From: Cornelia Huck <cohuck@redhat.com>
To: Halil Pasic <pasic@linux.ibm.com>
Cc: linux-s390@vger.kernel.org, Eric Farman <farman@linux.ibm.com>,
Alex Williamson <alex.williamson@redhat.com>,
Pierre Morel <pmorel@linux.ibm.com>,
kvm@vger.kernel.org, Farhan Ali <alifm@linux.ibm.com>,
qemu-devel@nongnu.org, qemu-s390x@nongnu.org
Subject: Re: [PATCH 0/3] vfio-ccw: support hsch/csch (kernel part)
Date: Tue, 4 Dec 2018 14:11:30 +0100 [thread overview]
Message-ID: <20181204141130.06496b9b.cohuck@redhat.com> (raw)
In-Reply-To: <20181204133810.66e8cfe5@oc2783563651>
On Tue, 4 Dec 2018 13:38:10 +0100
Halil Pasic <pasic@linux.ibm.com> wrote:
> On Thu, 22 Nov 2018 17:54:29 +0100
> Cornelia Huck <cohuck@redhat.com> wrote:
>
> > [This is the Linux kernel part, git tree is available at
> > https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw.git vfio-ccw-caps
> >
> > The companion QEMU patches are available at
> > https://github.com/cohuck/qemu vfio-ccw-caps]
> >
> > Currently, vfio-ccw only relays START SUBCHANNEL requests to the real
> > device. This tends to work well for the most common 'good path' scenarios;
> > however, as we emulate {HALT,CLEAR} SUBCHANNEL in QEMU, things like
> > clearing pending requests at the device is currently not supported.
> > This may be a problem for e.g. error recovery.
>
> I'm wondering: what about MODIFY SUBCHANNEL? Do we plan to add MSCH
> as well or is it supposed to remain 'userspace emulated'? AFAIR MSCH
> may have an effect on error recovery as well.
I think that would require a deeper change, as we have the requirement
to enable the subchannel before handing it to userspace. IOW, the guest
does not cause the subchannel to be enabled/disabled, but the host does.
Parameters (like for channel measurements) are a different game. It is
something we should look into, but it will need a different region.
> BTW I would like to have the concurrency discussion sorted out before
> I proceed with my review, because reviewing the stuff without a fair idea
> of what exactly are we trying to achieve would yield poor results.
I'm not sure what is unclear about what we're trying to achieve (enable
the guest to issue halt/clear on real hardware)?
But yes, we need to sort out that concurrency thing; I'm currently
unsure if the core should do some things as well or if it's more of a
vendor-driver thing.
next prev parent reply other threads:[~2018-12-04 13:11 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-22 16:54 [PATCH 0/3] vfio-ccw: support hsch/csch (kernel part) Cornelia Huck
2018-11-22 16:54 ` [PATCH 1/3] vfio-ccw: add capabilities chain Cornelia Huck
2018-11-23 12:28 ` Pierre Morel
2018-11-23 12:45 ` Cornelia Huck
2018-11-23 13:26 ` Pierre Morel
2018-11-27 19:04 ` Farhan Ali
2018-11-28 9:05 ` Cornelia Huck
2018-12-17 21:53 ` Eric Farman
2018-12-18 17:24 ` Cornelia Huck
2018-12-18 17:56 ` Eric Farman
2018-12-19 16:28 ` Alex Williamson
2018-12-21 11:12 ` Cornelia Huck
2018-11-22 16:54 ` [PATCH 2/3] s390/cio: export hsch to modules Cornelia Huck
2018-11-23 12:30 ` Pierre Morel
2018-11-22 16:54 ` [PATCH 3/3] vfio-ccw: add handling for asnyc channel instructions Cornelia Huck
2018-11-23 13:08 ` Pierre Morel
2018-11-26 9:47 ` Cornelia Huck
2018-11-27 19:09 ` Farhan Ali
2018-11-28 9:02 ` Cornelia Huck
2018-11-28 14:31 ` Farhan Ali
2018-11-28 14:52 ` Cornelia Huck
2018-11-28 15:00 ` Farhan Ali
2018-11-28 15:35 ` Cornelia Huck
2018-11-28 15:55 ` Farhan Ali
2019-01-18 13:53 ` Cornelia Huck
2018-11-27 19:57 ` Farhan Ali
2018-11-28 8:41 ` Cornelia Huck
2018-11-28 16:36 ` [qemu-s390x] " Halil Pasic
2018-11-29 16:52 ` Cornelia Huck
2018-11-29 17:24 ` Halil Pasic
2018-12-17 21:54 ` Eric Farman
2018-12-18 16:45 ` Cornelia Huck
2018-11-24 21:07 ` [qemu-s390x] [PATCH 0/3] vfio-ccw: support hsch/csch (kernel part) Halil Pasic
2018-11-26 9:26 ` Cornelia Huck
2018-11-26 18:57 ` Farhan Ali
2018-11-26 19:00 ` Cornelia Huck
2018-12-04 12:38 ` Halil Pasic
2018-12-04 13:11 ` Cornelia Huck [this message]
2018-12-04 15:02 ` Halil Pasic
2018-12-05 12:54 ` Cornelia Huck
2018-12-05 18:34 ` Farhan Ali
2018-12-06 14:39 ` Cornelia Huck
2018-12-06 15:26 ` Farhan Ali
2018-12-06 16:21 ` Cornelia Huck
2018-12-06 17:50 ` Farhan Ali
2018-12-07 9:34 ` Cornelia Huck
2018-12-06 18:47 ` Halil Pasic
2018-12-07 10:05 ` Cornelia Huck
2018-12-07 15:49 ` Halil Pasic
2018-12-07 16:54 ` Halil Pasic
2018-12-19 11:54 ` Cornelia Huck
2018-12-19 14:17 ` Halil Pasic
2018-12-21 11:23 ` Cornelia Huck
2018-12-21 12:42 ` Halil Pasic
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=20181204141130.06496b9b.cohuck@redhat.com \
--to=cohuck@redhat.com \
--cc=alex.williamson@redhat.com \
--cc=alifm@linux.ibm.com \
--cc=farman@linux.ibm.com \
--cc=kvm@vger.kernel.org \
--cc=linux-s390@vger.kernel.org \
--cc=pasic@linux.ibm.com \
--cc=pmorel@linux.ibm.com \
--cc=qemu-devel@nongnu.org \
--cc=qemu-s390x@nongnu.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).