From: "Roger Pau Monné" <roger.pau@citrix.com>
To: Paul Durrant <Paul.Durrant@citrix.com>
Cc: "jgross@suse.com" <jgross@suse.com>,
"annie.li@oracle.com" <annie.li@oracle.com>,
"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>,
David Vrabel <david.vrabel@citrix.com>,
Ian Jackson <Ian.Jackson@citrix.com>,
Roger Pau Monne <roger.pau@citrix.com>
Subject: Re: [PATCH] blkif.h: document scsi/0x12/0x<NN> node
Date: Wed, 23 Mar 2016 17:00:17 +0100 [thread overview]
Message-ID: <alpine.OSX.2.20.1603231655570.753@mac> (raw)
In-Reply-To: <03bc74b89cd84dab892b0bf93832098d@AMSPEX02CL03.citrite.net>
On Wed, 23 Mar 2016, Paul Durrant wrote:
> > -----Original Message-----
> [snip]
> > > > >
> > > > > For this part, there is ioctl() interface for all block device.
> > > > > Looking at virtio-blk in KVM world, it can accept almost all SCSI
> > commands
> > > > also in ioctl() even they already have virtio-scsi.
> > > > > But that's another story.
> > > > >
> > > >
> > > > So this means that you would then need to add a bunch of new request
> > > > types
> > > > to the PV block protocol in order to make use of this new exported
> > > > information?
> > > >
> > >
> > > No, why do you think that? The info is in xenstore so why does the blkif
> > protocol need to be involved at all?
> >
> > Sorry, I'm just trying to figure out how is this going to be used.
> >
> > Isn't this information going to have some impact on how the user uses
> > the block device? If not, why are we exporting it then?
> >
>
> I assume that the user will want to get this information from blkfront via ioctl (as Bob suggests), but blkfront can just pull it straight from xenstore. No need for any communication with blkback.
Yes, I understand this. What I want to know is what impact is this
information going to have on how the user uses the PV block device.
Is the information found in this magic page going to be used to try to
send requests of specfic size in order to take advantge of some hw
features?
And then my other question is, in order to take advantadge of this
information, will we need to add new PV block request types that
encapsulate SCSI commands?
TBH, ATM I don't see why this is useful at all.
Roger.
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
prev parent reply other threads:[~2016-03-23 16:00 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-23 11:47 [PATCH] blkif.h: document scsi/0x12/0x<NN> node Bob Liu
2016-03-23 12:23 ` Paul Durrant
2016-03-23 14:22 ` Ian Jackson
2016-03-23 12:33 ` Roger Pau Monné
2016-03-23 13:37 ` Bob Liu
2016-03-23 14:53 ` Roger Pau Monné
2016-03-23 14:55 ` Paul Durrant
2016-03-23 15:43 ` Roger Pau Monné
2016-03-23 15:45 ` Paul Durrant
2016-03-23 16:00 ` Roger Pau Monné [this message]
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=alpine.OSX.2.20.1603231655570.753@mac \
--to=roger.pau@citrix.com \
--cc=Ian.Jackson@citrix.com \
--cc=Paul.Durrant@citrix.com \
--cc=annie.li@oracle.com \
--cc=david.vrabel@citrix.com \
--cc=jgross@suse.com \
--cc=xen-devel@lists.xen.org \
/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).