On 7/18/2025 12:27 AM, Fuad Tabba wrote:
From: Ackerley Tng <ackerleytng@xxxxxxxxxx> Generalize the private_max_mapping_level x86 operation to max_mapping_level. The private_max_mapping_level operation allows platform-specific code to limit mapping levels (e.g., forcing 4K pages for certain memory types). While it was previously used exclusively for private memory, guest_memfd can now back both private and non-private memory. Platforms may have specific mapping level restrictions that apply to guest_memfd memory regardless of its privacy attribute. Therefore, generalize this operation. Rename the operation: Removes the "private" prefix to reflect its broader applicability to any guest_memfd-backed memory. Pass kvm_page_fault information: The operation is updated to receive a struct kvm_page_fault object instead of just the pfn. This provides platform-specific implementations (e.g., for TDX or SEV) with additional context about the fault, such as whether it is private or shared, allowing them to apply different mapping level rules as needed. Enforce "private-only" behavior (for now): Since the current consumers of this hook (TDX and SEV) still primarily use it to enforce private memory constraints, platform-specific implementations are made to return 0 for non-private pages. A return value of 0 signals to callers that platform-specific input should be ignored for that particular fault, indicating no specific platform-imposed mapping level limits for non-private pages. This allows the core MMU to continue determining the mapping level based on generic rules for such cases. Acked-by: David Hildenbrand <david@xxxxxxxxxx> Suggested-by: Sean Christoperson <seanjc@xxxxxxxxxx> Signed-off-by: Ackerley Tng <ackerleytng@xxxxxxxxxx> Signed-off-by: Fuad Tabba <tabba@xxxxxxxxxx>
Reviewed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
