On 07/27/2018 11:23 AM, Thomas Huth wrote:
On 07/26/2018 09:54 PM, Christian Borntraeger wrote:
[...]
+static void kvm_ap_merge_bitmasks(unsigned long *dst, unsigned long *mask1,
+ unsigned long *mask2, unsigned long nbits)
+{
+ int i;
+
+ for (i = 0; i < BITS_TO_LONGS(nbits); i++)
+ dst[i] = mask1[i] | mask2[i];
+}
Could you use the standard bitmap_or() function instead of implementing
your own version?
In a previous iteration of this patch, the bitmap_or() function was used.
It did not perform as expected when nbits > 32, so we rolled out own.
+static void vfio_ap_mdev_copy_masks(struct ap_matrix_mdev *matrix_mdev,
+ struct kvm_s390_crypto_cb *crycb)
+{
+ int nbytes;
+ unsigned long *apm, *aqm, *adm;
+
+ switch (matrix_mdev->kvm->arch.crypto.crycbd & CRYCB_FORMAT_MASK) {
+ case CRYCB_FORMAT2:
+ apm = (unsigned long *)crycb->apcb1.apm;
+ aqm = (unsigned long *)crycb->apcb1.aqm;
+ adm = (unsigned long *)crycb->apcb1.adm;
+ break;
+ case CRYCB_FORMAT1:
+ case CRYCB_FORMAT0:
+ default:
+ apm = (unsigned long *)crycb->apcb0.apm;
+ aqm = (unsigned long *)crycb->apcb0.aqm;
+ adm = (unsigned long *)crycb->apcb0.adm;
+ break;
+ }
+
+ nbytes = DIV_ROUND_UP(matrix_mdev->matrix.apm_max + 1, BITS_PER_BYTE);
+ memcpy(apm, matrix_mdev->matrix.apm, nbytes);
+ nbytes = DIV_ROUND_UP(matrix_mdev->matrix.aqm_max + 1, BITS_PER_BYTE);
+ memcpy(aqm, matrix_mdev->matrix.aqm, nbytes);
+ kvm_ap_merge_bitmasks(adm, aqm, adm, matrix_mdev->matrix.adm_max + 1);
+}
+
+static int vfio_ap_mdev_group_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ int ret;
+ struct ap_matrix_mdev *matrix_mdev;
+ struct kvm_s390_crypto_cb *crycb;
+
+ if (action == VFIO_GROUP_NOTIFY_SET_KVM) {
+ matrix_mdev = container_of(nb, struct ap_matrix_mdev,
+ group_notifier);
+ matrix_mdev->kvm = data;
+ crycb = matrix_mdev->kvm->arch.crypto.crycb;
+
+ ret = kvm_ap_validate_crypto_setup(matrix_mdev->kvm);
+ if (ret)
+ return ret;
+
+ /* NOTE: Happens before any vcpu is running (no hotplug). */
+ vfio_ap_mdev_copy_masks(matrix_mdev, crycb);
+ if (ret)
+ return ret;
+ }
+
+ return NOTIFY_OK;
+}
+
+/**
+ * vfio_ap_mdev_open_once
+ *
+ * @matrix_mdev: a mediated matrix device
+ *
+ * Return 0 if no other mediated matrix device has been opened for the
+ * KVM guest assigned to @matrix_mdev; otherwise, returns an error.
+ */
+static int vfio_ap_mdev_open_once(struct ap_matrix_mdev *matrix_mdev)
+{
+ int ret = 0;
+ struct ap_matrix_mdev *lstdev;
+
+ list_for_each_entry(lstdev, &matrix_dev.mdev_list, list) {
+ if ((lstdev->kvm == matrix_mdev->kvm) &&
+ (lstdev != matrix_mdev)) {
Too much parentheses again for my taste ;-)
I think we'll have to agree to disagree here. As I stated in a previous
response, it is my opinion that using parenthesis precludes having to
memorize operator preference rules.
+ ret = -EPERM;
+ break;
+ }
+ }
Thomas
