On 3/3/25 2:11 PM, Rorie Reyes wrote:
This patch is based on the s390/features branch
The guest's AP configuration is cleared when the mdev is removed, so
userspace must be notified that the AP configuration has changed. To this
end, this patch:
* Removes call to 'signal_guest_ap_cfg_changed()' function from the
'vfio_ap_mdev_unset_kvm()' function because it has no affect given it is
called after the mdev fd is closed.
* Adds call to 'signal_guest_ap_cfg_changed()' function to the
'vfio_ap_mdev_request()' function to notify userspace that the guest's
AP configuration has changed before signaling the request to remove the
mdev.
Minor change - Fixed an indentation issue in function
'signal_guest_ap_cfg_changed()'
Fixes: 2ba4410dd477 ("s390/vfio-ap: Signal eventfd when guest AP configuration is changed")
Signed-off-by: Rorie Reyes <rreyes@xxxxxxxxxxxxx>
---
drivers/s390/crypto/vfio_ap_ops.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 571f5dcb49c5..c1afac5ac555 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -652,8 +652,8 @@ static void vfio_ap_matrix_init(struct ap_config_info *info,
static void signal_guest_ap_cfg_changed(struct ap_matrix_mdev *matrix_mdev)
{
- if (matrix_mdev->cfg_chg_trigger)
- eventfd_signal(matrix_mdev->cfg_chg_trigger);
+ if (matrix_mdev->cfg_chg_trigger)
+ eventfd_signal(matrix_mdev->cfg_chg_trigger);
}
static void vfio_ap_mdev_update_guest_apcb(struct ap_matrix_mdev *matrix_mdev)
@@ -1870,7 +1870,6 @@ static void vfio_ap_mdev_unset_kvm(struct ap_matrix_mdev *matrix_mdev)
get_update_locks_for_kvm(kvm);
kvm_arch_crypto_clear_masks(kvm);
- signal_guest_ap_cfg_changed(matrix_mdev);
vfio_ap_mdev_reset_queues(matrix_mdev);
kvm_put_kvm(kvm);
matrix_mdev->kvm = NULL;
@@ -2057,6 +2056,14 @@ static void vfio_ap_mdev_request(struct vfio_device *vdev, unsigned int count)
matrix_mdev = container_of(vdev, struct ap_matrix_mdev, vdev);
+ if (matrix_mdev->kvm) {
+ get_update_locks_for_kvm(matrix_mdev->kvm);
I know we talked about this prior to submission of this patch, but
looking at this again I think
you should use the get_update_locks_for_mdev() function for two reasons:
1. It is safer because it will take the matrix_dev->guests_lock which
will prevent the matrix_mdev->kvm
field from changing before you check it
2. I will eliminate the need for the else
get_update_locks_for_mdev(matrix_mdev)
if (matrix_mdev->kvm) {
clear the masks
signal guest config changed
}
...
release_update_locks_for_mdev(matrix_mdev); Sorry about not seeing this
before you posted this patch.
+ kvm_arch_crypto_clear_masks(matrix_mdev->kvm);
+ signal_guest_ap_cfg_changed(matrix_mdev);
+ } else {
+ mutex_lock(&matrix_dev->mdevs_lock);
+ }
+
if (matrix_mdev->req_trigger) {
if (!(count % 10))
dev_notice_ratelimited(dev,
@@ -2068,6 +2075,12 @@ static void vfio_ap_mdev_request(struct vfio_device *vdev, unsigned int count)
dev_notice(dev,
"No device request registered, blocked until released by user\n");
}
+
+ if (matrix_mdev->kvm)
+ release_update_locks_for_kvm(matrix_mdev->kvm);
+ else
+ mutex_unlock(&matrix_dev->mdevs_lock);
+
}
static int vfio_ap_mdev_get_device_info(unsigned long arg)
