Manuel Bouyer wrote:
> >  - Can you run a GENERIC_MP kernel fully virtualized using HVM and
> >    take advantage of multiple CPUs that way?
> 
> This should work. I run a windows 2003 HVM which see multiple CPUs, so
> it should work with NetBSD too.

I built a -current kernel using the following configuration file
(NOFLOPPY.MP):

  include "arch/i386/conf/GENERIC.MP"
  no fdc0 at isa?
  no fd*  at fdc?

I then booted it under Xen 3.0.3 on an Intel Core 2 Quad Q6600 CPU,
using the following Xen configuration file:

  kernel = "/usr/lib/xen-ioemu-3.0/boot/hvmloader"
  builder = 'hvm'
  memory = 256
  name = "curvi"
  vcpus = 4
  acpi = 1
  apic = 1
  vif = [ 'type=ioemu, bridge=xenbr0,mac=00:16:3e:49:34:80' ]
  disk = ['phy:/dev/mapper/guesthouse-current,ioemu:hda,w']
  device_model = '/usr/lib/xen-ioemu-3.0/bin/qemu-dm'
  ne2000=0
  boot='c'
  serial = 'pty'
  nographic = 1

It hung while attaching the third CPU core:

  >> NetBSD/i386 BIOS Boot, Revision 3.3
  >> (root@guru.araneus.fi, Mon Aug  6 21:18:55 EEST 2007)
  >> Memory: 639/261120 k
  Press return to boot now, any other key for boot menu
  booting hd0a:netbsd - starting in 0 
  9165028+421316+363768 [461888+446360]=0xa5ca38
  BIOS CFG: Model-SubM-Rev: fc-00-01, 0x4074<EBDA,KBDINT,RTC,IC2,KBDF>
  Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
      2006, 2007
      The NetBSD Foundation, Inc.  All rights reserved.
  Copyright (c) 1982, 1986, 1989, 1991, 1993
      The Regents of the University of California.  All rights reserved.

  NetBSD 4.99.30 (NOFLOPPY.MP) #0: Wed Sep  5 19:10:40 EEST 2007
	  root@dhcppc1:/usr/src/sys/arch/i386/compile/NOFLOPPY.MP
  total memory = 255 MB
  rbus: rbus_min_start set to 0x40000000
  avail memory = 240 MB
  mainbus0 (root)
  cpu0 at mainbus0 apid 0: (boot processor)
  cpu0: Intel Core 2 (Merom) (686-class), 2400.24 MHz, id 0x6f7
  cpu0: "Intel(R) Core(TM)2 Quad CPU           @ 2.40GHz"
  cpu1 at mainbus0 apid 1: (application processor)
  cpu1: Intel Core 2 (Merom) (686-class), 2400.33 MHz, id 0x6f7
  cpu1: "Intel(R) Core(TM)2 Quad CPU           @ 2.40GHz"
  cpu2 at mainbus0 apid 2: (application processor)

There was no more output after that.  When I tried to destroy the hung
VM using "xm destroy curvi", the whole system locked up (including the
Linux dom0) and had to be rebooted.

If I set "vcpus = 2" in the configuration file, NetBSD boots
successfully.
-- 
Andreas Gustafsson, gson@gson.org