Reserve physical page
From: Vladimir Murzin <hidden>
Date: 2011-08-07 15:57:46
On Sat, Aug 6, 2011 at 11:36 AM, Prateek Sharma [off-list ref] 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. ? Thanks ! _______________________________________________ Kernelnewbies mailing list Kernelnewbies at kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Hi Prateek! I'm not completely sure, but why don't you hide needed page from kernel? I mean, you can provide kernel with memory layout configuration through mem= boot option. You can, for instance, use mem=32768K at 0K,mem=32764K at 32772K, i.e. you tell to kernel there is a gap (starting at 32768K from 0x0 in 4K size) in memory layout. Later, you can use this gap via ioremap call.