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[Xen-devel] [PATCH 0/4] qemu blkback implementation

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Subject: [Xen-devel] [PATCH 0/4] qemu blkback implementation
From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Date: Thu, 18 Nov 2010 13:00:14 +0000
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Hi all,
this patch series adds a pure userspace blkback implementation to qemu
that is used by default when blktap2 is not present in the system (for
example because your dom0 kernel doesn't have a blkback or blktap2
backend). For the moment the goal is just to make it easier for
developers to work with upstream 2.6.37 kernels as dom0 for debugging
and development.

The first patch backports xen_disk from upstream qemu to qemu-xen;
xen_disk is a pure userspace blkback implementation. Xen_disk looks for
qdisk paths on xenstore so it doesn' conflict with blkback or blktap.
The second patch adds support for qdisks in qemu for PV and HVM guests.
The third patch adds a second qdisk backend when qemu is run as backend
provider for stubdoms, so that it can serve both the stubdom and the
guest at the same time.
The last patch adds support for qdisk in libxl: qdisks are used only
when blktap2 is not available.

I want to highlight again that this series is not a substitute for
blktap2 but mainly a development and debugging tool, that allow you to
actually create and boot VMs on upstream 2.6.37 dom0 kernels!
Also this series doesn't start a qemu for PV guests by default yet, so
if you want to use qdisks make sure that you have a vfb configured in
your VM config file, even if you don't plan to use it.

Enjoy your shiny 2.6.37rc2 kernel,


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