On 20.05.25 12:28, Chenyi Qiang wrote:
With the introduction of the RamBlockAttribute object to manage
RAMBlocks with guest_memfd, it is more elegant to move KVM set attribute
into a RamDiscardListener.
The KVM attribute change RamDiscardListener is registered/unregistered
for each memory region section during kvm_region_add/del(). The listener
handler performs attribute change upon receiving notifications from
ram_block_attribute_state_change() calls. After this change, the
operations in kvm_convert_memory() can be removed.
Note that, errors can be returned in
ram_block_attribute_notify_to_discard() by KVM attribute changes,
although it is currently unlikely to happen. With in-place conversion
guest_memfd in the future, it would be more likely to encounter errors
and require error handling. For now, simply return the result, and
kvm_convert_memory() will cause QEMU to quit if any issue arises.
Signed-off-by: Chenyi Qiang <chenyi.qi...@intel.com>
---
[...]
static void kvm_region_commit(MemoryListener *listener)
@@ -3077,15 +3140,6 @@ int kvm_convert_memory(hwaddr start, hwaddr size, bool
to_private)
goto out_unref;
}
- if (to_private) {
- ret = kvm_set_memory_attributes_private(start, size);
- } else {
- ret = kvm_set_memory_attributes_shared(start, size);
- }
- if (ret) {
- goto out_unref;
- }
-
I wonder if it's best to leave that out for now. With in-place
conversion it will all get a bit more tricky, because we'd need to call
in different orders ...
e.g., do private -> shared before mapping to vfio, but to shared
->private after unmapping from vfio.
That can be easier handled when doing the calls from KVM code directly.
--
Cheers,
David / dhildenb
