[igt-dev] [PATCH i-g-t 5/5] tests/xe/mmap: sanity check small-bar

[Matthew Auld <matthew.auld@intel.com>]

Some basic sanity checks.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
---
 lib/xe/xe_ioctl.c  | 20 +++++++++--
 lib/xe/xe_ioctl.h  |  2 ++
 tests/xe/xe_mmap.c | 90 +++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 108 insertions(+), 4 deletions(-)

diff --git a/lib/xe/xe_ioctl.c b/lib/xe/xe_ioctl.c
index 9d5793df..566690b2 100644
--- a/lib/xe/xe_ioctl.c
+++ b/lib/xe/xe_ioctl.c
@@ -232,17 +232,31 @@ void xe_vm_destroy(int fd, uint32_t vm)
 	igt_assert_eq(igt_ioctl(fd, DRM_IOCTL_XE_VM_DESTROY, &destroy), 0);
 }
 
-uint32_t xe_bo_create_flags(int fd, uint32_t vm, uint64_t size, uint32_t flags)
+uint32_t __xe_bo_create_flags(int fd, uint32_t vm, uint64_t size, uint32_t flags,
+			      uint32_t *handle)
 {
 	struct drm_xe_gem_create create = {
 		.vm_id = vm,
 		.size = size,
 		.flags = flags,
 	};
+	int err;
 
-	igt_assert_eq(igt_ioctl(fd, DRM_IOCTL_XE_GEM_CREATE, &create), 0);
+	err = igt_ioctl(fd, DRM_IOCTL_XE_GEM_CREATE, &create);
+	if (err)
+		return err;
 
-	return create.handle;
+	*handle = create.handle;
+	return 0;
+}
+
+uint32_t xe_bo_create_flags(int fd, uint32_t vm, uint64_t size, uint32_t flags)
+{
+	uint32_t handle;
+
+	igt_assert_eq(__xe_bo_create_flags(fd, vm, size, flags, &handle), 0);
+
+	return handle;
 }
 
 uint32_t xe_bo_create(int fd, int gt, uint32_t vm, uint64_t size)
diff --git a/lib/xe/xe_ioctl.h b/lib/xe/xe_ioctl.h
index 5c7e773f..ddcefc6d 100644
--- a/lib/xe/xe_ioctl.h
+++ b/lib/xe/xe_ioctl.h
@@ -63,6 +63,8 @@ void xe_vm_unbind_all_async(int fd, uint32_t vm, uint32_t engine,
 			    uint32_t bo, struct drm_xe_sync *sync,
 			    uint32_t num_syncs);
 void xe_vm_destroy(int fd, uint32_t vm);
+uint32_t __xe_bo_create_flags(int fd, uint32_t vm, uint64_t size, uint32_t flags,
+			      uint32_t *handle);
 uint32_t xe_bo_create_flags(int fd, uint32_t vm, uint64_t size, uint32_t flags);
 uint32_t xe_bo_create(int fd, int gt, uint32_t vm, uint64_t size);
 uint32_t xe_engine_create(int fd, uint32_t vm,
diff --git a/tests/xe/xe_mmap.c b/tests/xe/xe_mmap.c
index b23ce10c..fab08a7a 100644
--- a/tests/xe/xe_mmap.c
+++ b/tests/xe/xe_mmap.c
@@ -17,14 +17,21 @@
 #include "xe/xe_ioctl.h"
 #include "xe/xe_query.h"
 
+#include <setjmp.h>
+#include <signal.h>
 #include <string.h>
 
-
 /**
  * SUBTEST: system
  * Description: Test mmap on system memory
  */
 
+/**
+ * SUBTEST: small-bar
+ * Description: Sanity check mmap behaviour on small-bar systems
+ * GPU requirements: GPU needs to have dedicated VRAM and using small-bar
+ */
+
 /**
  * SUBTEST: %s
  * Description: Test mmap on %arg[1] memory
@@ -57,6 +64,82 @@ test_mmap(int fd, uint32_t flags)
 	gem_close(fd, bo);
 }
 
+static jmp_buf jmp;
+
+__noreturn static void sigtrap(int sig)
+{
+	siglongjmp(jmp, sig);
+}
+
+static void trap_sigbus(uint32_t *ptr)
+{
+	sighandler_t old_sigbus;
+
+	old_sigbus = signal(SIGBUS, sigtrap);
+	switch (sigsetjmp(jmp, SIGBUS)) {
+	case SIGBUS:
+		break;
+	case 0:
+		*ptr = 0xdeadbeaf;
+	default:
+		igt_assert(!"reached");
+		break;
+	}
+	signal(SIGBUS, old_sigbus);
+}
+
+static void
+test_mmap_small_bar(int fd)
+{
+	uint32_t visible_size = xe_visible_vram_size(fd, 0);
+	uint32_t bo;
+	uint64_t mmo;
+	uint32_t *map;
+
+	/* Some 2BIG invalid cases */
+	igt_assert_neq(__xe_bo_create_flags(fd, 0, visible_size,
+					    visible_vram_memory(fd, 0), &bo),
+		       0);
+	igt_assert_neq(__xe_bo_create_flags(fd, 0, visible_size + 4096,
+					    visible_vram_memory(fd, 0), &bo),
+		       0);
+
+	/* Normal operation */
+	bo = xe_bo_create_flags(fd, 0, visible_size / 4,
+				visible_vram_memory(fd, 0));
+	mmo = xe_bo_mmap_offset(fd, bo);
+	map = mmap(NULL, 4096, PROT_WRITE, MAP_SHARED, fd, mmo);
+	igt_assert(map != MAP_FAILED);
+
+	map[0] = 0xdeadbeaf;
+
+	munmap(map, 4096);
+	gem_close(fd, bo);
+
+	/* Normal operation with system memory spilling */
+	bo = xe_bo_create_flags(fd, 0, visible_size,
+				visible_vram_memory(fd, 0) |
+				system_memory(fd));
+	mmo = xe_bo_mmap_offset(fd, bo);
+	map = mmap(NULL, 4096, PROT_WRITE, MAP_SHARED, fd, mmo);
+	igt_assert(map != MAP_FAILED);
+
+	map[0] = 0xdeadbeaf;
+
+	munmap(map, 4096);
+	gem_close(fd, bo);
+
+	/* Bogus operation with SIGBUS */
+	bo = xe_bo_create_flags(fd, 0, visible_size + 4096,
+				vram_memory(fd, 0));
+	mmo = xe_bo_mmap_offset(fd, bo);
+	map = mmap(NULL, 4096, PROT_WRITE, MAP_SHARED, fd, mmo);
+	igt_assert(map != MAP_FAILED);
+
+	trap_sigbus(map);
+	gem_close(fd, bo);
+}
+
 igt_main
 {
 	int fd;
@@ -75,6 +158,11 @@ igt_main
 	igt_subtest("vram-system")
 		test_mmap(fd, visible_vram_memory(fd, 0) | system_memory(fd));
 
+	igt_subtest("small-bar") {
+		igt_require(xe_visible_vram_size(fd, 0) < xe_vram_size(fd, 0));
+		test_mmap_small_bar(fd);
+	}
+
 	igt_fixture {
 		xe_device_put(fd);
 		close(fd);
-- 
2.39.2