On Tue, Jun 04, 2019 at 11:18:28AM +0200, Christian Borntraeger wrote: > From: Thomas Huth <thuth@xxxxxxxxxx> > > 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@xxxxxxxxxx> > Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx> > Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> > Signed-off-by: Thomas Huth <thuth@xxxxxxxxxx> > Message-Id: <20190523164309.13345-9-thuth@xxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> > [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
