[PATCH 4/4] introduction: address lnovich comments

["Michael S. Tsirkin" <mst@redhat.com>]

been implemented should be "have been implemented"
generally list of buses is out of date, list all supported buses.
Drop explicit mention of lguest since it's not part of the spec.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 introduction.tex | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/introduction.tex b/introduction.tex
index 4db5456..221e24e 100644
--- a/introduction.tex
+++ b/introduction.tex
@@ -20,12 +20,14 @@ inter-guest communication) requires copying.
   Standard: Virtio makes no assumptions about the environment in which
   it operates, beyond supporting the bus to which the device is
   attached.  Virtio
-  devices are implemented over PCI and other buses, and earlier drafts
-  been implemented on other buses not included in this specification.
-\footnote{The Linux implementation further separates the PCI virtio code
-from the specific virtio drivers: these drivers are shared with
-the non-PCI implementations (currently lguest and S/390).
-}
+  devices are implemented over MMIO, Channel I/O and PCI bus
+  transports
+\footnote{The Linux implementation further separates the virtio
+transport code from the specific virtio drivers: these drivers are shared
+between different transports.
+}, earlier drafts
+  have been implemented on other buses not included in this specification.
+
 
   Extensible: Virtio devices contain feature bits which are
   acknowledged by the guest operating system during device setup.
-- 
MST