To your 2nd question, there are several broad classes
of devices widely used in PV domains: Block, net and console (which are
the only ones I care about in my deployments), USB (new to 4.0), SCSI and
PCI. All these follow the front/back device model. Graphical
consoles in a PV domain may be used over any applicable network protocol (e.g.
X11, VNC).
I've never heard of a floppy disk or pc speaker for a PV
domain. I'd be curious as to who would need such a thing.
(I don't know the answer to your other question, and to be
honest I haven't looked at recent source. We've been getting by on the kernels
in CentOS 5.x, supplemented with the gitco RPM builds, for expediency's sake.)
From: Anh Nguyen
[mailto:nguyenminhanh@xxxxxxxxx]
Sent: Tuesday, May 04, 2010 2:41 PM
To: Jeff Sturm
Cc: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-users] Supported Dom U platform
Thanks Jeff,
That certainly answered my previous questions. But leads to
other ones :)
1. Why is the code for
binary translation and emulation of MIPs, Sparc... and so on still
exists in xen.3.4.2 default source ball (in tools\ioemu-qemu-xen). Is it because
no one find the need / or want to go through all the hassle to remove them from
qemu-xen code just to save a few KB?
2. If PV domains don't use QEMU. How are core devices
normally attached to the motherboard, such as keyboard controller, floppy disk
controller, pc speaker, emulated for PV domains? Do they also follow the
frontend / backend drivers model? If so where can I find the code for their
frontend / backend drivers?
Thanks a lot,
On Tue, May 4, 2010 at 10:20 AM, Jeff Sturm <jeff.sturm@xxxxxxxxxx> wrote:
Xen does virtualization, not
emulation. It supports several CPU architectures, but your domU
sees the same CPU as your dom0.
That said, on x86-64 platforms you can
mix/match 32-bit and 64-bit domains provided the hypervisor is a 64-bit
build. This works because the underlying hardware supports it, not
because any emulation is taking place.
As I understand it Xen uses QEMU solely
for device emulation. It's required for HVM domains. Pavarvirtualized
domains don't need QEMU at all.
Hi
everyone,
1.
Does anyone knows if Xen supports running Dom U (guest) platforms other than
x86 and amd64? For examples: MIPs, arm...
I
see MIPs and ARM related code inside tools\ioemu-qemu-xen but I am not sure if
that is enough.
2.
My understanding is Xen uses QEMU for HVM device emulation, and QEMU uses
binary translation. Does that mean Xen HVM guests will have to go through the
binary translation layer? Is this the case if the guest platform and the host
platform are the same?
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