<br><br><div class="gmail_quote">On Sun, Aug 7, 2011 at 9:27 PM, Vladimir Murzin <span dir="ltr"><<a href="mailto:murzin.v@gmail.com">murzin.v@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div><div></div><div class="h5">On Sat, Aug 6, 2011 at 11:36 AM, Prateek Sharma <<a href="mailto:prateek3.14@gmail.com">prateek3.14@gmail.com</a>> wrote:<br>
> Hello everyone,<br>
> I am wondering whether it is possible to reserve a particular physical<br>
> page in the kernel.<br>
> The GFP pages can start from _any_ location, and i cannot find a way to<br>
> specify a starting pfn.<br>
> I need a few dozen pages to store a bitmap starting at a particular physical<br>
> page frame number.<br>
> Perhaps i am trying to do this wrong? I am trying to establish a<br>
> (one-way) communication between KVM and a guest VM, by assuming that if KVM<br>
> knows the physical address in the VM , it can access that bitmap.<br>
><br>
> Thanks !<br>
><br>
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><br>
<br>
Hi Prateek!<br>
<br>
I'm not completely sure, but why don't you hide needed page from<br>
kernel? I mean, you can provide kernel with memory layout<br>
configuration through mem= boot option. You can, for instance, use<br>
mem=32768K@0K,mem=32764K@32772K, i.e. you tell to kernel there is a<br>
gap (starting at 32768K from 0x0 in 4K size) in memory layout. Later,<br>
you can use this gap via ioremap call.<br>
</blockquote></div><br>This looks like it will work. Thank you!<br>I will try this and report how this little experiment went. <br><br>Thanks again,<br><br>