Re: Missing memory with PVH domu's?

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Wed, Aug 28, 2024 at 06:39:19AM -0700, Brian Buhrow wrote:
> 	hello.   I recently began using PVH domu's with my xen installations.  I took working PV
> domu's, replaced the kernel with PVH capable kernels, changed the type in the domu config file
> and set things going.  All seemed to work well, except I notice a discrepancy between the
> amount of memory I configured in the config file and the amount of memory the domu sees.
> 
> For example:
> 
> Given the below config file, I think I should see 8GB of memory in the domu this controls.
> When it was configured as a PV domu, I did.  
> Now, I get 4GB:
> 
> Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
>     2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017,
>     2018, 2019, 2020, 2021 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 9.99.77 (MIRKWOOD_PVH) #0: Mon May 20 16:09:04 PDT 2024
>         buhrow%loth-9.nfbcal.org@localhost:/usr/src/sys/arch/amd64/compile/MIRKWOOD_PVH
> total memory = 4096 MB
> avail memory = 3944 MB
> entropy: no seed from bootloader
> 
> 
> This is with xen-4.16.0 with FreeBSD-13.1 running as the dom0.
> Any thoughts?
> 
> <Cut here for config file>
> 
> msr_relaxed = 1
> kernel = "/var/xen/nfbcal/loth_9/netbsd"
> type = "pvh"
> memory = 8192
> vcpus = 2
> name = "loth_9"
> vif = [  'mac=XX:XX:XX:XX:42:cc,bridge=bridge0' ]
> disk = [ 
> 'file:/var/xen/nfbcal/loth_9/disk0,0x1,rw'
>  ]
> boot = 'c'
> extra = ""
> on_poweroff = "restart"

Yes, you should see 8Gb. I do, with Xen 4.18 and NetBSD as dom0:
[     1.000000] NetBSD 10.0 (GENERIC) #0: Thu Mar 28 08:33:33 UTC 2024
[     1.000000]         mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC
[     1.000000] total memory = 8192 MB
[     1.000000] avail memory = 7900 MB

type="pvh"
kernel = "/usr/pkg/etc/xen/kernels/netbsd10-GENERIC.gz"
memory = 8192

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--