Re: [PATCH 3/4] KVM: VMX: Emulated real mode interrupt injection

[Avi Kivity <avi@redhat.com>]

  On 09/21/2010 05:36 PM, Marcelo Tosatti wrote:
> On Tue, Sep 21, 2010 at 01:56:50PM +0200, Avi Kivity wrote:
> >   On 09/20/2010 07:30 PM, Marcelo Tosatti wrote:
> >  >>    static void __vmx_complete_interrupts(struct vcpu_vmx *vmx,
> >  >>    				u32 idt_vectoring_info,
> >  >>    				int instr_len_field,
> >  >>   @@ -3864,9 +3814,6 @@ static void __vmx_complete_interrupts(struct vcpu_vmx *vmx,
> >  >>    	int type;
> >  >>    	bool idtv_info_valid;
> >  >>
> >  >>   -	if (vmx->rmode.irq.pending)
> >  >>   -		fixup_rmode_irq(vmx,&idt_vectoring_info);
> >  >>   -
> >  >
> >  >Don't you have to undo kvm_inject_realmode_interrupt if injection fails?
> >  >
> >  >
> >
> >  Injection cannot fail (at least, in the same sense as the vmx
> >  injections).  It's actually not about failures, it's about guest
> >  entry being cancelled due to a signal or some KVM_REQ that needs
> >  attention.  For vmx style injections, we need to undo the injection
> >  to keep things in a consistent state.  To realmode emulated
> >  injection, everything is in a consistent state already, so no need
> >  to undo anything (it's also impossible, since we overwrote memory on
> >  the stack).
>
> Aren't you going to push EFLAGS,CS,EIP on the stack twice if that
> occurs?
>

No, since we clear the pending flag (we do that even for vmx-injected 
interrupts; then cancel or injection failure re-sets the flag).

-- 
error compiling committee.c: too many arguments to function