Received-SPF: pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Received-SPF: Pass (protection.outlook.com: domain of amd.com designates
 165.204.84.17 as permitted sender) receiver=protection.outlook.com;
 client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C
From:   Alex Sierra <alex.sierra@amd.com>
To:     <jgg@nvidia.com>
CC:     <david@redhat.com>, <Felix.Kuehling@amd.com>, <linux-mm@kvack.org>,
        <rcampbell@nvidia.com>, <linux-ext4@vger.kernel.org>,
        <linux-xfs@vger.kernel.org>, <amd-gfx@lists.freedesktop.org>,
        <dri-devel@lists.freedesktop.org>, <hch@lst.de>,
        <jglisse@redhat.com>, <apopple@nvidia.com>, <willy@infradead.org>,
        <akpm@linux-foundation.org>
Subject: [PATCH v7 13/14] tools: add hmm gup tests for device coherent type
Date:   Tue, 28 Jun 2022 22:54:25 -0500
Message-ID: <20220629035426.20013-14-alex.sierra@amd.com>
In-Reply-To: <20220629035426.20013-1-alex.sierra@amd.com>
References: <20220629035426.20013-1-alex.sierra@amd.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 Jun 2022 03:55:15.6498
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: 3dc08675-f2dc-4912-43d3-08da59832d03
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com]
X-MS-Exchange-CrossTenant-AuthSource: BN8NAM11FT058.eop-nam11.prod.protection.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN9PR12MB5177
X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,
        RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS,T_SCC_BODY_TEXT_LINE
        autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-ext4.vger.kernel.org>
X-Mailing-List: linux-ext4@vger.kernel.org

The intention is to test hmm device coherent type under different get
user pages paths. Also, test gup with FOLL_LONGTERM flag set in
device coherent pages. These pages should get migrated back to system
memory.

Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
---
 tools/testing/selftests/vm/hmm-tests.c | 110 +++++++++++++++++++++++++
 1 file changed, 110 insertions(+)

diff --git a/tools/testing/selftests/vm/hmm-tests.c b/tools/testing/selftests/vm/hmm-tests.c
index 4b547188ec40..bb38b9777610 100644
--- a/tools/testing/selftests/vm/hmm-tests.c
+++ b/tools/testing/selftests/vm/hmm-tests.c
@@ -36,6 +36,7 @@
  * in the usual include/uapi/... directory.
  */
 #include "../../../../lib/test_hmm_uapi.h"
+#include "../../../../mm/gup_test.h"
 
 struct hmm_buffer {
 	void		*ptr;
@@ -59,6 +60,9 @@ enum {
 #define NTIMES		10
 
 #define ALIGN(x, a) (((x) + (a - 1)) & (~((a) - 1)))
+/* Just the flags we need, copied from mm.h: */
+#define FOLL_WRITE	0x01	/* check pte is writable */
+#define FOLL_LONGTERM   0x10000 /* mapping lifetime is indefinite */
 
 FIXTURE(hmm)
 {
@@ -1764,4 +1768,110 @@ TEST_F(hmm, exclusive_cow)
 	hmm_buffer_free(buffer);
 }
 
+static int gup_test_exec(int gup_fd, unsigned long addr, int cmd,
+			 int npages, int size, int flags)
+{
+	struct gup_test gup = {
+		.nr_pages_per_call	= npages,
+		.addr			= addr,
+		.gup_flags		= FOLL_WRITE | flags,
+		.size			= size,
+	};
+
+	if (ioctl(gup_fd, cmd, &gup)) {
+		perror("ioctl on error\n");
+		return errno;
+	}
+
+	return 0;
+}
+
+/*
+ * Test get user device pages through gup_test. Setting PIN_LONGTERM flag.
+ * This should trigger a migration back to system memory for both, private
+ * and coherent type pages.
+ * This test makes use of gup_test module. Make sure GUP_TEST_CONFIG is added
+ * to your configuration before you run it.
+ */
+TEST_F(hmm, hmm_gup_test)
+{
+	struct hmm_buffer *buffer;
+	int gup_fd;
+	unsigned long npages;
+	unsigned long size;
+	unsigned long i;
+	int *ptr;
+	int ret;
+	unsigned char *m;
+
+	gup_fd = open("/sys/kernel/debug/gup_test", O_RDWR);
+	if (gup_fd == -1)
+		SKIP(return, "Skipping test, could not find gup_test driver");
+
+	npages = 4;
+	size = npages << self->page_shift;
+
+	buffer = malloc(sizeof(*buffer));
+	ASSERT_NE(buffer, NULL);
+
+	buffer->fd = -1;
+	buffer->size = size;
+	buffer->mirror = malloc(size);
+	ASSERT_NE(buffer->mirror, NULL);
+
+	buffer->ptr = mmap(NULL, size,
+			   PROT_READ | PROT_WRITE,
+			   MAP_PRIVATE | MAP_ANONYMOUS,
+			   buffer->fd, 0);
+	ASSERT_NE(buffer->ptr, MAP_FAILED);
+
+	/* Initialize buffer in system memory. */
+	for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+		ptr[i] = i;
+
+	/* Migrate memory to device. */
+	ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
+	ASSERT_EQ(ret, 0);
+	ASSERT_EQ(buffer->cpages, npages);
+	/* Check what the device read. */
+	for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i)
+		ASSERT_EQ(ptr[i], i);
+
+	ASSERT_EQ(gup_test_exec(gup_fd,
+				(unsigned long)buffer->ptr,
+				GUP_BASIC_TEST, 1, self->page_size, 0), 0);
+	ASSERT_EQ(gup_test_exec(gup_fd,
+				(unsigned long)buffer->ptr + 1 * self->page_size,
+				GUP_FAST_BENCHMARK, 1, self->page_size, 0), 0);
+	ASSERT_EQ(gup_test_exec(gup_fd,
+				(unsigned long)buffer->ptr + 2 * self->page_size,
+				PIN_FAST_BENCHMARK, 1, self->page_size, FOLL_LONGTERM), 0);
+	ASSERT_EQ(gup_test_exec(gup_fd,
+				(unsigned long)buffer->ptr + 3 * self->page_size,
+				PIN_LONGTERM_BENCHMARK, 1, self->page_size, 0), 0);
+
+	/* Take snapshot to CPU pagetables */
+	ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_SNAPSHOT, buffer, npages);
+	ASSERT_EQ(ret, 0);
+	ASSERT_EQ(buffer->cpages, npages);
+	m = buffer->mirror;
+	if (hmm_is_coherent_type(variant->device_number)) {
+		ASSERT_EQ(HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL | HMM_DMIRROR_PROT_WRITE, m[0]);
+		ASSERT_EQ(HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL | HMM_DMIRROR_PROT_WRITE, m[1]);
+	} else {
+		ASSERT_EQ(HMM_DMIRROR_PROT_WRITE, m[0]);
+		ASSERT_EQ(HMM_DMIRROR_PROT_WRITE, m[1]);
+	}
+	ASSERT_EQ(HMM_DMIRROR_PROT_WRITE, m[2]);
+	ASSERT_EQ(HMM_DMIRROR_PROT_WRITE, m[3]);
+	/*
+	 * Check again the content on the pages. Make sure there's no
+	 * corrupted data.
+	 */
+	for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+		ASSERT_EQ(ptr[i], i);
+
+	close(gup_fd);
+	hmm_buffer_free(buffer);
+}
 TEST_HARNESS_MAIN
-- 
2.32.0