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Diffstat (limited to 'virtio-v1.0-wd01-part1-specification.txt')
| -rw-r--r-- | virtio-v1.0-wd01-part1-specification.txt | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/virtio-v1.0-wd01-part1-specification.txt b/virtio-v1.0-wd01-part1-specification.txt index b9e27ea..ae79444 100644 --- a/virtio-v1.0-wd01-part1-specification.txt +++ b/virtio-v1.0-wd01-part1-specification.txt @@ -67,6 +67,10 @@ Driver [RFC 2119] S. Bradner, Key words for use in RFCs to Indicate Requirement Levels, http://www.ietf.org/rfc/rfc2119.txt IETF (Internet Engineering Task Force) RFC 2119, March 1997. +[S390 PoP] z/Architecture Principles of Operation, IBM Publication SA22-7832 + +[S390 Common I/O] ESA/390 Common I/O-Device and Self-Description, IBM Publication SA22-7204 + 1.3. Non-Normative References ========================= @@ -1717,6 +1721,23 @@ virtio: #define CCW_CMD_WRITE_STATUS 0x31 #define CCW_CMD_READ_VQ_CONF 0x32 +The virtio-ccw device acts like a normal channel device, as specified +in [S390 PoP] and [S390 Common I/O]. In particular: + +- A device must post a unit check with command reject for any command + it does not support. + +- If a driver did not suppress length checks for a channel command, + the device must present a subchannel status as detailed in the + architecture when the actual length did not match the expected length. + +- If a driver did suppress length checks for a channel command, the + device must present a check condition if the transmitted data does + not contain enough data to process the command. If the driver submitted + a buffer that was too long, the device should accept the command. + The driver should attempt to provide the correct length even if it + suppresses length checks. + 2.3.3.2. Device Initialization ------------------------------ |