The per-VQ MSI-X interrupt handler needs to sync DMA mappings in the

same way that the shared interrupt handler does.  This is one of the
requirements of virtio_dequeue(), as specified in its comment above.

Without the DMA sync, it will not see a new entry on the ring and
return.  Since the interrupt is edge-triggered there won't be another
one and we'll get stuck.

ok dv@

diff --git a/sys/dev/pci/virtio_pci.c b/sys/dev/pci/virtio_pci.c
index 28087f1..398dc96 100644 (file)
--- a/sys/dev/pci/virtio_pci.c
+++ b/sys/dev/pci/virtio_pci.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: virtio_pci.c,v 1.34 2023/07/05 18:11:08 patrick Exp $ */
+/*     $OpenBSD: virtio_pci.c,v 1.35 2023/07/07 10:23:39 patrick Exp $ */
 /*     $NetBSD: virtio.c,v 1.3 2011/11/02 23:05:52 njoly Exp $ */
 
 /*
@@ -961,6 +961,13 @@ virtio_pci_setup_msix(struct virtio_pci_softc *sc, struct pci_attach_args *pa,
        struct virtio_softc *vsc = &sc->sc_sc;
        int i;
 
+       /* Shared needs config + queue */
+       if (shared && pci_intr_msix_count(pa) < 1 + 1)
+               return 1;
+       /* Per VQ needs config + N * queue */
+       if (!shared && pci_intr_msix_count(pa) < 1 + vsc->sc_nvqs)
+               return 1;
+
        if (virtio_pci_msix_establish(sc, pa, 0, virtio_pci_config_intr, vsc))
                return 1;
        sc->sc_devcfg_offset = VIRTIO_CONFIG_DEVICE_CONFIG_MSI;
@@ -1059,10 +1066,9 @@ int
 virtio_pci_queue_intr(void *arg)
 {
        struct virtqueue *vq = arg;
+       struct virtio_softc *vsc = vq->vq_owner;
 
-       if (vq->vq_done)
-               return (vq->vq_done)(vq);
-       return 0;
+       return virtio_check_vq(vsc, vq);
 }
 
 int

diff --git a/sys/dev/pv/virtio.c b/sys/dev/pv/virtio.c
index d085376..e9be61c 100644 (file)
--- a/sys/dev/pv/virtio.c
+++ b/sys/dev/pv/virtio.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: virtio.c,v 1.22 2023/04/20 19:28:31 jcs Exp $ */
+/*     $OpenBSD: virtio.c,v 1.23 2023/07/07 10:23:39 patrick Exp $     */
 /*     $NetBSD: virtio.c,v 1.3 2011/11/02 23:05:52 njoly Exp $ */
 
 /*
@@ -218,26 +218,31 @@ vq_sync_indirect(struct virtio_softc *sc, struct virtqueue *vq, int slot,
 int
 virtio_check_vqs(struct virtio_softc *sc)
 {
-       struct virtqueue *vq;
        int i, r = 0;
 
        /* going backwards is better for if_vio */
-       for (i = sc->sc_nvqs - 1; i >= 0; i--) {
-               vq = &sc->sc_vqs[i];
-               if (vq->vq_queued) {
-                       vq->vq_queued = 0;
-                       vq_sync_aring(sc, vq, BUS_DMASYNC_POSTWRITE);
-               }
-               vq_sync_uring(sc, vq, BUS_DMASYNC_POSTREAD);
-               if (vq->vq_used_idx != vq->vq_used->idx) {
-                       if (vq->vq_done)
-                               r |= (vq->vq_done)(vq);
-               }
-       }
+       for (i = sc->sc_nvqs - 1; i >= 0; i--)
+               r |= virtio_check_vq(sc, &sc->sc_vqs[i]);
 
        return r;
 }
 
+int
+virtio_check_vq(struct virtio_softc *sc, struct virtqueue *vq)
+{
+       if (vq->vq_queued) {
+               vq->vq_queued = 0;
+               vq_sync_aring(sc, vq, BUS_DMASYNC_POSTWRITE);
+       }
+       vq_sync_uring(sc, vq, BUS_DMASYNC_POSTREAD);
+       if (vq->vq_used_idx != vq->vq_used->idx) {
+               if (vq->vq_done)
+                       return (vq->vq_done)(vq);
+       }
+
+       return 0;
+}
+
 /*
  * Initialize vq structure.
  */

diff --git a/sys/dev/pv/virtiovar.h b/sys/dev/pv/virtiovar.h
index 9e3e9c9..7f2aea7 100644 (file)
--- a/sys/dev/pv/virtiovar.h
+++ b/sys/dev/pv/virtiovar.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: virtiovar.h,v 1.14 2019/05/26 15:22:31 sf Exp $       */
+/*     $OpenBSD: virtiovar.h,v 1.15 2023/07/07 10:23:39 patrick Exp $  */
 /*     $NetBSD: virtiovar.h,v 1.1 2011/10/30 12:12:21 hannken Exp $    */
 
 /*
@@ -233,6 +233,7 @@ int virtio_dequeue_commit(struct virtqueue*, int);
 
 int virtio_intr(void *arg);
 int virtio_check_vqs(struct virtio_softc *);
+int virtio_check_vq(struct virtio_softc *, struct virtqueue *);
 void virtio_stop_vq_intr(struct virtio_softc *, struct virtqueue *);
 int virtio_start_vq_intr(struct virtio_softc *, struct virtqueue *);