From: "Lorenzo Stoakes (ARM)" <ljs@kernel.org>
To: Fuad Tabba <fuad.tabba@linux.dev>
Cc: sashiko-reviews@lists.linux.dev, Oliver Upton <oupton@kernel.org>,
kvmarm@lists.linux.dev, Marc Zyngier <maz@kernel.org>,
kvm@vger.kernel.org
Subject: Re: [PATCH v3 07/14] KVM: arm64: Size the stage-2 memcache from the fault MMU
Date: Wed, 23 Sep 2026 14:30:18 +0100 [thread overview]
Message-ID: <arPUT7DyofLwFhjt@gremlin> (raw)
In-Reply-To: <CA+EHjTziT=qEvCpjGriVhC5g7=nyQNfvEQenw-JXSJuWtJwTRg@mail.gmail.com>
On Wed, Sep 23, 2026 at 12:00:55PM +0100, Fuad Tabba wrote:
> Hi Lorenzo,
>
> On Tue, 22 Sep 2026 15:31:56 +0100, sashiko-bot@kernel.org wrote:
> [...]
> > Does this decoupling of s2fd->mmu and vcpu->arch.hw_mmu cause a spurious
> > allocation downstream in kvm_s2_fault_map()?
> [...]
> > Could this lead to an unnecessary allocation in the ioctl path that might
> > spuriously fail and return -ENOMEM to userspace?
>
> Sashiko might be right about this one, though the mismatch comes from
> patch 5 rather than this patch: patch 5 moves kvm_s2_fault_map()'s pgt
> to s2fd->mmu and leaves the allocation check above it on
> s2fd->vcpu->arch.hw_mmu. Could patch 5 switch that check to s2fd->mmu
> as well, the way gmem_abort() tests pgt->mmu?
Yeah oops, will do that for v4.
>
> This patch looks fine to me though.
>
> Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev>
Thanks!
>
> Cheers,
> /fuad
--
Cheers, Lorenzo
next prev parent reply other threads:[~2026-09-23 13:30 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-22 14:17 [PATCH v3 00/14] KVM: arm64: Add KVM_PRE_FAULT_MEMORY support Lorenzo Stoakes (ARM)
2026-09-22 14:17 ` [PATCH v3 01/14] KVM: Allow architectures to disallow pre-fault Lorenzo Stoakes (ARM)
2026-09-22 16:49 ` Oliver Upton
2026-09-22 17:23 ` Sean Christopherson
2026-09-22 17:30 ` Lorenzo Stoakes (ARM)
2026-09-22 17:36 ` Sean Christopherson
2026-09-22 18:01 ` Lorenzo Stoakes (ARM)
2026-09-22 18:40 ` Sean Christopherson
2026-09-22 18:52 ` Lorenzo Stoakes (ARM)
2026-09-22 18:07 ` Oliver Upton
2026-09-22 18:35 ` Lorenzo Stoakes (ARM)
2026-09-22 18:46 ` Sean Christopherson
2026-09-22 18:54 ` Lorenzo Stoakes (ARM)
2026-09-23 10:54 ` Fuad Tabba
2026-09-23 13:26 ` Lorenzo Stoakes (ARM)
2026-09-22 17:31 ` Lorenzo Stoakes (ARM)
2026-09-22 14:17 ` [PATCH v3 02/14] arm64: Add ESR fault helpers Lorenzo Stoakes (ARM)
2026-09-22 17:00 ` Oliver Upton
2026-09-22 17:45 ` Lorenzo Stoakes (ARM)
2026-09-22 18:13 ` Oliver Upton
2026-09-22 14:17 ` [PATCH v3 03/14] KVM: arm64: Use ESR helpers in guest abort handling Lorenzo Stoakes (ARM)
2026-09-22 14:17 ` [PATCH v3 04/14] KVM: arm64: Propagate and use esr in s2fd when handling guest aborts Lorenzo Stoakes (ARM)
2026-09-22 14:17 ` [PATCH v3 05/14] KVM: arm64: Propagate and use mmu " Lorenzo Stoakes (ARM)
2026-09-22 14:18 ` [PATCH v3 06/14] KVM: arm64: Propagate and use kvm_s2_fault_result on S2 fault Lorenzo Stoakes (ARM)
2026-09-22 14:18 ` [PATCH v3 07/14] KVM: arm64: Size the stage-2 memcache from the fault MMU Lorenzo Stoakes (ARM)
2026-09-22 14:31 ` sashiko-bot
2026-09-23 11:00 ` Fuad Tabba
2026-09-23 13:30 ` Lorenzo Stoakes (ARM) [this message]
2026-09-22 14:18 ` [PATCH v3 08/14] KVM: arm64: Propagate EHWPOISON in kvm_s2_fault_pin_pfn() Lorenzo Stoakes (ARM)
2026-09-23 11:05 ` Fuad Tabba
2026-09-22 14:18 ` [PATCH v3 09/14] KVM: arm64: Pass walk flags to kvm_pgtable_get_leaf() Lorenzo Stoakes (ARM)
2026-09-23 11:07 ` Fuad Tabba
2026-09-22 14:18 ` [PATCH v3 10/14] KVM: arm64: Implement KVM_PRE_FAULT_MEMORY Lorenzo Stoakes (ARM)
2026-09-23 11:18 ` Fuad Tabba
2026-09-23 13:28 ` Lorenzo Stoakes (ARM)
2026-09-23 13:32 ` Lorenzo Stoakes (ARM)
2026-09-23 13:33 ` Lorenzo Stoakes (ARM)
2026-09-22 14:18 ` [PATCH v3 11/14] Documentation: KVM: document arm64 KVM_PRE_FAULT_MEMORY Lorenzo Stoakes (ARM)
2026-09-22 14:18 ` [PATCH v3 12/14] KVM: selftests: Enable pre_fault_memory_test for arm64 Lorenzo Stoakes (ARM)
2026-09-22 14:18 ` [PATCH v3 13/14] KVM: selftests: Add option for different backing in pre-fault tests Lorenzo Stoakes (ARM)
2026-09-22 14:18 ` [PATCH v3 14/14] KVM: selftests: Add nested pre-fault test for arm64 Lorenzo Stoakes (ARM)
2026-09-22 20:42 ` [PATCH v3 00/14] KVM: arm64: Add KVM_PRE_FAULT_MEMORY support Oliver Upton
2026-09-23 10:03 ` Fuad Tabba
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