4.19-stable patches

added patches:
	vhost-add-smp_rmb-in-vhost_vq_avail_empty.patch

diff --git a/queue-4.19/series b/queue-4.19/series
index 72b4ab1dfcaae67345f823ccc6e0e6d7a02cafb0..0b5e833681ce4ebfae4932e3c724665aa8d6d28f 100644 (file)
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -7,3 +7,4 @@ ipv4-route-avoid-unused-but-set-variable-warning.patch
 ipv6-fix-race-condition-between-ipv6_get_ifaddr-and-.patch
 net-mlx5-properly-link-new-fs-rules-into-the-tree.patch
 tracing-hide-unused-ftrace_event_id_fops.patch
+vhost-add-smp_rmb-in-vhost_vq_avail_empty.patch

diff --git a/queue-4.19/tracing-hide-unused-ftrace_event_id_fops.patch b/queue-4.19/tracing-hide-unused-ftrace_event_id_fops.patch
index 360924503b8a736d4338aaf030ea7698bc2f91bc..4b81337e821947ba4fe712f32d800fc008b12a63 100644 (file)
--- a/queue-4.19/tracing-hide-unused-ftrace_event_id_fops.patch
+++ b/queue-4.19/tracing-hide-unused-ftrace_event_id_fops.patch
@@ -35,14 +35,12 @@ Signed-off-by: Arnd Bergmann <arnd@arndb.de>
 Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 Signed-off-by: Sasha Levin <sashal@kernel.org>
 ---
- kernel/trace/trace_events.c | 4 ++++
+ kernel/trace/trace_events.c |    4 ++++
  1 file changed, 4 insertions(+)
 
-diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
-index ed39d3ec202e6..2830a9cbe648e 100644
 --- a/kernel/trace/trace_events.c
 +++ b/kernel/trace/trace_events.c
-@@ -1309,6 +1309,7 @@ static int trace_format_open(struct inode *inode, struct file *file)
+@@ -1309,6 +1309,7 @@ static int trace_format_open(struct inod
        return 0;
  }
  
@@ -50,7 +48,7 @@ index ed39d3ec202e6..2830a9cbe648e 100644
  static ssize_t
  event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
  {
-@@ -1323,6 +1324,7 @@ event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
+@@ -1323,6 +1324,7 @@ event_id_read(struct file *filp, char __
  
        return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
  }
@@ -58,7 +56,7 @@ index ed39d3ec202e6..2830a9cbe648e 100644
  
  static ssize_t
  event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
-@@ -1727,10 +1729,12 @@ static const struct file_operations ftrace_event_format_fops = {
+@@ -1727,10 +1729,12 @@ static const struct file_operations ftra
        .release = seq_release,
  };
  
@@ -71,6 +69,3 @@ index ed39d3ec202e6..2830a9cbe648e 100644
  
  static const struct file_operations ftrace_event_filter_fops = {
        .open = tracing_open_generic,
--- 
-2.43.0
-

diff --git a/queue-4.19/vhost-add-smp_rmb-in-vhost_vq_avail_empty.patch b/queue-4.19/vhost-add-smp_rmb-in-vhost_vq_avail_empty.patch
new file mode 100644 (file)
index 0000000..ada23a1
--- /dev/null
+++ b/queue-4.19/vhost-add-smp_rmb-in-vhost_vq_avail_empty.patch
@@ -0,0 +1,70 @@
+From 22e1992cf7b034db5325660e98c41ca5afa5f519 Mon Sep 17 00:00:00 2001
+From: Gavin Shan <gshan@redhat.com>
+Date: Thu, 28 Mar 2024 10:21:47 +1000
+Subject: vhost: Add smp_rmb() in vhost_vq_avail_empty()
+
+From: Gavin Shan <gshan@redhat.com>
+
+commit 22e1992cf7b034db5325660e98c41ca5afa5f519 upstream.
+
+A smp_rmb() has been missed in vhost_vq_avail_empty(), spotted by
+Will. Otherwise, it's not ensured the available ring entries pushed
+by guest can be observed by vhost in time, leading to stale available
+ring entries fetched by vhost in vhost_get_vq_desc(), as reported by
+Yihuang Yu on NVidia's grace-hopper (ARM64) platform.
+
+  /home/gavin/sandbox/qemu.main/build/qemu-system-aarch64      \
+  -accel kvm -machine virt,gic-version=host -cpu host          \
+  -smp maxcpus=1,cpus=1,sockets=1,clusters=1,cores=1,threads=1 \
+  -m 4096M,slots=16,maxmem=64G                                 \
+  -object memory-backend-ram,id=mem0,size=4096M                \
+   :                                                           \
+  -netdev tap,id=vnet0,vhost=true                              \
+  -device virtio-net-pci,bus=pcie.8,netdev=vnet0,mac=52:54:00:f1:26:b0
+   :
+  guest# netperf -H 10.26.1.81 -l 60 -C -c -t UDP_STREAM
+  virtio_net virtio0: output.0:id 100 is not a head!
+
+Add the missed smp_rmb() in vhost_vq_avail_empty(). When tx_can_batch()
+returns true, it means there's still pending tx buffers. Since it might
+read indices, so it still can bypass the smp_rmb() in vhost_get_vq_desc().
+Note that it should be safe until vq->avail_idx is changed by commit
+275bf960ac697 ("vhost: better detection of available buffers").
+
+Fixes: 275bf960ac69 ("vhost: better detection of available buffers")
+Cc: <stable@kernel.org> # v4.11+
+Reported-by: Yihuang Yu <yihyu@redhat.com>
+Suggested-by: Will Deacon <will@kernel.org>
+Signed-off-by: Gavin Shan <gshan@redhat.com>
+Acked-by: Jason Wang <jasowang@redhat.com>
+Message-Id: <20240328002149.1141302-2-gshan@redhat.com>
+Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
+Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/vhost/vhost.c |   12 +++++++++++-
+ 1 file changed, 11 insertions(+), 1 deletion(-)
+
+--- a/drivers/vhost/vhost.c
++++ b/drivers/vhost/vhost.c
+@@ -2426,9 +2426,19 @@ bool vhost_vq_avail_empty(struct vhost_d
+       r = vhost_get_avail(vq, avail_idx, &vq->avail->idx);
+       if (unlikely(r))
+               return false;
++
+       vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
++      if (vq->avail_idx != vq->last_avail_idx) {
++              /* Since we have updated avail_idx, the following
++               * call to vhost_get_vq_desc() will read available
++               * ring entries. Make sure that read happens after
++               * the avail_idx read.
++               */
++              smp_rmb();
++              return false;
++      }
+ 
+-      return vq->avail_idx == vq->last_avail_idx;
++      return true;
+ }
+ EXPORT_SYMBOL_GPL(vhost_vq_avail_empty);
+