Re: Reserve physical page

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 





On Sat, Aug 6, 2011 at 11:35 PM, Thayumanavar S <thayumker@xxxxxxxxx> wrote:
> Hello everyone,
>    I am wondering whether it is possible to reserve a particular physical
> page in the kernel.
> The GFP pages can start from _any_ location, and i cannot find a way to
> specify a starting pfn.
> I need a few dozen pages to store a bitmap starting at a particular physical
> page frame number.
>    Perhaps i am trying to do this wrong? I am trying to establish a
> (one-way) communication between KVM and a guest VM, by assuming that if KVM
> knows the physical address in the VM , it can access that bitmap.

you can covert pa to pfn to struct page (there are some macros in the
kernel that does this, you grep the kernel source for it) and directly
set the PG_reserved flag of that struct page.


Ok. But in this case i have to ensure that the pfn is not mapped by the kernel, right?
Will scanning mem_map to find such a pfn help?
I'm wondering if there are regions which are typically 'free' which i can reserve and use.

Thanks for the reply,


_______________________________________________
Kernelnewbies mailing list
Kernelnewbies@xxxxxxxxxxxxxxxxx
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

[Index of Archives]     [Newbies FAQ]     [Linux Kernel Mentors]     [Linux Kernel Development]     [IETF Annouce]     [Git]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux SCSI]     [Linux ACPI]
  Powered by Linux