From: Oliver Upton <oliver.upton@linux.dev>
To: Sebastian Ene <sebastianene@google.com>
Cc: will@kernel.org, James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
catalin.marinas@arm.com, mark.rutland@arm.com,
akpm@linux-foundation.org, maz@kernel.org,
kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, kernel-team@android.com,
vdonnefort@google.com, qperret@google.com, smostafa@google.com
Subject: Re: [PATCH v3 10/10] arm64: ptdump: Add support for guest stage-2 pagetables dumping
Date: Wed, 22 Nov 2023 23:35:57 +0000 [thread overview]
Message-ID: <ZV6QXSV_SrYjjoE_@linux.dev> (raw)
In-Reply-To: <20231115171639.2852644-12-sebastianene@google.com>
On Wed, Nov 15, 2023 at 05:16:40PM +0000, Sebastian Ene wrote:
> +struct ptdump_registered_guest {
> + struct list_head reg_list;
> + struct ptdump_info info;
> + struct kvm_pgtable_snapshot snapshot;
> + rwlock_t *lock;
> +};
Why can't we just store a pointer directly to struct kvm in ::private?
Also, shouldn't you take a reference on struct kvm when the file is
opened to protect against VM teardown?
> +static LIST_HEAD(ptdump_guest_list);
> +static DEFINE_MUTEX(ptdump_list_lock);
What is the list for?
> static phys_addr_t ptdump_host_pa(void *addr)
> {
> return __pa(addr);
> @@ -757,6 +768,63 @@ static void stage2_ptdump_walk(struct seq_file *s, struct ptdump_info *info)
> kvm_pgtable_walk(pgtable, start_ipa, end_ipa, &walker);
> }
>
> +static void guest_stage2_ptdump_walk(struct seq_file *s,
> + struct ptdump_info *info)
> +{
> + struct ptdump_info_file_priv *f_priv =
> + container_of(info, struct ptdump_info_file_priv, info);
> + struct ptdump_registered_guest *guest = info->priv;
> +
> + f_priv->file_priv = &guest->snapshot;
> +
> + read_lock(guest->lock);
> + stage2_ptdump_walk(s, info);
> + read_unlock(guest->lock);
Taking the mmu lock for read allows other table walkers to add new
mappings and adjust the granularity of existing ones. Should this
instead take the mmu lock for write?
> +}
> +
> +int ptdump_register_guest_stage2(struct kvm *kvm)
> +{
> + struct ptdump_registered_guest *guest;
> + struct kvm_s2_mmu *mmu = &kvm->arch.mmu;
> + struct kvm_pgtable *pgt = mmu->pgt;
> +
> + guest = kzalloc(sizeof(struct ptdump_registered_guest), GFP_KERNEL);
You want GFP_KERNEL_ACCOUNT here.
--
Thanks,
Oliver
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next prev parent reply other threads:[~2023-11-22 23:36 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-15 17:16 [PATCH v3 00/10] arm64: ptdump: View the second stage page-tables Sebastian Ene
2023-11-15 17:16 ` [PATCH v3 01/10] KVM: arm64: Add snap shooting the host stage-2 pagetables Sebastian Ene
2023-11-21 14:12 ` Vincent Donnefort
2023-11-23 14:40 ` Sebastian Ene
2023-11-15 17:16 ` [PATCH v3 02/10] arm64: ptdump: Use the mask from the state structure Sebastian Ene
2023-11-15 17:16 ` [PATCH v3 03/10] arm64: ptdump: Add the walker function to the ptdump info structure Sebastian Ene
2023-11-15 17:16 ` [PATCH v3 04/10] KVM: arm64: Move pagetable definitions to common header Sebastian Ene
2023-11-15 17:16 ` [PATCH v3 05/10] arm64: ptdump: Add hooks on debugfs file operations Sebastian Ene
2023-11-22 14:36 ` Vincent Donnefort
2023-11-15 17:16 ` [PATCH v3 06/10] arm64: ptdump: Register a debugfs entry for the host stage-2 tables Sebastian Ene
2023-11-21 17:13 ` Vincent Donnefort
2023-11-23 14:48 ` Sebastian Ene
2023-11-15 17:16 ` [PATCH v3 07/10] arm64: ptdump: Parse the host stage-2 page-tables from the snapshot Sebastian Ene
2023-11-15 21:57 ` kernel test robot
2023-11-18 22:39 ` kernel test robot
2023-11-15 17:16 ` [PATCH v3 08/10] arm64: ptdump: Interpret memory attributes based on runtime configuration Sebastian Ene
2023-11-15 17:16 ` [PATCH v3 09/10] arm64: ptdump: Interpret pKVM ownership annotations Sebastian Ene
2023-11-15 17:16 ` [PATCH v3 10/10] arm64: ptdump: Add support for guest stage-2 pagetables dumping Sebastian Ene
2023-11-22 23:35 ` Oliver Upton [this message]
2023-11-23 10:58 ` Sebastian Ene
2023-11-22 23:18 ` [PATCH v3 00/10] arm64: ptdump: View the second stage page-tables Oliver Upton
2023-11-23 9:49 ` Sebastian Ene
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