From: David Brazdil <dbrazdil@google.com>
To: Will Deacon <will@kernel.org>
Cc: kvmarm@lists.cs.columbia.edu,
Catalin Marinas <catalin.marinas@arm.com>,
Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Dennis Zhou <dennis@kernel.org>, Tejun Heo <tj@kernel.org>,
Christoph Lameter <cl@linux.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, kernel-team@android.com
Subject: Re: [PATCH v3 07/11] kvm: arm64: Duplicate arm64_ssbd_callback_required for nVHE hyp
Date: Tue, 22 Sep 2020 19:07:45 +0100 [thread overview]
Message-ID: <20200922180745.m6bjgjzz6cwercgf@google.com> (raw)
In-Reply-To: <20200918115911.GB31096@willie-the-truck>
> > u64 *ptr;
> >
> > - ptr = per_cpu_ptr(&arm64_ssbd_callback_required, cpu);
> > + ptr = per_cpu_ptr_nvhe(arm64_ssbd_callback_required, cpu);
> > err = create_hyp_mappings(ptr, ptr + 1, PAGE_HYP);
> > if (err)
> > return err;
> > +
> > + /* Copy value from kernel to hyp. */
> > + *ptr = per_cpu(arm64_ssbd_callback_required, cpu);
>
> Hmm. Is this correct for late arriving CPUs, where we don't know whether
> a callback is required at the point we do the copy?
>
> That sounds fiddly to resolve, but this _might_ all be moot because I'm
> about to post a series that allows us to remove the hyp mapping of this
> variable entirely. So leave this for now, but maybe stick a comment in
> that it doesn't work for late cpus.
Ah, good point. I'll move the value copy at the end of cpu_init_hyp_mode().
It must be known at that point. And if your series gets rid of this completely,
even better.
next prev parent reply other threads:[~2020-09-22 18:07 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-16 17:34 [PATCH v3 00/10] Independent per-CPU data section for nVHE David Brazdil
2020-09-16 17:34 ` [PATCH v3 01/11] kvm: arm64: Partially link nVHE hyp code, simplify HYPCOPY David Brazdil
2020-09-18 8:51 ` Will Deacon
2020-09-22 17:55 ` David Brazdil
2020-09-16 17:34 ` [PATCH v3 02/11] kvm: arm64: Move nVHE hyp namespace macros to hyp_image.h David Brazdil
2020-09-18 8:52 ` Will Deacon
2020-09-16 17:34 ` [PATCH v3 03/11] kvm: arm64: Only define __kvm_ex_table for CONFIG_KVM David Brazdil
2020-09-18 9:00 ` Will Deacon
2020-09-16 17:34 ` [PATCH v3 04/11] kvm: arm64: Remove __hyp_this_cpu_read David Brazdil
2020-09-18 9:00 ` Will Deacon
2020-09-21 13:43 ` David Brazdil
2020-09-16 17:34 ` [PATCH v3 05/11] kvm: arm64: Remove hyp_adr/ldr_this_cpu David Brazdil
2020-09-18 9:05 ` Will Deacon
2020-09-21 14:53 ` David Brazdil
2020-09-21 17:15 ` Will Deacon
2020-09-16 17:34 ` [PATCH v3 06/11] kvm: arm64: Add helpers for accessing nVHE hyp per-cpu vars David Brazdil
2020-09-18 9:24 ` Will Deacon
2020-09-16 17:34 ` [PATCH v3 07/11] kvm: arm64: Duplicate arm64_ssbd_callback_required for nVHE hyp David Brazdil
2020-09-18 11:59 ` Will Deacon
2020-09-22 18:07 ` David Brazdil [this message]
2020-09-16 17:34 ` [PATCH v3 08/11] kvm: arm64: Create separate instances of kvm_host_data for VHE/nVHE David Brazdil
2020-09-18 11:58 ` Will Deacon
2020-09-16 17:34 ` [PATCH v3 09/11] kvm: arm64: Mark hyp stack pages reserved David Brazdil
2020-09-18 12:00 ` Will Deacon
2020-09-22 18:08 ` David Brazdil
2020-09-16 17:34 ` [PATCH v3 10/11] kvm: arm64: Set up hyp percpu data for nVHE David Brazdil
2020-09-18 12:22 ` Will Deacon
2020-09-22 18:34 ` David Brazdil
2020-09-16 17:34 ` [PATCH v3 11/11] kvm: arm64: Remove unnecessary hyp mappings David Brazdil
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