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Subject: Re: [PATCH 6/9] KVM: arm64: Provide a PV_TIME device to user space
To:     Marc Zyngier <maz@kernel.org>
Cc:     kvm@vger.kernel.org, linux-doc@vger.kernel.org,
        Catalin Marinas <catalin.marinas@arm.com>,
        linux-kernel@vger.kernel.org, Russell King <linux@armlinux.org.uk>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Will Deacon <will@kernel.org>, kvmarm@lists.cs.columbia.edu,
        linux-arm-kernel@lists.infradead.org
References: <20190802145017.42543-1-steven.price@arm.com>
 <20190802145017.42543-7-steven.price@arm.com> <20190803135113.6cdf500c@why>
 <20190803183335.149e0113@why>
From:   Steven Price <steven.price@arm.com>
Message-ID: <5aa54066-b9f6-22d1-fa2b-ce5cbf244ab5@arm.com>
Date:   Wed, 7 Aug 2019 14:39:13 +0100
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On 03/08/2019 18:34, Marc Zyngier wrote:
> On Sat, 3 Aug 2019 13:51:13 +0100
> Marc Zyngier <maz@kernel.org> wrote:
> 
> [forgot that one]
> 
>> On Fri,  2 Aug 2019 15:50:14 +0100
>> Steven Price <steven.price@arm.com> wrote:
> 
> [...]
> 
>>> +static int __init kvm_pvtime_init(void)
>>> +{
>>> +	kvm_register_device_ops(&pvtime_ops, KVM_DEV_TYPE_ARM_PV_TIME);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +late_initcall(kvm_pvtime_init);
> 
> Why is it an initcall? So far, the only initcall we've used is the one
> that initializes KVM itself. Can't we just the device_ops just like we
> do for the vgic?

So would you prefer a direct call from init_subsystems() in
virt/kvm/arm/arm.c?

The benefit of initcall is just that it keeps the code self-contained.
In init_subsystems() I'd either need a #ifdef CONFIG_ARM64 or a dummy
function for arm.

Steve