From: Ackerley Tng ackerleytng@google.com
If guest memory is backed by restricted memfd
+ UPM is being used, hence encrypted memory region has to be registered + Can avoid making a copy of guest memory before getting TDX to initialize the memory region
Signed-off-by: Ackerley Tng ackerleytng@google.com Signed-off-by: Sagi Shahar sagis@google.com --- .../selftests/kvm/lib/x86/tdx/tdx_util.c | 38 +++++++++++++++---- 1 file changed, 30 insertions(+), 8 deletions(-)
diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c index bb074af4a476..e2bf9766dc03 100644 --- a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c +++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c @@ -324,6 +324,21 @@ static void tdx_td_finalize_mr(struct kvm_vm *vm) tdx_ioctl(vm->fd, KVM_TDX_FINALIZE_VM, 0, NULL); }
+/* + * Other ioctls + */ + +/* + * Register a memory region that may contain encrypted data in KVM. + */ +static void register_encrypted_memory_region(struct kvm_vm *vm, + struct userspace_mem_region *region) +{ + vm_set_memory_attributes(vm, region->region.guest_phys_addr, + region->region.memory_size, + KVM_MEMORY_ATTRIBUTE_PRIVATE); +} + /* * TD creation/setup/finalization */ @@ -459,28 +474,35 @@ static void load_td_memory_region(struct kvm_vm *vm, if (!sparsebit_any_set(pages)) return;
+ if (region->region.guest_memfd != -1) + register_encrypted_memory_region(vm, region); + sparsebit_for_each_set_range(pages, i, j) { const uint64_t size_to_load = (j - i + 1) * vm->page_size; const uint64_t offset = (i - lowest_page_in_region) * vm->page_size; const uint64_t hva = hva_base + offset; const uint64_t gpa = gpa_base + offset; - void *source_addr; + void *source_addr = (void *)hva;
/* * KVM_TDX_INIT_MEM_REGION ioctl cannot encrypt memory in place. * Make a copy if there's only one backing memory source. */ - source_addr = mmap(NULL, size_to_load, PROT_READ | PROT_WRITE, - MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); - TEST_ASSERT(source_addr, - "Could not allocate memory for loading memory region"); - - memcpy(source_addr, (void *)hva, size_to_load); + if (region->region.guest_memfd == -1) { + source_addr = mmap(NULL, size_to_load, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); + TEST_ASSERT(source_addr, + "Could not allocate memory for loading memory region"); + + memcpy(source_addr, (void *)hva, size_to_load); + memset((void *)hva, 0, size_to_load); + }
tdx_init_mem_region(vm, source_addr, gpa, size_to_load);
- munmap(source_addr, size_to_load); + if (region->region.guest_memfd == -1) + munmap(source_addr, size_to_load); } }