On Mon, Apr 19, 2021 at 12:46:53PM -0500, Brijesh Singh wrote: > - KVM calls alloc_page() to allocate a VMSA page. The allocator returns > 0xffffc80000200000 (PFN 0x200, page-level=2M). The VMSA page is private > page so KVM will call RMPUPDATE to add the page as a private page in the > RMP table. While adding the RMP entry the KVM will use the page level=4K.
Right, and *here* we split the 2M page on the *host* so that there's no discrepancy between the host pagetable and the RMP. I guess your patch does exactly that. :) And AFAIR, set_memory.c doesn't have the functionality to coalesce 4K pages back into the corresponding 2M page. Which means, the RMP table is in sync, more or less. Thx and thanks for elaborating. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette