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Subject: Re: [PATCH v9 5/7] vfio: Define vfio based dma-buf operations
From: Gerd Hoffmann <kraxel@redhat.com>
To: Kirti Wankhede <kwankhede@nvidia.com>,
        Alex Williamson <alex.williamson@redhat.com>
Cc: Xiaoguang Chen <xiaoguang.chen@intel.com>, chris@chris-wilson.co.uk,
        intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        zhenyuw@linux.intel.com, zhiyuan.lv@intel.com,
        intel-gvt-dev@lists.freedesktop.org, zhi.a.wang@intel.com,
        kevin.tian@intel.com
Date: Wed, 21 Jun 2017 09:22:38 +0200
In-Reply-To: <791b0316-1c83-622c-9cef-d54dae1209f9@nvidia.com>
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  Hi,

> We don't support cursor for console vnc. Ideally console vnc should
> be
> used by admin for configuration or during maintenance, which refresh
> primary surface at low refresh rate, 10 fps.

But you surely want a mouse pointer for the admin?
You render it directly to the primary surface then I guess?

> Right we need to know this at device initialization time for both
> cases
> to initialize VGACommonState structure for that device

Why do you need a VGACommonState?

> and also need
> NONE to decide whether to init console vnc or not. We have a
> mechanism
> to disable console vnc path and we recommend to disable it for better
> performance.

Hmm, maybe we should have a ioctl to configure the refresh rate, or a
ioctl to allow qemu ask for a refresh when needed?

qemu can throttle the display update rate, which for example happens in
case no vnc client is connected.  qemu updates the display only once
every few seconds then.

cheers,
  Gerd