Module Name: src
Committed By: jakllsch
Date: Tue Jan 3 19:33:32 UTC 2023
Modified Files:
src/sys/dev/pci: virtio.c
Log Message:
Subtly adjust criteria for notification of Virtio devices in
VIRTIO_F_RING_EVENT_IDX mode.
This fixes stalls in the vioif(4) transmit path that would happen sooner
or later, depending on interface transmit utilization, and were
particularly noticable with a NetBSD guest transmitting to its x86 KVM
host at multi-gigabit speeds.
To generate a diff of this commit:
cvs rdiff -u -r1.64 -r1.65 src/sys/dev/pci/virtio.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/pci/virtio.c
diff -u src/sys/dev/pci/virtio.c:1.64 src/sys/dev/pci/virtio.c:1.65
--- src/sys/dev/pci/virtio.c:1.64 Fri Dec 30 21:38:13 2022
+++ src/sys/dev/pci/virtio.c Tue Jan 3 19:33:31 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: virtio.c,v 1.64 2022/12/30 21:38:13 jakllsch Exp $ */
+/* $NetBSD: virtio.c,v 1.65 2023/01/03 19:33:31 jakllsch Exp $ */
/*
* Copyright (c) 2020 The NetBSD Foundation, Inc.
@@ -28,7 +28,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: virtio.c,v 1.64 2022/12/30 21:38:13 jakllsch Exp $");
+__KERNEL_RCSID(0, "$NetBSD: virtio.c,v 1.65 2023/01/03 19:33:31 jakllsch Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -1148,7 +1148,7 @@ notify:
uint16_t o, n, t;
uint16_t flags;
- o = virtio_rw16(sc, vq->vq_avail->idx);
+ o = virtio_rw16(sc, vq->vq_avail->idx) - 1;
n = vq->vq_avail_idx;
/*
