[libvirt] [PATCH] dosc: schema: fix usb source address device attribute format

[Laine Stump]

On 1/26/19 9:16 AM, John Ferlan wrote:
>
> On 1/21/19 3:57 AM, Nikolay Shirokovskiy wrote:
>> Device attribute does not have dotted "portAddr" format. Instead it
>> has single number format described but "usbAddr" which corresponds
>> to device parsing code in virDomainHostdevSubsysUSBDefParseXML.
>>
>> Looks like [1] mistakenly changed device format for hostdev devices.
>> And [2] copy-n-paste this for hostdev network interfaces.
>>
>> [1] 31710a53 Modify USB port to be defined as a port path
>> [2] 3b1c191f conf: parse/format type='hostdev' network interfaces
>>
>> Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy at virtuozzo.com>
>> ---
>>   docs/schemas/domaincommon.rng | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
> This a really strange/involved one, but seemingly correct. It also seems
> that an <interface type='hostdev'... <source ... where the source is USB
> couldn't or doesn't use the startupPolicy that would be present in a
> normal <hostdev mode='subsystem' type='usb'...>...


The parser and formatter will parse and format an <interface 
type='hostdev'> where the source device is USB, but that isn't supported 
by any hypervisor (it would require a standard method of setting the MAC 
address of the USB netdev before giving it to the guest, and AFAIK that 
doesn't exist). In the original commit I mention that it's allowed by 
the parser only for completeness' sake.


> Anyway, I'm certainly not the expert there - something Laine would
> perhaps be better suited for, but certainly missing from the interface
> RNG, but is processed in virDomainHostdevDefParseXMLSubsys. It also
> seems to be a hostdevsubsyspci property as well.
>
> What I was looking for was a way for the <interface...> RNG to perhaps
> make use of the hostdevsubsyspci and hostdevsubsysusb, but some of what
> goes on in RNG rules is like black magic voodoo ;-)...


In the hypothetical/mythical future where such a thing exists and 
support is added, the RNG would presumably be changed. For now it 
doesn't exist, so the RNG is fine as-is.