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authorChao Peng <chao.p.peng@linux.intel.com>2022-08-16 20:53:22 +0800
committerPaolo Bonzini <pbonzini@redhat.com>2022-08-19 04:05:41 -0400
commit20ec3ebd707c77fb9b11b37193449193d4649f33 (patch)
tree2107161ea95066619aab7118c12182208189ed5d /virt
parentbdd1c37a315bc50ab14066c4852bc8dcf070451e (diff)
KVM: Rename mmu_notifier_* to mmu_invalidate_*
The motivation of this renaming is to make these variables and related helper functions less mmu_notifier bound and can also be used for non mmu_notifier based page invalidation. mmu_invalidate_* was chosen to better describe the purpose of 'invalidating' a page that those variables are used for. - mmu_notifier_seq/range_start/range_end are renamed to mmu_invalidate_seq/range_start/range_end. - mmu_notifier_retry{_hva} helper functions are renamed to mmu_invalidate_retry{_hva}. - mmu_notifier_count is renamed to mmu_invalidate_in_progress to avoid confusion with mn_active_invalidate_count. - While here, also update kvm_inc/dec_notifier_count() to kvm_mmu_invalidate_begin/end() to match the change for mmu_notifier_count. No functional change intended. Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> Message-Id: <20220816125322.1110439-3-chao.p.peng@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/kvm_main.c52
-rw-r--r--virt/kvm/pfncache.c17
2 files changed, 36 insertions, 33 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 44b92d773156..5142c054b03c 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -702,30 +702,31 @@ static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
/*
* .change_pte() must be surrounded by .invalidate_range_{start,end}().
- * If mmu_notifier_count is zero, then no in-progress invalidations,
- * including this one, found a relevant memslot at start(); rechecking
- * memslots here is unnecessary. Note, a false positive (count elevated
- * by a different invalidation) is sub-optimal but functionally ok.
+ * If mmu_invalidate_in_progress is zero, then no in-progress
+ * invalidations, including this one, found a relevant memslot at
+ * start(); rechecking memslots here is unnecessary. Note, a false
+ * positive (count elevated by a different invalidation) is sub-optimal
+ * but functionally ok.
*/
WARN_ON_ONCE(!READ_ONCE(kvm->mn_active_invalidate_count));
- if (!READ_ONCE(kvm->mmu_notifier_count))
+ if (!READ_ONCE(kvm->mmu_invalidate_in_progress))
return;
kvm_handle_hva_range(mn, address, address + 1, pte, kvm_set_spte_gfn);
}
-void kvm_inc_notifier_count(struct kvm *kvm, unsigned long start,
- unsigned long end)
+void kvm_mmu_invalidate_begin(struct kvm *kvm, unsigned long start,
+ unsigned long end)
{
/*
* The count increase must become visible at unlock time as no
* spte can be established without taking the mmu_lock and
* count is also read inside the mmu_lock critical section.
*/
- kvm->mmu_notifier_count++;
- if (likely(kvm->mmu_notifier_count == 1)) {
- kvm->mmu_notifier_range_start = start;
- kvm->mmu_notifier_range_end = end;
+ kvm->mmu_invalidate_in_progress++;
+ if (likely(kvm->mmu_invalidate_in_progress == 1)) {
+ kvm->mmu_invalidate_range_start = start;
+ kvm->mmu_invalidate_range_end = end;
} else {
/*
* Fully tracking multiple concurrent ranges has diminishing
@@ -736,10 +737,10 @@ void kvm_inc_notifier_count(struct kvm *kvm, unsigned long start,
* accumulate and persist until all outstanding invalidates
* complete.
*/
- kvm->mmu_notifier_range_start =
- min(kvm->mmu_notifier_range_start, start);
- kvm->mmu_notifier_range_end =
- max(kvm->mmu_notifier_range_end, end);
+ kvm->mmu_invalidate_range_start =
+ min(kvm->mmu_invalidate_range_start, start);
+ kvm->mmu_invalidate_range_end =
+ max(kvm->mmu_invalidate_range_end, end);
}
}
@@ -752,7 +753,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
.end = range->end,
.pte = __pte(0),
.handler = kvm_unmap_gfn_range,
- .on_lock = kvm_inc_notifier_count,
+ .on_lock = kvm_mmu_invalidate_begin,
.on_unlock = kvm_arch_guest_memory_reclaimed,
.flush_on_ret = true,
.may_block = mmu_notifier_range_blockable(range),
@@ -763,7 +764,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
/*
* Prevent memslot modification between range_start() and range_end()
* so that conditionally locking provides the same result in both
- * functions. Without that guarantee, the mmu_notifier_count
+ * functions. Without that guarantee, the mmu_invalidate_in_progress
* adjustments will be imbalanced.
