Re: [QUESTION] x86_64 -> i386/i686 CPU translation between xl and qemu binary?

["Alex Braunegg" <alex.braunegg@gmail.com>]

Hi Andrew,

The Windows 2008 .cfg was built up using guidance from
http://www.virtuatopia.com/index.php/Virtualizing_Windows_Server_2008_with_X
en

If shadow_memory is not required - easy enough remove and retest. (which
after removing this line, the guest started without issue)

The physical server itself is an Intel S5000xvn motherboard with 2 x E5320
CPU's:

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 15
model name      : Intel(R) Xeon(R) CPU           E5320  @ 1.86GHz
stepping        : 7
microcode       : 0x69
cpu MHz         : 1861.990
cache size      : 4096 KB
physical id     : 0
siblings        : 1
core id         : 0
cpu cores       : 1
apicid          : 0
initial apicid  : 0
fpu             : yes
fpu_exception   : yes
cpuid level     : 10
wp              : yes
flags           : fpu de tsc msr pae mce cx8 apic sep mca cmov pat clflush
acpi mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc arch_perfmon
rep_good nopl pni monitor est ssse3 cx16 hypervisor lahf_lm dtherm
bugs            :
bogomips        : 3723.98
clflush size    : 64
cache_alignment : 64
address sizes   : 36 bits physical, 48 bits virtual
power management:


Best regards,

Alex


-----Original Message-----
From: Andrew Cooper [mailto:amc96@hermes.cam.ac.uk] On Behalf Of Andrew
Cooper
Sent: Friday, 5 February 2016 11:04 AM
To: Alex Braunegg; xen-devel@lists.xen.org
Subject: Re: [Xen-devel] [QUESTION] x86_64 -> i386/i686 CPU translation
between xl and qemu binary?

On 04/02/2016 23:44, Alex Braunegg wrote:
> Hi Andrew,
>
> I don't know enough on the internals of xen / qemu here - however, based
on
> what you said, an x86_64 OS with >4Gb memory should boot via xl - however
in
> my case here it fails to start up:
>
> -------------------------------------------------------------
>
> [root@mynas-s5000xvn ~]# xl -vvvv create
/etc/xen/config/Windows_2008_R2.cfg
>
> Parsing config from /etc/xen/config/Windows_2008_R2.cfg
> libxl: debug: libxl_create.c:1560:do_domain_create: ao 0x735690: create:
> how=(nil) callback=(nil) poller=0x734b70
> libxl: debug: libxl_device.c:269:libxl__device_disk_set_backend: Disk
> vdev=hda spec.backend=unknown
> libxl: debug: libxl_device.c:298:libxl__device_disk_set_backend: Disk
> vdev=hda, using backend phy
> libxl: debug: libxl_device.c:269:libxl__device_disk_set_backend: Disk
> vdev=hdc spec.backend=unknown
> libxl: debug: libxl_device.c:298:libxl__device_disk_set_backend: Disk
> vdev=hdc, using backend phy
> libxl: debug: libxl_create.c:945:initiate_domain_create: running
bootloader
> libxl: debug: libxl_bootloader.c:324:libxl__bootloader_run: not a PV
domain,
> skipping bootloader
> libxl: debug: libxl_event.c:691:libxl__ev_xswatch_deregister: watch
> w=0x736078: deregister unregistered
> xc: detail: elf_parse_binary: phdr: paddr=0x100000 memsz=0x5b3a4
> xc: detail: elf_parse_binary: memory: 0x100000 -> 0x15b3a4
> xc: detail: VIRTUAL MEMORY ARRANGEMENT:
> xc: detail:   Loader:   0000000000100000->000000000015b3a4
> xc: detail:   Modules:  0000000000000000->0000000000000000
> xc: detail:   TOTAL:    0000000000000000->000000017f000000
> xc: detail:   ENTRY:    0000000000100600
> xc: detail: PHYSICAL MEMORY ALLOCATION:
> xc: detail:   4KB PAGES: 0x0000000000000200
> xc: detail:   2MB PAGES: 0x00000000000005f7
> xc: detail:   1GB PAGES: 0x0000000000000003
> xc: detail: elf_load_binary: phdr 0 at 0x7efc906d7000 -> 0x7efc90728910
> xc: error: Could not clear special pages (22 = Invalid argument): Internal
> error
> libxl: error: libxl_dom.c:1003:libxl__build_hvm: hvm building failed

The problem is here, but it isn't immediately apparent why (other than
"failed to map special pages").

> Guest Config:
> =============
>
> -------------------------------------------------------------
>
> builder='hvm'
> memory = 6144
> shadow_memory = 8

These values look suspicious to me.  What hardware is this running on?
Either you are on more modern hardware and shouldn't touch
shadow_memory, or you are on rather older hardware, at which point 8M of
shadow memory is probably too small for a 6G VM.

~Andrew