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From: Paul Brook <paul@codesourcery.com>
To: qemu-devel@nongnu.org
Cc: Hai Shan Bai <haishan.bai@gmail.com>
Subject: Re: [Qemu-devel] [PATCH - V3] Port codes from qemu-kvm to support booting from SCSI disk image
Date: Wed, 18 Aug 2010 16:08:55 +0100	[thread overview]
Message-ID: <201008181608.55759.paul@codesourcery.com> (raw)
In-Reply-To: <AANLkTimdV8kcDPPxFmYBAryVVK=Hyzo33SLE_+UEge8U@mail.gmail.com>

> The qemu-kvm could boot from SCSI disk image by utilizing seabios, this
> patch ported codes
> from qemu-kvm to let upstream qemu to support booting from SCSI disk image.

No. This has nothing to do with SCSI.

What it does is add a really cheap and nasty block storage device that aliases 
one of the other block devices in the system. This is bad. The OS has no way 
of knowing which devices are aliased, and we really don't want yet another 
braindead guest visible interface (c.f. recent performance issues where -
kernel/fw_cfg were being abused)

This has been discussed several times before. The proper solution is to teach 
the bios how to boot off SCSI devices. IIRC support for virtio devices already 
exists, implementing support for the SCSI controller shouldn't be that much 
harder.

Paul

  parent reply	other threads:[~2010-08-18 15:09 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-08-18  2:06 [Qemu-devel] [PATCH - V3] Port codes from qemu-kvm to support booting from SCSI disk image Hai Shan Bai
2010-08-18  2:20 ` haishan
2010-08-18 15:08 ` Paul Brook [this message]
2010-08-18 15:16   ` Alexander Graf
2010-08-18 15:31     ` Haishan Bai
2010-08-18 15:37     ` Gleb Natapov
2010-08-18 16:04       ` Paul Brook
2010-08-19 18:14         ` Blue Swirl
2010-08-18 15:54     ` Paul Brook
2010-08-20  7:44     ` Gerd Hoffmann
2010-08-20 13:42       ` Anthony Liguori
2010-08-20 14:09         ` Gerd Hoffmann
2010-08-20 14:39           ` Anthony Liguori
2010-08-21 14:20             ` Kevin O'Connor
2010-08-23  8:52               ` Gerd Hoffmann

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