Re: [libvirt] [PATCH] interface: Check for interface (in-)activity on some operations
On 07/15/2011 10:36 AM, Michal Privoznik wrote: On 15.07.2011 16:29, Eric Blake wrote: On 07/15/2011 07:58 AM, Michal Privoznik wrote: Right now it is possible to undefine an active interface, or destroy inactive. This patch add some checking to these operations to prevent this. Also fix test driver. I'm inclined to NACK this on design principles (I haven't read the patch itself, though). Given the discussion about domains and undefine, the ability to undefine an active interface is a feature, provided we support the concept of a transient interface like we do for transient domains. That is, we have the following transitions: nothing - transient/running via Create nothing - persistent/inactive via Define persistent/inactive - persistent/active via Start persistent/inactive - gone via Undefine persistent/running - persistent/inactive via Destroy persistent/running - transient/running via Undefine transient/running - gone via Destroy transient/running - persistent/running via Define and rejecting Undefine on a running interface would prevent the ability to transistion a persistent over to a transient interface. On the other hand, if we don't support transient interfaces, then the above analysis which works for domains would have to be adjusted for interfaces, so you may have something to patch after all. Well, although we have function interfaceCreate, it is actually (from semantic POV) interfaceStart, because it just start inactive but defined interface. So we do not support transient interfaces. Therefore transitions for interfaces are slightly different from transitions for domains. That's why I think we do need this patch. Since I was the original author of this file, I guess I'd better get into the conversation :-) The odd part of this is that I recall having a conversation about allowing/not allowing undefine of an interface that is active, and I *thought* that it didn't allow it (but obviously it does). A couple of points: 1) The fact that we don't support transient interfaces now doesn't preclude supporting them in the future (although we may use some method other than netcf to do it). 2) We should be careful changing this, in case it has any effects on virt-manager's use of the API. -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] [PATCH] interface: Check for interface (in-)activity on some operations
On 07/15/2011 07:58 AM, Michal Privoznik wrote: Right now it is possible to undefine an active interface, or destroy inactive. This patch add some checking to these operations to prevent this. Also fix test driver. I'm inclined to NACK this on design principles (I haven't read the patch itself, though). Given the discussion about domains and undefine, the ability to undefine an active interface is a feature, provided we support the concept of a transient interface like we do for transient domains. That is, we have the following transitions: nothing - transient/running via Create nothing - persistent/inactive via Define persistent/inactive - persistent/active via Start persistent/inactive - gone via Undefine persistent/running - persistent/inactive via Destroy persistent/running - transient/running via Undefine transient/running - gone via Destroy transient/running - persistent/running via Define and rejecting Undefine on a running interface would prevent the ability to transistion a persistent over to a transient interface. On the other hand, if we don't support transient interfaces, then the above analysis which works for domains would have to be adjusted for interfaces, so you may have something to patch after all. -- Eric Blake ebl...@redhat.com+1-801-349-2682 Libvirt virtualization library http://libvirt.org signature.asc Description: OpenPGP digital signature -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] [PATCH] interface: Check for interface (in-)activity on some operations
On 15.07.2011 16:29, Eric Blake wrote: On 07/15/2011 07:58 AM, Michal Privoznik wrote: Right now it is possible to undefine an active interface, or destroy inactive. This patch add some checking to these operations to prevent this. Also fix test driver. I'm inclined to NACK this on design principles (I haven't read the patch itself, though). Given the discussion about domains and undefine, the ability to undefine an active interface is a feature, provided we support the concept of a transient interface like we do for transient domains. That is, we have the following transitions: nothing - transient/running via Create nothing - persistent/inactive via Define persistent/inactive - persistent/active via Start persistent/inactive - gone via Undefine persistent/running - persistent/inactive via Destroy persistent/running - transient/running via Undefine transient/running - gone via Destroy transient/running - persistent/running via Define and rejecting Undefine on a running interface would prevent the ability to transistion a persistent over to a transient interface. On the other hand, if we don't support transient interfaces, then the above analysis which works for domains would have to be adjusted for interfaces, so you may have something to patch after all. Well, although we have function interfaceCreate, it is actually (from semantic POV) interfaceStart, because it just start inactive but defined interface. So we do not support transient interfaces. Therefore transitions for interfaces are slightly different from transitions for domains. That's why I think we do need this patch. Michal -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] [PATCH] interface: Check for interface (in-)activity on some operations
On 15.07.2011 16:45, Eric Blake wrote: On 07/15/2011 08:36 AM, Michal Privoznik wrote: On the other hand, if we don't support transient interfaces, then the above analysis which works for domains would have to be adjusted for interfaces, so you may have something to patch after all. Well, although we have function interfaceCreate, it is actually (from semantic POV) interfaceStart, because it just start inactive but defined interface. So we do not support transient interfaces. Therefore transitions for interfaces are slightly different from transitions for domains. That's why I think we do need this patch. Let's nail down the transitions that we plan to support, then, just as I did earlier for domains. It would be even cooler to have a life cycle diagram with the API used to transition between states documented somewhere. I seem to recall seeing one for domains once, but couldn't find it in 5 minutes of searching right now. You mean http://wiki.libvirt.org/page/VM_lifecycle#States_that_a_guest_domain_can_be_in ? -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] [PATCH] interface: Check for interface (in-)activity on some operations
