From mboxrd@z Thu Jan 1 00:00:00 1970 To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> In-reply-to: Your message of "Fri, 13 Jun 2008 19:52:22 EDT." From: Bakul Shah Date: Fri, 13 Jun 2008 17:40:52 -0700 Message-Id: <20080614004052.9F76C5B46@mail.bitblocks.com> Subject: Re: [9fans] I/O load crashes Qemu Topicbox-Message-UUID: c0709ac6-ead3-11e9-9d60-3106f5b1d025 On Fri, 13 Jun 2008 19:52:22 EDT erik quanstrom wrote: > > You don't need this sort of code in a virtualizable processor. > > See for example > > http://en.wikipedia.org/wiki/Popek_and_Goldberg_virtualization_requiremen > ts > > i'm not convinced that the illusion that the virtualized environment > is in every way equivalent to the bare iron is always useful or worth > the effort. why should a virtualized operating system need to worry > about what nic the machine has? Well the URL was more to get the point across. Whether your virtual OS uses simplified virtual devices or emulated real devices, you shouldn't have to emulate each instruction in software! I won't argue with "worth the effort" but it can be useful (e.g. running dusty decks, debugging etc). My argument is more that real device intefaces should be designed to make virtualization efficient. > for example vmware doesn't provide this sort of virtualized environment. > it provides the same virtual network card interface regardless of > what hardware the machine has. It is doable but it took them years to get there and provide good efficiency. May be even more years that VM/370?!