On 13.10.2022 13:05, Henry Wang wrote: >> -----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.
Isn't that a (perhaps just minor) mistake? Jan
