From: Andrew Walbran <qwandor@google.com>
To: Quentin Perret <qperret@google.com>
Cc: Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>,
alexandru.elisei@arm.com,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
ardb@kernel.org, Fuad Tabba <tabba@google.com>,
David Brazdil <dbrazdil@google.com>,
Android Kernel Team <kernel-team@android.com>
Subject: Re: [PATCH v4 04/21] KVM: arm64: Introduce helper to retrieve a PTE and its level
Date: Tue, 17 Aug 2021 14:53:11 +0100 [thread overview]
Message-ID: <CA+_y_2EsStP+zNOfykjrmJBx6a1pxaewC2X9TnXnj3kNpixsWg@mail.gmail.com> (raw)
In-Reply-To: <20210809152448.1810400-5-qperret@google.com>
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On Mon, 9 Aug 2021 at 16:25, Quentin Perret <qperret@google.com> wrote:
>
> From: Marc Zyngier <maz@kernel.org>
>
> It is becoming a common need to fetch the PTE for a given address
> together with its level. Add such a helper.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> Signed-off-by: Quentin Perret <qperret@google.com>
> ---
> arch/arm64/include/asm/kvm_pgtable.h | 19 ++++++++++++++
> arch/arm64/kvm/hyp/pgtable.c | 39 ++++++++++++++++++++++++++++
> 2 files changed, 58 insertions(+)
>
> diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
> index f004c0115d89..082b9d65f40b 100644
> --- a/arch/arm64/include/asm/kvm_pgtable.h
> +++ b/arch/arm64/include/asm/kvm_pgtable.h
> @@ -432,6 +432,25 @@ int kvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size);
> int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size,
> struct kvm_pgtable_walker *walker);
>
> +/**
> + * kvm_pgtable_get_leaf() - Walk a page-table and retrieve the leaf entry
> + * with its level.
> + * @pgt: Page-table structure initialised by kvm_pgtable_*_init().
> + * @addr: Input address for the start of the walk.
> + * @ptep: Pointer to storage for the retrieved PTE.
> + * @level: Pointer to storage for the level of the retrieved PTE.
> + *
> + * The offset of @addr within a page is ignored.
> + *
> + * The walker will walk the page-table entries corresponding to the input
> + * address specified, retrieving the leaf corresponding to this address.
> + * Invalid entries are treated as leaf entries.
> + *
> + * Return: 0 on success, negative error code on failure.
> + */
> +int kvm_pgtable_get_leaf(struct kvm_pgtable *pgt, u64 addr,
> + kvm_pte_t *ptep, u32 *level);
> +
> /**
> * kvm_pgtable_stage2_find_range() - Find a range of Intermediate Physical
> * Addresses with compatible permission
> diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
> index 05321f4165e3..78f36bd5df6c 100644
> --- a/arch/arm64/kvm/hyp/pgtable.c
> +++ b/arch/arm64/kvm/hyp/pgtable.c
> @@ -326,6 +326,45 @@ int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size,
> return _kvm_pgtable_walk(&walk_data);
> }
>
> +struct leaf_walk_data {
> + kvm_pte_t pte;
> + u32 level;
> +};
> +
> +static int leaf_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
> + enum kvm_pgtable_walk_flags flag, void * const arg)
> +{
> + struct leaf_walk_data *data = arg;
> +
> + data->pte = *ptep;
> + data->level = level;
> +
> + return 0;
> +}
> +
> +int kvm_pgtable_get_leaf(struct kvm_pgtable *pgt, u64 addr,
> + kvm_pte_t *ptep, u32 *level)
> +{
> + struct leaf_walk_data data;
> + struct kvm_pgtable_walker walker = {
> + .cb = leaf_walker,
