On Tue, Jun 23, 2026 at 06:17:32AM -0400, Zhenzhong Duan wrote: > Currently, allocate_unaccepted_bitmap() only scans the initial EFI > boot memory map. This misses hotpluggable ranges described in the > ACPI SRAT. Without early tracking, hotplug pages are accessed without > acceptance and this triggers guest crash. > > Introduce a lightweight ACPI SRAT parser to scan these regions early. > If a region has both ACPI_SRAT_MEM_ENABLED and ACPI_SRAT_MEM_HOT_PLUGGABLE > flags, expand the tracking boundaries. This avoids pulling in the full > ACPI subsystem while ensuring the bitmap covers both static memory and > hotplug memory.
Ugh.. Parsing SRAT there is ugly. I would rather avoid it. Do I understand correctly that we don't have a way represent pluggable, but not present memory in EFI memory map? IIUC, EFI_MEMORY_HOT_PLUGGABLE is actually present, but unpluggable memory. Maybe it would be better just allocate bitmap upto maxmem? And fix EFI spec to add pluggable-but-not-present attribute. -- Kiryl Shutsemau / Kirill A. Shutemov
