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Re: [Qemu-block] Virtio-BLK/SCSI write requests and data payload checksu
From: |
Peter Lieven |
Subject: |
Re: [Qemu-block] Virtio-BLK/SCSI write requests and data payload checksums |
Date: |
Tue, 18 Dec 2018 15:45:00 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 |
Am 18.12.18 um 14:15 schrieb Vadim Rozenfeld:
> Peter, I must be missing something here, but what exactly the problem
> is?
The issue is that I see concurrent read requests coming in from Windows Guest
with vioscsi as driver that
have the same buffer address from guest memory space. I noticed this because I
have Data Digests enabled
and the calculated Digest has a wrong CRC32C. This happens because the CRC is
calculated while or after data
from a second requests reads into the same buffer. I see this only with Windows
and the request size seems
to be always 4K. This is either a bug in Windows, vioscsi or a mad application
issuing concurrent reads using
the same buffer. From what I have seen in the dumps of the data that has been
read it seems not to be one
common application.
Best,
Peter