From mboxrd@z Thu Jan  1 00:00:00 1970
From: Paul Mackerras <paulus@ozlabs.org>
Date: Mon, 20 Jan 2020 04:04:12 +0000
Subject: Re: [PATCH v2 12/45] KVM: PPC: Allocate vcpu struct in common PPC code
Message-Id: <20200120040412.GF14307@blackberry>
List-Id: <kvm-ppc.vger.kernel.org>
References: <20191218215530.2280-1-sean.j.christopherson@intel.com>
 <20191218215530.2280-13-sean.j.christopherson@intel.com>
In-Reply-To: <20191218215530.2280-13-sean.j.christopherson@intel.com>
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To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Marc Zyngier <maz@kernel.org>, James Hogan <jhogan@kernel.org>, Christian Borntraeger <borntraeger@de.ibm.com>, Janosch Frank <frankja@linux.ibm.com>, Paolo Bonzini <pbonzini@redhat.com>, James Morse <james.morse@arm.com>, Julien Thierry <julien.thierry.kdev@gmail.com>, Suzuki K Poulose <suzuki.poulose@arm.com>, David Hildenbrand <david@redhat.com>, Cornelia Huck <cohuck@redhat.com>, Vitaly Kuznetsov <vkuznets@redhat.com>, Wanpeng Li <wanpengli@tencent.com>, Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org, kvm-ppc@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Greg Kurz <groug@kaod.org>

On Wed, Dec 18, 2019 at 01:54:57PM -0800, Sean Christopherson wrote:
> Move allocation of all flavors of PPC vCPUs to common PPC code.  All
> variants either allocate 'struct kvm_vcpu' directly, or require that
> the embedded 'struct kvm_vcpu' member be located at offset 0, i.e.
> guarantee that the allocation can be directly interpreted as a 'struct
> kvm_vcpu' object.
> 
> Remove the message from the build-time assertion regarding placement of
> the struct, as compatibility with the arch usercopy region is no longer
> the sole dependent on 'struct kvm_vcpu' being at offset zero.
> 
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>

This fails to compile for Book E configs:

  CC      arch/powerpc/kvm/e500.o
/home/paulus/kernel/kvm/arch/powerpc/kvm/e500.c: In function ‘kvmppc_core_vcpu_create_e500’:
/home/paulus/kernel/kvm/arch/powerpc/kvm/e500.c:464:9: error: return makes integer from pointer without a cast [-Werror=int-conversion]
  return vcpu;
         ^
cc1: all warnings being treated as errors
make[3]: *** [/home/paulus/kernel/kvm/scripts/Makefile.build:266: arch/powerpc/kvm/e500.o] Error 1

There is a "return vcpu" statement in kvmppc_core_vcpu_create_e500(),
and another in kvmppc_core_vcpu_create_e500mc(), which both need to be
changed to "return 0".

(By the way, I do appreciate you fixing the PPC code, even if there
are some errors.)

Paul.