• Greg Kurz's avatar
    kvm: introduce KVM_MAX_VCPU_ID · 0b1b1dfd
    Greg Kurz authored
    The KVM_MAX_VCPUS define provides the maximum number of vCPUs per guest, and
    also the upper limit for vCPU ids. This is okay for all archs except PowerPC
    which can have higher ids, depending on the cpu/core/thread topology. In the
    worst case (single threaded guest, host with 8 threads per core), it limits
    the maximum number of vCPUS to KVM_MAX_VCPUS / 8.
    
    This patch separates the vCPU numbering from the total number of vCPUs, with
    the introduction of KVM_MAX_VCPU_ID, as the maximal valid value for vCPU ids
    plus one.
    
    The corresponding KVM_CAP_MAX_VCPU_ID allows userspace to validate vCPU ids
    before passing them to KVM_CREATE_VCPU.
    
    This patch only implements KVM_MAX_VCPU_ID with a specific value for PowerPC.
    Other archs continue to return KVM_MAX_VCPUS instead.
    Suggested-by: default avatarRadim Krcmar <rkrcmar@redhat.com>
    Signed-off-by: default avatarGreg Kurz <gkurz@linux.vnet.ibm.com>
    Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
    Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
    0b1b1dfd
kvm_host.h 17.7 KB