From: Paolo Bonzini <pbonzini@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: amit.shah@redhat.com, uobergfe@redhat.com, owasserm@redhat.com,
qemu-devel@nongnu.org, armbru@redhat.com
Subject: Re: [Qemu-devel] [PATCH 3/3] virtio-blk: note optional features
Date: Tue, 06 Mar 2012 16:58:26 +0100 [thread overview]
Message-ID: <4F563422.8010401@redhat.com> (raw)
In-Reply-To: <20120306145319.GE12096@redhat.com>
Il 06/03/2012 15:53, Michael S. Tsirkin ha scritto:
> > The guest must already be prepared to see SG_IO support
> > disappear from under its feet, for example if migration
> > refers to a block device on the source and file-based
> > storage on the destination; or more likely, if the source
> > kernel allows (gasp) SG_IO on a partition and the destination
> > does not. So, we can migrate safely even if the source
> > had VIRTIO_BLK_F_SCSI and the destination does not.
> >
> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>
> My first reaction is you want a new non guest
> visible flag to control whether SG_IO fails on host.
> guest visible ones must be consistent across migration.
So scsi=off/on would control VIRTIO_BLK_F_SCSI, while the new flag would
cause requests to fail. Then it's simpler to do the other way round.
Make the "new non guest-visible flag" be scsi=on/off and set
VIRTIO_BLK_F_SCSI unconditionally as you suggested first.
Paolo
next prev parent reply other threads:[~2012-03-06 15:58 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-06 12:22 [Qemu-devel] [PATCH 0/3] Make virtio_load permissive when possible Paolo Bonzini
2012-03-06 12:22 ` [Qemu-devel] [PATCH 1/3] virtio: let devices be permissive on enabled features Paolo Bonzini
2012-03-06 13:33 ` Michael S. Tsirkin
2012-03-06 13:57 ` Paolo Bonzini
2012-03-06 14:22 ` Orit Wasserman
2012-03-06 12:22 ` [Qemu-devel] [PATCH 2/3] virtio-balloon: note optional features Paolo Bonzini
2012-03-06 14:55 ` Michael S. Tsirkin
2012-03-06 14:59 ` Paolo Bonzini
2012-03-06 15:08 ` Michael S. Tsirkin
2012-03-06 15:13 ` Paolo Bonzini
2012-03-06 12:22 ` [Qemu-devel] [PATCH 3/3] virtio-blk: " Paolo Bonzini
2012-03-06 14:53 ` Michael S. Tsirkin
2012-03-06 15:58 ` Paolo Bonzini [this message]
2012-03-06 17:03 ` Anthony Liguori
2012-03-06 17:12 ` Paolo Bonzini
2012-03-06 17:15 ` Anthony Liguori
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=4F563422.8010401@redhat.com \
--to=pbonzini@redhat.com \
--cc=amit.shah@redhat.com \
--cc=armbru@redhat.com \
--cc=mst@redhat.com \
--cc=owasserm@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=uobergfe@redhat.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).