forgive me if this has been beaten to death but I''ve been thinking again about the problem of running Windows as a guest OS under xen. I understand and accept all the arguments of why you need to modify the core OS for your virtualization process. Under the opinion that there is no crime if optimization fails on incorrect code, would it not be appropriate to do all the things necessary to run Windows unmodified albeit poorly slash slowly? assuming of course that people want to run Windows. The only reason I do is because of speech recognition requirements but that''s a very different conversation. of course, Linux would continue to run at its normal speed. ---eric -- "Part of the problem with the Wal-Mart business model is that it requires more poverty in order to grow." http://www.salon.com/mwt/feature/2004/11/22/wal_mart/print.html ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/ _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
> Under the opinion that there is no crime if optimization fails on incorrect > code, would it not be appropriate to do all the things necessary to run > Windows unmodified albeit poorly slash slowly?It''s not just that the modifications improve performance, guests actually need to be modified to work on Xen at all. When Intel''s VT extensions come out, supporting unmodified guests will be rather easier. If you want a free means of running a Windows virtual machine your best bet right now is probably QEmu. Faster than Bochs although with less complete machine emulation. The author intends to enhance it further to eventually get VMWare levels of performance (although that''s a non-trivial undertaking!).> assuming of course that people want to run Windows. The only reason I do is > because of speech recognition requirements but that''s a very different > conversation.Yeah, speech recognition on Linux (and others) is a bit of a pain. There are a few open source products (e.g. sphinx, perlbox) but I doubt they''re usuable for dictation, if that''s what you want. Out of interest, does Wine have any success at running NaturallySpeaking / ViaVoice / whatever? Cheers, Mark ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/ _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
> forgive me if this has been beaten to death but I''ve been thinking again > about the problem of running Windows as a guest OS under xen. I > understand and accept all the arguments of why you need to modify the > core OS for your virtualization process. > > Under the opinion that there is no crime if optimization fails on > incorrect code, would it not be appropriate to do all the things > necessary to run Windows unmodified albeit poorly slash slowly? > assuming of course that people want to run Windows. The only reason I > do is because of speech recognition requirements but that''s a very > different conversation.To run unmodified arbitrary OS images you need to be able to a) provide ''shadow mode'' page tables and segmentation b) trap and virtualize trappable instructions, c) dynamically scan code for untrappable instructions and rewrite. We do most of (a) already; doing (b) is not hard but not done. Doing (c) is tedious, difficult and fragile. We''re happy for anyone out there to have a go at this, but we''re unlikely to put any effort into it ourselves at this time. There may be hardware support in the future which makes (a) and (b) easier and (c) disappear; or MS may themselves produce a version of XP which doesn''t require (c). Who knows if and when either of these will happen tho... cheers, S. ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/ _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
Mark Williamson wrote:>> Under the opinion that there is no crime if optimization fails on >> incorrect code, would it not be appropriate to do all the things >> necessary to run Windows unmodified albeit poorly slash slowly? > > > It''s not just that the modifications improve performance, guests > actually need to be modified to work on Xen at all.I''m sorry. I misunderstood what was written. I was under the impression that to run Windows or unmodified operating systems quickly required a great deal of complexity on the order of vmware and that you could run Windows slower (under certain circumstances) with "simple" emulation features> If you want a free means of running a Windows virtual machine your best > bet right now is probably QEmu. Faster than Bochs although with less > complete machine emulation. The author intends to enhance it further to > eventually get VMWare levels of performance (although that''s a > non-trivial undertaking!).I was under the impression that the performance degradation for qemu was on the order of 3x native which would be a bit problematic for speech recognition. Is this impression wrong as well?> Yeah, speech recognition on Linux (and others) is a bit of a pain. There > are a few open source products (e.g. sphinx, perlbox) but I doubt > they''re usuable for dictation, if that''s what you want. Out of > interest, does Wine have any success at running NaturallySpeaking / > ViaVoice / whatever?tell me about it. I am heavily involved in the Open Source Speech Recognition Initiative (www.ossri.org) and just trying to figure out what''s necessary to make NaturallySpeaking work on wine is a handful because we need to make it tremendous number of assumptions about NaturallySpeaking. Scansoft, the current owner of the desktop speech recognition monopoly, views customers as a hostile necessity and doesn''t provide any support to anybody for any reason unless you show up with a big fat checkbook. The open source speech recognition engines are "cute research projects". To get something useful will take approximately five to eight years of work and $40 million. in other words, we''re going to need some major grants. as for wine and NaturallySpeaking, we can''t get past install. Again we are going to hunt for grants sometime after the first of the year to pay for the evaluation and development. It wouldn''t be entirely fair to go to the wine community without some compensation for their efforts. ---eric -- "Part of the problem with the Wal-Mart business model is that it requires more poverty in order to grow." http://www.salon.com/mwt/feature/2004/11/22/wal_mart/print.html ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/ _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
> I''m sorry. I misunderstood what was written. I was under the > impression that to run Windows or unmodified operating systems quickly > required a great deal of complexity on the order of vmware and that you > could run Windows slower (under certain circumstances) with "simple" > emulation featuresFor virtualisation in general, this statement is true: slower solutions (e.g. QEmu) that support unmodified OSs are easier to do than VMWare-style virtualisation. For Xen right now you''d be looking at running something like this on top of XenLinux in order to run unmodified OSs.> I was under the impression that the performance degradation for qemu was > on the order of 3x native which would be a bit problematic for speech > recognition. Is this impression wrong as well?No, it''s pretty slow at the moment. I imagine you''d have the power to get some speech recognition running, even with this performance hit but it doesn''t seem very sane to burn all of your CPU on it and only get a low performance out :-( Also, I just discovered that QEmu doesn''t emulate sound *input* at the moment, which is also a problem!> The open source speech recognition engines are "cute research projects". > To get something useful will take approximately five to eight years of > work and $40 million. in other words, we''re going to need some major > grants.Good luck with this stuff. I do miss speech recognition when using Linux... Cheers, Mark ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/ _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
Mark Williamson wrote:>> Under the opinion that there is no crime if optimization fails on >> incorrect code, would it not be appropriate to do all the things >> necessary to run Windows unmodified albeit poorly slash slowly? > > It''s not just that the modifications improve performance, guests > actually need to be modified to work on Xen at all.Supporting full virtualization on x86 is *much* more complicated than Xen-style paravirtualization, mainly because the x86 has some instructions that are not privileged, but reveal state that needs to be virtualized.> When Intel''s VT extensions come out, supporting unmodified guests will > be rather easier.Is there any information available on what the extensions will be?> Yeah, speech recognition on Linux (and others) is a bit of a pain.There was recently a big fanfare about IBM open-sourcing some of their speech recognition code, but I don''t know how much development it needs. -- David Hopwood <david.nospam.hopwood@blueyonder.co.uk> ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/ _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel