-1) again",
+		},
+		{
+			.addr = ((void *)(addr_switch_hint - pagesize)),
+			.size = pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(addr_switch_hint - pagesize, pagesize)",
+			.low_addr_required = 1,
+		},
+		{
+			.addr = (void *)(addr_switch_hint - pagesize),
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(addr_switch_hint - pagesize, 2 * pagesize)",
+			.low_addr_required = 1,
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *)(addr_switch_hint - pagesize / 2),
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(addr_switch_hint - pagesize/2 , 2 * pagesize)",
+			.low_addr_required = 1,
+			.keep_mapped = 1,
+		},
+		{
+			.addr = ((void *)(addr_switch_hint)),
+			.size = pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(addr_switch_hint, pagesize)",
+		},
+		{
+			.addr = (void *)(addr_switch_hint),
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
+			.msg = "mmap(addr_switch_hint, 2 * pagesize, MAP_FIXED)",
+		},
+	};
+
+	struct testcase ht[] = {
+		{
+			.addr = NULL,
+			.size = hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(NULL, MAP_HUGETLB)",
+			.low_addr_required = 1,
+		},
+		{
+			.addr = (void *)low_addr,
+			.size = hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(low_addr, MAP_HUGETLB)",
+			.low_addr_required = 1,
+		},
+		{
+			.addr = (void *)high_addr,
+			.size = hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(high_addr, MAP_HUGETLB)",
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *)high_addr,
+			.size = hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(high_addr, MAP_HUGETLB) again",
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *)high_addr,
+			.size = hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
+			.msg = "mmap(high_addr, MAP_FIXED | MAP_HUGETLB)",
+		},
+		{
+			.addr = (void *) -1,
+			.size = hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(-1, MAP_HUGETLB)",
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *) -1,
+			.size = hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(-1, MAP_HUGETLB) again",
+		},
+		{
+			.addr = (void *)(addr_switch_hint - pagesize),
+			.size = 2 * hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(addr_switch_hint - pagesize, 2*hugepagesize, MAP_HUGETLB)",
+			.low_addr_required = 1,
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *)(addr_switch_hint),
+			.size = 2 * hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
+			.msg = "mmap(addr_switch_hint , 2*hugepagesize, MAP_FIXED | MAP_HUGETLB)",
+		},
+	};
+
+	testcases = malloc(sizeof(t));
+	hugetlb_testcases = malloc(sizeof(ht));
+
+	/* Copy into global arrays */
+	memcpy(testcases, t, sizeof(t));
+	memcpy(hugetlb_testcases, ht, sizeof(ht));
+
+	sz_testcases = ARRAY_SIZE(t);
+	sz_hugetlb_testcases = ARRAY_SIZE(ht);
+	switch_hint = addr_switch_hint;
+}
 
 static int run_test(struct testcase *test, int count)
 {
@@ -267,7 +275,7 @@ static int run_test(struct testcase *test, int count)
 			continue;
 		}
 
-		if (t->low_addr_required && p >= (void *)(ADDR_SWITCH_HINT)) {
+		if (t->low_addr_required && p >= (void *)(switch_hint)) {
 			printf("FAILED\n");
 			ret = KSFT_FAIL;
 		} else {
@@ -292,7 +300,7 @@ static int supported_arch(void)
 #elif defined(__x86_64__)
 	return 1;
 #elif defined(__aarch64__)
-	return getpagesize() == PAGE_SIZE;
+	return 1;
 #else
 	return 0;
 #endif
@@ -305,8 +313,10 @@ int main(int argc, char **argv)
 	if (!supported_arch())
 		return KSFT_SKIP;
 
-	ret = run_test(testcases, ARRAY_SIZE(testcases));
+	testcases_init();
+
+	ret = run_test(testcases, sz_testcases);
 	if (argc == 2 && !strcmp(argv[1], "--run-hugetlb"))
-		ret = run_test(hugetlb_testcases, ARRAY_SIZE(hugetlb_testcases));
+		ret = run_test(hugetlb_testcases, sz_hugetlb_testcases);
 	return ret;
 }
-- 
2.34.1