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| author | Andrea Parri (Microsoft) <parri.andrea@gmail.com> | 2020-04-06 03:15:12 +0300 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2020-04-23 16:17:12 +0300 |
| commit | d570aec0f2154e1bfba14ffd0df164a185e363b5 (patch) | |
| tree | 1320751b4fc7a1b8cb1e0f794d535c030a59b6b1 /drivers/hv/hv.c | |
| parent | 8ef4c4abbbcdcd9d4bc0fd9454df03e6dac24b73 (diff) | |
| download | linux-d570aec0f2154e1bfba14ffd0df164a185e363b5.tar.xz | |
Drivers: hv: vmbus: Synchronize init_vp_index() vs. CPU hotplug
init_vp_index() may access the cpu_online_mask mask via its calls of
cpumask_of_node(). Make sure to protect these accesses with a
cpus_read_lock() critical section.
Also, remove some (hardcoded) instances of CPU(0) from init_vp_index()
and replace them with VMBUS_CONNECT_CPU. The connect CPU can not go
offline, since Hyper-V does not provide a way to change it.
Finally, order the accesses of target_cpu from init_vp_index() and
hv_synic_cleanup() by relying on the channel_mutex; this is achieved
by moving the call of init_vp_index() into vmbus_process_offer().
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200406001514.19876-10-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Diffstat (limited to 'drivers/hv/hv.c')
| -rw-r--r-- | drivers/hv/hv.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c index 17bf1f229152..188b42b07f07 100644 --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -256,9 +256,10 @@ int hv_synic_cleanup(unsigned int cpu) /* * Search for channels which are bound to the CPU we're about to - * cleanup. In case we find one and vmbus is still connected we need to - * fail, this will effectively prevent CPU offlining. There is no way - * we can re-bind channels to different CPUs for now. + * cleanup. In case we find one and vmbus is still connected, we + * fail; this will effectively prevent CPU offlining. + * + * TODO: Re-bind the channels to different CPUs. */ mutex_lock(&vmbus_connection.channel_mutex); list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { |