From mboxrd@z Thu Jan  1 00:00:00 1970
From: Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: RFC: KVM _CREATE_DEVICE considered harmful?
Date: Wed, 16 Oct 2013 16:59:14 +0200
Message-ID: <525EA9C2.90805@redhat.com>
References: <525E8DC3.70409@borntraeger.net> <525E8F53.3090603@redhat.com> <525EA150.3060107@de.ibm.com>
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Cc: Alexander Graf <agraf@suse.de>, Gleb Natapov <gleb@redhat.com>,
	Jens Freimann <jfrei@linux.vnet.ibm.com>,
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To: Christian Borntraeger <borntraeger@de.ibm.com>
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Il 16/10/2013 16:23, Christian Borntraeger ha scritto:
> That would work, but it would change the ioctl number of KVM_*_DEVICE_ADDR,
> due to the changed size of struct kvm_device_attr. We would then need compat
>  handlers in the kernel.

Actually I did that on purpose :) but perhaps you're right that the
complication would be too high.

> If we could encode it in the existing interface the impact would be smaller.
> e.g. 
> 
> #define ATTR_ATTR_MASK 0xffffffffULL
> #define ATTR_LEN_MASK 0xffffffff00000000ULL
> 
> 
>     switch (attr->attr) {
> ---> 
>     switch (attr->attr & ATTR_ATTR_MASK) {
> 
> Then we could keep the device model abstraction.

That makes sense too.

Paolo