On Tue, Jun 04, 2019 at 11:18:28AM +0200, Christian Borntraeger wrote:
From: Thomas Huth thuth@redhat.com
KVM_CAP_MAX_VCPU_ID is currently always reporting KVM_MAX_VCPU_ID on all architectures. However, on s390x, the amount of usable CPUs is determined during runtime - it is depending on the features of the machine the code is running on. Since we are using the vcpu_id as an index into the SCA structures that are defined by the hardware (see e.g. the sca_add_vcpu() function), it is not only the amount of CPUs that is limited by the hard- ware, but also the range of IDs that we can use. Thus KVM_CAP_MAX_VCPU_ID must be determined during runtime on s390x, too. So the handling of KVM_CAP_MAX_VCPU_ID has to be moved from the common code into the architecture specific code, and on s390x we have to return the same value here as for KVM_CAP_MAX_VCPUS. This problem has been discovered with the kvm_create_max_vcpus selftest. With this change applied, the selftest now passes on s390x, too.
Reviewed-by: Andrew Jones drjones@redhat.com Reviewed-by: Cornelia Huck cohuck@redhat.com Reviewed-by: David Hildenbrand david@redhat.com Signed-off-by: Thomas Huth thuth@redhat.com Message-Id: 20190523164309.13345-9-thuth@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Christian Borntraeger borntraeger@de.ibm.com [backport to 5.1 and older]
Now queued up, but next time, give me a hint and put the git sha1 id of the commit in Linus's tree somewhere in here...
thanks,
greg k-h