From: Will Deacon <will@kernel.org>
To: Marc Zyngier <maz@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org, kernel-team@android.com,
ascull@google.com, tabba@google.com, dbrazdil@google.com,
James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>
Subject: Re: [PATCH] KVM: arm64: Clarify vcpu reset behaviour
Date: Thu, 8 Apr 2021 11:53:35 +0100 [thread overview]
Message-ID: <20210408105334.GA17280@willie-the-truck> (raw)
In-Reply-To: <bbb4d999fe0bc9762c930dafa56a8847@kernel.org>
On Thu, Apr 08, 2021 at 11:36:34AM +0100, Marc Zyngier wrote:
> On 2021-04-07 21:35, Will Deacon wrote:
> > On Tue, Apr 06, 2021 at 01:58:41PM +0100, Marc Zyngier wrote:
> > > Although the KVM_ARM_VCPU_INIT documentation mention that the
> > > registers are reset to their "initial values", it doesn't
> > > describe what these values are.
> > >
> > > Describe this state explicitly.
> > >
> > > Signed-off-by: Marc Zyngier <maz@kernel.org>
> > > ---
> > > Documentation/virt/kvm/api.rst | 10 ++++++++++
> > > 1 file changed, 10 insertions(+)
> > >
> > > diff --git a/Documentation/virt/kvm/api.rst
> > > b/Documentation/virt/kvm/api.rst
> > > index 38e327d4b479..e2237e4e10ba 100644
> > > --- a/Documentation/virt/kvm/api.rst
> > > +++ b/Documentation/virt/kvm/api.rst
> > > @@ -3115,6 +3115,16 @@ optional features it should have. This will
> > > cause a reset of the cpu
> > > registers to their initial values. If this is not called, KVM_RUN
> > > will
> > > return ENOEXEC for that vcpu.
> > >
> > > +The initial values are defined as:
> > > + - Processor state:
> > > + * AArch64: EL1h, D, A, I and F bits set
> > > + * Aarch32: SVC, D, A, I and F bits set
> >
> > nit, but capitalisation should be "AArch32"
> >
> > Is "SVC" sufficient, or do we also need to describe Arm vs Thumb?
>
> SVC doesn't describe the instruction set, but we don't say that PSR.T
> is set, which implies ARM.
Ah yes, thanks.
> I can add something like "All other bits are set to 0", if that makes it
> clearer.
I think that would be worth adding. With that and the minor typo fix:
Acked-by: Will Deacon <will@kernel.org>
Will
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next prev parent reply other threads:[~2021-04-08 10:55 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-06 12:58 [PATCH] KVM: arm64: Clarify vcpu reset behaviour Marc Zyngier
2021-04-07 15:59 ` Alexandru Elisei
2021-04-07 16:26 ` Marc Zyngier
2021-04-07 20:35 ` Will Deacon
2021-04-08 10:36 ` Marc Zyngier
2021-04-08 10:53 ` Will Deacon [this message]
2021-04-08 13:14 ` Marc Zyngier
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