From: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
To: Bagas Sanjaya <bagasdotme@gmail.com>,
Christian Borntraeger <borntraeger@linux.ibm.com>,
Janosch Frank <frankja@linux.ibm.com>,
Claudio Imbrenda <imbrenda@linux.ibm.com>,
Heiko Carstens <hca@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Alexander Gordeev <agordeev@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>,
Jonathan Corbet <corbet@lwn.net>,
kvm@vger.kernel.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
linux-s390@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
Shuah Khan <shuah@kernel.org>,
Sven Schnelle <svens@linux.ibm.com>
Subject: Re: [PATCH v3 2/9] Documentation: KVM: s390: Describe KVM_S390_MEMOP_F_CMPXCHG
Date: Mon, 21 Nov 2022 18:44:42 +0100 [thread overview]
Message-ID: <e56e2c58477626dbdc6d4ddcd806459e7ce93b28.camel@linux.ibm.com> (raw)
In-Reply-To: <73ecf737-c523-b4ab-f11f-431bb5fb2c37@gmail.com>
On Fri, 2022-11-18 at 08:50 +0700, Bagas Sanjaya wrote:
> On 11/18/22 05:17, Janis Schoetterl-Glausch wrote:
> > +For write accesses, the KVM_S390_MEMOP_F_CMPXCHG might be supported.
> > +In this case, instead of doing an unconditional write, the access occurs only
> > +if the target location contains the "size" byte long value pointed to by
> > +"old_p". This is performed as an atomic cmpxchg. "size" must be a power of two
> > +up to and including 16.
> > +The value at the target location is written to the location "old_p" points to.
> > +If the exchange did not take place because the target value doesn't match the
> > +old value KVM_S390_MEMOP_R_NO_XCHG is returned.
> > +The KVM_S390_MEMOP_F_CMPXCHG flag is supported if KVM_CAP_S390_MEM_OP_EXTENSION
> > +has bit 1 (i.e. bit with value 2) set.
> >
>
> Is KVM_S390_MEMOP_F_CMPXCHG supported with conditions (as you implied)?
>
I'm afraid I don't quite understand the question.
It is supported if the capability says it is, i.e. if bit 1 is set.
next prev parent reply other threads:[~2022-11-21 17:45 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-17 22:17 [PATCH v3 0/9] KVM: s390: Extend MEM_OP ioctl by storage key checked cmpxchg Janis Schoetterl-Glausch
2022-11-17 22:17 ` [PATCH v3 1/9] " Janis Schoetterl-Glausch
2022-11-18 10:12 ` Heiko Carstens
2022-11-18 14:37 ` Thomas Huth
2022-11-18 15:15 ` Heiko Carstens
2022-11-21 17:41 ` Janis Schoetterl-Glausch
2022-12-01 16:15 ` Claudio Imbrenda
2022-12-01 17:44 ` Janis Schoetterl-Glausch
2022-12-02 9:00 ` Claudio Imbrenda
2022-11-17 22:17 ` [PATCH v3 2/9] Documentation: KVM: s390: Describe KVM_S390_MEMOP_F_CMPXCHG Janis Schoetterl-Glausch
2022-11-18 1:50 ` Bagas Sanjaya
2022-11-21 17:44 ` Janis Schoetterl-Glausch [this message]
2022-11-22 7:47 ` Thomas Huth
2022-11-22 13:10 ` Janis Schoetterl-Glausch
2022-11-25 8:52 ` Nico Boehr
2022-12-01 16:21 ` Claudio Imbrenda
2022-11-17 22:17 ` [PATCH v3 3/9] KVM: s390: selftest: memop: Pass mop_desc via pointer Janis Schoetterl-Glausch
2022-11-17 22:17 ` [PATCH v3 4/9] KVM: s390: selftest: memop: Replace macros by functions Janis Schoetterl-Glausch
2022-12-01 16:28 ` Claudio Imbrenda
2022-12-01 17:58 ` Janis Schoetterl-Glausch
2022-11-17 22:17 ` [PATCH v3 5/9] KVM: s390: selftest: memop: Move testlist into main Janis Schoetterl-Glausch
2022-11-22 7:52 ` Thomas Huth
2022-11-22 9:34 ` Janis Schoetterl-Glausch
2022-11-17 22:17 ` [PATCH v3 6/9] KVM: s390: selftest: memop: Add cmpxchg tests Janis Schoetterl-Glausch
2022-11-17 22:17 ` [PATCH v3 7/9] KVM: s390: selftest: memop: Add bad address test Janis Schoetterl-Glausch
2022-11-17 22:17 ` [PATCH v3 8/9] KVM: s390: selftest: memop: Fix typo Janis Schoetterl-Glausch
2022-11-17 22:17 ` [PATCH v3 9/9] KVM: s390: selftest: memop: Fix wrong address being used in test Janis Schoetterl-Glausch
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