From: cross@spitfire.i.gajendra.net   
      
   In article ,   
   Scott Lurndal  wrote:   
   >cross@spitfire.i.gajendra.net (Dan Cross) writes:   
   >>Oh cool.  I always thought that MIPS would be hard to virtualize   
   >>because of the ksegs and soft-TLBs.   
   >   
   >Indeed, it took another decade and a half before MIPS added   
   >virtualization support to the architecture, IIRC;  Cavium   
   >was also a MIPS shop (until 2012, when we started the switch   
   >to ARM64) and we had looked at the MIPS virtualization extensions around   
   >that time.   
      
   Same with x86, of course: how long after VMWare did their   
   binary-rewriting thing before Intel introduced VMX?   
      
   >The SGI skunkworks project used a 2 processor HP Kayak with   
   >Pentium II (IIRC) processors; we had an instance of windows   
   >running alongside an instance of linux.   Microsoft had   
   >given us the source for NT4 - this was about the time   
   >that SGI was looking to move the graphics workstations   
   >to intel/microsoft based boxen.   
      
   Ah, very interesting; this was roughly the same era as VMWare's   
   initial offerings: I'm guessing you pulled the same incrememntal   
   rewriting trick they did?   
      
   >>  It was never clear to me   
   >>how a hypervisor could, in general, know the format of the guest   
   >>page tables.  I know the Disco folks had to make some changes to   
   >>Irix to get it to work.   
   >   
   >When I was working on IRIX, I was not fond of either the software   
   >managed TLB, coloring or the Kseg stuff; the MIPS project I worked on was   
   called   
   >Teak and was a distributed version of Irix (eventually cancelled)   
   >for networks of R10k boxes.   
      
   I get it from a hardware perspective: fewer transistors with a   
   software-managed TLB, but man...so many drawbacks.   
      
   	- Dan C.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)