On 5/22/2026 7:16 AM, Lisa Wang wrote:
> Set the initial state of the first memory region as shared if it is
> backed by guest_memfd, so that the KVM selftest framework functions can
> populate mmap()-ed guest_memfd memory the same way memory from other
> memory providers are populated.
>
> For CoCo VMs, pages that need to be private are explicitly set to
> private before executing the VM.
>
> Signed-off-by: Lisa Wang <[email protected]>
> ---
> tools/testing/selftests/kvm/lib/kvm_util.c | 16 ++++++++++------
> 1 file changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c
> b/tools/testing/selftests/kvm/lib/kvm_util.c
> index 9a29540fff40..1bab7d76a59c 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -484,8 +484,10 @@ struct kvm_vm *__vm_create(struct vm_shape shape, u32
> nr_runnable_vcpus,
> u64 nr_pages = vm_nr_pages_required(shape.mode, nr_runnable_vcpus,
> nr_extra_pages);
> struct userspace_mem_region *slot0;
> + u64 gmem_flags = 0;
> struct kvm_vm *vm;
> - int i, flags;
> + int flags = 0;
> + int i;
>
> kvm_set_files_rlimit(nr_runnable_vcpus);
>
> @@ -495,14 +497,16 @@ struct kvm_vm *__vm_create(struct vm_shape shape, u32
> nr_runnable_vcpus,
> vm = ____vm_create(shape);
>
> /*
> - * Force GUEST_MEMFD for the primary memory region if necessary, e.g.
> - * for CoCo VMs that require GUEST_MEMFD backed private memory.
> + * Force GUEST_MEMFD for the primary memory region if necessary, and
> + * initialize it as shared so the selftest framework can populate it
> + * exactly like other memory providers.
> */
> - flags = 0;
> - if (is_guest_memfd_required(shape))
> + if (is_guest_memfd_required(shape)) {
> flags |= KVM_MEM_GUEST_MEMFD;
> + gmem_flags |= GUEST_MEMFD_FLAG_INIT_SHARED;
> + }
>
> - vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 0, 0, nr_pages,
> flags);
> + vm_mem_add(vm, VM_MEM_SRC_ANONYMOUS, 0, 0, nr_pages, flags, -1, 0,
> gmem_flags);
The build failed due to this:
lib/kvm_util.c: In function ‘__vm_create’:
lib/kvm_util.c:507:9: error: too many arguments to function ‘vm_mem_add’
507 | vm_mem_add(vm, VM_MEM_SRC_ANONYMOUS, 0, 0, nr_pages, flags, -1,
0, gmem_flags);
| ^~~~~~~~~~
In file included from lib/kvm_util.c:9:
include/kvm_util.h:714:6: note: declared here
714 | void vm_mem_add(struct kvm_vm *vm, enum vm_mem_backing_src_type
src_type,
| ^~~~~~~~~~
lib/kvm_util.c: At top level:
cc1: note: unrecognized command-line option
‘-Wno-gnu-variable-sized-type-not-at-end’ may have been intended to silence
earlier diagnostics
It seems the patch set doesn't wire gmem_flags parameter to vm_mem_add().
> for (i = 0; i < NR_MEM_REGIONS; i++)
> vm->memslots[i] = 0;
>
>
