Re: Troubles running Xen on Raspberry Pi 4 with 5.6.1 DomU

[Corey Minyard <minyard@xxxxxxx>]

On Sat, May 02, 2020 at 06:48:27PM +0100, Julien Grall wrote:
> 
> 
> On 02/05/2020 18:35, Corey Minyard wrote:
> > On Sat, May 02, 2020 at 12:46:14PM +0100, Julien Grall wrote:
> > No.  If I am understanding this correctly, all the memory in dom0 below
> > 1GB would have to be physically below 1GB.
> 
> Well, dom0 is directly mapped. In other word, dom0 physical address == host
> physical address. So if we allocate memory below 1GB in Xen, then it will
> mapped below 1GB on dom0 as well.
> 
> The patch I suggested would try to allocate as much as possible memory below
> 1GB. I believe this should do the trick for you here.

Yes, that does seem to do the trick:

root@raspberrypi4-64-xen:~# xl info
host                   : raspberrypi4-64-xen
release                : 4.19.115-v8
version                : #1 SMP PREEMPT Thu Apr 16 13:53:57 UTC 2020
machine                : aarch64
nr_cpus                : 4
max_cpu_id             : 3
nr_nodes               : 1
cores_per_socket       : 1
threads_per_core       : 1
cpu_mhz                : 54.000
hw_caps                : 
00000000:00000000:00000000:00000000:00000000:00000000:00000000:00000000
virt_caps              : hvm hap
total_memory           : 3956
free_memory            : 3634
sharing_freed_memory   : 0
sharing_used_memory    : 0
outstanding_claims     : 0
free_cpus              : 0
xen_major              : 4
xen_minor              : 13
xen_extra              : .0
xen_version            : 4.13.0
xen_caps               : xen-3.0-aarch64 xen-3.0-armv7l
xen_scheduler          : credit2
xen_pagesize           : 4096
platform_params        : virt_start=0x200000
xen_changeset          : Tue Dec 17 14:19:49 2019 +0000 git:a2e84d8e42-dirty
xen_commandline        : console=dtuart dtuart=/soc/serial@7e215040 
sync_console dom0_mem=256M bootscrub=0
cc_compiler            : aarch64-montavista-linux-gcc (GCC) 9.3.0
cc_compile_by          : xen-4.13+gitAUT
cc_compile_domain      : mvista-cgx
cc_compile_date        : 2019-12-17
build_id               : b0e9b4af9d83f67953e1640976f0720452a88f6a
xend_config_format     : 4

Thanks for the fix.

-corey

> 
> Cheers,
> 
> -- 
> Julien Grall