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From:   Fuad Tabba <tabba@google.com>
Date:   Mon, 2 Aug 2021 16:52:31 +0200
Message-ID: <CA+EHjTxrdA3wVsBe7zwvvGUGgoWuaGwuWCBL0k2+FcAdTGB=Qw@mail.gmail.com>
Subject: Re: [PATCH v3 15/21] KVM: arm64: Introduce addr_is_memory()
To:     Quentin Perret <qperret@google.com>
Cc:     maz@kernel.org, james.morse@arm.com, alexandru.elisei@arm.com,
        suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org,
        linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu,
        linux-kernel@vger.kernel.org, ardb@kernel.org, qwandor@google.com,
        dbrazdil@google.com, kernel-team@android.com
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Hi Quentin.

On Thu, Jul 29, 2021 at 3:28 PM Quentin Perret <qperret@google.com> wrote:
>
> Introduce a helper usable in nVHE protected mode to check whether a
> physical address is in a RAM region or not.
>
> Signed-off-by: Quentin Perret <qperret@google.com>
> ---
>  arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 1 +
>  arch/arm64/kvm/hyp/nvhe/mem_protect.c         | 7 +++++++
>  2 files changed, 8 insertions(+)
>
> diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
> index cc86598654b9..5968fbbb3514 100644
> --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
> +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
> @@ -51,6 +51,7 @@ extern const u8 pkvm_hyp_id;
>  int __pkvm_prot_finalize(void);
>  int __pkvm_mark_hyp(phys_addr_t start, phys_addr_t end);
>
> +bool addr_is_memory(phys_addr_t phys);

I'm just wondering about the naming of the function. I understand what
you're trying to achieve with it, but an address without a unit that
conveys size or type seems to be missing something. Would
memregion_addr_is_memory or something like that be a better
description, since it is what find_mem_range finds?

Thanks,
/fuad


>  int host_stage2_idmap_locked(u64 start, u64 end, enum kvm_pgtable_prot prot);
>  int host_stage2_set_owner_locked(u64 start, u64 end, u8 owner_id);
>  int kvm_host_prepare_stage2(void *pgt_pool_base);
> diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
> index bb18940c3d12..4532f3d55a1a 100644
> --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
> +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
> @@ -196,6 +196,13 @@ static bool find_mem_range(phys_addr_t addr, struct kvm_mem_range *range)
>         return false;
>  }
>
> +bool addr_is_memory(phys_addr_t phys)
> +{
> +       struct kvm_mem_range range;
> +
> +       return find_mem_range(phys, &range);
> +}
> +
>  static bool range_is_memory(u64 start, u64 end)
>  {
>         struct kvm_mem_range r1, r2;
> --
> 2.32.0.432.gabb21c7263-goog
>