Re: [PATCH v3 10/15] KVM: arm64: Introduce wrappers for host and hyp spin lock accessors

Will Deacon
2021-12-14T14:54:09Z

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