Re: [PATCH 12/15] KVM: MTRR: introduce mtrr_for_each_mem_type

From: Xiao Guangrong <guangrong.xiao@linux.intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: gleb@kernel.org, mtosatti@redhat.com, kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 12/15] KVM: MTRR: introduce mtrr_for_each_mem_type
Date: Wed, 03 Jun 2015 10:40:43 +0800	[thread overview]
Message-ID: <556E692B.6000500@linux.intel.com> (raw)
In-Reply-To: <556C26D4.6030205@redhat.com>

On 06/01/2015 05:33 PM, Paolo Bonzini wrote:
>
>
> On 30/05/2015 12:59, Xiao Guangrong wrote:
>> +struct mtrr_looker {
>> +	/* input fields. */
>> +	struct kvm_mtrr *mtrr_state;
>> +	u64 start;
>> +	u64 end;
>
> s/looker/iter/ or s/looker/lookup/

Good to me.

>
>> +static void mtrr_lookup_start(struct mtrr_looker *looker)
>> +{
>> +	looker->mem_type = -1;
>> +
>> +	if (!looker->mtrr_state->mtrr_enabled) {
>> +		looker->partial_map = true;
>> +		return;
>> +	}
>> +
>> +	if (!mtrr_lookup_fixed_start(looker))
>> +		mtrr_lookup_var_start(looker);
>> +}
>> +
>
> Separating mtrr_lookup_start and mtrr_lookup_init is weird.

Agreed, will fold mtrr_lookup_start() into mtrr_lookup_init().

>
> There are common parts of mtrr_lookup_*_start and mtrr_lookup_*_next.
> For example this:
>
>> +	looker->mem_type = looker->mtrr_state->fixed_ranges[index];
>> +	looker->start = fixed_mtrr_range_end_addr(seg, index);
>> +	return true;
>
> in mtrr_lookup_fixed_start is the same as this:
>
>>
>> +	end = fixed_mtrr_range_end_addr(looker->seg, looker->index);
>> +
>> +	/* switch to next segment. */
>> +	if (end >= eseg->end) {
>> +		looker->seg++;
>> +		looker->index = 0;
>> +
>> +		/* have looked up for all fixed MTRRs. */
>> +		if (looker->seg >= ARRAY_SIZE(fixed_seg_table))
>> +			return mtrr_lookup_var_start(looker);
>> +
>> +		end = fixed_mtrr_range_end_addr(looker->seg, looker->index);
>> +	}
>> +
>> +	looker->mem_type = mtrr_state->fixed_ranges[looker->index];
>> +	looker->start = end;
>
> in mtrr_lookup_fixed_next.  Can you try to make them more common?

Yes, i will check them carefully and introduce common functions to do
it.

>
> Basically you should have
>
> +#define mtrr_for_each_mem_type(_looker_, _mtrr_, _gpa_start_, _gpa_end_) \
> +	for (mtrr_lookup_init(_looker_, _mtrr_, _gpa_start_, _gpa_end_); \
> +	     !mtrr_lookup_end(_looker_); mtrr_lookup_next(_looker_))

Good idea, will do it in v2.