diff options
| author | Cornelia Huck <cohuck@redhat.com> | 2019-05-06 19:11:48 +0200 |
|---|---|---|
| committer | Cornelia Huck <cohuck@redhat.com> | 2019-05-17 08:16:02 +0200 |
| commit | 85fa94e16927af2717093e5b8fe225206ec39e16 (patch) | |
| tree | 68e029690d90be5d0d9d7151a3a2b4a87cf99cec /hw/s390x/css.c | |
| parent | 1e3f9c69a42ab0365ac381035e501c94c411b007 (diff) | |
s390/css: handle CCW_FLAG_SKIP
If a ccw has CCW_FLAG_SKIP set, and the command is of type
read, read backwards, or sense, no data should be written
to the guest for that command.
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20190516133327.11430-1-cohuck@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Diffstat (limited to 'hw/s390x/css.c')
| -rw-r--r-- | hw/s390x/css.c | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/hw/s390x/css.c b/hw/s390x/css.c index 8fc9e35ba5..ad310b9f94 100644 --- a/hw/s390x/css.c +++ b/hw/s390x/css.c @@ -830,8 +830,12 @@ static int ccw_dstream_rw_noflags(CcwDataStream *cds, void *buff, int len, if (op == CDS_OP_A) { goto incr; } - ret = address_space_rw(&address_space_memory, cds->cda, - MEMTXATTRS_UNSPECIFIED, buff, len, op); + if (!cds->do_skip) { + ret = address_space_rw(&address_space_memory, cds->cda, + MEMTXATTRS_UNSPECIFIED, buff, len, op); + } else { + ret = MEMTX_OK; + } if (ret != MEMTX_OK) { cds->flags |= CDS_F_STREAM_BROKEN; return -EINVAL; @@ -928,8 +932,13 @@ static int ccw_dstream_rw_ida(CcwDataStream *cds, void *buff, int len, do { iter_len = MIN(len, cont_left); if (op != CDS_OP_A) { - ret = address_space_rw(&address_space_memory, cds->cda, - MEMTXATTRS_UNSPECIFIED, buff, iter_len, op); + if (!cds->do_skip) { + ret = address_space_rw(&address_space_memory, cds->cda, + MEMTXATTRS_UNSPECIFIED, buff, iter_len, + op); + } else { + ret = MEMTX_OK; + } if (ret != MEMTX_OK) { /* assume inaccessible address */ ret = -EINVAL; /* channel program check */ @@ -968,6 +977,11 @@ void ccw_dstream_init(CcwDataStream *cds, CCW1 const *ccw, ORB const *orb) cds->count = ccw->count; cds->cda_orig = ccw->cda; + /* skip is only effective for read, read backwards, or sense commands */ + cds->do_skip = (ccw->flags & CCW_FLAG_SKIP) && + ((ccw->cmd_code & 0x0f) == CCW_CMD_BASIC_SENSE || + (ccw->cmd_code & 0x03) == 0x02 /* read */ || + (ccw->cmd_code & 0x0f) == 0x0c /* read backwards */); ccw_dstream_rewind(cds); if (!(cds->flags & CDS_F_IDA)) { cds->op_handler = ccw_dstream_rw_noflags; |