On 13.10.2022 12:58, Julien Grall wrote: > On 13/10/2022 10:21, Henry Wang wrote: >>> -----Original Message----- >>> From: Julien Grall <jul...@xen.org> >>> Subject: Re: [PATCH] xen/arm: p2m: Populate pages for GICv2 mapping in >>> arch_domain_create() >>> >>> On 13/10/2022 09:38, Henry Wang wrote: >>>> Hardware using GICv2 needs to create a P2M mapping of 8KB GICv2 area >>>> when the domain is created. Considering the worst case of page tables >>> >>> Can you describe in the commit message what is the worst case scenario? >> >> The two pages will be consecutive but not necessarily in the same L3 page >> table so the worst case is 4 + 2, is that correct? > > So I agree that the worse case is 6. But I don't understand what you > mean by '4 + 2' here.
Assuming you have 4 (N) page table levels, isn't it 7 (1 + 2 * (N - 1))? Or is the root table not taken from the p2m pool? Jan
