HV: Add log info when setup hvlog share buf

We have two sbuf for hvlog: one is allocated by hv for "early hvlog" and
the other one is allocated by SOS. Once SOS allocate the later one, the
hv allocated sbufs would be released after the contents being copied, we
call it sbuf switch.

And there is a trick here to guarantee that the switch of a certain per_cpu
sbuf is being done on exactly the certain physical CPU, that is doing the
switch at the first print after SOS allocated and setup its sbuf.

Because there are few logmsg within our current code, so will wait a bit long
for the next print. For ordinary case, it should be ok. However, for the
BTM(Boot Time Measurement) case, we need the content of "early hvlog" for
boot time calculation and it is not ok. So, we print those prints to force
the sbuf switch.

Signed-off-by: Kaige Fu <kaige.fu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>

hypervisor/debug/sbuf.c

@@ -186,5 +186,8 @@ int sbuf_share_setup(uint32_t pcpu_id, uint32_t sbuf_id, uint64_t *hva)
 		return -EINVAL;
 
 	per_cpu(sbuf, pcpu_id)[sbuf_id] = hva;
+	pr_info("%s share sbuf for pCPU[%u] with sbuf_id[%u] setup successfully",
+			__func__, pcpu_id, sbuf_id);
+
 	return 0;
 }