From: Oliver Upton <oliver.upton@linux.dev>
To: Ricardo Koller <ricarkol@google.com>
Cc: Ben Gardon <bgardon@google.com>,
pbonzini@redhat.com, maz@kernel.org, yuzenghui@huawei.com,
dmatlack@google.com, kvm@vger.kernel.org, kvmarm@lists.linux.dev,
qperret@google.com, catalin.marinas@arm.com,
andrew.jones@linux.dev, seanjc@google.com,
alexandru.elisei@arm.com, suzuki.poulose@arm.com,
eric.auger@redhat.com, gshan@redhat.com, reijiw@google.com,
rananta@google.com, ricarkol@gmail.com
Subject: Re: [PATCH 3/9] KVM: arm64: Add kvm_pgtable_stage2_split()
Date: Tue, 24 Jan 2023 17:11:19 +0000 [thread overview]
Message-ID: <Y9ARN5hWlAYVFBoK@google.com> (raw)
In-Reply-To: <Y9ALgtnd+h9ivn90@google.com>
On Tue, Jan 24, 2023 at 08:46:58AM -0800, Ricardo Koller wrote:
> On Mon, Jan 23, 2023 at 05:03:23PM -0800, Ben Gardon wrote:
[...]
> > Would it be accurate to say:
> > /* No huge pages can exist at the root level, so there's nothing to
> > split here. */
> >
> > I think of "last level" as the lowest/leaf/4k level but
> > KVM_PGTABLE_MAX_LEVELS - 1 is 3?
>
> Right, this is the 4k level.
>
> > Does ARM do the level numbering in
> > reverse order to x86?
>
> Yes, it does. Interesting, x86 does
>
> iter->level--;
>
> while arm does:
>
> ret = __kvm_pgtable_walk(data, mm_ops, childp, level + 1);
>
> I don't think this numbering scheme is encoded anywhere in the PTEs, so
> either architecture could use the other.
The numbering we use in the page table walkers is deliberate, as it
directly matches the Arm ARM. While we can certainly use either scheme
I'd prefer we keep aligned with the architecture.
--
Thanks,
Oliver
next prev parent reply other threads:[~2023-01-24 17:11 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-13 3:49 [PATCH 0/9] KVM: arm64: Eager Huge-page splitting for dirty-logging Ricardo Koller
2023-01-13 3:49 ` [PATCH 1/9] KVM: arm64: Add KVM_PGTABLE_WALK_REMOVED into ctx->flags Ricardo Koller
2023-01-24 0:51 ` Ben Gardon
2023-01-24 0:56 ` Oliver Upton
2023-01-24 16:32 ` Ricardo Koller
2023-01-24 18:00 ` Ben Gardon
2023-01-26 18:48 ` Ricardo Koller
2023-01-24 16:30 ` Ricardo Koller
2023-01-13 3:49 ` [PATCH 2/9] KVM: arm64: Add helper for creating removed stage2 subtrees Ricardo Koller
2023-01-24 0:55 ` Ben Gardon
2023-01-24 16:35 ` Ricardo Koller
2023-01-24 17:07 ` Oliver Upton
2023-01-13 3:49 ` [PATCH 3/9] KVM: arm64: Add kvm_pgtable_stage2_split() Ricardo Koller
2023-01-24 1:03 ` Ben Gardon
2023-01-24 16:46 ` Ricardo Koller
2023-01-24 17:11 ` Oliver Upton [this message]
2023-01-24 17:18 ` Ricardo Koller
2023-01-24 17:48 ` David Matlack
2023-01-24 20:28 ` Oliver Upton
2023-02-06 9:20 ` Zheng Chuan
2023-02-06 16:28 ` Ricardo Koller
2023-01-13 3:49 ` [PATCH 4/9] KVM: arm64: Refactor kvm_arch_commit_memory_region() Ricardo Koller
2023-01-13 3:49 ` [PATCH 5/9] KVM: arm64: Add kvm_uninit_stage2_mmu() Ricardo Koller
2023-01-13 3:49 ` [PATCH 6/9] KVM: arm64: Split huge pages when dirty logging is enabled Ricardo Koller
2023-01-24 17:52 ` Ben Gardon
2023-01-24 22:19 ` Oliver Upton
2023-01-24 22:45 ` Oliver Upton
2023-01-26 18:45 ` Ricardo Koller
2023-01-26 19:25 ` Ricardo Koller
2023-01-26 20:10 ` Marc Zyngier
2023-01-27 15:45 ` Ricardo Koller
2023-01-30 21:18 ` Oliver Upton
2023-01-31 1:18 ` Sean Christopherson
2023-01-31 17:45 ` Oliver Upton
2023-01-31 17:54 ` Sean Christopherson
2023-01-31 19:06 ` Oliver Upton
2023-01-31 18:01 ` David Matlack
2023-01-31 18:19 ` Ricardo Koller
2023-01-31 18:35 ` Oliver Upton
2023-01-31 10:31 ` Marc Zyngier
2023-01-31 10:28 ` Marc Zyngier
2023-02-06 16:35 ` Ricardo Koller
2023-01-13 3:49 ` [PATCH 7/9] KVM: arm64: Open-code kvm_mmu_write_protect_pt_masked() Ricardo Koller
2023-01-13 3:49 ` [PATCH 8/9] KVM: arm64: Split huge pages during KVM_CLEAR_DIRTY_LOG Ricardo Koller
2023-01-13 3:50 ` [PATCH 9/9] KVM: arm64: Use local TLBI on permission relaxation Ricardo Koller
2023-01-24 0:48 ` [PATCH 0/9] KVM: arm64: Eager Huge-page splitting for dirty-logging Ben Gardon
2023-01-24 16:50 ` Ricardo Koller
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