Re: xen cache colors in ARM

[Michal Orzel <michal.orzel@xxxxxxx>]

On 19/04/2023 11:36, Oleg Nikitenko wrote:
>       
> 
> 
> Hi Michal,
> 
> I corrected xen's command line.
> Now it is
> xen,xen-bootargs = "console=dtuart dtuart=serial0 dom0_mem=1600M 
> dom0_max_vcpus=2 dom0_vcpus_pin bootscrub=0 vwfi=native sched=null 
> timer_slop=0 way_size=65536 xen_colors=0-3 dom0_colors=4-7";
> 
> Unfortunately the result was the same.
> 
> (XEN)  - Dom0 mode: Relaxed
> (XEN) P2M: 40-bit IPA with 40-bit PA and 8-bit VMID
> (XEN) P2M: 3 levels with order-1 root, VTCR 0x0000000080023558
> (XEN) Scheduling granularity: cpu, 1 CPU per sched-resource
> (XEN) Coloring general information
> (XEN) Way size: 64kB
> (XEN) Max. number of colors available: 16
> (XEN) Xen color(s): [ 0 ]
> (XEN) alternatives: Patching with alt table 00000000002cc690 -> 
> 00000000002ccc0c
> (XEN) Color array allocation failed for dom0
> (XEN)
> (XEN) ****************************************
> (XEN) Panic on CPU 0:
> (XEN) Error creating domain 0
> (XEN) ****************************************
> (XEN)
> (XEN) Reboot in five seconds...
> 
> I am going to find out how command line arguments passed and parsed.
Best would be to cross-check the cmdline you provided with the one Xen sees.
For that you would need to enable early printk, so that Xen will print the 
cmdline (+ the boot modules).
Is yocto the only workflow to build Xen in your case?

Early printk for zynqMP can be enabled through menuconfig:
Debugging Options->Early printk->Early printk with Cadence UART for Xilinx 
ZynqMP SOCs
This will automatically set early UART address to serial0 which is at 
0xff000000.

I think using Yocto, you could either do something like:
bitbake xen -c menuconfig
or provide the necessary Kconfig options in a config file added to SCR_URI 
(most likely you already have
such file with CONFIG_COLORING=y as it is not enabled by default).

~Michal

> 
> Regards,
> Oleg
> 
> ср, 19 апр. 2023 г. в 11:25, Oleg Nikitenko <oleshiiwood@xxxxxxxxx 
> <mailto:oleshiiwood@xxxxxxxxx>>:
> 
>     Hi Michal,
> 
>     You put my nose into the problem. Thank you.
>     I am going to use your point.
>     Let's see what happens.
> 
>     Regards,
>     Oleg
> 
> 
>     ср, 19 апр. 2023 г. в 10:37, Michal Orzel <michal.orzel@xxxxxxx 
> <mailto:michal.orzel@xxxxxxx>>:
> 
>         Hi Oleg,
> 
>         On 19/04/2023 09:03, Oleg Nikitenko wrote:
>         >       
>         >
>         >
>         > Hello Stefano,
>         >
>         > Thanks for the clarification.
>         > My company uses yocto for image generation.
>         > What kind of information do you need to consult me in this case ?
>         >
>         > Maybe modules sizes/addresses which were mentioned by @Julien Grall 
> <mailto:julien@xxxxxxx <mailto:julien@xxxxxxx>> ?
> 
>         Sorry for jumping into discussion, but FWICS the Xen command line you 
> provided seems to be not the one
>         Xen booted with. The error you are observing most likely is due to 
> dom0 colors configuration not being
>         specified (i.e. lack of dom0_colors=<> parameter). Although in the 
> command line you provided, this parameter
>         is set, I strongly doubt that this is the actual command line in use.
> 
>         You wrote:
>         xen,xen-bootargs = "console=dtuart dtuart=serial0 dom0_mem=1600M 
> dom0_max_vcpus=2 dom0_vcpus_pin bootscrub=0 vwfi=native sched=null 
> timer_slop=0 way_szize=65536 xen_colors=0-3 dom0_colors=4-7";
> 
>         but:
>         1) way_szize has a typo
>         2) you specified 4 colors (0-3) for Xen, but the boot log says that 
> Xen has only one:
>         (XEN) Xen color(s): [ 0 ]
> 
>         This makes me believe that no colors configuration actually end up in 
> command line that Xen booted with.
>         Single color for Xen is a "default if not specified" and way size was 
> probably calculated by asking HW.
> 
>         So I would suggest to first cross-check the command line in use.
> 
>         ~Michal
> 
> 
>         >
>         > Regards,
>         > Oleg
>         >
>         > вт, 18 апр. 2023 г. в 20:44, Stefano Stabellini 
> <sstabellini@xxxxxxxxxx <mailto:sstabellini@xxxxxxxxxx> 
> <mailto:sstabellini@xxxxxxxxxx <mailto:sstabellini@xxxxxxxxxx>>>:
>         >
>         >     On Tue, 18 Apr 2023, Oleg Nikitenko wrote:
>         >     > Hi Julien,
>         >     >
>         >     > >> This feature has not been merged in Xen upstream yet
>         >     >
>         >     > > would assume that upstream + the series on the ML [1] work
>         >     >
>         >     > Please clarify this point.
>         >     > Because the two thoughts are controversial.
>         >
>         >     Hi Oleg,
>         >
>         >     As Julien wrote, there is nothing controversial. As you are 
> aware,
>         >     Xilinx maintains a separate Xen tree specific for Xilinx here:
>         >     https://github.com/xilinx/xen <https://github.com/xilinx/xen> 
> <https://github.com/xilinx/xen <https://github.com/xilinx/xen>>
>         >
>         >     and the branch you are using (xlnx_rebase_4.16) comes from 
> there.
>         >
>         >
>         >     Instead, the upstream Xen tree lives here:
>         >     https://xenbits.xen.org/gitweb/?p=xen.git;a=summary 
> <https://xenbits.xen.org/gitweb/?p=xen.git;a=summary> 
> <https://xenbits.xen.org/gitweb/?p=xen.git;a=summary 
> <https://xenbits.xen.org/gitweb/?p=xen.git;a=summary>>
>         >
>         >
>         >     The Cache Coloring feature that you are trying to configure is 
> present
>         >     in xlnx_rebase_4.16, but not yet present upstream (there is an
>         >     outstanding patch series to add cache coloring to Xen upstream 
> but it
>         >     hasn't been merged yet.)
>         >
>         >
>         >     Anyway, if you are using xlnx_rebase_4.16 it doesn't matter too 
> much for
>         >     you as you already have Cache Coloring as a feature there.
>         >
>         >
>         >     I take you are using ImageBuilder to generate the boot 
> configuration? If
>         >     so, please post the ImageBuilder config file that you are using.
>         >
>         >     But from the boot message, it looks like the colors 
> configuration for
>         >     Dom0 is incorrect.
>         >
>