Re: [PATCH] hardware debug register handling

[Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>]

Nguyen Anh Quynh wrote:
> Currently, when handling hardware breakpoints, we always set values
> for all the 4 hardware debug registers, regardless it is needed or
> not. This patch fixes the bug.

Why is this a problem?  Only enabled breakpoints are programmed into dr7.

> @@ -1519,12 +1522,18 @@ static void do_interrupt_requests(struct kvm_vcpu *vcpu,
>  
>  static void kvm_guest_debug_pre(struct kvm_vcpu *vcpu)
>  {
> +#define SET_DEBUGREG(i) \
> +	if (dbg->bp[i].enabled) { \
> +		set_debugreg(dbg->bp[i].address, i); \
> +	}
> +
>  	struct kvm_guest_debug *dbg = &vcpu->guest_debug;
>  
> -	set_debugreg(dbg->bp[0], 0);
> -	set_debugreg(dbg->bp[1], 1);
> -	set_debugreg(dbg->bp[2], 2);
> -	set_debugreg(dbg->bp[3], 3);
> +	SET_DEBUGREG(0);
> +	SET_DEBUGREG(1);
> +	SET_DEBUGREG(2);
> +	SET_DEBUGREG(3);
> +#undef SET_DEBUGREG
>   

Why those ugly macros?

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


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