From: Marc Zyngier <maz@kernel.org>
To: Quentin Perret <qperret@google.com>
Cc: 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, tabba@google.com,
dbrazdil@google.com, kernel-team@android.com
Subject: Re: [PATCH v2 04/16] KVM: arm64: Optimize host memory aborts
Date: Mon, 26 Jul 2021 14:24:43 +0100 [thread overview]
Message-ID: <87mtq9dx7o.wl-maz@kernel.org> (raw)
In-Reply-To: <YP604j6B1pkhAnT1@google.com>
On Mon, 26 Jul 2021 14:13:06 +0100,
Quentin Perret <qperret@google.com> wrote:
>
> On Monday 26 Jul 2021 at 11:35:10 (+0100), Marc Zyngier wrote:
[...]
> > You could also use a kvm_mem_range for the iteration, and add a helper
> > that checks for the inclusion.
>
> Something like this (untested)?
>
> diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
> index 75273166d2c5..07d228163090 100644
> --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
> +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
> @@ -234,9 +234,15 @@ static inline int __host_stage2_idmap(u64 start, u64 end,
> __ret; \
> })
>
> +static inline bool range_included(struct kvm_mem_range *child,
> + struct kvm_mem_range *parent)
> +{
> + return parent->start <= child->start && child->end <= parent->end;
> +}
> +
> static int host_stage2_find_range(u64 addr, struct kvm_mem_range *range)
> {
> - u64 granule, start, end;
> + struct kvm_mem_range cur;
> kvm_pte_t pte;
> u32 level;
> int ret;
> @@ -252,16 +258,15 @@ static int host_stage2_find_range(u64 addr, struct kvm_mem_range *range)
> return -EPERM;
>
> do {
> - granule = kvm_granule_size(level);
> - start = ALIGN_DOWN(addr, granule);
> - end = start + granule;
> + u64 granule = kvm_granule_size(level);
> + cur.start = ALIGN_DOWN(addr, granule);
> + cur.end = cur.start + granule;
> level++;
> } while ((level < KVM_PGTABLE_MAX_LEVELS) &&
> - (!kvm_level_supports_block_mapping(level) ||
> - start < range->start || range->end < end));
> + !(kvm_level_supports_block_mapping(level) &&
> + range_included(&cur, parent)));
>
> - range->start = start;
> - range->end = end;
> + *range = cur;
>
> return 0;
> }
>
Beautiful.
M.
--
Without deviation from the norm, progress is not possible.
next prev parent reply other threads:[~2021-07-26 13:24 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-26 9:28 [PATCH v2 00/16] Track shared pages at EL2 in protected mode Quentin Perret
2021-07-26 9:28 ` [PATCH v2 01/16] KVM: arm64: Introduce helper to retrieve a PTE and its level Quentin Perret
2021-07-26 9:28 ` [PATCH v2 02/16] KVM: arm64: Provide the host_stage2_try() helper macro Quentin Perret
2021-07-26 9:28 ` [PATCH v2 03/16] KVM: arm64: Expose page-table helpers Quentin Perret
2021-07-26 9:28 ` [PATCH v2 04/16] KVM: arm64: Optimize host memory aborts Quentin Perret
2021-07-26 10:35 ` Marc Zyngier
2021-07-26 13:13 ` Quentin Perret
2021-07-26 13:24 ` Marc Zyngier [this message]
2021-07-26 9:28 ` [PATCH v2 05/16] KVM: arm64: Rename KVM_PTE_LEAF_ATTR_S2_IGNORED Quentin Perret
2021-07-26 9:28 ` [PATCH v2 06/16] KVM: arm64: Don't overwrite software bits with owner id Quentin Perret
2021-07-26 9:28 ` [PATCH v2 07/16] KVM: arm64: Tolerate re-creating hyp mappings to set software bits Quentin Perret
2021-07-26 9:28 ` [PATCH v2 08/16] KVM: arm64: Enable forcing page-level stage-2 mappings Quentin Perret
2021-07-26 9:28 ` [PATCH v2 09/16] KVM: arm64: Allow populating software bits Quentin Perret
2021-07-26 9:28 ` [PATCH v2 10/16] KVM: arm64: Add helpers to tag shared pages in SW bits Quentin Perret
2021-07-26 9:29 ` [PATCH v2 11/16] KVM: arm64: Introduce and export host_stage2_idmap_locked() Quentin Perret
2021-07-26 9:29 ` [PATCH v2 12/16] KVM: arm64: Mark host bss and rodata section as shared Quentin Perret
2021-07-28 12:14 ` Quentin Perret
2021-07-26 9:29 ` [PATCH v2 13/16] KVM: arm64: Enable retrieving protections attributes of PTEs Quentin Perret
2021-07-26 9:29 ` [PATCH v2 14/16] KVM: arm64: Refactor protected nVHE stage-1 locking Quentin Perret
2021-07-26 9:29 ` [PATCH v2 15/16] KVM: arm64: Restrict EL2 stage-1 changes in protected mode Quentin Perret
2021-07-26 11:27 ` Marc Zyngier
2021-07-26 12:55 ` Quentin Perret
2021-07-26 9:29 ` [PATCH v2 16/16] KVM: arm64: Make __pkvm_create_mappings static Quentin Perret
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