Re: [meta-virtualization] Loading the module xen-gntdev on boot

[Bertrand Marquis <Bertrand.Marquis@arm.com>]

Hi Bruce

> On 23 Mar 2022, at 09:38, Bertrand Marquis via lists.yoctoproject.org <bertrand.marquis=arm.com@lists.yoctoproject.org> wrote:
> 
> Hi Paulo
> 
>> On 22 Mar 2022, at 16:52, Paulo Sherring via lists.yoctoproject.org <pauloasherring=gmail.com@lists.yoctoproject.org> wrote:
>> 
>> Hello Diego, Bertrand,
>> Just confirmed that by bringing these changes into hardknott, the
>> modules get correctly probed on bootup.
> 
> Great thanks for the info.
> 
> @Bruce: Maybe it would make sense to backport this as hardknott is LTS ?
> If yes, please ping me if you need support to do it.

In fact hardnott is not LTS (my mistake) but as support is broken it would still make sense to backport this I think.

Cheers
Bertrand

> 
> Cheers
> Bertrand
> 
>> 
>> The xen.conf content, just for completeness:
>> xen-evtchn
>> xen-gntdev
>> xen-gntalloc
>> xen-blkback
>> xen-netback
>> xen-pciback
>> evtchn
>> gntdev
>> netbk
>> blkbk
>> xen-scsibk
>> usbbk
>> pciback
>> 
>> Thanks for the support :)
>> Kind regards, Paulo.
>> 
>> On Tue, Mar 22, 2022 at 3:30 PM Diego Sueiro <Diego.Sueiro@arm.com> wrote:
>>> 
>>> The xen modules load from systemd was fixed in master as https://git.yoctoproject.org/meta-virtualization/commit/?id=44dad5105d408e7b6217600eba3672e72db0f42f and honister as https://git.yoctoproject.org/meta-virtualization/commit/?h=honister&id=6cde8f2ccbde5ecc9997cf727939a0ae5e0fe11d.
>>> 
>>> You might need to backport this to hardknott as well.
>>> 
>>> --
>>> Diego Sueiro
>>> Staff Software Developer - Automotive and Industrial Solutions (CE-OSS)
>>> 
>>>> -----Original Message-----
>>>> From: meta-virtualization@lists.yoctoproject.org <meta-
>>>> virtualization@lists.yoctoproject.org> On Behalf Of Bertrand Marquis via
>>>> lists.yoctoproject.org
>>>> Sent: 22 March 2022 15:23
>>>> To: Paulo Sherring <pauloasherring@gmail.com>
>>>> Cc: meta-virtualization@lists.yoctoproject.org; nd <nd@arm.com>; Bruce
>>>> Ashfield <bruce.ashfield@gmail.com>
>>>> Subject: Re: [meta-virtualization] Loading the module xen-gntdev on boot
>>>> 
>>>> Hi Paulo,
>>>> 
>>>>> On 22 Mar 2022, at 16:01, Paulo Sherring <pauloasherring@gmail.com>
>>>> wrote:
>>>>> 
>>>>> Hi Bertrand,
>>>>> One very important piece of information I missed to disclose: I am not
>>>>> using runqemu, as it was not being properly set by the resulting
>>>>> bitbake build (the resulting image was pointing to the kernel instead
>>>>> of the xen binary).
>>>> 
>>>> This should not impact the module loading.
>>>> 
>>>>> 
>>>>> So, I am launching it "by hand":
>>>>> 
>>>>> ./tmp/work/x86_64-linux/qemu-helper-native/1.0-r1/recipe-sysroot-nativ
>>>>> e/usr/bin/qemu-system-aarch64
>>>>> \
>>>>> -nographic  \
>>>>> -machine virt,gic-version=3 \
>>>>> -machine virtualization=true \
>>>>> -cpu cortex-a57 -smp 4 -m 4G -machine type=virt \ -bios
>>>>> ./tmp/deploy/images/qemuarm64/u-boot-qemuarm64.bin \ -device
>>>>> loader,file=./tmp/deploy/images/qemuarm64/xen-
>>>> qemuarm64,addr=0x4500000
>>>>> 0
>>>>> \
>>>>> -device
>>>>> loader,file=./tmp/deploy/images/qemuarm64/Image--
>>>> 5.10.103+git0+792f127
