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Message-ID: <5e98e9666bfeb275ec168df24bb8e9a33781229e.camel@cyberus-technology.de>
Subject: Re: [PATCH 2/3] drm/i915/gvt: make gvt oblivious of kvmgt data
 structures
From:   Julian Stecklina <julian.stecklina@cyberus-technology.de>
To:     Jani Nikula <jani.nikula@linux.intel.com>,
        intel-gvt-dev@lists.freedesktop.org
Cc:     linux-kernel@vger.kernel.org, hang.yuan@intel.com,
        dri-devel@lists.freedesktop.org, zhiyuan.lv@intel.com
Date:   Wed, 08 Jan 2020 18:08:28 +0200
In-Reply-To: <87tv56qm9m.fsf@intel.com>
References: <20200106140622.14393-1-julian.stecklina@cyberus-technology.de>
         <20200106140622.14393-2-julian.stecklina@cyberus-technology.de>
         <87tv56qm9m.fsf@intel.com>
Organization: Cyberus Technology GmbH
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On Wed, 2020-01-08 at 12:24 +0200, Jani Nikula wrote:
> On Mon, 06 Jan 2020, Julian Stecklina <julian.stecklina@cyberus-technology.de>
> wrote:
[...]
> > +	/* Hypervisor-specific device state. */
> > +	void *vdev;
> 
> I have no clue about the relative merits of the patch, but you can use
> the actual type for the pointer with a forward declaration. You don't
> need the definition for that.
> 
> i.e.
> 
> struct kvmgt_vdev;
> ...
> 	struct kvmgt_vdev *vdev;

The goal here is to make the GVT code independent of the hypervisor backend.
Different hypervisor backends need to keep different per-device state, so using
the KVM type here defeats the purpose.

I assume this is not only useful for us, but also for other hypervisor backends,
such as Xen or 3rd-party hypervisors.

Julian