Following the same line of reasoning, what if vmx->nested.nested_vmx_secondary_ctls_high is 0 after clearing SECONDARY_EXEC_ENABLE_VMFUNC? Does it make sense to report CPU_BASED_ACTIVATE_SECONDARY_CONTROLS if we don't actually support any of the secondary controls?
Reviewed-by: Jim Mattson <[email protected]> On Mon, Oct 16, 2017 at 9:03 PM, Wanpeng Li <[email protected]> wrote: > From: Wanpeng Li <[email protected]> > > I can use vmxcap tool to observe "EPTP Switching yes" even if EPT is not > exposed to L1. > > EPT switching is advertised unconditionally since it is emulated, however, > it can be treated as an extended feature for EPT and it should not be > advertised if EPT itself is not exposed. This patch fixes it. > > Cc: Paolo Bonzini <[email protected]> > Cc: Radim Krčmář <[email protected]> > Cc: Jim Mattson <[email protected]> > Signed-off-by: Wanpeng Li <[email protected]> > --- > v1 -> v2: > * don't advertise "EPT VM Functions" in secondary processor-based > VM-execution > controls if we don't actually support any VM Functions. > > arch/x86/kvm/vmx.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index c460b0b..a6861ca 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -2842,8 +2842,12 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx > *vmx) > * Advertise EPTP switching unconditionally > * since we emulate it > */ > - vmx->nested.nested_vmx_vmfunc_controls = > - VMX_VMFUNC_EPTP_SWITCHING; > + if (enable_ept) { > + vmx->nested.nested_vmx_vmfunc_controls = > + VMX_VMFUNC_EPTP_SWITCHING; > + } else > + vmx->nested.nested_vmx_secondary_ctls_high &= > + ~SECONDARY_EXEC_ENABLE_VMFUNC; > } > > /* > -- > 2.7.4 >
