OASIS Virtual I/O Device (VIRTIO) TC

Reserve device ID 0 (zero) as invalid ------------------------------------- Key: VIRTIO-7 URL: http://tools.oasis-open.org/issues/browse/VIRTIO-7 Project: OASIS Virtual I/O Device (VIRTIO) TC Issue Type: Improvement Reporter: Pawel Moll Make the virtio device ID 0 reserved (or illegal). This value is illegal for PCI devices anyway, and mmio driver can consider such ID as "non present". -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://tools.oasis-open.org/issues/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

OASIS Issues Tracker <workgroup_mailer@lists.oasis-open.org> writes: > Reserve device ID 0 (zero) as invalid > ------------------------------------- > > Key: VIRTIO-7 > URL: http://tools.oasis-open.org/issues/browse/VIRTIO-7 > Project: OASIS Virtual I/O Device (VIRTIO) TC > Issue Type: Improvement > Reporter: Pawel Moll > > > Make the virtio device ID 0 reserved (or illegal). This value is illegal for PCI devices anyway, and mmio driver can consider such ID as "non present". Something like this? commit d8a995390a273bc6d209cf8a6f8a178b424a6438 Author: Rusty Russell <rusty@au1.ibm.com> Date: Tue Aug 20 16:13:19 2013 +0930 Reserve device ID 0 (zero) as invalid See http://tools.oasis-open.org/issues/browse/VIRTIO-7 Signed-off-by: Rusty Russell <rusty@au1.ibm.com> diff --git a/virtio-v1.0-wd01-part1-specification.txt b/virtio-v1.0-wd01-part1-specification.txt index 8fc96b2..f989630 100644 --- a/virtio-v1.0-wd01-part1-specification.txt +++ b/virtio-v1.0-wd01-part1-specification.txt @@ -1069,6 +1069,8 @@ Discovering what devices are available and their type is bus-dependent. Device ID Virtio Device +------------+--------------------+ +------------+--------------------+ + 0 none (ignore) ++------------+--------------------+ 1 network card +------------+--------------------+ 2 block device @@ -1094,6 +1096,8 @@ Discovering what devices are available and their type is bus-dependent. 12 virtio CAIF +------------+--------------------+ +When a device is discovered with a device ID of 0, it should be ignored. + 2.5.1 Network Device ====================

On Tue, 2013-08-20 at 07:44 +0100, Rusty Russell wrote: > OASIS Issues Tracker <workgroup_mailer@lists.oasis-open.org> writes: > > Reserve device ID 0 (zero) as invalid > > ------------------------------------- > > > > Key: VIRTIO-7 > > URL: http://tools.oasis-open.org/issues/browse/VIRTIO-7 > > Project: OASIS Virtual I/O Device (VIRTIO) TC > > Issue Type: Improvement > > Reporter: Pawel Moll > > > > > > Make the virtio device ID 0 reserved (or illegal). This value is illegal for PCI devices anyway, and mmio driver can consider such ID as "non present". > > Something like this? > > commit d8a995390a273bc6d209cf8a6f8a178b424a6438 > Author: Rusty Russell <rusty@au1.ibm.com> > Date: Tue Aug 20 16:13:19 2013 +0930 > > Reserve device ID 0 (zero) as invalid > > See http://tools.oasis-open.org/issues/browse/VIRTIO-7 > > Signed-off-by: Rusty Russell <rusty@au1.ibm.com> > > diff --git a/virtio-v1.0-wd01-part1-specification.txt b/virtio-v1.0-wd01-part1-specification.txt > index 8fc96b2..f989630 100644 > --- a/virtio-v1.0-wd01-part1-specification.txt > +++ b/virtio-v1.0-wd01-part1-specification.txt > @@ -1069,6 +1069,8 @@ Discovering what devices are available and their type is bus-dependent. > Device ID Virtio Device > +------------+--------------------+ > +------------+--------------------+ > + 0 none (ignore) > ++------------+--------------------+ > 1 network card > +------------+--------------------+ > 2 block device > @@ -1094,6 +1096,8 @@ Discovering what devices are available and their type is bus-dependent. > 12 virtio CAIF > +------------+--------------------+ > > +When a device is discovered with a device ID of 0, it should be ignored. > + > 2.5.1 Network Device > ==================== Acked-by: Pawel Moll <pawel.moll@arm.com> Cheers! Pawel

