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References: <20210809152448.1810400-1-qperret@google.com> <20210809152448.1810400-14-qperret@google.com>
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From:   Fuad Tabba <tabba@google.com>
Date:   Tue, 10 Aug 2021 06:36:27 +0200
Message-ID: <CA+EHjTyb2Ge1QBXyRaTmXfjB=2uy2y-EDxag-Oyy03paAt4tvg@mail.gmail.com>
Subject: Re: [PATCH v4 13/21] KVM: arm64: Expose host stage-2 manipulation helpers
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 Mon, Aug 9, 2021 at 5:25 PM Quentin Perret <qperret@google.com> wrote:
>
> We will need to manipulate the host stage-2 page-table from outside
> mem_protect.c soon. Introduce two functions allowing this, and make
> them usable to users of mem_protect.h.
>
> Signed-off-by: Quentin Perret <qperret@google.com>

Reviewed-by: Fuad Tabba <tabba@google.com>

Thanks,
/fuad

> ---
>  arch/arm64/kvm/hyp/include/nvhe/mem_protect.h |  2 ++
>  arch/arm64/kvm/hyp/nvhe/mem_protect.c         | 18 +++++++++++++++++-
>  2 files changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
> index 87b1690c439f..0849ee8fa260 100644
> --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
> +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
> @@ -49,6 +49,8 @@ extern struct host_kvm host_kvm;
>  int __pkvm_prot_finalize(void);
>  int __pkvm_mark_hyp(phys_addr_t start, phys_addr_t end);
>
> +int host_stage2_idmap_locked(phys_addr_t addr, u64 size, enum kvm_pgtable_prot prot);
> +int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id);
>  int kvm_host_prepare_stage2(void *pgt_pool_base);
>  void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt);
>
> diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
> index 6fed6772c673..f95a5a4aa09c 100644
> --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
> +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
> @@ -273,6 +273,22 @@ static int host_stage2_adjust_range(u64 addr, struct kvm_mem_range *range)
>         return 0;
>  }
>
> +int host_stage2_idmap_locked(phys_addr_t addr, u64 size,
> +                            enum kvm_pgtable_prot prot)
> +{
> +       hyp_assert_lock_held(&host_kvm.lock);
> +
> +       return host_stage2_try(__host_stage2_idmap, addr, addr + size, prot);
> +}
> +
> +int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id)
> +{
> +       hyp_assert_lock_held(&host_kvm.lock);
> +
> +       return host_stage2_try(kvm_pgtable_stage2_set_owner, &host_kvm.pgt,
> +                              addr, size, &host_s2_pool, owner_id);
> +}
> +
>  static bool host_stage2_force_pte_cb(u64 addr, u64 end, enum kvm_pgtable_prot prot)
>  {
>         /*
> @@ -309,7 +325,7 @@ static int host_stage2_idmap(u64 addr)
>         if (ret)
>                 goto unlock;
>
> -       ret = host_stage2_try(__host_stage2_idmap, range.start, range.end, prot);
> +       ret = host_stage2_idmap_locked(range.start, range.end - range.start, prot);
>  unlock:
>         hyp_spin_unlock(&host_kvm.lock);
>
> --
> 2.32.0.605.g8dce9f2422-goog
>