On 03/03/20 00:56, Sean Christopherson wrote: > > bool kvm_mpx_supported(void) > { > - return ((host_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR)) > - && kvm_x86_ops->mpx_supported()); > + return supported_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR); > } Better check that both bits are set. Paolo