• Alexander Graf's avatar
    KVM: Activate Virtualization On Demand · 10474ae8
    Alexander Graf authored
    X86 CPUs need to have some magic happening to enable the virtualization
    extensions on them. This magic can result in unpleasant results for
    users, like blocking other VMMs from working (vmx) or using invalid TLB
    entries (svm).
    
    Currently KVM activates virtualization when the respective kernel module
    is loaded. This blocks us from autoloading KVM modules without breaking
    other VMMs.
    
    To circumvent this problem at least a bit, this patch introduces on
    demand activation of virtualization. This means, that instead
    virtualization is enabled on creation of the first virtual machine
    and disabled on destruction of the last one.
    
    So using this, KVM can be easily autoloaded, while keeping other
    hypervisors usable.
    Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
    Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
    Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
    10474ae8
x86.c 119 KB