From: Will Deacon <will@kernel.org>
To: Andrew Walbran <qwandor@google.com>
Cc: Quentin Perret <qperret@google.com>,
Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
kernel-team@android.com
Subject: Re: [PATCH v3 10/15] KVM: arm64: Introduce wrappers for host and hyp spin lock accessors
Date: Tue, 14 Dec 2021 14:52:23 +0000 [thread overview]
Message-ID: <20211214145222.GC14837@willie-the-truck> (raw)
In-Reply-To: <CA+_y_2HKwtm5839QyEY9D8PaZWky_Zvn3msrw2gcR2Z7UZgObQ@mail.gmail.com>
On Tue, Dec 14, 2021 at 02:48:30PM +0000, Andrew Walbran wrote:
> On Wed, 1 Dec 2021 at 17:04, 'Quentin Perret' via kernel-team
> <kernel-team@android.com> wrote:
> >
> > From: Will Deacon <will@kernel.org>
> >
> > In preparation for adding additional locked sections for manipulating
> > page-tables at EL2, introduce some simple wrappers around the host and
> > hypervisor locks so that it's a bit easier to read and bit more difficult
> > to take the wrong lock (or even take them in the wrong order).
> Looks good, but how does this help prevent taking locks in the wrong order?
I just found that I would easily forget what exactly was protected by
"pkvm_pgd_lock" and so relating that back to "take host before hyp" was
error-prone. Having helpers with "host" and "hyp" in the name helps me with
that, at least.
Will
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next prev parent reply other threads:[~2021-12-14 14:54 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-01 17:03 [PATCH v3 00/15] KVM: arm64: Introduce kvm_share_hyp() Quentin Perret
2021-12-01 17:03 ` [PATCH v3 01/15] KVM: arm64: Check if running in VHE from kvm_host_owns_hyp_mappings() Quentin Perret
2021-12-09 10:10 ` Will Deacon
2021-12-10 13:37 ` Quentin Perret
2021-12-01 17:03 ` [PATCH v3 02/15] KVM: arm64: Provide {get, put}_page() stubs for early hyp allocator Quentin Perret
2021-12-09 10:12 ` [PATCH v3 02/15] KVM: arm64: Provide {get,put}_page() " Will Deacon
2021-12-01 17:03 ` [PATCH v3 03/15] KVM: arm64: Refcount hyp stage-1 pgtable pages Quentin Perret
2021-12-09 10:29 ` Will Deacon
2021-12-10 14:34 ` Quentin Perret
2021-12-13 12:53 ` Will Deacon
2021-12-01 17:03 ` [PATCH v3 04/15] KVM: arm64: Fixup hyp stage-1 refcount Quentin Perret
2021-12-09 11:09 ` Will Deacon
2021-12-01 17:03 ` [PATCH v3 05/15] KVM: arm64: Hook up ->page_count() for hypervisor stage-1 page-table Quentin Perret
2021-12-01 17:04 ` [PATCH v3 06/15] KVM: arm64: Implement kvm_pgtable_hyp_unmap() at EL2 Quentin Perret
2021-12-07 14:47 ` Andrew Walbran
2021-12-08 9:51 ` Quentin Perret
2021-12-08 14:40 ` Andrew Walbran
2021-12-15 16:02 ` Quentin Perret
2021-12-01 17:04 ` [PATCH v3 07/15] KVM: arm64: Introduce kvm_share_hyp() Quentin Perret
2021-12-09 11:13 ` Will Deacon
2021-12-10 14:37 ` Quentin Perret
2021-12-01 17:04 ` [PATCH v3 08/15] KVM: arm64: pkvm: Refcount the pages shared with EL2 Quentin Perret
2021-12-09 11:16 ` Will Deacon
2021-12-01 17:04 ` [PATCH v3 09/15] KVM: arm64: Extend pkvm_page_state enumeration to handle absent pages Quentin Perret
2021-12-14 14:47 ` Andrew Walbran
2021-12-01 17:04 ` [PATCH v3 10/15] KVM: arm64: Introduce wrappers for host and hyp spin lock accessors Quentin Perret
2021-12-14 14:48 ` Andrew Walbran
2021-12-14 14:52 ` Will Deacon [this message]
2021-12-01 17:04 ` [PATCH v3 11/15] KVM: arm64: Implement do_share() helper for sharing memory Quentin Perret
2021-12-10 15:18 ` Andrew Walbran
2021-12-01 17:04 ` [PATCH v3 12/15] KVM: arm64: Implement __pkvm_host_share_hyp() using do_share() Quentin Perret
2021-12-01 17:04 ` [PATCH v3 13/15] KVM: arm64: Implement do_unshare() helper for unsharing memory Quentin Perret
2021-12-10 15:08 ` Andrew Walbran
2021-12-01 17:04 ` [PATCH v3 14/15] KVM: arm64: Expose unshare hypercall to the host Quentin Perret
2021-12-01 17:04 ` [PATCH v3 15/15] KVM: arm64: pkvm: Unshare guest structs during teardown Quentin Perret
2021-12-09 11:22 ` Will Deacon
2021-12-10 14:48 ` Quentin Perret
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