On 8/13/2025 10:42 PM, Reinette Chatre wrote:
Hi Binbin,
On 8/13/25 2:23 AM, Binbin Wu wrote:
On 8/12/2025 4:31 AM, Sean Christopherson wrote:
On Thu, Aug 07, 2025, Sagi Shahar wrote:
[...]
+
/*
* 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) {
Oh, here's the "if".
Is it still possible for "region->region.guest_memfd == -1" case?
KVM_TDX_INIT_MEM_REGION can only work with guest memfd, right?
This is still used and supports test "KVM: selftests: TDX: Test
LOG_DIRTY_PAGES flag to a non-GUEST_MEMFD memslot" found in patch #30 that
was created to support the issue encountered when QEMU attaches an emulated
VGA device to a TD. More details available in the fix:
fbb4adadea55 ("KVM: x86: Make cpu_dirty_log_size a per-VM value")
I think load_td_memory_region() should return directly for non-guest_memfd
region.
In current upstream version, KVM_TDX_INIT_MEM_REGION doesn't support
non-guest_memfd region.
The mmap/memcpy/munmap sequence should be removed because it does nothing but
zero out the original content.
Reinette
