I just tried to run Xen (updated daily from unstable) with an incompatible version of XenoLinux (I forgot to rebuild the XenoLinux tree). Dom0 just died with no messages (non-debug build). It worked fine once I realized that the interface version had changed, and had to rebuild xenolinux? I know it is sort of chicken, and egg thing, but could you somehow print an error message that says that there is a hypervisor interface version mismatch? Barry Silverman ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
> I just tried to run Xen (updated daily from unstable) with an incompatible > version of XenoLinux (I forgot to rebuild the XenoLinux tree). Dom0 just > died with no messages (non-debug build). It worked fine once I realized that > the interface version had changed, and had to rebuild xenolinux? > > I know it is sort of chicken, and egg thing, but could you somehow print an > error message that says that there is a hypervisor interface version > mismatch?Absolutely. Christian made the very sensible suggestion that we should pass the interface version number in to the domain in one of the registers. It could then refuse to run or use a compatibility mode. (hopefully the interface version would be sufficiently close for it to be able to use HYPERVISOR_console_write to tell someone!) One for the todo list... Ian ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
> > I just tried to run Xen (updated daily from unstable) with an incompatible > > version of XenoLinux (I forgot to rebuild the XenoLinux tree). Dom0 just > > died with no messages (non-debug build). It worked fine once I realized that > > the interface version had changed, and had to rebuild xenolinux? > > > > I know it is sort of chicken, and egg thing, but could you somehow print an > > error message that says that there is a hypervisor interface version > > mismatch? > > Absolutely. > > Christian made the very sensible suggestion that we should pass > the interface version number in to the domain in one of the > registers. It could then refuse to run or use a compatibility > mode. (hopefully the interface version would be sufficiently > close for it to be able to use HYPERVISOR_console_write to tell > someone!) > > One for the todo list...Yes. It would be good to get error information from a domain when it dies. At some point we should probably freeze such domains and notify DOM0 so that error info (and other useful stuff such as a traceback) can be picked up. In the nearer term, writing error information to the ''emergency console'' would be better than nothing. -- Keir ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
On Fri, 2004-03-12 at 00:40, Ian Pratt wrote:> Christian made the very sensible suggestion that we should pass > the interface version number in to the domain in one of the > registers. It could then refuse to run or use a compatibility > mode. (hopefully the interface version would be sufficiently > close for it to be able to use HYPERVISOR_console_write to tell > someone!)One of the things I liked about working with L4 (and Linux btw) was that the syscall interface was fairly stable and well-documented. Do you think the Xen interface will stabilise over time, so that most Xen nodes out there will be binary compatible? Jacob ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
> On Fri, 2004-03-12 at 00:40, Ian Pratt wrote: > > > Christian made the very sensible suggestion that we should pass > > the interface version number in to the domain in one of the > > registers. It could then refuse to run or use a compatibility > > mode. (hopefully the interface version would be sufficiently > > close for it to be able to use HYPERVISOR_console_write to tell > > someone!) > > One of the things I liked about working with L4 (and Linux btw) was that > the syscall > interface was fairly stable and well-documented. Do you think the Xen > interface will stabilise over time, so that most Xen nodes out there > will be binary compatible?That''s obviously a desirable aim, but it extends to more than just the hypercall interface -- for example, the format of I/O buffers and the shared_info dat astructure. At the very least I want to avoid changing the interfaces after a point release ''stabilises'' (eg. 1.2 interfaces will not change now, but 1.3 is still volatile). There is now a hypercall (xen_version()) which returns the currently-runnign point release. This can be used to implement guest OSes that are portable across stable point releases, where that matters. There are a couple more things which may change the interfaces somewhat (I/O virtualisation and, to some extent, SMP guest OSes). Once these are done I''d like to get a 2.0 release out the door with firmer guarantees regarding interface stability. Currently each stable point release is providing sufficient extra functionality that there is strong motivation to upgrade and not look back. :-) -- Keir ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel