Messages in this thread | | | Date | Fri, 24 May 2019 11:13:23 +0200 | From | Cornelia Huck <> | Subject | Re: [PATCH 8/9] KVM: s390: Do not report unusabled IDs via KVM_CAP_MAX_VCPU_ID |
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On Thu, 23 May 2019 18:43:08 +0200 Thomas Huth <thuth@redhat.com> wrote:
In the subject: s/unusabled/unusable/
> 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. > > Signed-off-by: Thomas Huth <thuth@redhat.com> > --- > arch/mips/kvm/mips.c | 3 +++ > arch/powerpc/kvm/powerpc.c | 3 +++ > arch/s390/kvm/kvm-s390.c | 1 + > arch/x86/kvm/x86.c | 3 +++ > virt/kvm/arm/arm.c | 3 +++ > virt/kvm/kvm_main.c | 2 -- > 6 files changed, 13 insertions(+), 2 deletions(-)
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
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