Re: [Xen-devel] how page faults are handled in paravirtualized xenguests?

[Daniel Stodden <stodden@xxxxxxxxxx>]

On Tue, 2008-03-11 at 10:37 -0500, weiming wrote:
> and how can xen tell if the hypercall is from kernel space or user
> space in x86_64?

The VMM simply keeps track of it in software. Starting from kernel mode,
an IRET will return to virtual user mode, a subsequent 'SYSCALL' will
move control back to the kernel.

hth,
daniel

-- 
Daniel Stodden
LRR     -      Lehrstuhl fÃr Rechnertechnik und Rechnerorganisation
Institut fÃr Informatik der TU MÃnchen             D-85748 Garching
http://www.lrr.in.tum.de/~stodden         mailto:stodden@xxxxxxxxxx
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