On Wed, Sep 27, 2023 at 07:46:36PM -0700, Stanislav Kinsburskii wrote: > I'd answer yes, "System MAP" must be persisted across kexec. > Could you elaborate on why there should be a mechanism to tell the > kernel anything special about the existent "System map" in this context? > Say, one can reserve a CMA region (or a crash kernel region, etc), store > there some data, and then pass it across kexec. Reserved CMA region will > still be a part of the "System MAP", won't it? Em. When crash kernel starts all System RAM of the the first kernel becomes E820_TYPE_RESERVED and only memory pre-allocated for crash scenario becomes E820_TYPE_RAM. See crash_setup_memmap_entries(). Can't you go the same path? Report all deposited memory as E820_TYPE_RESERVED. Or do you have too many deposited memory ranges, so we would run out of e820 entries? -- Kiryl Shutsemau / Kirill A. Shutemov
