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From: Eric Farman <farman@linux.ibm.com>
To: Thomas Huth <thuth@redhat.com>,
	Janosch Frank <frankja@linux.ibm.com>,
	Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>,
	kvm@vger.kernel.org, linux-s390@vger.kernel.org,
	Eric Farman <farman@linux.ibm.com>
Subject: [PATCH kvm-unit-tests v1 1/6] lib: s390x: smp: Retry SIGP SENSE on CC2
Date: Thu,  3 Mar 2022 22:04:20 +0100	[thread overview]
Message-ID: <20220303210425.1693486-2-farman@linux.ibm.com> (raw)
In-Reply-To: <20220303210425.1693486-1-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>
---
 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


  reply	other threads:[~2022-03-03 21:04 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-03 21:04 [PATCH kvm-unit-tests v1 0/6] s390x: SIGP fixes Eric Farman
2022-03-03 21:04 ` Eric Farman [this message]
2022-03-07 11:50   ` [PATCH kvm-unit-tests v1 1/6] lib: s390x: smp: Retry SIGP SENSE on CC2 Nico Boehr
2022-03-07 15:20   ` Claudio Imbrenda
2022-03-03 21:04 ` [PATCH kvm-unit-tests v1 2/6] s390x: smp: Test SIGP RESTART against stopped CPU Eric Farman
2022-03-04 10:43   ` Janosch Frank
2022-03-04 14:20     ` Eric Farman
2022-03-07 12:42   ` Nico Boehr
2022-03-07 15:22   ` Claudio Imbrenda
2022-03-03 21:04 ` [PATCH kvm-unit-tests v1 3/6] s390x: smp: Fix checks for SIGP STOP STORE STATUS Eric Farman
2022-03-04 10:40   ` Janosch Frank
2022-03-04 14:38     ` Eric Farman
2022-03-07 18:30       ` Eric Farman
2022-03-03 21:04 ` [PATCH kvm-unit-tests v1 4/6] s390x: smp: Create and use a non-waiting CPU stop Eric Farman
2022-03-07 13:31   ` Nico Boehr
2022-03-07 19:01     ` Eric Farman
2022-03-07 15:30   ` Claudio Imbrenda
2022-03-07 19:03     ` Eric Farman
2022-03-08 10:31       ` Claudio Imbrenda
2022-03-08 21:18         ` Eric Farman
2022-03-09  9:27           ` Claudio Imbrenda
2022-03-03 21:04 ` [PATCH kvm-unit-tests v1 5/6] s390x: smp: Create and use a non-waiting CPU restart Eric Farman
2022-03-07 15:31   ` Claudio Imbrenda
2022-03-03 21:04 ` [PATCH kvm-unit-tests v1 6/6] lib: s390x: smp: Convert remaining smp_sigp to _retry Eric Farman
2022-03-04 10:56   ` Janosch Frank
2022-03-04 14:15     ` Eric Farman
2022-03-07 14:42     ` Nico Boehr
2022-03-07 20:15       ` Eric Farman
2022-03-08  9:03         ` Janosch Frank

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