From: Paolo Bonzini <pbonzini@redhat.com>
To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>,
zwanp@cn.ibm.com, linuxram@us.ibm.com, qemu-devel@nongnu.org,
virtualization@lists.linux-foundation.org,
Cong Meng <mc@linux.vnet.ibm.com>
Subject: Re: [Qemu-devel] [PATCH 1/2 v1] blkdrv: Add queue limits parameters for sg block drive
Date: Thu, 23 Aug 2012 12:52:48 +0200 [thread overview]
Message-ID: <50360B80.1080609@redhat.com> (raw)
In-Reply-To: <CAJSP0QXG3yzxnwAJd3s0M0eSUM39XRdYEmGtj0h83_de4mxaAA@mail.gmail.com>
Il 23/08/2012 12:08, Stefan Hajnoczi ha scritto:
>> I'm still trying to understand the extent of the problem.
>>
>> The problem occurs for _USB_ CD-ROMs according to Ben. Passthrough of
>> USB storage devices should be done via USB passthrough, not virtio-scsi.
>> If we do USB passthrough via the SCSI layer we miss on all the quirks
>> that the OS may do based on the USB product/vendor pairs. There's no
>> end to these, and some of the quirks may cause the device to lock up or
>> corruption.
>>
>> I'd rather see a reproducer using SAS/ATA/ATAPI disks before punting.
>
> This issue affects passthrough: either an entire sg device or at least
> a SG_IO ioctl (e.g. a non-READ/WRITE SCSI command).
>
> To reproduce it, check host queue limits and guest virtio-scsi queue
> limits. Then pick a command that can exceed the limits and try it
> from inside the guest :).
Yes, so much is clear. But does it happen _in practice_? Do initiators
actually issue commands that are that big?
Paolo
next prev parent reply other threads:[~2012-08-23 10:53 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-21 8:23 [Qemu-devel] [PATCH 1/2 v1] blkdrv: Add queue limits parameters for sg block drive Cong Meng
2012-08-21 8:23 ` [Qemu-devel] [PATCH 2/2 v1] virtio-scsi: set per-LUN queue limits for sg devices Cong Meng
2012-08-21 9:56 ` Stefan Hajnoczi
2012-08-21 8:48 ` [Qemu-devel] [PATCH 1/2 v1] blkdrv: Add queue limits parameters for sg block drive Paolo Bonzini
2012-08-21 9:41 ` Cong Meng
2012-08-21 9:52 ` Stefan Hajnoczi
2012-08-21 10:14 ` Paolo Bonzini
2012-08-22 11:04 ` Cong Meng
2012-08-22 12:09 ` Paolo Bonzini
2012-08-22 13:13 ` Stefan Hajnoczi
2012-08-22 14:13 ` Paolo Bonzini
2012-08-23 9:31 ` Cong Meng
2012-08-23 10:03 ` Paolo Bonzini
2012-08-23 10:08 ` Stefan Hajnoczi
2012-08-23 10:52 ` Paolo Bonzini [this message]
2012-08-23 12:08 ` Stefan Hajnoczi
2012-08-24 0:45 ` Nicholas A. Bellinger
2012-08-24 7:56 ` Paolo Bonzini
2012-08-24 10:43 ` Hannes Reinecke
2012-08-24 9:05 ` Stefan Hajnoczi
2012-08-24 9:14 ` Paolo Bonzini
2012-08-21 9:49 ` Stefan Hajnoczi
2012-08-21 18:31 ` Blue Swirl
2012-08-22 8:25 ` Stefan Hajnoczi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=50360B80.1080609@redhat.com \
--to=pbonzini@redhat.com \
--cc=linuxram@us.ibm.com \
--cc=mc@linux.vnet.ibm.com \
--cc=qemu-devel@nongnu.org \
--cc=stefanha@gmail.com \
--cc=stefanha@linux.vnet.ibm.com \
--cc=virtualization@lists.linux-foundation.org \
--cc=zwanp@cn.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).