>>>>> 2dd_3aab5bb12b-r0-qemuarm64-20220317212819.bin,addr=0x46000000
>>>>> \
>>>>> -device
>>>>> loader,file=./tmp/deploy/images/qemuarm64/Image--
>>>> 5.10.103+git0+792f127
>>>>> 2dd_3aab5bb12b-r0-qemuarm64-20220317212819.bin,addr=0x48000000
>>>>> \
>>>>> -device loader,file=./virt.dtb,addr=0x44000000 \ -drive
>>>>> id=disk0,file=./tmp/deploy/images/qemuarm64/xen-image-minimal-
>>>> qemuarm6
>>>>> 4.ext4,if=none,index=0,format=raw
>>>>> \
>>>>> -device virtio-blk-device,drive=disk0 \
>>>>> 
>>>>> And then stop it on u-boot, and setup the fdt:
>>>>> ## Dom0 only:
>>>>> fdt addr 0x44000000
>>>>> fdt resize
>>>>> fdt set /chosen \#address-cells <1>
>>>>> fdt set /chosen \#size-cells <1>
>>>>> fdt set /chosen xen,xen-bootargs "dom0_mem=512M"
>>>>> fdt mknod /chosen module@0
>>>>> fdt set /chosen/module@0 compatible "xen,linux-zimage" "xen,multiboot-
>>>> module"
>>>>> fdt set /chosen/module@0 reg <0x46000000 0x1373a00> fdt set
>>>>> /chosen/module@0 bootargs "dom0_mem=512M root=/dev/vda rw
>>>>> earlyprintk=serial,ttyAMA0 console=ttyAMA0,115200n8 earlycon=xenboot"
>>>>> booti 0x45000000 - 0x44000000
>>>>> 
>>>>> Please find also some more information below:
>>>>> 
>>>>> On Tue, Mar 22, 2022 at 12:59 PM Bertrand Marquis
>>>>> <Bertrand.Marquis@arm.com> wrote:
>>>>>> 
>>>>>> Hi Paulo,
>>>>>> 
>>>>>> Hardknott is long term while honister is not but both are stable releases.
>>>>>> 
>>>>>> I am not quite sure I get your 4.14 pulling 4.16. The 4.14 recipe is building
>>>> the latest 4.14 version of Xen.
>>>>>> 
>>>>> That was just me being silly. I was looking into xen_git.bb which
>>>>> clearly is not the preferred provider. I am in fact using Xen 4.14, as
>>>>> you pointed out. Sorry for the mistake.
>>>>>> From what I see modules to load are in a xen.conf in modules-load.d
>>>> generated by Xen tools compilation.
>>>>>> Gntdev is properly listed in the current xen source tree as one of the
>>>> default modules to actually load on boot.
>>>>>> 
>>>>>> Can you check the content of modules-load.d/xen.conf (somewhere in /etc
>>>> in your dom0 roots) ?
>>>>>> 
>>>>> I have nothing there. But, I did have two hits when searching the rootfs:
>>>>> /etc/tmpfiles.d/xen.conf
>>>>> /lib/systemd/modules-load.d/xen.conf
>>>> 
>>>> This is the interesting file.
>>>> It shall be used by systemd on boot to load the modules required by Xen.
>>>> Please check if gntdev is listed there.
>>>> 
>>>> If yes then this is a systemd issue, if not this is a Xen issue which appear to be
>>>> solved in xen master and I will have to check in the 4.14 version used by Yocto
>>>> LTS.
>>>> 
>>>> 
>>>>> Not sure if there there is some sort of startup script that was
>>>>> supposed to move around these files or even if
>>>>> systemd-modules-load.service would be supposed to be looking
>>>>> elsewhere.
>>>> 
>>>> No the lib one is the right one for systemd.
>>>> 
>>>> Cheers
>>>> Bertrand
>>>>> 
>>>>>> It could be that this was actually missing in the xen release you are building
>>>> or that systemd is not actually loading modules listed there.
>>>>>> 
>>>>>> Cheers
>>>>>> Bertrand
>>>>> Cheers, Paulo.
>>>> 
>>> 
>> 
>> 
>> 
> 
> 
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