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authorrusty <rusty@0c8fb4dd-22a2-4bb5-bc14-6c75a5f43652>2014-05-22 04:43:13 +0000
committerrusty <rusty@0c8fb4dd-22a2-4bb5-bc14-6c75a5f43652>2014-05-22 04:43:13 +0000
commitad147dd69e8f9ad4d22814686f1442166c1190d7 (patch)
treeac9c5bb46e4b9e056617a77c97fb73660fb9cb54 /content.tex
parent24d4065de2b1c4c500b07cde6b535abe5713a5f9 (diff)
content.tex: add support for protection information (VIRTIO-108)
This is a new feature that was suggested by Nicholas Bellinger, who also provided a prototype implementation for vhost-scsi. (As per minutes of meeting 2014-05-20: https://lists.oasis-open.org/archives/virtio/201405/msg00034.html ) Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Rusty Russell <rusty@au1.ibm.com> git-svn-id: https://tools.oasis-open.org/version-control/svn/virtio@371 0c8fb4dd-22a2-4bb5-bc14-6c75a5f43652
Diffstat (limited to 'content.tex')
-rw-r--r--content.tex41
1 files changed, 37 insertions, 4 deletions
diff --git a/content.tex b/content.tex
index a745599..7e88411 100644
--- a/content.tex
+++ b/content.tex
@@ -4420,6 +4420,9 @@ This section relies on definitions from \hyperref[intro:SAM]{SAM}.
\item[VIRTIO_SCSI_F_CHANGE (2)] The host will report changes to LUN
parameters via a VIRTIO_SCSI_T_PARAM_CHANGE event.
+
+\item[VIRTIO_SCSI_F_T10_PI (3)] The extended fields for T10 protection
+ information (DIF/DIX) are included in the SCSI request header.
\end{description}
\subsection{Device configuration layout}\label{sec:Device Types / SCSI Host Device / Device configuration layout}
@@ -4532,7 +4535,12 @@ struct virtio_scsi_req_cmd {
u8 prio;
u8 crn;
u8 cdb[cdb_size];
+ // The next two fields are only present if VIRTIO_SCSI_F_T10_PI
+ // is negotiated.
+ u32 pi_bytesout;
+ u8 pi_out[pi_bytesout];
u8 dataout[];
+
// Device-writable part
le32 sense_len;
le32 residual;
@@ -4540,6 +4548,10 @@ struct virtio_scsi_req_cmd {
u8 status;
u8 response;
u8 sense[sense_size];
+ // The next two fields are only present if VIRTIO_SCSI_F_T10_PI
+ // is negotiated
+ u32 pi_bytesin;
+ u8 pi_in[pi_bytesin];
u8 datain[];
};
@@ -4580,13 +4592,25 @@ by clients, but is generally expected to be 0. The maximum CRN
value defined by the protocol is 255, since CRN is stored in an
8-bit integer.
-All of these fields are defined in \hyperref[intro:SAM]{SAM}. They are always
-device-readable, as are \field{cdb} and \field{dataout}. \field{cdb_size} is
-taken from the configuration space.
+The CDB is included in \field{cdb} and its size, \field{cdb_size},
+is taken from the configuration space.
+
+All of these fields are defined in \hyperref[intro:SAM]{SAM} and are
+always device-readable.
+
+\field{pi_bytesout} determines the size of the \field{pi_out} field
+in bytes. If it is nonzero, the \field{pi_out} field contains outgoing
+protection information for write operations. Both fields are only
+present if VIRTIO_SCSI_F_T10_PI has been negotiated.
+
+The remainder of the device-readable part is the data output buffer,
+\field{dataout}.
\field{sense} and subsequent fields are always device-writable. \field{sense_len}
indicates the number of bytes actually written to the sense
-buffer. \field{residual} indicates the residual size,
+buffer.
+
+\field{residual} indicates the residual size,
calculated as ``data_length - number_of_transferred_bytes'', for
read or write operations. For bidirectional commands, the
number_of_transferred_bytes includes both read and written bytes.
@@ -4596,6 +4620,15 @@ exceeds the size of \field{datain} means that \field{dataout} was
processed partially and \field{datain} was not processed at
all.
+\field{pi_bytesin} determines the size of the \field{pi_in} field
+in bytes. If it is nonzero, the \field{pi_in} field contains incoming
+protection information for read operations. Both fields are only present
+if VIRTIO_SCSI_F_T10_PI has been negotiated.
+
+The remainder of the device-writable part is the data input buffer,
+\field{datain}.
+
+
\devicenormative{\paragraph}{Device Operation: Request Queues}{Device Types / SCSI Host Device / Device Operation / Device Operation: Request Queues}
The device MUST write the \field{status} byte as the status code as