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[kvm-unit-tests,GIT,PULL,01/27] lib: s390x: smp: Retry SIGP SENSE on CC2

Message ID 20220401111620.366435-2-imbrenda@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series s390x: smp, vm lib updates; I/O and smp tests | expand

Commit Message

Claudio Imbrenda April 1, 2022, 11:15 a.m. UTC 
From: Eric Farman <farman@linux.ibm.com>

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>
Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 lib/s390x/smp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
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Patch

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));
 }