Messages in this thread | | | Subject | Re: [PATCH v9 17/22] s390: vfio-ap: zeroize the AP queues. | From | Tony Krowiak <> | Date | Wed, 15 Aug 2018 16:36:32 -0400 |
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On 08/15/2018 12:24 PM, Cornelia Huck wrote: > On Mon, 13 Aug 2018 17:48:14 -0400 > Tony Krowiak <akrowiak@linux.vnet.ibm.com> wrote: > > Nit: please drop the leading period in the subject.
I assume you mean the ending period?
> >> From: Tony Krowiak <akrowiak@linux.ibm.com> >> >> Let's call PAPQ(ZAPQ) to zeroize a queue: >> >> * For each queue configured for a mediated matrix device >> when it is released. >> >> Zeroizing a queue resets the queue, clears all pending >> messages for the queue entries and disables adapter interruptions >> associated with the queue. >> >> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com> >> Reviewed-by: Halil Pasic <pasic@linux.ibm.com> >> Tested-by: Michael Mueller <mimu@linux.ibm.com> >> Tested-by: Farhan Ali <alifm@linux.ibm.com> >> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> >> --- >> drivers/s390/crypto/vfio_ap_ops.c | 25 +++++++++++++++++++++++++ >> drivers/s390/crypto/vfio_ap_private.h | 25 +++++++++++++++++++++++++ >> 2 files changed, 50 insertions(+), 0 deletions(-) >> >> diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h >> index 3e8534b..34f982a 100644 >> --- a/drivers/s390/crypto/vfio_ap_private.h >> +++ b/drivers/s390/crypto/vfio_ap_private.h >> @@ -74,4 +74,29 @@ struct ap_matrix_mdev { >> extern int vfio_ap_mdev_register(void); >> extern void vfio_ap_mdev_unregister(void); >> >> +static inline int vfio_ap_reset_queue(unsigned int apid, unsigned int apqi, >> + unsigned int retry) >> +{ >> + struct ap_queue_status status; >> + >> + do { >> + status = ap_zapq(AP_MKQID(apid, apqi)); >> + switch (status.response_code) { >> + case AP_RESPONSE_NORMAL: >> + return 0; >> + case AP_RESPONSE_RESET_IN_PROGRESS: >> + case AP_RESPONSE_BUSY: >> + msleep(20); >> + break; >> + default: >> + pr_warn("%s: error zeroizing %02x.%04x: response code %d\n", >> + VFIO_AP_MODULE_NAME, apid, apqi, >> + status.response_code); > How can we end up here? Does this mean that we just don't know what to > do with this response, or is this something that should never happen? > (How much sense does it make to print an error?)
There are additional response codes that could be returned; for example, in the case of a catastrophic failure such as: The function can not be performed because the AP was somehow deconfigured or the functiona cannot be performed due to a machine check failure that caused the AP path to be removed. It shouldn't happen, but all are possibilities. I can get rid of the message and just return -EIO if you prefer.
> >> + return -EIO; >> + } >> + } while (retry--); >> + >> + return -EBUSY; >> +} >> + >> #endif /* _VFIO_AP_PRIVATE_H_ */
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