lkml.org 
[lkml]   [2021]   [Oct]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH v5 05/13] KVM: Integrate gfn_to_memslot_approx() into search_memslots()
On Mon, Sep 20, 2021, Maciej S. Szmigiero wrote:
> @@ -1267,7 +1280,7 @@ search_memslots(struct kvm_memslots *slots, gfn_t gfn, int *index)
> * itself isn't here as an inline because that would bloat other code too much.
> */
> static inline struct kvm_memory_slot *
> -__gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn)
> +__gfn_to_memslot_approx(struct kvm_memslots *slots, gfn_t gfn, bool approx)

This function name is a misnomer. The helper is not an "approx" version, it's an
inner helper that takes an @approx param. Unless someone has a more clever name,
the dreaded four underscores seems like the way to go. Warning away users is a
good thing in this case...

> {
> struct kvm_memory_slot *slot;
> int slot_index = atomic_read(&slots->last_used_slot);
> @@ -1276,7 +1289,7 @@ __gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn)
> if (slot)
> return slot;
>
> - slot = search_memslots(slots, gfn, &slot_index);
> + slot = search_memslots(slots, gfn, &slot_index, approx);
> if (slot) {
> atomic_set(&slots->last_used_slot, slot_index);
> return slot;
> @@ -1285,6 +1298,12 @@ __gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn)
> return NULL;
> }
>

There's a comment that doesn't show up in this diff that should also be moved,
and opportunistically updated.

> +static inline struct kvm_memory_slot *
> +__gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn)
> +{
> + return __gfn_to_memslot_approx(slots, gfn, false);
> +}
> +
> static inline unsigned long
> __gfn_to_hva_memslot(const struct kvm_memory_slot *slot, gfn_t gfn)
> {

E.g. this as fixup?

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 540fa948baa5..2964c773b36c 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1964,10 +1964,15 @@ static int kvm_s390_peek_cmma(struct kvm *kvm, struct kvm_s390_cmma_log *args,
return 0;
}

+static int gfn_to_memslot_approx(struct kvm_memslots *slots, gfn_t gfn)
+{
+ return ____gfn_to_memslot(slots, cur_gfn, true);
+}
+
static unsigned long kvm_s390_next_dirty_cmma(struct kvm_memslots *slots,
unsigned long cur_gfn)
{
- struct kvm_memory_slot *ms = __gfn_to_memslot_approx(slots, cur_gfn, true);
+ struct kvm_memory_slot *ms = gfn_to_memslot_approx(slots, cur_gfn);
int slotidx = ms - slots->memslots;
unsigned long ofs = cur_gfn - ms->base_gfn;

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 8fd9644f40b2..ec1a074c2f6e 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1274,13 +1274,8 @@ search_memslots(struct kvm_memslots *slots, gfn_t gfn, int *index, bool approx)
return NULL;
}

-/*
- * __gfn_to_memslot() and its descendants are here because it is called from
- * non-modular code in arch/powerpc/kvm/book3s_64_vio{,_hv}.c. gfn_to_memslot()
- * itself isn't here as an inline because that would bloat other code too much.
- */
static inline struct kvm_memory_slot *
-__gfn_to_memslot_approx(struct kvm_memslots *slots, gfn_t gfn, bool approx)
+____gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn, bool approx)
{
struct kvm_memory_slot *slot;
int slot_index = atomic_read(&slots->last_used_slot);
@@ -1298,10 +1293,15 @@ __gfn_to_memslot_approx(struct kvm_memslots *slots, gfn_t gfn, bool approx)
return NULL;
}

+/*
+ * __gfn_to_memslot() and its descendants are here to allow arch code to inline
+ * the lookups in hot paths. gfn_to_memslot() itself isn't here as an inline
+ * because that would bloat other code too much.
+ */
static inline struct kvm_memory_slot *
__gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn)
{
- return __gfn_to_memslot_approx(slots, gfn, false);
+ return ____gfn_to_memslot(slots, gfn, false);
}

static inline unsigned long
\
 
 \ /
  Last update: 2021-10-20 01:39    [W:0.314 / U:0.400 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site