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

From: Axel Rasmussen
Date: Wed May 19 2021 - 16:04:17 EST


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@xxxxxxxxxx>
---
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