Hello,<br><br>Some might correct what I'll say, I dunno if i'm 100% right (or just 50%?).<br><br>Virtualisation is a wonderfull new toy for SI ;) which relies on providing some HAL to unmodified OS so they can run on top of hypervisor just like if it was bare metal. Then you can have plenty of OSes on the same machine as you're not longer relying on hardware. Seems to me like the "basic idea" of commercial virtualization :p<br>
I recommand you to have a look on Popek and Goldberg about virtualization, and their rules about "how virtualization should be" (most of code should run on processor, not being emulated / should exhibit an effect identical as if it was on bare metal / hypervisor should have a complete control of system)<br>
<br>However, IA-32 (x86) has a huge problem : it's not "virtualization compliant" (well, now, it tend to be), and then you have to watch the execution of your virtual machine to avoid big problems. That's why virtualization is slow.........<br>
However (2), some guys come up with PARA-virtualization : modifying the guest(s) OS(es) so they are "aware" of being on top of hypervisor. (That's Xen and so on...). This idea bring better performances, "near natives" says some, but need to change OS.<br>
However (3), some other guys come up with PRE-virtualization : annotating the guest(s) OS(es) at compilation time, so they can run on bare-metal and on specific hypervisors... Yet this idea was not commercialized.<br><br>
Now, to the question "how to do with dual guest os", which I understand as "how to run 2 guest OS", I'd answer that's seems easy on OKL4 : just have to change some configuration files, so there would be (for example) not one OKLinux but several. <br>
Then you might answer "and priorities?" OKLinux runs on 99 (main threads) and 100, but can share them. I dunno about the perf then :p <br>I'd ask you : how do you want your two OSes to run ? Is there one RT or with some higher priority ? for 100% of its execution time or less? (you can had an OS with higher priority, or divide it to higher and lower priority (...))<br>
<br>Ok, might not be the answer you wanted :p Maybe you should have a look into /package/iguana/SConscruct ? It would show you how stuff are linked inside one image ( so how to put L4+l4test or l4+polls+oklinux ...)<br>
<br><div class="gmail_quote">2008/5/15 quanchen <<a href="mailto:westwolf2008@gmail.com">westwolf2008@gmail.com</a>>:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<br>
Hi all<br>
i am a student.and now i am studying os virtualization.l4 is<br>
wonderful,but there is not enough information<br>
about how to do with dual guest os,may i get some help at here?<br>
<br>
Best Regards,<br>
quanchen<br>
2008-05-15<br>
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