[POC PATCH 2/5] KVM: selftests: Use guest_memfd memory contents in-place for SNP launch update
From: Ackerley Tng
Date: Thu May 07 2026 - 16:37:21 EST
Update the SEV-SNP launch update flow to utilize guest_memfd in-place
conversion.
Include the KVM_SET_MEMORY_ATTRIBUTES2_PRESERVE flag when setting memory
attributes to private. This is permitted before the SNP VM is finalized.
In snp_launch_update_data, pass 0 as the host virtual address. This
instructs the kernel to perform the launch update using the guest_memfd
backing the guest physical address rather than a userspace-provided
buffer.
Signed-off-by: Ackerley Tng <ackerleytng@xxxxxxxxxx>
---
tools/testing/selftests/kvm/lib/x86/sev.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kvm/lib/x86/sev.c b/tools/testing/selftests/kvm/lib/x86/sev.c
index 93f9169034617..074ab0eff1e27 100644
--- a/tools/testing/selftests/kvm/lib/x86/sev.c
+++ b/tools/testing/selftests/kvm/lib/x86/sev.c
@@ -37,8 +37,7 @@ static void encrypt_region(struct kvm_vm *vm, struct userspace_mem_region *regio
if (is_sev_snp_vm(vm))
snp_launch_update_data(vm, gpa_base + offset,
- (u64)addr_gpa2hva(vm, gpa_base + offset),
- size, page_type);
+ 0, size, page_type);
else
sev_launch_update_data(vm, gpa_base + offset, size);
--
2.54.0.563.g4f69b47b94-goog