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Re: [PATCH 0/1] vmx: Fix <genid/> mapping
From: |
Richard W.M. Jones |
Subject: |
Re: [PATCH 0/1] vmx: Fix <genid/> mapping |
Date: |
Thu, 30 Sep 2021 10:16:20 +0100 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Thu, Sep 30, 2021 at 09:47:01AM +0100, Daniel P. Berrangé wrote:
> On Thu, Sep 30, 2021 at 08:33:48AM +0100, Richard W.M. Jones wrote:
> > I propose we deprecate the guid parameter in:
> >
> > -device vmgenid,guid=8987940a-0951-2cc5-e815-10634ff550b9,id=vmgenid0
> >
> > Instead it will be replaced by bytes= which will simply write
> > the bytes, in the order they appear, into guest memory with no
> > attempt to interpret or byte-swap. Something like:
> >
> > -device vmgenid,bytes=112233445566778899aabbccddeeff00,id=vmgenid0
> >
> > (guid although deprecated will need to be kept around for a while,
> > along with its weird byte-swapping behaviour).
> >
> > We will then have a plain and simple method to emulate the behaviour
> > of other hypervisors. We will look at exactly what bytes they write
> > to guest memory and copy that behaviour when v2v converting from those
> > hypervisors.
>
> From the libvirt POV, I'm not expecting anything in QEMU to change
> in this respect. If guid is replaced by a new attribute taking data
> in a different way, then libvirt will have to remap itself, so that
> existing usage in libvirt keeps working the same way as it did with
> guid. Essentially from libvirt's POV, it is simply a documentation
> issue to specify how the libvirt XML representation translates to
> the guest visible representation, and ensure that all libvirt drivers
> implement it the same way. The QEMU genid support arrived first so
> that set the standard for how libvirt will represent it, that all
> further libvirt hypervisor drivers need to match.
I was going to suggest something like:
<genid type="guid">aa-bb-cc..</genid>
or
<genid type="binary">aabbcc..</genid>
with the type defaulting to guid for backwards compatibility.
Does libvirt XML have any other fields were you're passing
essentially small snippets of binary data?
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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- Re: [PATCH 0/1] vmx: Fix <genid/> mapping, (continued)
- Re: [PATCH 0/1] vmx: Fix <genid/> mapping, Richard W.M. Jones, 2021/09/29
- Re: [PATCH 0/1] vmx: Fix <genid/> mapping, Daniel P . Berrangé, 2021/09/29
- Re: [PATCH 0/1] vmx: Fix <genid/> mapping, Richard W.M. Jones, 2021/09/29
- Re: [PATCH 0/1] vmx: Fix <genid/> mapping, Richard W.M. Jones, 2021/09/30
- Re: [PATCH 0/1] vmx: Fix <genid/> mapping, Laszlo Ersek, 2021/09/30
- Re: [PATCH 0/1] vmx: Fix <genid/> mapping, Daniel P . Berrangé, 2021/09/30
- Re: [PATCH 0/1] vmx: Fix <genid/> mapping,
Richard W.M. Jones <=