From: Jason Wang <jasowang@redhat.com>
To: mst@redhat.com, kvm@vger.kernel.org,
virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, jgg@ziepe.ca,
Jason Wang <jasowang@redhat.com>
Subject: [PATCH V4 9/9] vhost: do not return -EAGAIN for non blocking invalidation too early
Date: Wed, 7 Aug 2019 03:06:17 -0400 [thread overview]
Message-ID: <20190807070617.23716-10-jasowang@redhat.com> (raw)
In-Reply-To: <20190807070617.23716-1-jasowang@redhat.com>
Instead of returning -EAGAIN unconditionally, we'd better do that only
we're sure the range is overlapped with the metadata area.
Reported-by: Jason Gunthorpe <jgg@ziepe.ca>
Fixes: 7f466032dc9e ("vhost: access vq metadata through kernel virtual address")
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/vhost/vhost.c | 32 +++++++++++++++++++-------------
1 file changed, 19 insertions(+), 13 deletions(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 6650a3ff88c1..0271f853fa9c 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -395,16 +395,19 @@ static void inline vhost_vq_sync_access(struct vhost_virtqueue *vq)
smp_mb();
}
-static void vhost_invalidate_vq_start(struct vhost_virtqueue *vq,
- int index,
- unsigned long start,
- unsigned long end)
+static int vhost_invalidate_vq_start(struct vhost_virtqueue *vq,
+ int index,
+ unsigned long start,
+ unsigned long end,
+ bool blockable)
{
struct vhost_uaddr *uaddr = &vq->uaddrs[index];
struct vhost_map *map;
if (!vhost_map_range_overlap(uaddr, start, end))
- return;
+ return 0;
+ else if (!blockable)
+ return -EAGAIN;
spin_lock(&vq->mmu_lock);
++vq->invalidate_count;
@@ -419,6 +422,8 @@ static void vhost_invalidate_vq_start(struct vhost_virtqueue *vq,
vhost_set_map_dirty(vq, map, index);
vhost_map_unprefetch(map);
}
+
+ return 0;
}
static void vhost_invalidate_vq_end(struct vhost_virtqueue *vq,
@@ -439,18 +444,19 @@ static int vhost_invalidate_range_start(struct mmu_notifier *mn,
{
struct vhost_dev *dev = container_of(mn, struct vhost_dev,
mmu_notifier);
- int i, j;
-
- if (!mmu_notifier_range_blockable(range))
- return -EAGAIN;
+ bool blockable = mmu_notifier_range_blockable(range);
+ int i, j, ret;
for (i = 0; i < dev->nvqs; i++) {
struct vhost_virtqueue *vq = dev->vqs[i];
- for (j = 0; j < VHOST_NUM_ADDRS; j++)
- vhost_invalidate_vq_start(vq, j,
- range->start,
- range->end);
+ for (j = 0; j < VHOST_NUM_ADDRS; j++) {
+ ret = vhost_invalidate_vq_start(vq, j,
+ range->start,
+ range->end, blockable);
+ if (ret)
+ return ret;
+ }
}
return 0;
--
2.18.1
next prev parent reply other threads:[~2019-08-07 7:06 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-07 7:06 [PATCH V4 0/9] Fixes for metadata accelreation Jason Wang
2019-08-07 7:06 ` [PATCH V4 1/9] vhost: don't set uaddr for invalid address Jason Wang
2019-08-07 7:06 ` [PATCH V4 2/9] vhost: validate MMU notifier registration Jason Wang
2019-08-07 7:06 ` [PATCH V4 3/9] vhost: fix vhost map leak Jason Wang
2019-08-07 7:06 ` [PATCH V4 4/9] vhost: reset invalidate_count in vhost_set_vring_num_addr() Jason Wang
2019-08-07 7:06 ` [PATCH V4 5/9] vhost: mark dirty pages during map uninit Jason Wang
2019-08-07 7:06 ` [PATCH V4 6/9] vhost: don't do synchronize_rcu() in vhost_uninit_vq_maps() Jason Wang
2019-08-07 7:06 ` [PATCH V4 7/9] vhost: do not use RCU to synchronize MMU notifier with worker Jason Wang
2019-08-07 12:07 ` Jason Gunthorpe
2019-08-07 14:02 ` Jason Wang
2019-08-08 12:54 ` Jason Wang
2019-08-08 13:01 ` Jason Wang
2019-08-08 13:05 ` Jason Gunthorpe
2019-08-10 19:12 ` [PATCH V5 0/9] Fixes for vhost metadata acceleration Michael S. Tsirkin
2019-08-07 7:06 ` [PATCH V4 8/9] vhost: correctly set dirty pages in MMU notifiers callback Jason Wang
2019-08-07 7:06 ` Jason Wang [this message]
2019-08-09 5:15 ` [PATCH V4 0/9] Fixes for metadata accelreation David Miller
2019-08-09 5:35 ` Jason Wang
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