Hi Jan > -----Original Message----- > From: Jan Beulich <jbeul...@suse.com> > Subject: Re: [PATCH] xen/arm: p2m: Populate pages for GICv2 mapping in > arch_domain_create() > > 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?
Correct, on arm the root is not taken from the pool. Kind regards, Henry > > Jan
