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Date:   Fri, 17 Jul 2020 10:45:56 +0000
From:   Wei Liu <wei.liu@kernel.org>
To:     Nathan Chancellor <natechancellor@gmail.com>
Cc:     t-mabelt@microsoft.com, kys@microsoft.com, haiyangz@microsoft.com,
        sthemmin@microsoft.com, wei.liu@kernel.org,
        linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
        mikelley@microsoft.com, parri.andrea@gmail.com,
        Andres Beltran <lkmlabelt@gmail.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        linux-scsi@vger.kernel.org
Subject: Re: [PATCH v4 2/3] scsi: storvsc: Use vmbus_requestor to generate
 transaction IDs for VMBus hardening
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 <20200708092105.7af7sf2olpaysh33@liuwe-devbox-debian-v2>
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On Wed, Jul 08, 2020 at 09:25:12AM +0000, Wei Liu wrote:
> On Wed, Jul 08, 2020 at 09:21:05AM +0000, Wei Liu wrote:
> [...]
> > > If I revert this commit, everything works fine:
> > > 
> > > PS C:\Users\natec> wsl --shutdown
> > > PS C:\Users\natec> wsl -d ubuntu -- /bin/bash
> > > nathan@Ryzen-9-3900X:/mnt/c/Users/natec$ cat /proc/version
> > > Linux version 5.8.0-rc4-next-20200707-microsoft-standard+ (nathan@Ryzen-9-3900X) (gcc (Ubuntu 9.3.0-10ubuntu2) 9.3.0, GNU ld (GNU Binutils for Ubuntu) 2.34) #1 SMP Tue Jul 7 16:35:06 MST 2020
> > > nathan@Ryzen-9-3900X:/mnt/c/Users/natec$ git -C ~/src/linux-next lo -2
> > > 0ff017dff922 (HEAD -> master) Revert "scsi: storvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening"
> > > 5b2a702f85b3 (tag: next-20200707, origin/master, origin/HEAD) Add linux-next specific files for 20200707
> > > nathan@Ryzen-9-3900X:/mnt/c/Users/natec$
> > > 
> > > The kernel was built using the following commands:
> > > 
> > > $ mkdir -p out/x86_64
> > > 
> > > $ curl -LSso out/x86_64/.config https://github.com/microsoft/WSL2-Linux-Kernel/raw/linux-msft-wsl-4.19.y/Microsoft/config-wsl
> > > 
> > > $ scripts/config --file out/x86_64/.config -d RAID6_PQ_BENCHMARK -e NET_9P_VIRTIO
> > > 
> > > $ make -skj"$(nproc)" O=out/x86_64 olddefconfig bzImage
> > > 
> > > I don't really know how to get more information than this as WSL seems
> > > rather opaque but I am happy to provide any information.
> > 
> > Linux kernel uses Hyper-V's crash reporting facility to spit out
> > information when it dies. It is said that you can see that information
> > in the "Event Viewer" program.
> > 
> > (I've never tried this though -- not using WSL2)
> > 
> 
> If this doesn't work, another idea is to install a traditional VM on
> Hyper-V and replace the kernel with your own.
> 
> With such setup, you should be able to add an emulated serial port to
> the VM and grab more information.

Hi Nathan, do you need more help on this?

MSFT is also working on reproducing this internally.

We're ~2 weeks away from the next merge window so it would be good if we
can get to the bottom of this as quickly as possible.

Wei.

> 
> Wei.