*
* Pairs with the decrement in range_end().
@@ -779,7 +780,8 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
* any given time, and the caches themselves can check for hva overlap,
* i.e. don't need to rely on memslot overlap checks for performance.
* Because this runs without holding mmu_lock, the pfn caches must use
- * mn_active_invalidate_count (see above) instead of mmu_notifier_count.
+ * mn_active_invalidate_count (see above) instead of
+ * mmu_invalidate_in_progress.
*/
gfn_to_pfn_cache_invalidate_start(kvm, range->start, range->end,
hva_range.may_block);
@@ -789,22 +791,22 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
return 0;
}
-void kvm_dec_notifier_count(struct kvm *kvm, unsigned long start,
- unsigned long end)
+void kvm_mmu_invalidate_end(struct kvm *kvm, unsigned long start,
+ unsigned long end)
{
/*
* This sequence increase will notify the kvm page fault that
* the page that is going to be mapped in the spte could have
* been freed.
*/
- kvm->mmu_notifier_seq++;
+ kvm->mmu_invalidate_seq++;
smp_wmb();
/*
* The above sequence increase must be visible before the
* below count decrease, which is ensured by the smp_wmb above
- * in conjunction with the smp_rmb in mmu_notifier_retry().
+ * in conjunction with the smp_rmb in mmu_invalidate_retry().
*/
- kvm->mmu_notifier_count--;
+ kvm->mmu_invalidate_in_progress--;
}
static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
@@ -816,7 +818,7 @@ static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
.end = range->end,
.pte = __pte(0),
.handler = (void *)kvm_null_fn,
- .on_lock = kvm_dec_notifier_count,
+ .on_lock = kvm_mmu_invalidate_end,
.on_unlock = (void *)kvm_null_fn,
.flush_on_ret = false,
.may_block = mmu_notifier_range_blockable(range),
@@ -837,7 +839,7 @@ static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
if (wake)
rcuwait_wake_up(&kvm->mn_memslots_update_rcuwait);
- BUG_ON(kvm->mmu_notifier_count < 0);
+ BUG_ON(kvm->mmu_invalidate_in_progress < 0);
}
static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c
index ab519f72f2cd..68ff41d39545 100644
--- a/virt/kvm/pfncache.c
+++ b/virt/kvm/pfncache.c
@@ -112,27 +112,28 @@ static inline bool mmu_notifier_retry_cache(struct kvm *kvm, unsigned long mmu_s
{
/*
* mn_active_invalidate_count acts for all intents and purposes
- * like mmu_notifier_count here; but the latter cannot be used
- * here because the invalidation of caches in the mmu_notifier
- * event occurs _before_ mmu_notifier_count is elevated.
+ * like mmu_invalidate_in_progress here; but the latter cannot
+ * be used here because the invalidation of caches in the
+ * mmu_notifier event occurs _before_ mmu_invalidate_in_progress
+ * is elevated.
*
* Note, it does not matter that mn_active_invalidate_count
* is not protected by gpc->lock. It is guaranteed to
* be elevated before the mmu_notifier acquires gpc->lock, and
- * isn't dropped until after mmu_notifier_seq is updated.
+ * isn't dropped until after mmu_invalidate_seq is updated.
*/
if (kvm->mn_active_invalidate_count)
return true;
/*
* Ensure mn_active_invalidate_count is read before
- * mmu_notifier_seq. This pairs with the smp_wmb() in
+ * mmu_invalidate_seq. This pairs with the smp_wmb() in
* mmu_notifier_invalidate_range_end() to guarantee either the
* old (non-zero) value of mn_active_invalidate_count or the
- * new (incremented) value of mmu_notifier_seq is observed.
+ * new (incremented) value of mmu_invalidate_seq is observed.
*/
smp_rmb();
- return kvm->mmu_notifier_seq != mmu_seq;
+ return kvm->mmu_invalidate_seq != mmu_seq;
}
static kvm_pfn_t hva_to_pfn_retry(struct kvm *kvm, struct gfn_to_pfn_cache *gpc)
@@ -155,7 +156,7 @@ static kvm_pfn_t hva_to_pfn_retry(struct kvm *kvm, struct gfn_to_pfn_cache *gpc)
gpc->valid = false;
do {
- mmu_seq = kvm->mmu_notifier_seq;
+ mmu_seq = kvm->mmu_invalidate_seq;
smp_rmb();
write_unlock_irq(&gpc->lock);