[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.

[Alex Sanderson]

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

Alex