On 4/22/20 7:36 AM, Cornelia Huck wrote:
> On Fri, 17 Apr 2020 04:34:36 +0200
> Eric Farman <far...@linux.ibm.com> wrote:
>
>> From: Farhan Ali <al...@linux.ibm.com>
>>
>> The schib region can be used to obtain the latest SCHIB from the host
>> passthrough subchannel. Since the guest SCHIB is virtualized,
>> we currently only update the path related information so that the
>> guest is aware of any path related changes when it issues the
>> 'stsch' instruction.
>>
>> Signed-off-by: Farhan Ali <al...@linux.ibm.com>
>> Signed-off-by: Eric Farman <far...@linux.ibm.com>
>> ---
>>
>> Notes:
>> v1->v2:
>> - Remove silly variable intialization, and add a block comment,
>> to css_do_stsch() [CH]
>> - Add a TODO statement to s390_ccw_store(), for myself to sort
>> out while we go over kernel code more closely [CH/EF]
>> - In vfio_ccw_handle_store(),
>> - Set schib pointer once region is determined to be non-NULL [CH]
>> - Return cc=0 if pread() fails, and log an error [CH]
>>
>> v0->v1: [EF]
>> - Change various incarnations of "update chp status" to
>> "handle_store", to reflect the STSCH instruction that will
>> drive this code
>> - Remove temporary variable for casting/testing purposes in
>> s390_ccw_store(), and add a block comment of WHY its there.
>> - Add a few comments to vfio_ccw_handle_store()
>>
>> hw/s390x/css.c | 13 ++++++--
>> hw/s390x/s390-ccw.c | 28 +++++++++++++++++
>> hw/vfio/ccw.c | 63 +++++++++++++++++++++++++++++++++++++
>> include/hw/s390x/css.h | 3 +-
>> include/hw/s390x/s390-ccw.h | 1 +
>> target/s390x/ioinst.c | 3 +-
>> 6 files changed, 106 insertions(+), 5 deletions(-)
>>
>
>> +IOInstEnding s390_ccw_store(SubchDev *sch)
>> +{
>> + S390CCWDeviceClass *cdc = NULL;
>> + int ret = IOINST_CC_EXPECTED;
>> +
>> + /*
>> + * This only applies to passthrough devices, so we can't unconditionally
>> + * set this variable like we would for halt/clear.
>> + *
>> + * TODO from Conny on v1:
>> + * "We have a generic ccw_cb in the subchannel structure for ccw
>> + * interpretation; would it make sense to add a generic callback
>> + * for stsch there as well?
>> + *
>> + * "(This works fine, though. Might want to add the check for
>> + * halt/clear as well, but that might be a bit overkill.)"
>
> Do you plan to look into that for the next version? If not, don't feel
> pressured.
Ah, yes. Clearly I missed this before v3.
>
>> + */
>> + if (object_dynamic_cast(OBJECT(sch->driver_data), TYPE_S390_CCW)) {
>> + cdc = S390_CCW_DEVICE_GET_CLASS(sch->driver_data);
>> + }
>> +
>> + if (cdc && cdc->handle_store) {
>> + ret = cdc->handle_store(sch);
>> + }
>> +
>> + return ret;
>> +}
>> +
>> static void s390_ccw_get_dev_info(S390CCWDevice *cdev,
>> char *sysfsdev,
>> Error **errp)
>
> Generally, looks sane.
>
