Re: [PATCH] transitional issues: add new IDs for all devices

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Sep 11, 2013 at 05:02:25PM +0300, Michael S. Tsirkin wrote:
> non-transitional devices should have been able to simply update
> revision ID to make sure legacy drivers are not loaded.
> Unfortunately, mistakes were made:
> - we didn't stress that drivers must check revision ID,
>   and of course there's no easy way for drivers to
>   test this failure path,
>   so older versions of Windows drivers ignored revision
>   (latest vision matches revision correctly)
> - CCW lacks revision ID field
> 
> Both facts mean a non-transitional device would need
> a separate mechanism to prevent legacy drivers from
> loading.
> We aren't running out of device IDs yet, so
> let's use up some to resolve this.
> 
> I incremented all IDs by 0x100 intentionally -
> for the PCI bindings, this should help remind people they can't
> just stick the Subsystem ID into the low byte of the Device ID.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Ouch sent a wrong diff. Sorry.
Pls ignore will send v2 shortly.

> ---
>  virtio-v1.0-wd01-part1-specification.txt | 77 +++++++++++++++++++-------------
>  1 file changed, 47 insertions(+), 30 deletions(-)
> 
> diff --git a/virtio-v1.0-wd01-part1-specification.txt b/virtio-v1.0-wd01-part1-specification.txt
> index a96b2e3..68cc6d4 100644
> --- a/virtio-v1.0-wd01-part1-specification.txt
> +++ b/virtio-v1.0-wd01-part1-specification.txt
> @@ -728,6 +728,9 @@ Any PCI device with Vendor ID 0x1AF4, and Device ID 0x1000 through
>  0x103F inclusive is a virtio device[3]. The device must also have a
>  Revision ID of 0 to match this specification.
>  
> +NB: Drivers must not match, or attempt to use devices where Revision
> +ID does not match 0.
> +
>  The Subsystem Device ID indicates which virtio device is
>  supported by the device. The Subsystem Vendor ID should reflect
>  the PCI Vendor ID of the environment (it's currently only used
> @@ -1251,7 +1254,7 @@ configuration space. The following list presents their layout:
>   Device version number. Currently must be 1.
>  
>  • 0x008 | R | DeviceID
> - Virtio Subsystem Device ID (ie. 1 for network card).
> + Virtio Subsystem Device ID (ie. 0x1 for network card).
>  
>  • 0x00c | R | VendorID
>   Virtio Subsystem Vendor ID.
> @@ -1462,37 +1465,51 @@ defined in this standard.
>  
>  Discovering what devices are available and their type is bus-dependent.
>  
> ++-------------+--------------------+
> +| Device IDs  |   Virtio Device    |
> ++-------------+--------------------+
> ++-------------+--------------------+
> +| 0x0         | reserved (invalid) |
>  +------------+--------------------+
> -| Device ID  |   Virtio Device    |
> -+------------+--------------------+
> -+------------+--------------------+
> -| 0          | reserved (invalid) |
> +| 0x1, 0x101  |   network card     |
>  +------------+--------------------+
> -| 1          |   network card     |
> +| 0x2, 0x102  |   block device     |
>  +------------+--------------------+
> -| 2          |   block device     |
> +| 0x3, 0x103  |      console       |
>  +------------+--------------------+
> -| 3          |      console       |
> +| 0x4, 0x104  |  entropy source    |
>  +------------+--------------------+
> -| 4          |  entropy source    |
> +| 0x5, 0x105  | memory ballooning  |
>  +------------+--------------------+
> -| 5          | memory ballooning  |
> +| 0x6, 0x106  |     ioMemory       |
>  +------------+--------------------+
> -| 6          |     ioMemory       |
> +| 0x7, 0x107  |       rpmsg        |
>  +------------+--------------------+
> -| 7          |       rpmsg        |
> +| 0x8, 0x108  |     SCSI host      |
>  +------------+--------------------+
> -| 8          |     SCSI host      |
> +| 0x9, 0x109  |   9P transport     |
>  +------------+--------------------+
> -| 9          |   9P transport     |
> +| 0xA, 0x10A  |   mac80211 wlan    |
>  +------------+--------------------+
> -| 10         |   mac80211 wlan    |
> +| 0xB, 0x10B  |   rproc serial     |
>  +------------+--------------------+
> -| 11         |   rproc serial     |
> -+------------+--------------------+
> -| 12         |   virtio CAIF      |
> +| 0xC, 0x10C  |   virtio CAIF      |
>  +------------+--------------------+
>  
> +2.4.0 Legacy Interface: A Note on Device IDs
> +--------------------------------------
> +Where two distinct IDs can identify a single virtio device, the
> +following rules should be obeyed:
> +
> +Transitional devices must use the smaller of the IDs.
> +For example use Device ID=0x1 for a network card.
> +
> +Non-transitional devices must use the larger of the IDs.
> +For example use Device ID=0x101 for a network card.
> +
> +Both transitional and non-transitional drivers must match all
> +IDs for a given device type.
> +
>  2.4.1. Network Device
>  ====================
>  
> @@ -1505,10 +1522,10 @@ packets are enqueued into another for transmission in that order.
>  A third command queue is used to control advanced filtering
>  features.
>  
> -2.4.1.1. Device ID
> +2.4.1.1. Device IDs
>  -----------------
>  
> - 1
> + 0x1, 0x101
>  
>  2.4.1.2. Virtqueues
>  ------------------
> @@ -1910,9 +1927,9 @@ disk). Read and write requests (and other exotic requests) are
>  placed in the queue, and serviced (probably out of order) by the
>  device except where noted.
>  
> -2.4.2.1. Device ID
> +2.4.2.1. Device IDs
>  -----------------
> -  2
> +  0x2, 0x102
>  
>  2.4.2.2. Virtqueues
>  ------------------
> @@ -2092,10 +2109,10 @@ successfully added, port open/close, etc.. For data IO, one or
>  more empty buffers are placed in the receive queue for incoming
>  data and outgoing characters are placed in the transmit queue.
>  
> -2.4.3.1. Device ID
> +2.4.3.1. Device IDs
>  -----------------
>  
> -  3
> +  0x3, 0x103
>  
>  2.4.3.2. Virtqueues
>  ------------------
> @@ -2203,9 +2220,9 @@ data and outgoing characters are placed in the transmit queue.
>  The virtio entropy device supplies high-quality randomness for
>  guest use.
>  
> -2.4.4.1. Device ID
> +2.4.4.1. Device IDs
>  -----------------
> -  4
> +  0x4, 0x104
>  
>  2.4.4.2. Virtqueues
>  ------------------
> @@ -2242,9 +2259,9 @@ changes in allowance of underlying physical memory. If the
>  feature is negotiated, the device can also be used to communicate
>  guest memory statistics to the host.
>  
> -2.4.5.1. Device ID
> +2.4.5.1. Device IDs
>  -----------------
> -  5
> +  0x5, 0x105
>  
>  2.4.5.2. Virtqueues
>  ------------------
> @@ -2405,9 +2422,9 @@ medium. In the transport protocol, the virtio driver acts as the
>  initiator, while the virtio SCSI host provides one or more
>  targets that receive and process the requests.
>  
> -2.4.6.1. Device ID
> +2.4.6.1. Device IDs
>  -----------------
> -  8
> +  0x8, 0x108
>  
>  2.4.6.2. Virtqueues
>  ------------------
> -- 
> MST