Drivers: hv: vmbus: Implement per-CPU mapping of relid to channel

Currently the mapping of the relID to channel is done under the protection of a
single spin lock. Starting with ws2012, each channel is bound to a specific VCPU
in the guest. Use this binding to eliminate the spin lock by setting up
per-cpu state for mapping relId to the channel.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index bcb49502c3b..edfc8488cb0 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -383,6 +383,8 @@ void hv_synic_init(void *arg)
 	 */
 	rdmsrl(HV_X64_MSR_VP_INDEX, vp_index);
 	hv_context.vp_index[cpu] = (u32)vp_index;
+
+	INIT_LIST_HEAD(&hv_context.percpu_list[cpu]);
 	return;
 }