From 760615584b708a45b9ade52f746e716da0a8eb92 Mon Sep 17 00:00:00 2001 From: Eric Auger Date: Tue, 17 Jan 2023 10:15:18 -0500 Subject: [PATCH] vhost/net: Clear the pending messages when the backend is removed [ Upstream commit 9526f9a2b762af16be94a72aca5d65c677d28f50 ] When the vhost iotlb is used along with a guest virtual iommu and the guest gets rebooted, some MISS messages may have been recorded just before the reboot and spuriously executed by the virtual iommu after the reboot. As vhost does not have any explicit reset user API, VHOST_NET_SET_BACKEND looks a reasonable point where to clear the pending messages, in case the backend is removed. Export vhost_clear_msg() and call it in vhost_net_set_backend() when fd == -1. Signed-off-by: Eric Auger Suggested-by: Jason Wang Fixes: ac35b12314c73 ("vhost: new device IOTLB API") Message-Id: <20230117151518.44725-3-eric.auger@redhat.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin --- drivers/vhost/net.c | 3 +++ drivers/vhost/vhost.c | 3 ++- drivers/vhost/vhost.h | 1 + 3 files changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 20265393aee7c..c7e44d8182524 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -1511,6 +1511,9 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) nvq = &n->vqs[index]; mutex_lock(&vq->mutex); + if (fd == -1) + vhost_clear_msg(&n->dev); + /* Verify that ring has been setup correctly. */ if (!vhost_vq_access_ok(vq)) { r = -EFAULT; diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 3c2359570df9d..547f89a6940f3 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -661,7 +661,7 @@ void vhost_dev_stop(struct vhost_dev *dev) } EXPORT_SYMBOL_GPL(vhost_dev_stop); -static void vhost_clear_msg(struct vhost_dev *dev) +void vhost_clear_msg(struct vhost_dev *dev) { struct vhost_msg_node *node, *n; @@ -679,6 +679,7 @@ static void vhost_clear_msg(struct vhost_dev *dev) spin_unlock(&dev->iotlb_lock); } +EXPORT_SYMBOL_GPL(vhost_clear_msg); void vhost_dev_cleanup(struct vhost_dev *dev) { diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index d9109107af087..790b296271f1e 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -181,6 +181,7 @@ long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp); bool vhost_vq_access_ok(struct vhost_virtqueue *vq); bool vhost_log_access_ok(struct vhost_dev *); +void vhost_clear_msg(struct vhost_dev *dev); int vhost_get_vq_desc(struct vhost_virtqueue *, struct iovec iov[], unsigned int iov_count, -- 2.39.5