Re: [PATCH v14 12/22] KVM: selftests: Require guest_memfd for TDX VMs

[Xiaoyao Li <xiaoyao.li@intel.com>]

On 7/23/2026 7:13 AM, Lisa Wang wrote:
> Force guest_memfd for TDX VMs.
> 
> KVM supports guest_memfd for TDX private memory. Without in-place
> conversion supports, all pages default attributes are private. Thus,
> set page to "shared" for shared pages.
> 
> Signed-off-by: Lisa Wang <wyihan@google.com>
> ---
>   tools/testing/selftests/kvm/lib/kvm_util.c     | 2 +-
>   tools/testing/selftests/kvm/lib/ucall_common.c | 8 ++++++++
>   2 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index 0b9d2d383bfa..4a48c4b42095 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -472,7 +472,7 @@ void kvm_set_files_rlimit(u32 nr_vcpus)
>   static bool is_guest_memfd_required(struct vm_shape shape)
>   {
>   #ifdef __x86_64__
> -	return shape.type == KVM_X86_SNP_VM;
> +	return (shape.type == KVM_X86_SNP_VM || shape.type == KVM_X86_TDX_VM);

Instead of updating is_guest_memfd_required(), I'm thinking how about 
just replacing is_guest_memfd_required() with 
vm_arch_has_protected_memory()?

>   #else
>   	return false;
>   #endif
> diff --git a/tools/testing/selftests/kvm/lib/ucall_common.c b/tools/testing/selftests/kvm/lib/ucall_common.c
> index 029ce21f9f2f..c03dfc763172 100644
> --- a/tools/testing/selftests/kvm/lib/ucall_common.c
> +++ b/tools/testing/selftests/kvm/lib/ucall_common.c
> @@ -27,6 +27,7 @@ static struct ucall_header *ucall_pool;
>   
>   void ucall_init(struct kvm_vm *vm, gpa_t mmio_gpa)
>   {
> +	struct userspace_mem_region *region;
>   	struct ucall_header *hdr;
>   	struct ucall *uc;
>   	gva_t gva;
> @@ -37,6 +38,13 @@ void ucall_init(struct kvm_vm *vm, gpa_t mmio_gpa)
>   	hdr = (struct ucall_header *)addr_gva2hva(vm, gva);
>   	memset(hdr, 0, sizeof(*hdr));
>   
> +	region = vm_get_mem_region(vm, MEM_REGION_DATA);
> +	if (region->region.flags & KVM_MEM_GUEST_MEMFD) {
> +		size_t aligned_sz = align_up(sizeof(*hdr), vm->page_size);
> +
> +		vm_mem_set_shared(vm, addr_gva2gpa(vm, gva), aligned_sz);
> +	}

this diff about the ucall needs to be a separate patch. What's the 
reason to add it to this patch in this version?

>   	for (i = 0; i < KVM_MAX_VCPUS; ++i) {
>   		uc = &hdr->ucalls[i];
>   		uc->hva = uc;
>