[Pkg-xen-devel] Bug#963607: Bug#963607: xen-hypervisor-4.11-amd64: Xen Hypervisor kernel fails to load arcmsr module with "arcmsr0: dma_alloc_coherent got error" message.

[Hans van Kranenburg]

Hi,

On 6/25/20 1:44 PM, Alex Sanderson wrote:
> 
> Hi Hans,
> 
> Thank you for your assistance with this.  I hesitated to log this with
> xen-dev but thought I should wait for a response here first. 
> 
> 
> On 25/06/2020 01:30, Hans van Kranenburg wrote:
>> Hi Alex,
>>
>> On 6/24/20 12:31 PM, Alex Sanderson wrote:
>>> Package: xen-hypervisor-4.11-amd64
>>> Version: 4.11.3+24-g14b62ab3e5-1~deb10u1
>>> Severity: important
>>>
>>> Dear Maintainer,
>>>
>>> After updating to Buster and Xen 4.11 our machine no longer boots the Xen kernel.  The default kernel 4.19.118-2+deb10u1 boots normally.
>> When booting with Xen, the computer first starts the Xen hypervisor
>> code. This is the part where you see all the lines with (XEN) at the
>> beginning appear.
>>
>> Afterwards, it starts the same 4.19.118-2+deb10u1 Linux kernel that is
>> used when running without Xen, but it's started as the first virtual
>> machine, that has extra privileges to access all hardware.
>>
>> So, Linux vs. Xen + Linux.
>>
>>> The machine has an Areca 1882IX-16 card in it when the arcmsr module
>>> tries to load the following error appears. 
>>>
>>> 	Areca RAID Controller0: Model ARC-1882, F/W V1.56 2019-07-30
>>> 	arcmsr0: dma_alloc_coherent got error
>>>
>>> No drives are discovered and the initramfs prompt is shown.
>> Ok, so booting the Xen part succeeded, but apparently, when starting the
>> Linux kernel inside, there's apparently a problem with accessing the
>> raid controller hardware. Interesting.
>>
>> This likely means it's not a problem in the Debian packaging part, it's
>> a problem somewhere in the upstream Xen or Linux code. That means that I
>> cannot solve this for you, but I can help with tips to gather the right
>> information, and help finding out what the best place is where we can
>> report the issue.
>>
>>> The machine:
>>>  * Supermicro X9DRW 
>>>  * Dual Intel(R) Xeon(R) CPU E5-2630L v2 @ 2.40GHz
>>>  * 128G RAM
>>>  * Areca ARC-1882IX-16 (1G onboard cache)
>>>
>>> Nothing I have tried is effective:
>>>  * Turning on BIOS above 4G decoding stops the Intel 10GBE ixgbe driver from functioning and doesn't fix the arcmsr
>>>  * Unloading and reloading the arcmsr module from initramfs prompt
>>>  * Downgrading the Areca 1882 bios to v1.52 as per http://faq.areca.com.tw/index.php?action=artikel&cat=7&id=902&artlang=en
>>>  * Kernel parameters
>>>  ** pci=nocrs 
>>>  ** dom0_mem=8G 
>>>  ** mem=3072M
>>>  ** mem2048M cma=1024M
>>>  ** cma=2048
>>>  ** cma=3076 at 512M
>>>  ** iommu=1 intel_iommu=1 
>>>  ** arcmsr.host_can_queue=64 as per http://faq.areca.com.tw/index.php?action=artikel&cat=15&id=387&artlang=en
>>>
>>> I expected the arcmsr module to load and detect disks as it does with
>>> the stock kernel.
>>>
>>> I can provide sysctl and dmesg output if it helps.
>> Yes. The first thing needed is full startup logs, and for the Xen part
>> preferably extra logging. In /etc/default/grub.d/xen.cfg in the
>> GRUB_CMDLINE_XEN_DEFAULT setting, you can add loglvl=all, and then run
>> update-grub and try to boot Xen+Linux again.
>>
>> Do you have a way to capture the logging during boot? Like, a working
>> serial console or something similar?
>>
>> The output of dmesg when starting Linux without Xen is of course also
>> interesting, so we can compare both scenarios.
>>
>> Hans
> 
> I tried using debian's paste https://paste.debian.net but it always
> thought it was spam.
> 
> dmesg output Xen Hypervisor 4.11 https://pastebin.com/3wUyYg0P

This one shows a Linux kernel boot, not the Xen Hypervisor, which should
go first (with all the (XEN) lines). By default the Xen output should
show up on your (serial) console. If you do dmesg after starting Linux
as dom0 after starting Xen, then you just get the Linux part of it.

If it actually boots and it's usable to login and get a shell prompt
etc, then you can immediately use xl dmesg to see the xen part, and if
it doesn't, then you need to make sure you have some sort of serial
console to capture the lines.

To do a bug report upstream, we'll need that information.

> dmesg output Debian Kernel 4.19.118-2+deb10u1 https://pastebin.com/GHzzW3vi

K