From: Greg Kroah-Hartman Date: Mon, 15 Apr 2024 12:46:45 +0000 (+0200) Subject: 4.19-stable patches X-Git-Tag: v5.15.156~44 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=df78ab32fdd4968c5b2c54382fbe171a6a6f4adf;p=thirdparty%2Fkernel%2Fstable-queue.git 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 72b4ab1dfca..0b5e833681c 100644 --- 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 360924503b8..4b81337e821 100644 --- 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 Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin --- - 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 index 00000000000..ada23a1d590 --- /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 +Date: Thu, 28 Mar 2024 10:21:47 +1000 +Subject: vhost: Add smp_rmb() in vhost_vq_avail_empty() + +From: Gavin Shan + +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: # v4.11+ +Reported-by: Yihuang Yu +Suggested-by: Will Deacon +Signed-off-by: Gavin Shan +Acked-by: Jason Wang +Message-Id: <20240328002149.1141302-2-gshan@redhat.com> +Signed-off-by: Michael S. Tsirkin +Reviewed-by: Stefano Garzarella +Signed-off-by: Greg Kroah-Hartman +--- + 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); +