Li, Liang Z wrote on 2015-05-20: > The MPX feature requires eager KVM FPU restore support. We have > verified that MPX cannot work correctly with the current lazy KVM FPU > restore mechanism. Eager KVM FPU restore should be enabled if the MPX > feature is exposed to VM. > > Signed-off-by: Liang Li <liang.z.li@xxxxxxxxx> > --- > arch/x86/kvm/vmx.c | 2 ++ > arch/x86/kvm/x86.c | 3 ++- > 2 files changed, 4 insertions(+), 1 deletion(-) > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index > f7b6168..e2cccbe 100644 --- a/arch/x86/kvm/vmx.c +++ > b/arch/x86/kvm/vmx.c @@ -8445,6 +8445,8 @@ static struct kvm_vcpu > *vmx_create_vcpu(struct kvm *kvm, unsigned int id) > goto free_vmcs; > } > + if (vmx_mpx_supported()) Is it better to use guest_cpuid_has_mpx() instead of vmx_mpx_supported()? > + vmx_fpu_activate(&vmx->vcpu); > return &vmx->vcpu; > > free_vmcs: > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index > 5f38188..5993f5f 100644 --- a/arch/x86/kvm/x86.c +++ > b/arch/x86/kvm/x86.c @@ -7060,7 +7060,8 @@ void kvm_put_guest_fpu(struct > kvm_vcpu *vcpu) > fpu_save_init(&vcpu->arch.guest_fpu); > __kernel_fpu_end(); > ++vcpu->stat.fpu_reload; > - kvm_make_request(KVM_REQ_DEACTIVATE_FPU, vcpu); > + if (!kvm_x86_ops->mpx_supported()) > + kvm_make_request(KVM_REQ_DEACTIVATE_FPU, vcpu); > trace_kvm_fpu(0); > } Best regards, Yang -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
