On 03/05/2019 23:14, Tony Krowiak wrote:
Refactors the AP queue reset function to wait until the queue is empty
after the PQAP(ZAPQ) instruction is executed to zero out the queue as
required by the AP architecture.
Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
---
drivers/s390/crypto/vfio_ap_ops.c | 35 ++++++++++++++++++++++++++++++++---
1 file changed, 32 insertions(+), 3 deletions(-)
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 900b9cf20ca5..b88a2a2ba075 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -271,6 +271,32 @@ static int vfio_ap_mdev_verify_no_sharing(struct ap_matrix_mdev *matrix_mdev)
return 0;
}
+static void vfio_ap_mdev_wait_for_qempty(unsigned long apid, unsigned long apqi)
+{
+ struct ap_queue_status status;
+ ap_qid_t qid = AP_MKQID(apid, apqi);
+ int retry = 5;
+
+ do {
+ status = ap_tapq(qid, NULL);
+ switch (status.response_code) {
+ case AP_RESPONSE_NORMAL:
+ if (status.queue_empty)
+ return;
+ msleep(20);
NIT: Fall through ?
+ break;
+ case AP_RESPONSE_RESET_IN_PROGRESS:
+ case AP_RESPONSE_BUSY:
+ msleep(20);
+ break;
+ default:
+ pr_warn("%s: tapq err %02x: %04lx.%02lx may not be empty\n",
+ __func__, status.response_code, apid, apqi);
I do not thing the warning sentence is appropriate:
The only possible errors here are if the AP is not available due to AP
checkstop, deconfigured AP or invalid APQN.
+ return;
+ }
+ } while (--retry);
+}
+
/**
* assign_adapter_store
*
@@ -790,15 +816,18 @@ static int vfio_ap_mdev_group_notifier(struct notifier_block *nb,
return NOTIFY_OK;
}
-static int vfio_ap_mdev_reset_queue(unsigned int apid, unsigned int apqi,
- unsigned int retry)
+int vfio_ap_mdev_reset_queue(unsigned int apid, unsigned int apqi)
{
struct ap_queue_status status;
+ int retry = 5;
do {
status = ap_zapq(AP_MKQID(apid, apqi));
switch (status.response_code) {
case AP_RESPONSE_NORMAL:
+ vfio_ap_mdev_wait_for_qempty(apid, apqi);
+ return 0;
+ case AP_RESPONSE_DECONFIGURED:
Since you modify the switch, you can return for all the following cases:
AP_RESPONSE_DECONFIGURE
..._CHECKSTOP
..._INVALID_APQN
And you should wait for qempty on AP_RESET_IN_PROGRESS along with
AP_RESPONSE_NORMAL
return 0;
case AP_RESPONSE_RESET_IN_PROGRESS:
case AP_RESPONSE_BUSY:
While at modifying this function, the AP_RESPONSE_BUSY is not a valid
code for ZAPQ, you can remove this.
@@ -824,7 +853,7 @@ static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev)
matrix_mdev->matrix.apm_max + 1) {
for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm,
matrix_mdev->matrix.aqm_max + 1) {
- ret = vfio_ap_mdev_reset_queue(apid, apqi, 1);
+ ret = vfio_ap_mdev_reset_queue(apid, apqi);
IMHO, since you are at changing this call, passing the apqn as parameter
would be a good simplification.
/*
* Regardless whether a queue turns out to be busy, or
* is not operational, we need to continue resetting
Depends on why the reset failed, but this is out of scope.
--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany
