Re: [Minios-devel] Mini-OS Support for Suspend

[Simon Kuenzer <simon.kuenzer@xxxxxxxxx>]

Hey Bruno,

I am Simon from NEC Labs. A former colleague of mine did implement the 
suspend functionality on our mini-os tree a couple of years ago (please 
do not blame me for design decisions ;-) and it was working fine for us).
In order to get our suspend/resume working, you need to provide a 
function that has to have the following name and signature:
void app_shutdown(unsigned reason)

This function will be called from a newly introduced thread (called 
shutdown) which listens for suspend or shutdown requests. Since Mini-OS 
has a cooperative scheduler, your main() should either block, sleep, or 
call schedule() from time to time; so that this schedule can do its 
work. The reasons are defined in <mini-os/shutdown.h>.
As soon as you catch one of the requests, you can call kernel_suspend() 
or kernel_shutdown(action).
I remember that VIFs and block devices should be supported by our 
implementation - not sure about the consoles.
Thanks,

Simon


On 07.12.2017 00:53, Bruno Alvisio wrote:
> Hi all,
>
> I wanted to be able to save and suspend mini-os but found that mini-os 
> doesn't handle "suspend" requests.
> I also found that the mini-os repository from NEC Labs Systems and 
> Machine Learning (sysml) has some support to handle suspends: There is a 
> kernel_suspend() function that does the suspend operations such as 
> unmapping the shared info page and suspending Xenstore.
> I have tried to port the suspend functions from the sysml mini-os 
> repository to the current xenbits mini-os repository but I was not able 
> to make suspend work. Also looked at what the mirage OS does for suspend 
> and replicate it without luck. The branch can be found in:
> https://github.com/balvisio/mini-os/tree/feature/mini-os-suspend-support
>
>
> Currently the "xl save" command fails with the following messages:
>
> root@debianxen:/home/balvisio# xl -vvv save minios minios.chkpt
>
> libxl: debug: libxl_domain.c:1687:libxl_retrieve_domain_configuration: 
> Domain 58:No disk from xenstore
> libxl: debug: libxl_domain.c:1687:libxl_retrieve_domain_configuration: 
> Domain 58:No nic from xenstore
> libxl: debug: libxl_domain.c:1687:libxl_retrieve_domain_configuration: 
> Domain 58:No vtpm from xenstore
> libxl: debug: libxl_domain.c:1687:libxl_retrieve_domain_configuration: 
> Domain 58:No usbctrl from xenstore
> libxl: debug: libxl_domain.c:1687:libxl_retrieve_domain_configuration: 
> Domain 58:No usbdev from xenstore
> libxl: debug: libxl_domain.c:1687:libxl_retrieve_domain_configuration: 
> Domain 58:No pci from xenstore
> libxl: debug: libxl_domain.c:1687:libxl_retrieve_domain_configuration: 
> Domain 58:No vdispl from xenstore
> Saving to minios.chkpt new xl format (info 0x3/0x0/705)
>
> libxl: debug: libxl_domain.c:492:libxl_domain_suspend: Domain 58:ao 
> 0x560af0252d40: create: how=(nil) callback=(nil) poller=0x560af024fb30
> libxl: debug: libxl.c:719:libxl__fd_flags_modify_save: fnctl F_GETFL 
> flags for fd 9 are 0x8001
> libxl: debug: libxl.c:727:libxl__fd_flags_modify_save: fnctl F_SETFL of 
> fd 9 to 0x8001
> libxl: debug: libxl_domain.c:520:libxl_domain_suspend: Domain 58:ao 
> 0x560af0252d40: inprogress: poller=0x560af024fb30, flags=i
> libxl-save-helper: debug: starting save: Success
>
> xc: detail: fd 9, dom 58, flags 0, hvm 0
>
> xc: info: Saving domain 58, type x86 PV
>
> xc: detail: 64 bits, 4 levels
>
> xc: detail: max_mfn 0x440000
>
> xc: detail: max_pfn 0x3fff, p2m_frames 32
>
> libxl: debug: libxl_dom_suspend.c:191:domain_suspend_callback_common: 
> Domain 58:issuing PV suspend request via XenBus control node
> libxl: debug: libxl_event.c:636:libxl__ev_xswatch_register: watch 
> w=0x560af02502d8 wpath=/local/domain/58/control/shutdown token=3/0: 
> register slotnum=3
