Hi Marc > -----Original Message----- > From: Will Deacon <w...@kernel.org> > Sent: Thursday, March 4, 2021 5:13 AM > To: Marc Zyngier <m...@kernel.org> > Cc: Justin He <justin...@arm.com>; kvm...@lists.cs.columbia.edu; James > Morse <james.mo...@arm.com>; Julien Thierry <julien.thierry.k...@gmail.com>; > Suzuki Poulose <suzuki.poul...@arm.com>; Catalin Marinas > <catalin.mari...@arm.com>; Gavin Shan <gs...@redhat.com>; Yanan Wang > <wangyana...@huawei.com>; Quentin Perret <qper...@google.com>; linux-arm- > ker...@lists.infradead.org; linux-kernel@vger.kernel.org > Subject: Re: [PATCH] KVM: arm64: Fix unaligned addr case in mmu walking > > On Wed, Mar 03, 2021 at 07:07:37PM +0000, Marc Zyngier wrote: > > From e0524b41a71e0f17d6dc8f197e421e677d584e72 Mon Sep 17 00:00:00 2001 > > From: Jia He <justin...@arm.com> > > Date: Wed, 3 Mar 2021 10:42:25 +0800 > > Subject: [PATCH] KVM: arm64: Fix range alignment when walking page tables > > > > When walking the page tables at a given level, and if the start > > address for the range isn't aligned for that level, we propagate > > the misalignment on each iteration at that level. > > > > This results in the walker ignoring a number of entries (depending > > on the original misalignment) on each subsequent iteration. > > > > Properly aligning the address at the before the next iteration > > "at the before the next" ??? > > > addresses the issue. > > > > Cc: sta...@vger.kernel.org > > Reported-by: Howard Zhang <howard.zh...@arm.com> > > Signed-off-by: Jia He <justin...@arm.com> > > Fixes: b1e57de62cfb ("KVM: arm64: Add stand-alone page-table walker > infrastructure") > > [maz: rewrite commit message] > > Signed-off-by: Marc Zyngier <m...@kernel.org> > > Link: https://lore.kernel.org/r/20210303024225.2591-1-justin...@arm.com > > --- > > arch/arm64/kvm/hyp/pgtable.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c > > index 4d177ce1d536..124cd2f93020 100644 > > --- a/arch/arm64/kvm/hyp/pgtable.c > > +++ b/arch/arm64/kvm/hyp/pgtable.c > > @@ -223,7 +223,7 @@ static inline int __kvm_pgtable_visit(struct > kvm_pgtable_walk_data *data, > > goto out; > > > > if (!table) { > > - data->addr += kvm_granule_size(level); > > + data->addr = ALIGN(data->addr, kvm_granule_size(level));
What if previous data->addr is already aligned with kvm_granule_size(level)? Hence a deadloop? Am I missing anything else? -- Cheers, Justin (Jia He) > > goto out; > > } > > If Jia is happy with it, please feel free to add: > > Acked-by: Will Deacon <w...@kernel.org> > > Will