From mboxrd@z Thu Jan  1 00:00:00 1970
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Subject: Re: [PATCH] KVM: Directly return result from
 kvm_arch_check_processor_compat()
References: <20190420051817.5644-1-sean.j.christopherson@intel.com>
From: Marc Zyngier <marc.zyngier@arm.com>
Message-ID: <0d34d373-5bba-2aac-2213-cf95184aa605@arm.com>
Date: Tue, 23 Apr 2019 11:14:58 +0100
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To: Sean Christopherson <sean.j.christopherson@intel.com>, James Hogan <jhogan@kernel.org>, Paul Mackerras <paulus@ozlabs.org>, Christian Borntraeger <borntraeger@de.ibm.com>, Janosch Frank <frankja@linux.ibm.com>, Paolo Bonzini <pbonzini@redhat.com>, =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= <rkrcmar@redhat.com>, Joerg Roedel <joro@8bytes.org>, Christoffer Dall <christoffer.dall@arm.com>
Cc: David Hildenbrand <david@redhat.com>, Cornelia Huck <cohuck@redhat.com>, James Morse <james.morse@arm.com>, Julien Thierry <julien.thierry@arm.com>, Suzuki K Pouloze <suzuki.poulose@arm.com>, linux-mips@vger.kernel.org, kvm-ppc@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu
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On 20/04/2019 06:18, Sean Christopherson wrote:
> Add a wrapper to invoke kvm_arch_check_processor_compat() so that the
> boilerplate ugliness of checking virtualization support on all CPUs is
> hidden from the arch specific code.  x86's implementation in particular
> is quite heinous, as it unnecessarily propagates the out-param pattern
> into kvm_x86_ops.
> 
> While the x86 specific issue could be resolved solely by changing
> kvm_x86_ops, make the change for all architectures as returning a value
> directly is prettier and technically more robust, e.g. s390 doesn't set
> the out param, which could lead to subtle breakage in the (highly
> unlikely) scenario where the out-param was not pre-initialized by the
> caller.
> 
> Opportunistically annotate svm_check_processor_compat() with __init.
> 
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>

Acked-by: Marc Zyngier <marc.zyngier@arm.com>

	M.
-- 
Jazz is not dead. It just smells funny...