> libxl: debug: libxl_event.c:573:watchfd_callback: watch w=0x560af02502d8 
> wpath=/local/domain/58/control/shutdown token=3/0: event 
> epath=/local/domain/58/control/shutdown
> libxl: debug: libxl_event.c:673:libxl__ev_xswatch_deregister: watch 
> w=0x560af02502d8 wpath=/local/domain/58/control/shutdown token=3/0: 
> deregister slotnum=3
> libxl: debug: 
> libxl_dom_suspend.c:273:domain_suspend_common_pvcontrol_suspending: 
> Domain 58:guest acknowledged suspend request
> libxl: debug: libxl_dom_suspend.c:292:domain_suspend_common_wait_guest: 
> Domain 58:wait for the guest to suspend
> libxl: debug: libxl_event.c:636:libxl__ev_xswatch_register: watch 
> w=0x560af02502f0 wpath=@releaseDomain token=3/1: register slotnum=3
> libxl: debug: libxl_event.c:573:watchfd_callback: watch w=0x560af02502f0 
> wpath=@releaseDomain token=3/1: event epath=@releaseDomain
> libxl: debug: libxl_dom_suspend.c:346:suspend_common_wait_guest_check: 
> Domain 58:guest we were suspending has shut down with unexpected reason 
> code 0
> libxl: debug: libxl_event.c:673:libxl__ev_xswatch_deregister: watch 
> w=0x560af02502f0 wpath=@releaseDomain token=3/1: deregister slotnum=3
> xc: error: save callback suspend() failed: 0: Internal error
>
> xc: error: Save failed (22 = Invalid argument): Internal error
>
> libxl-save-helper: debug: complete r=-1: Invalid argument
>
> libxl: error: libxl_stream_write.c:350:libxl__xc_domain_save_done: 
> Domain 58:saving domain: domain responded to suspend request: Invalid 
> argument
> libxl: debug: libxl.c:746:libxl__fd_flags_restore: fnctl F_SETFL of fd 9 
> to 0x8001
> libxl: debug: libxl_event.c:1869:libxl__ao_complete: ao 0x560af0252d40: 
> complete, rc=-3
> libxl: debug: libxl_event.c:1838:libxl__ao__destroy: ao 0x560af0252d40: 
> destroy
> Failed to save domain, resuming domain
>
> libxl: debug: libxl_domain.c:180:libxl_domain_resume: Domain 58:ao 
> 0x560af0253550: create: how=(nil) callback=(nil) poller=0x560af024fb30
> libxl: error: libxl_dom.c:38:libxl__domain_type: unable to get domain 
> type for domid=58
> libxl: debug: libxl_event.c:1869:libxl__ao_complete: ao 0x560af0253550: 
> complete, rc=-3
> libxl: debug: libxl_domain.c:183:libxl_domain_resume: Domain 58:ao 
> 0x560af0253550: inprogress: poller=0x560af024fb30, flags=ic
> libxl: debug: libxl_event.c:1838:libxl__ao__destroy: ao 0x560af0253550: 
> destroy
> xencall:buffer: debug: total allocations:47 total releases:47
>
> xencall:buffer: debug: current allocations:0 maximum allocations:2
>
> xencall:buffer: debug: cache current size:2
>
> xencall:buffer: debug: cache hits:36 misses:2 toobig:9
>
> xencall:buffer: debug: total allocations:0 total releases:0
>
> xencall:buffer: debug: current allocations:0 maximum allocations:0
>
> xencall:buffer: debug: cache current size:0
>
> xencall:buffer: debug: cache hits:0 misses:0 toobig:0
>
>
>
> I also tried to compile the mini-OS from the NEC repository but I was 
> not able to.
> Any help/pointers to make suspend work in mini-OS or on how to build 
> mini-OS from the NEC-sysml repository would be greatly appreciated.
> Cheers,
>
> Bruno
>
>
>
>
>
>
> _______________________________________________
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--
============================================================
Simon Kuenzer
シモン クゥンツァー
Research Scientist,
Networked Systems and Data Analytics Group
NEC Laboratories Europe, Network Research Division
Kurfuerstenanlage 36, D-69115 Heidelberg
Tel.     +49 (0)6221 4342-264
Fax:     +49 (0)6221 4342-5264
e-mail:  simon.kuenzer@xxxxxxxxx
============================================================
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Business Park, West End Road, London, HA4 6QE, GB
Registered in England 2832014

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