xen: implement Xen write_msr operation
authorJeremy Fitzhardinge <jeremy@goop.org>
Tue, 8 Jul 2008 22:07:16 +0000 (15:07 -0700)
committerIngo Molnar <mingo@elte.hu>
Wed, 16 Jul 2008 09:06:20 +0000 (11:06 +0200)
commit1153968a48e3ca3e2b7a437e8b82ec9e6f768e24
tree1dd347e5ae7a472f2757915d5927eaca4404d15a
parentbf18bf94dc72db998d0fbebc846c07c858a59c90
xen: implement Xen write_msr operation

64-bit uses MSRs for important things like the base for fs and
gs-prefixed addresses.  It's more efficient to use a hypercall to
update these, rather than go via the trap and emulate path.

Other MSR writes are just passed through; in an unprivileged domain
they do nothing, but it might be useful later.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/xen/enlighten.c