Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <20181025183739.9375-1-robert.foss@collabora.com>
 <20181025183739.9375-3-robert.foss@collabora.com> <20181030061127.hp4n2scw5f3j2rqq@sirius.home.kraxel.org>
In-Reply-To: <20181030061127.hp4n2scw5f3j2rqq@sirius.home.kraxel.org>
From:   Emil Velikov <emil.l.velikov@gmail.com>
Date:   Tue, 30 Oct 2018 11:31:04 +0000
Message-ID: <CACvgo50MK1jU0jKMCfZJQSaSmpQ8mmYj1=4GP2NQvM_DHOaW-Q@mail.gmail.com>
Subject: Re: [PATCH 2/5] drm/virtio: add uapi for in and out explicit fences
To:     Gerd Hoffmann <kraxel@redhat.com>
Cc:     Robert Foss <robert.foss@collabora.com>,
        David Airlie <airlied@linux.ie>,
        "Linux-Kernel@Vger. Kernel. Org" <linux-kernel@vger.kernel.org>,
        ML dri-devel <dri-devel@lists.freedesktop.org>,
        "open list:VIRTIO GPU DRIVER" 
        <virtualization@lists.linux-foundation.org>,
        Gustavo Padovan <gustavo.padovan@collabora.com>,
        Emil Velikov <emil.velikov@collabora.com>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

HI Gerd,

On Tue, 30 Oct 2018 at 06:11, Gerd Hoffmann <kraxel@redhat.com> wrote:
>
>   Hi,
>
> > The execbuffer IOCTL is now read-write to allow the userspace to read the
> > out-fence.
>
> >  #define DRM_IOCTL_VIRTGPU_EXECBUFFER \
> > -     DRM_IOW(DRM_COMMAND_BASE + DRM_VIRTGPU_EXECBUFFER,\
> > +     DRM_IOWR(DRM_COMMAND_BASE + DRM_VIRTGPU_EXECBUFFER,\
> >               struct drm_virtgpu_execbuffer)
>
> That changes the ioctl number and breaks the userspace api.
>
Have you looked at the drm_ioctl() implementation? AFAICT it
explicitly caters for this kind of changes.

-Emil