Re: [RFC PATCH 3/4] KVM: x86: add support for emulating UMIP

[Radim KrÄmÃÅ]

2016-07-12 21:20+0200, Paolo Bonzini:
> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> ---
> diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
> @@ -3738,6 +3747,10 @@ static int em_lidt(struct x86_emulate_ctxt *ctxt)
>  
>  static int em_smsw(struct x86_emulate_ctxt *ctxt)
>  {
> +	if ((ctxt->ops->get_cr(ctxt, 4) & X86_CR4_UMIP) &&
> +	    ctxt->ops->cpl(ctxt) > 0)

UMIP should #GP(0) in virtual-8086 mode too (for SMSW, SIDT, and SGDT),
but cpl() returns 0 in vm86.

> +		return emulate_gp(ctxt, 0);