On 07/15/2011 08:45 AM, Eric Blake wrote: On 07/15/2011 08:36 AM, Michal Privoznik wrote: On the other hand, if we don't support transient interfaces, then the above analysis which works for domains would have to be adjusted for interfaces, so you may have something to patch after all. Well, although we have function interfaceCreate, it is actually (from semantic POV) interfaceStart, because it just start inactive but defined interface. So we do not support transient interfaces. Therefore transitions for interfaces are slightly different from transitions for domains. That's why I think we do need this patch. Let's nail down the transitions that we plan to support, then, just as I did earlier for domains. It would be even cooler to have a life cycle diagram with the API used to transition between states documented somewhere. I seem to recall seeing one for domains once, but couldn't find it in 5 minutes of searching right now. Found it: http://libvirt.org/guide/html-single/#Application_Development_Guide-Guest_Domains-Lifecycle That diagram completely lacks transient domains. It also shows persistent/running to persistent/inactive via Shutdown, while I mentioned Destroy (both APIs work for that transition, although Shutdown requires guest response). Something that could certainly use some TLC! -- Eric Blake ebl...@redhat.com+1-801-349-2682 Libvirt virtualization library http://libvirt.org signature.asc Description: OpenPGP digital signature -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] [PATCH] interface: Check for interface (in-)activity on some operations
On 07/15/2011 08:48 AM, Michal Privoznik wrote: On 15.07.2011 16:45, Eric Blake wrote: On 07/15/2011 08:36 AM, Michal Privoznik wrote: On the other hand, if we don't support transient interfaces, then the above analysis which works for domains would have to be adjusted for interfaces, so you may have something to patch after all. Well, although we have function interfaceCreate, it is actually (from semantic POV) interfaceStart, because it just start inactive but defined interface. So we do not support transient interfaces. Therefore transitions for interfaces are slightly different from transitions for domains. That's why I think we do need this patch. Let's nail down the transitions that we plan to support, then, just as I did earlier for domains. It would be even cooler to have a life cycle diagram with the API used to transition between states documented somewhere. I seem to recall seeing one for domains once, but couldn't find it in 5 minutes of searching right now. You mean http://wiki.libvirt.org/page/VM_lifecycle#States_that_a_guest_domain_can_be_in You found a different one than me, but that one also has the problem of no mention of a transient domain. -- Eric Blake ebl...@redhat.com+1-801-349-2682 Libvirt virtualization library http://libvirt.org signature.asc Description: OpenPGP digital signature -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] [PATCH] interface: Check for interface (in-)activity on some operations
2011/7/15 Eric Blake ebl...@redhat.com: On 07/15/2011 08:45 AM, Eric Blake wrote: On 07/15/2011 08:36 AM, Michal Privoznik wrote: On the other hand, if we don't support transient interfaces, then the above analysis which works for domains would have to be adjusted for interfaces, so you may have something to patch after all. Well, although we have function interfaceCreate, it is actually (from semantic POV) interfaceStart, because it just start inactive but defined interface. So we do not support transient interfaces. Therefore transitions for interfaces are slightly different from transitions for domains. That's why I think we do need this patch. Let's nail down the transitions that we plan to support, then, just as I did earlier for domains. It would be even cooler to have a life cycle diagram with the API used to transition between states documented somewhere. I seem to recall seeing one for domains once, but couldn't find it in 5 minutes of searching right now. Found it: http://libvirt.org/guide/html-single/#Application_Development_Guide-Guest_Domains-Lifecycle For some reason the anchor doesn't work for me, just for reference a link that involves less scrolling :) http://libvirt.org/guide/html/Application_Development_Guide-Guest_Domains-Lifecycle.html That diagram completely lacks transient domains. It also shows persistent/running to persistent/inactive via Shutdown, while I mentioned Destroy (both APIs work for that transition, although Shutdown requires guest response). Something that could certainly use some TLC! Also that diagram is wrong about the saved state. There is nothing like that in context of virDomainSave/virDomainRestore. Also the diagram misses managedsave. In the context of managedsave there is actually a saved state. -- Matthias Bolte http://photron.blogspot.com -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] [PATCH] interface: Check for interface (in-)activity on some operations
2011/7/15 Eric Blake ebl...@redhat.com: On 07/15/2011 08:48 AM, Michal Privoznik wrote: On 15.07.2011 16:45, Eric Blake wrote: On 07/15/2011 08:36 AM, Michal Privoznik wrote: On the other hand, if we don't support transient interfaces, then the above analysis which works for domains would have to be adjusted for interfaces, so you may have something to patch after all. Well, although we have function interfaceCreate, it is actually (from semantic POV) interfaceStart, because it just start inactive but defined interface. So we do not support transient interfaces. Therefore transitions for interfaces are slightly different from transitions for domains. That's why I think we do need this patch. Let's nail down the transitions that we plan to support, then, just as I did earlier for domains. It would be even cooler to have a life cycle diagram with the API used to transition between states documented somewhere. I seem to recall seeing one for domains once, but couldn't find it in 5 minutes of searching right now. You mean http://wiki.libvirt.org/page/VM_lifecycle#States_that_a_guest_domain_can_be_in You found a different one than me, but that one also has the problem of no mention of a transient domain. That one actually covers transient domain partly. Look at the create/shutdown transition between undefined and running states. -- Matthias Bolte http://photron.blogspot.com -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
