On 04/12/2014 12:11, Wanpeng Li wrote: > SDM 30.3 VMWRITE > > ELSIF secondary source operand does not correspond to any VMCS field > THEN VMfailValid(VMREAD/VMWRITE from/to unsupported VMCS component); > > We can't suppose L1 VMM expose MPX to L2 just if L0 support MPX. There > will be VMfailValid if L0 doesn't support MPX and L1 expose MPX to L2 > when L0 writes vmcs02/vmcs01, in addition, there is no need to read > GUEST_BNDCFGS if L1 VMM doesn't expose it to L2. This patch fix it by > both check L0 support xsaves and L1 expose MPX to L2. Did you have a reproducer for this? It should not be needed, because the bndcfgs entry/exit controls are hidden from nested_vmx_exit_ctls_high and nested_vmx_entry_ctls_high if !vmx_mpx_supported(). This hunk is also not correct: > - if (vmx_mpx_supported()) > + if (vmx_mpx_supported() && > + (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS)) > vmcs12->guest_bndcfgs = vmcs_read64(GUEST_BNDCFGS); > if (nested_cpu_has_xsaves(vmcs12)) > vmcs12->xss_exit_bitmap = vmcs_read64(XSS_EXIT_BITMAP); because there is no "save BNDCFGS" exit control; the guest BNDCFGS is saved unconditionally into the vmcs. Paolo -- 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
