From: Rusty Russell <rusty@rustcorp.com.au>
To: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: linux-s390 <linux-s390@vger.kernel.org>,
Anthony Liguori <aliguori@us.ibm.com>, KVM <kvm@vger.kernel.org>,
Carsten Otte <cotte@de.ibm.com>,
Sebastian Ott <sebott@linux.vnet.ibm.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
qemu-devel <qemu-devel@nongnu.org>,
Alexander Graf <agraf@suse.de>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Avi Kivity <avi@redhat.com>,
Martin Schwidefsky <schwidefsky@de.ibm.com>
Subject: Re: [PATCH 3/4] s390/kvm: Add a channel I/O based virtio transport driver.
Date: Wed, 15 Aug 2012 12:45:26 +0930 [thread overview]
Message-ID: <87r4r8rgkx.fsf@rustcorp.com.au> (raw)
In-Reply-To: <20120814130334.79ba51b5@BR9GNB5Z>
On Tue, 14 Aug 2012 13:03:34 +0200, Cornelia Huck <cornelia.huck@de.ibm.com> wrote:
> > It would be per-machine; per-device would be a bit crazy. We'd
> > deprecate the old ring format.
> >
> > There's been no consistent thread on the ideas for a ring change,
> > unfortunately, but you can find interesting parts here, off this thread:
> >
> > Message-ID: <8762gj6q5r.fsf@rustcorp.com.au>
> > Subject: Re: [RFC 7/11] virtio_pci: new, capability-aware driver.
>
> I've read a bit through this and it looks like this is really virtio-2
> or so. How about discoverability by the guest? Guests will likely have
> to support both formats, and forcing them to look at the feature bits
> for each device in order to figure out the queue format feels wrong if
> it is going to be the same format for the whole machine anyway.
Yes, it needs some out-of-band acknowledgement mechanism by the guest.
Might be worth putting a max version number somewhere, which the guest
writes to acknowledge (ie. currently it would be 1, and the guest would
always write a 1).
Cheers,
Rusty.
WARNING: multiple messages have this Message-ID (diff)
From: Rusty Russell <rusty@rustcorp.com.au>
To: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: linux-s390 <linux-s390@vger.kernel.org>,
Anthony Liguori <aliguori@us.ibm.com>, KVM <kvm@vger.kernel.org>,
Carsten Otte <cotte@de.ibm.com>,
Sebastian Ott <sebott@linux.vnet.ibm.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
qemu-devel <qemu-devel@nongnu.org>,
Alexander Graf <agraf@suse.de>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Avi Kivity <avi@redhat.com>,
Martin Schwidefsky <schwidefsky@de.ibm.com>
Subject: Re: [Qemu-devel] [PATCH 3/4] s390/kvm: Add a channel I/O based virtio transport driver.
Date: Wed, 15 Aug 2012 12:45:26 +0930 [thread overview]
Message-ID: <87r4r8rgkx.fsf@rustcorp.com.au> (raw)
In-Reply-To: <20120814130334.79ba51b5@BR9GNB5Z>
On Tue, 14 Aug 2012 13:03:34 +0200, Cornelia Huck <cornelia.huck@de.ibm.com> wrote:
> > It would be per-machine; per-device would be a bit crazy. We'd
> > deprecate the old ring format.
> >
> > There's been no consistent thread on the ideas for a ring change,
> > unfortunately, but you can find interesting parts here, off this thread:
> >
> > Message-ID: <8762gj6q5r.fsf@rustcorp.com.au>
> > Subject: Re: [RFC 7/11] virtio_pci: new, capability-aware driver.
>
> I've read a bit through this and it looks like this is really virtio-2
> or so. How about discoverability by the guest? Guests will likely have
> to support both formats, and forcing them to look at the feature bits
> for each device in order to figure out the queue format feels wrong if
> it is going to be the same format for the whole machine anyway.
Yes, it needs some out-of-band acknowledgement mechanism by the guest.
Might be worth putting a max version number somewhere, which the guest
writes to acknowledge (ie. currently it would be 1, and the guest would
always write a 1).
Cheers,
Rusty.
next prev parent reply other threads:[~2012-08-15 3:15 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-07 14:52 [RFC PATCH 0/4] s390: virtio-ccw guest kernel support Cornelia Huck
2012-08-07 14:52 ` [Qemu-devel] " Cornelia Huck
2012-08-07 14:52 ` [PATCH 1/4] s390/kvm: Handle hosts not supporting s390-virtio Cornelia Huck
2012-08-07 14:52 ` [Qemu-devel] " Cornelia Huck
2012-08-09 10:03 ` Avi Kivity
2012-08-09 10:03 ` [Qemu-devel] " Avi Kivity
2012-08-09 10:41 ` Cornelia Huck
2012-08-09 10:41 ` [Qemu-devel] " Cornelia Huck
2012-08-10 8:42 ` Heiko Carstens
2012-08-10 8:42 ` [Qemu-devel] " Heiko Carstens
2012-08-10 11:03 ` Cornelia Huck
2012-08-10 11:03 ` [Qemu-devel] " Cornelia Huck
2012-08-09 23:09 ` Alexander Graf
2012-08-09 23:09 ` [Qemu-devel] " Alexander Graf
2012-08-10 7:45 ` Cornelia Huck
2012-08-10 7:45 ` [Qemu-devel] " Cornelia Huck
2012-08-07 14:52 ` [PATCH 2/4] s390: Add a mechanism to get the subchannel id Cornelia Huck
2012-08-07 14:52 ` [Qemu-devel] " Cornelia Huck
2012-08-13 17:16 ` Sebastian Ott
2012-08-13 17:16 ` [Qemu-devel] " Sebastian Ott
2012-08-14 8:52 ` Sebastian Ott
2012-08-14 8:52 ` [Qemu-devel] " Sebastian Ott
2012-08-14 10:38 ` Cornelia Huck
2012-08-14 10:38 ` [Qemu-devel] " Cornelia Huck
2012-08-14 10:53 ` Sebastian Ott
2012-08-14 10:53 ` [Qemu-devel] " Sebastian Ott
2012-08-07 14:52 ` [PATCH 3/4] s390/kvm: Add a channel I/O based virtio transport driver Cornelia Huck
2012-08-07 14:52 ` [Qemu-devel] " Cornelia Huck
2012-08-08 4:22 ` Rusty Russell
2012-08-08 4:22 ` [Qemu-devel] " Rusty Russell
2012-08-13 8:56 ` Cornelia Huck
2012-08-13 8:56 ` [Qemu-devel] " Cornelia Huck
2012-08-14 0:10 ` Rusty Russell
2012-08-14 0:10 ` [Qemu-devel] " Rusty Russell
2012-08-14 11:03 ` Cornelia Huck
2012-08-14 11:03 ` [Qemu-devel] " Cornelia Huck
2012-08-15 3:15 ` Rusty Russell [this message]
2012-08-15 3:15 ` Rusty Russell
2012-08-14 19:56 ` Anthony Liguori
2012-08-14 19:56 ` [Qemu-devel] " Anthony Liguori
2012-08-15 7:28 ` Rusty Russell
2012-08-15 7:28 ` [Qemu-devel] " Rusty Russell
2012-08-15 7:48 ` Christian Borntraeger
2012-08-15 7:48 ` [Qemu-devel] " Christian Borntraeger
2012-08-21 5:35 ` Rusty Russell
2012-08-21 5:35 ` [Qemu-devel] " Rusty Russell
2012-08-07 14:52 ` [PATCH 4/4] s390/kvm: Split out early console code Cornelia Huck
2012-08-07 14:52 ` [Qemu-devel] " Cornelia Huck
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