[PATCH kvm-unit-tests v1 1/6] lib: s390x: smp: Retry SIGP SENSE on CC2

Eric Farman
2022-03-03T21:04:36Z

The routine smp_cpu_stopped() issues a SIGP SENSE, and returns true
if it received a CC1 (STATUS STORED) with the STOPPED or CHECK STOP
bits enabled. Otherwise, it returns false.

This is misleading, because a CC2 (BUSY) merely indicates that the
order code could not be processed, not that the CPU is operating.
It could be operating but in the process of being stopped.

Convert the invocation of the SIGP SENSE to retry when a CC2 is
received, so we get a more definitive answer.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
---
lib/s390x/smp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/s390x/smp.c b/lib/s390x/smp.c
index 46e1b022..368d6add 100644
--- a/lib/s390x/smp.c
+++ b/lib/s390x/smp.c
@@ -78,7 +78,7 @@ bool smp_cpu_stopped(uint16_t idx)
{
uint32_t status;

- if (smp_sigp(idx, SIGP_SENSE, 0, &status) != SIGP_CC_STATUS_STORED)
+ if (smp_sigp_retry(idx, SIGP_SENSE, 0, &status) != SIGP_CC_STATUS_STORED)
return false;
return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
}
--
2.32.0