From: Peter Maydell <peter.maydell@linaro.org>
To: Dean <664543912@qq.com>
Cc: qemu-devel <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] virtio_mmio address mapping
Date: Mon, 30 May 2016 13:43:15 +0100 [thread overview]
Message-ID: <CAFEAcA8hhqSbAMJYkLu8fGEgDjyn6vq-K4w6zgdenYUKPD0ZtQ@mail.gmail.com> (raw)
In-Reply-To: <tencent_7D180F2B2FF724537D0BF36E@qq.com>
On 30 May 2016 at 13:24, Dean <664543912@qq.com> wrote:
> I am writing a UIO linux driver for a virtio_mmio device and find out that all those virtio_mmio devices' registers are arrange in one single 4K aligned page.
> which makes writing an UIO driver hard since linux doesn't allow UIO driver to map a register space smaller than page size.
> would you consider divide them into defferent pages?
>
> what I am talking about is devices like:
> a003000.virtio_mmio
> a003c00.virtio_mmio
> a003e00.virtio_mmio
>
> what I am dealing with is a003e00.virtio_mmio
Unfortunately we can't really move them, for backwards
compatibility reasons. Also, virtio-mmio is now pretty
much obsolete since you can use virtio-pci instead, and
we wouldn't want it to take up much more of the physical
address space.
thanks
-- PMM
prev parent reply other threads:[~2016-05-30 12:43 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-30 12:24 [Qemu-devel] virtio_mmio address mapping Dean
2016-05-30 12:43 ` Peter Maydell [this message]
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