Re: [libvirt] XML support for arbitrary command line arguments

On 9/21/2010 10:02 AM, Daniel P. Berrange wrote: > On Mon, Sep 20, 2010 at 04:07:32PM -0700, Venkateswararao Jujjuri > (JV) wrote: >> On 9/14/2010 9:34 AM, Venkateswararao Jujjuri (JV) wrote: >>> On 9/14/2010 2:43 AM, Daniel P. Berrange wrote: >>>> On Tue, Sep 14, 2010 at 11:03:04AM +0530, Harsh Bora wrote: >>>>> As QEMU provides support for accessing such shared directory with >>>>> the >>>>> help of 9p server, and therefore need to be passed additional >>>>> commandline argument while starting, I wanted to test it using >>>>> XML and >>>>> libvirt. >>>> >>>>> So, if the idea looks good to everyone, we can have something like: >>>>> >>>>> <shareddir fstype=local path='/folder/to/share' >>>>> mount_tag='unique_tag' >>>>> security_model='as_applicable'> >>> >>> fstype may not be 'local' all the time. So in the XML description, >>> I would >>> propose something like >>> fstype='filesystem type' or something like that. For now only QEMU >>> supports local. >>> This keyword represents all local filesystems like ext3/ext4 etc. >>>> >>>> We already have an XML syntax defined for filesystems using >>>> the<filesystem> element. I've proposed an impl for QEMU using >>>> p9fs before, but we didn't apply it yet. >>>> >>>> http://www.redhat.com/archives/libvir-list/2010-July/msg00458.html >> >> >> Taking a closer look at the Danial's patch above, it covers almost >> all our >> needs. >> Except that the fstype and security models are hard coded. > > fstype is hardcoded to local only in so much as there aren't > any other options in QEMU for fstype. If QEMU adds other > fstype options, we'll extend<filesystem type='XXXX'> to > cover them. Currently type='bind' in the XML maps to fstype=local > in QEMU.

local is the only option now. But we expect it to have more options sooner if not later. It will be great if there is a way we can make it a tag/variable in this attempt. If you think it is better to deal with it later..sure we can live with that. :) > >> >> + virBufferAddLit(&opt, "local,security_model=mapped"); >> >> Any reason why it was not taken yet? > > I wanted to decide on best setting for security model. I think it > might be better to make it use passthrough by default, since that > gives better interoperability for users with matching host/guest > IDs. Sure passthrough is the most compatible option. Can you please explain what do you mean by "best setting"? you mean the tag name? Can we introduce new tags for security_mode and fstype(instead of overloading type=bind)? Thanks, JV > > Daniel