anant
2006-Dec-06 11:24 UTC
[Xen-users] communication of guest OSes with host system over FC6 with xen
Hi i was just wondering about this issue, how does the communication works between guest OSes and main dom0 for checking WMI values like win32BIOS, win 32 baseport, physical and logical drives etc...over FC6 with XEN as the main host. thanks -- View this message in context: http://www.nabble.com/communication-of-guest-OSes-with-host-system-over-FC6-with-xen-tf2767467.html#a7717560 Sent from the Xen - User mailing list archive at Nabble.com. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Petersson, Mats
2006-Dec-06 11:46 UTC
RE: [Xen-users] communication of guest OSes with host system over FC6 with xen
> -----Original Message----- > From: xen-users-bounces@lists.xensource.com > [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of anant > Sent: 06 December 2006 11:25 > To: xen-users@lists.xensource.com > Subject: [Xen-users] communication of guest OSes with host > system over FC6 with xen > > > Hi > i was just wondering about this issue, how does the > communication works > between guest OSes and main dom0 for checking WMI values like > win32BIOS, win > 32 baseport, physical and logical drives etc...over FC6 with > XEN as the main host.Not sure if this is really the question you''re asking, but here''s my answer: 1. The BIOS in your system isn''t the BIOS used by the Windows guest on top of Xen - it has a "special" BIOS ("the BIOS" in the text following) that is supplied as part of the Xen distribution (it''s actually part of the binary called "hvmloader", which is a part of the "startup" of a HVM guest). 2. Physical/logical drivers are detected by the BIOS via qemu-dm - see more about qemu-dm below. The detection is actually done exactly like in hardware, by sending a command "identify" to the drive - the only difference is that it''s not ACTUALLY going to a real hard-drive (at least not directly), but to qemu-dm, which responds with size/brand/etc. Qemu-dm is the "device model", which essentially means that it''s the target of ANY hardware accesses done by the guest. If the guest wants to read the hard-disk, it goes to qemu-dm. If it wants to read the keyboard, the guest needs to talk to qemu-dm, etc, etc. There are some (frequently accessed) hardware elements that reside in the hypervisor (Xen) itself - the interrupt controller and time-keeping devices, as this reduces the time it takes to access the "hardware". Qemu-dm lives in Dom0 (Linux) will translate a disk-access into a file-read of a suitable type. Likewise, qemu-dm''s "display window" will be used to display the graphics output from the guest, and any keyboard activities or mouse-clicks will be transmitted to the guest when performed within the window. I hope this explains what you wanted to know. Please feel free to ask further questions if you wish. -- Mats> thanks > -- > View this message in context: > http://www.nabble.com/communication-of-guest-OSes-with-host-sy > stem-over-FC6-with-xen-tf2767467.html#a7717560 > Sent from the Xen - User mailing list archive at Nabble.com. > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users > > >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users