Reserve physical page

[Thayumanavar S]

> 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.

thanks,
thayumanavar