From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: "Kashmira. K." <chimnee@yahoo.com>
Cc: winterfi@cisco.com, xen-devel@lists.xensource.com
Subject: Re: Contiguous DMAble memory in Dom0 user space linux process
Date: Wed, 20 Jan 2010 16:42:10 -0500 [thread overview]
Message-ID: <20100120214210.GA13823@phenom.dumpdata.com> (raw)
In-Reply-To: <709670.16467.qm@web50604.mail.re2.yahoo.com>
On Wed, Jan 20, 2010 at 01:10:24PM -0800, Kashmira. K. wrote:
> Hi Konard,
>
> Thanks you for your reply.
>
> On the (non xen) linux system, the hardware was visible to the userspace app. The PCI bars were mapped. So I do need to get the same functionality on xen capable linux.
>
> I'm still a newbie to the xen internals, but I was wondering if I could write a simple linux kernel driver for a xen capable linux to do the following
> - Map the PCI address (BAR).
> - Get contiguous memory.
> - Provide user space ioctl call to get the mapped PCI BAR
> - Provide user space ioctl to get pointer to the contiguous memory.
>
> Will that work?
Sure. I would recommend you look at the 3w-xxxx.c driver for a simple
ioctl subsystem and how to get contiguous memory mapped in. For mmap functionality
hpet.c is pretty simple. Foremost, make sure you get a PDF copy of
"Understanding the Linux Kernel" as that will answer a lot of your questions.
prev parent reply other threads:[~2010-01-20 21:42 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-13 21:03 Contiguous DMAble memory in Dom0 user space linux process Kashmira. K.
2010-01-13 21:31 ` Konrad Rzeszutek Wilk
2010-01-15 2:16 ` Kashmira. K.
2010-01-15 16:59 ` Konrad Rzeszutek Wilk
2010-01-20 21:10 ` Kashmira. K.
2010-01-20 21:42 ` Konrad Rzeszutek Wilk [this message]
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