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

From: Paolo Bonzini
Date: Mon Jun 01 2015 - 05:33:28 EST




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/

> +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.

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?

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_))

Paolo
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