[Lguest] [kvm-devel] [PATCH 2/6] virtio_config

Avi Kivity avi at qumranet.com
Thu Sep 20 22:36:40 EST 2007


Rusty Russell wrote:
> Previous versions of virtio didn't commonalize probing.  For every
> driver, every virtio implementation (KVM, lguest, etc) needed an
> in-kernel stub to join their bus to the probe code.
>
> To solve this, we introduce a "virtio_config" mechanism, which is
> simply a set of [u8 type][u8 len][...data...] fields for each device.
> Some convenient wrapper functions make this fairly easy for drivers to
> unpack their configuration data themselves.
>
> This configuration data could be PCI config space, or an unrelated bus
> (eg. lguest) or manufactured by the kernel itself.  It's designed to
> be extensible: fields get marked as the device reads them so a host
> supporting some future extension can tell if the guest driver
> understood it.  This also applies to bitfields: the guest explicitly
> acks the bits it understands.
>
> There's also a simple status bitmask useful for low-level host
> analysis of what the guest is doing with the device.
>
>   

Lovely.

-- 
error compiling committee.c: too many arguments to function




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