Re: [Qemu-devel] virtual pc hash table vs physical pc hash table

[陳韋任]

On Fri, Jan 20, 2012 at 08:49:56AM -0500, Xin Tong wrote:
> maybe one of the reasons of having the virtual pc hash table is that
> the pc does not need to be tranlated to a physical pc which is used in
> the physical pc hash table.

  Take context switch as an example. Before context switching, you can use
process A's virtual pc to index the virtual pc hash table. After context
switching, the original virtual pc hash table is no longer valid since
process B has the same virtual address space. Therefore, QEMU turns to use
(guest) physical pc to index the physical pc hash table. If the tb of process
B is existed, QEMU refill the virtual pc hash table. Otherwise, it does
the translation.

Regards,
chenwj

-- 
Wei-Ren Chen (陳韋任)
Computer Systems Lab, Institute of Information Science,
Academia Sinica, Taiwan (R.O.C.)
Tel:886-2-2788-3799 #1667
Homepage: http://people.cs.nctu.edu.tw/~chenwj