On Tue, 2013-08-20 at 07:44 +0100, Rusty Russell wrote: > OASIS Issues Tracker <workgroup_mailer@lists.oasis-open.org> writes: > > Reserve device ID 0 (zero) as invalid > > ------------------------------------- > > > > Key: VIRTIO-7 > > URL: http://tools.oasis-open.org/issues/browse/VIRTIO-7 > > Project: OASIS Virtual I/O Device (VIRTIO) TC > > Issue Type: Improvement > > Reporter: Pawel Moll > > > > > > Make the virtio device ID 0 reserved (or illegal). This value is illegal for PCI devices anyway, and mmio driver can consider such ID as "non present". > > Something like this? > > commit d8a995390a273bc6d209cf8a6f8a178b424a6438 > Author: Rusty Russell <rusty@au1.ibm.com> > Date: Tue Aug 20 16:13:19 2013 +0930 > > Reserve device ID 0 (zero) as invalid > > See http://tools.oasis-open.org/issues/browse/VIRTIO-7 > > Signed-off-by: Rusty Russell <rusty@au1.ibm.com> > > diff --git a/virtio-v1.0-wd01-part1-specification.txt b/virtio-v1.0-wd01-part1-specification.txt > index 8fc96b2..f989630 100644 > --- a/virtio-v1.0-wd01-part1-specification.txt > +++ b/virtio-v1.0-wd01-part1-specification.txt > @@ -1069,6 +1069,8 @@ Discovering what devices are available and their type is bus-dependent. > Device ID Virtio Device > +------------+--------------------+ > +------------+--------------------+ > + 0 none (ignore) > ++------------+--------------------+ > 1 network card > +------------+--------------------+ > 2 block device > @@ -1094,6 +1096,8 @@ Discovering what devices are available and their type is bus-dependent. > 12 virtio CAIF > +------------+--------------------+ > > +When a device is discovered with a device ID of 0, it should be ignored. How about: 0 reserved (invalid) No device will ever have an ID of 0 (zero). Transports may choose to ignore such devices.

Pawel Moll <pawel.moll@arm.com> writes: > On Tue, 2013-08-20 at 07:44 +0100, Rusty Russell wrote: >> diff --git a/virtio-v1.0-wd01-part1-specification.txt b/virtio-v1.0-wd01-part1-specification.txt >> index 8fc96b2..f989630 100644 >> --- a/virtio-v1.0-wd01-part1-specification.txt >> +++ b/virtio-v1.0-wd01-part1-specification.txt >> @@ -1069,6 +1069,8 @@ Discovering what devices are available and their type is bus-dependent. >> Device ID Virtio Device >> +------------+--------------------+ >> +------------+--------------------+ >> + 0 none (ignore) >> ++------------+--------------------+ >> 1 network card >> +------------+--------------------+ >> 2 block device >> @@ -1094,6 +1096,8 @@ Discovering what devices are available and their type is bus-dependent. >> 12 virtio CAIF >> +------------+--------------------+ >> >> +When a device is discovered with a device ID of 0, it should be ignored. > > How about: > > 0 reserved (invalid) > > No device will ever have an ID of 0 (zero). Transports may choose to > ignore such devices. Mark it as reserved (invalid), then put a section under MMIO explicitly stating that such devices are possible but must be ignored? Cheers, Rusty.

On Mon, 2013-09-02 at 02:31 +0100, Rusty Russell wrote: > Pawel Moll <pawel.moll@arm.com> writes: > > On Tue, 2013-08-20 at 07:44 +0100, Rusty Russell wrote: > >> diff --git a/virtio-v1.0-wd01-part1-specification.txt b/virtio-v1.0-wd01-part1-specification.txt > >> index 8fc96b2..f989630 100644 > >> --- a/virtio-v1.0-wd01-part1-specification.txt > >> +++ b/virtio-v1.0-wd01-part1-specification.txt > >> @@ -1069,6 +1069,8 @@ Discovering what devices are available and their type is bus-dependent. > >> Device ID Virtio Device > >> +------------+--------------------+ > >> +------------+--------------------+ > >> + 0 none (ignore) > >> ++------------+--------------------+ > >> 1 network card > >> +------------+--------------------+ > >> 2 block device > >> @@ -1094,6 +1096,8 @@ Discovering what devices are available and their type is bus-dependent. > >> 12 virtio CAIF > >> +------------+--------------------+ > >> > >> +When a device is discovered with a device ID of 0, it should be ignored. > > > > How about: > > > > 0 reserved (invalid) > > > > No device will ever have an ID of 0 (zero). Transports may choose to > > ignore such devices. > > Mark it as reserved (invalid), then put a section under MMIO explicitly > stating that such devices are possible but must be ignored? Fine by me. I was going to add such statement in the MMIO chapter anyway :-) Pawel