[PATCH v2 06/10] KVM: selftests: refactor vm_mem_backing_src_type flags

From: Axel Rasmussen <axelrasmussen@google.com>
To: Aaron Lewis <aaronlewis@google.com>,
	Alexander Graf <graf@amazon.com>,
	Andrew Jones <drjones@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Ben Gardon <bgardon@google.com>,
	Emanuele Giuseppe Esposito <eesposit@redhat.com>,
	Eric Auger <eric.auger@redhat.com>,
	Jacob Xu <jacobhxu@google.com>,
	Makarand Sonare <makarandsonare@google.com>,
	Oliver Upton <oupton@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>, Peter Xu <peterx@redhat.com>,
	Shuah Khan <shuah@kernel.org>,
	Yanan Wang <wangyanan55@huawei.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-kselftest@vger.kernel.org,
	Axel Rasmussen <axelrasmussen@google.com>
Subject: [PATCH v2 06/10] KVM: selftests: refactor vm_mem_backing_src_type flags
Date: Wed, 19 May 2021 13:03:35 -0700	[thread overview]
Message-ID: <20210519200339.829146-7-axelrasmussen@google.com> (raw)
In-Reply-To: <20210519200339.829146-1-axelrasmussen@google.com>

Each struct vm_mem_backing_src_alias has a flags field, which denotes
the flags used to mmap() an area of that type. Previously, this field
never included MAP_PRIVATE | MAP_ANONYMOUS, because
vm_userspace_mem_region_add assumed that *all* types would always use
those flags, and so it hardcoded them.

In a follow-up commit, we'll add a new type: shmem. Areas of this type
must not have MAP_PRIVATE | MAP_ANONYMOUS, and instead they must have
MAP_SHARED.

So, refactor things. Make it so that the flags field of
struct vm_mem_backing_src_alias really is a complete set of flags, and
don't add in any extras in vm_userspace_mem_region_add. This will let us
easily tack on shmem.

Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
---
 tools/testing/selftests/kvm/lib/kvm_util.c  |  5 ++-
 tools/testing/selftests/kvm/lib/test_util.c | 35 +++++++++++----------
 2 files changed, 21 insertions(+), 19 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 0d6ddee429b9..bc405785ac8b 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -759,9 +759,8 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm,
 
 	region->mmap_start = mmap(NULL, region->mmap_size,
 				  PROT_READ | PROT_WRITE,
-				  MAP_PRIVATE | MAP_ANONYMOUS
-				  | vm_mem_backing_src_alias(src_type)->flag,
-				  -1, 0);
+				  vm_mem_backing_src_alias(src_type)->flag,
+				  region->fd, 0);
 	TEST_ASSERT(region->mmap_start != MAP_FAILED,
 		    "test_malloc failed, mmap_start: %p errno: %i",
 		    region->mmap_start, errno);
diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c
index 63d2bc7d757b..06ddde068736 100644
--- a/tools/testing/selftests/kvm/lib/test_util.c
+++ b/tools/testing/selftests/kvm/lib/test_util.c
@@ -168,70 +168,73 @@ size_t get_def_hugetlb_pagesz(void)
 
 const struct vm_mem_backing_src_alias *vm_mem_backing_src_alias(uint32_t i)
 {
+	static const int anon_flags = MAP_PRIVATE | MAP_ANONYMOUS;
+	static const int anon_huge_flags = anon_flags | MAP_HUGETLB;
+
 	static const struct vm_mem_backing_src_alias aliases[] = {
 		[VM_MEM_SRC_ANONYMOUS] = {
 			.name = "anonymous",
-			.flag = 0,
+			.flag = anon_flags,
 		},
 		[VM_MEM_SRC_ANONYMOUS_THP] = {
 			.name = "anonymous_thp",
-			.flag = 0,
+			.flag = anon_flags,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB] = {
 			.name = "anonymous_hugetlb",
-			.flag = MAP_HUGETLB,
+			.flag = anon_huge_flags,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_16KB] = {
 			.name = "anonymous_hugetlb_16kb",
-			.flag = MAP_HUGETLB | MAP_HUGE_16KB,
+			.flag = anon_huge_flags | MAP_HUGE_16KB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_64KB] = {
 			.name = "anonymous_hugetlb_64kb",
-			.flag = MAP_HUGETLB | MAP_HUGE_64KB,
+			.flag = anon_huge_flags | MAP_HUGE_64KB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_512KB] = {
 			.name = "anonymous_hugetlb_512kb",
-			.flag = MAP_HUGETLB | MAP_HUGE_512KB,
+			.flag = anon_huge_flags | MAP_HUGE_512KB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_1MB] = {
 			.name = "anonymous_hugetlb_1mb",
-			.flag = MAP_HUGETLB | MAP_HUGE_1MB,
+			.flag = anon_huge_flags | MAP_HUGE_1MB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_2MB] = {
 			.name = "anonymous_hugetlb_2mb",
-			.flag = MAP_HUGETLB | MAP_HUGE_2MB,
+			.flag = anon_huge_flags | MAP_HUGE_2MB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_8MB] = {
 			.name = "anonymous_hugetlb_8mb",
-			.flag = MAP_HUGETLB | MAP_HUGE_8MB,
+			.flag = anon_huge_flags | MAP_HUGE_8MB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_16MB] = {
 			.name = "anonymous_hugetlb_16mb",
-			.flag = MAP_HUGETLB | MAP_HUGE_16MB,
+			.flag = anon_huge_flags | MAP_HUGE_16MB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_32MB] = {
 			.name = "anonymous_hugetlb_32mb",
-			.flag = MAP_HUGETLB | MAP_HUGE_32MB,
+			.flag = anon_huge_flags | MAP_HUGE_32MB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_256MB] = {
 			.name = "anonymous_hugetlb_256mb",
-			.flag = MAP_HUGETLB | MAP_HUGE_256MB,
+			.flag = anon_huge_flags | MAP_HUGE_256MB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_512MB] = {
 			.name = "anonymous_hugetlb_512mb",
-			.flag = MAP_HUGETLB | MAP_HUGE_512MB,
+			.flag = anon_huge_flags | MAP_HUGE_512MB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_1GB] = {
 			.name = "anonymous_hugetlb_1gb",
-			.flag = MAP_HUGETLB | MAP_HUGE_1GB,
+			.flag = anon_huge_flags | MAP_HUGE_1GB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_2GB] = {
 			.name = "anonymous_hugetlb_2gb",
-			.flag = MAP_HUGETLB | MAP_HUGE_2GB,
+			.flag = anon_huge_flags | MAP_HUGE_2GB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_16GB] = {
 			.name = "anonymous_hugetlb_16gb",
-			.flag = MAP_HUGETLB | MAP_HUGE_16GB,
+			.flag = anon_huge_flags | MAP_HUGE_16GB,
 		},
 	};
 	_Static_assert(ARRAY_SIZE(aliases) == NUM_SRC_TYPES,
-- 
2.31.1.751.gd2f1c929bd-goog

