Diff for /wikisrc/ports/xen/howto.mdwn between versions 1.191 and 1.195

version 1.191, 2021/02/26 19:03:20 version 1.195, 2021/03/03 15:03:13
Line 167  menu=Xen:load /netbsd-XEN3_DOM0.gz conso Line 167  menu=Xen:load /netbsd-XEN3_DOM0.gz conso
 menu=Xen single user:load /netbsd-XEN3_DOM0.gz console=pc -s;multiboot /xen.gz dom0_mem=512M  menu=Xen single user:load /netbsd-XEN3_DOM0.gz console=pc -s;multiboot /xen.gz dom0_mem=512M
 """]]  """]]
   
 \todo Explain why console=pc is given.  Perhaps there is some notion  
 of a separate console instead of xencons.  
   
 \todo Check the single user line.  
   
 This specifies that the dom0 should have 512MB of ram, leaving the rest  This specifies that the dom0 should have 512MB of ram, leaving the rest
 to be allocated for domUs.  to be allocated for domUs.
   
Line 181  want to set it as default.  It is highly Line 176  want to set it as default.  It is highly
 trouble at some point, and keeping an up-to-date GENERIC for use in  trouble at some point, and keeping an up-to-date GENERIC for use in
 fixing problems is the standard prudent approach.  fixing problems is the standard prudent approach.
   
   \todo Explain why rndseed is not set with Xen as part of the dom0
   subconfiguration.
   
   Beware that userconf statements must be attached to the dom0 load, and
   may not be at top-level, because then they would try to configure the
   hypervisor, if there is a way to pass them via multiboot .  It appears
   that adding `userconf=pckbc` to `/boot.cfg` causes Xen to crash very
   early with a heap overflow.
   
 ### Console selection  ### Console selection
   
 See boot_console(8).  Understand that you should start from a place of  See boot_console(8).  Understand that you should start from a place of
 having console setup correct for booting GENERIC before trying to  having console setup correct for booting GENERIC before trying to
 configure Xen.  configure Xen.
   
 By default, the hypervisor (Xen itself) will use \todo as the console  Generally for GENERIC, one sets the console in bootxx_ffsv1 or
   equivalent, and this is passed on to /boot (where one typically does
 By default, the NetBSD dom0 kernel will use xencons(4) (the man page  not set the console).  This configuration of bootxx_ffsv1 should also
 does not exist) as console.  be in place for Xen systems, to allow seeing messages from /boot and
   use of a keyboard to select a line from the menu.  And, one should
 To use a serial console for the Xen hypervisor, add settings as follows:  have a working boot path to GENERIC for rescue situations.
   
   With GENERIC, the boot options are passed on to /netbsd, but there is
   currently no mechanism to pass these via multiboot to the hypervisor.
   Thus, in addition to configuring the console in the boot blocks, one
   must also configure it for Xen.
   
   By default, the hypervisor (Xen itself) will use some sort of vga
   device as the console, much like GENERIC uses by default.  The vga
   console is relinquished at the conclusion of hypervisor boot, before
   the dom0 is started.  Xen when using a vga console does not process
   console input.
   
   The hypervisor can be configured to use a serial port console, e.g.
 [[!template id=filecontent name="/boot.cfg" text="""  [[!template id=filecontent name="/boot.cfg" text="""
 menu=Xen:load /netbsd-XEN3_DOM0.gz;multiboot /xen.gz dom0_mem=512M console=com1 com1=9600,8n1  menu=Xen:losad /netbsd-XEN3_DOM0.gz console=com0;multiboot /xen.gz dom0_mem=512M console=com1 com1=9600,8n1
 """]]  """]]
   This example uses the first serial port (Xen counts from 1; this is
 which will use the first serial port for Xen (which counts starting  what NetBSD would call com0), and sets speed and parity.  (The dom0 is
 from 1, unlike NetBSD which counts starting from 0), forcing  then configured to use the same serial port in this example.)
 speed/parity.  Because the NetBSD command line lacks a  
 "console=pc" argument, it will use the default "xencons" console device,  With the hypervisor configured for a serial console, it can get input,
 which directs the console I/O through Xen to the same console device Xen  and there is a notion of passing this input to the dom0.  \todo
 itself uses (in this case, the serial port).  Explain why, if Xen has a serial console, the dom0 console is
   typically also configured to open that same serial port, instead of
 \todo Explain why boot.cfg shows forcing the dom0 console also,  getting the passthrough input via the xen console.
 separately from the hypervisor console.  
   One also configures the console for the dom0.  While one might expect
   console=pc to be default, following behavior of GENERIC, a hasty read
   of the code suggests there is no default and booting without a
   selected console might lead to a panic.  Also, there is merit in
   explicit configuration.  Therefore the standard approach is to place
   console=pc as part of the load statement for the dom0 kernel, or
   alternatively console=com0.
   
   The NetBSD dom0 kernel will attach xencons(4) (the man page does not
   exist), but this is not used as a console.  It is used to obtain the
   messages from the hypervisor's console; run `xl dmesg` to see them.
   
 ### Tuning  ### Tuning
   
Line 527  and the pseudo-terminals. These can be f Line 554  and the pseudo-terminals. These can be f
   
 Finally, all screens must be commented out from `/etc/wscons.conf`.  Finally, all screens must be commented out from `/etc/wscons.conf`.
   
 It is also desirable to add  One should also run `powerd` in a domU, but this should not need
   configuring.  With powerd, the domain will run a controlled shutdown
         powerd=YES  if `xl shutdown -R` or `xl shutdown -H` is used on the dom0, via
   receiving a synthetic `power button pressed` signal.  In 9 and
 in rc.conf. This way, the domain will be properly shut down if  current, `powerd` is run by default under Xen kernels (or if ACPI is
 `xl shutdown -R` or `xl shutdown -H` is used on the dom0.  present), and it can be added to rc.conf if not.
 \todo Check the translation to xl.  
   
 It is not strictly necessary to have a kernel (as /netbsd) in the domU  It is not strictly necessary to have a kernel (as /netbsd) in the domU
 file system.  However, various programs (e.g. netstat) will use that  file system.  However, various programs (e.g. netstat) will use that

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