> + .flags = KVM_PGTABLE_WALK_LEAF,
> + .arg = &data,
> + };
> + int ret;
> +
> + ret = kvm_pgtable_walk(pgt, ALIGN_DOWN(addr, PAGE_SIZE),
> + PAGE_SIZE, &walker);
> + if (!ret) {
> + if (ptep)
> + *ptep = data.pte;
> + if (level)
> + *level = data.level;
> + }
> +
> + return ret;
> +}
> +
> struct hyp_map_data {
> u64 phys;
> kvm_pte_t attr;
> --
> 2.32.0.605.g8dce9f2422-goog
>
Reviewed-by: Andrew Walbran <qwandor@google.com>
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next prev parent reply other threads:[~2021-08-17 13:53 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-09 15:24 [PATCH v4 00/21] Track shared pages at EL2 in protected mode Quentin Perret
2021-08-09 15:24 ` [PATCH v4 01/21] KVM: arm64: Add hyp_spin_is_locked() for basic locking assertions at EL2 Quentin Perret
2021-08-09 15:24 ` [PATCH v4 02/21] KVM: arm64: Introduce hyp_assert_lock_held() Quentin Perret
2021-08-09 15:24 ` [PATCH v4 03/21] KVM: arm64: Provide the host_stage2_try() helper macro Quentin Perret
2021-08-09 15:24 ` [PATCH v4 04/21] KVM: arm64: Introduce helper to retrieve a PTE and its level Quentin Perret
2021-08-17 13:53 ` Andrew Walbran [this message]
2021-08-09 15:24 ` [PATCH v4 05/21] KVM: arm64: Expose page-table helpers Quentin Perret
2021-08-10 4:56 ` Fuad Tabba
2021-08-09 15:24 ` [PATCH v4 06/21] KVM: arm64: Optimize host memory aborts Quentin Perret
2021-08-09 15:24 ` [PATCH v4 07/21] KVM: arm64: Rename KVM_PTE_LEAF_ATTR_S2_IGNORED Quentin Perret
2021-08-09 15:24 ` [PATCH v4 08/21] KVM: arm64: Don't overwrite software bits with owner id Quentin Perret
2021-08-09 15:24 ` [PATCH v4 09/21] KVM: arm64: Tolerate re-creating hyp mappings to set software bits Quentin Perret
2021-08-09 15:24 ` [PATCH v4 10/21] KVM: arm64: Enable forcing page-level stage-2 mappings Quentin Perret
2021-08-10 4:33 ` Fuad Tabba
2021-08-09 15:24 ` [PATCH v4 11/21] KVM: arm64: Allow populating software bits Quentin Perret
2021-08-10 4:56 ` Fuad Tabba
2021-08-09 15:24 ` [PATCH v4 12/21] KVM: arm64: Add helpers to tag shared pages in SW bits Quentin Perret
2021-08-09 15:24 ` [PATCH v4 13/21] KVM: arm64: Expose host stage-2 manipulation helpers Quentin Perret
2021-08-10 4:36 ` Fuad Tabba
2021-08-09 15:24 ` [PATCH v4 14/21] KVM: arm64: Expose pkvm_hyp_id Quentin Perret
2021-08-10 4:57 ` Fuad Tabba
2021-08-09 15:24 ` [PATCH v4 15/21] KVM: arm64: Introduce addr_is_memory() Quentin Perret
2021-08-10 4:37 ` Fuad Tabba
2021-08-09 15:24 ` [PATCH v4 16/21] KVM: arm64: Enable retrieving protections attributes of PTEs Quentin Perret
2021-08-10 4:38 ` Fuad Tabba
2021-08-09 15:24 ` [PATCH v4 17/21] KVM: arm64: Mark host bss and rodata section as shared Quentin Perret
2021-08-10 4:40 ` Fuad Tabba
2021-08-09 15:24 ` [PATCH v4 18/21] KVM: arm64: Remove __pkvm_mark_hyp Quentin Perret
2021-08-10 4:55 ` Fuad Tabba
2021-08-09 15:24 ` [PATCH v4 19/21] KVM: arm64: Refactor protected nVHE stage-1 locking Quentin Perret
2021-08-10 4:41 ` Fuad Tabba
2021-08-09 15:24 ` [PATCH v4 20/21] KVM: arm64: Restrict EL2 stage-1 changes in protected mode Quentin Perret
2021-08-10 4:43 ` Fuad Tabba
2021-08-09 15:24 ` [PATCH v4 21/21] KVM: arm64: Make __pkvm_create_mappings static Quentin Perret
2021-08-10 4:55 ` Fuad Tabba
2021-08-11 11:25 ` [PATCH v4 00/21] Track shared pages at EL2 in protected mode Marc Zyngier
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