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KVM: x86/mmu: Morph kvm_handle_gfn_range() into an aging specific helper

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Rework kvm_handle_gfn_range() into an aging-specic helper,
kvm_rmap_age_gfn_range().  In addition to purging a bunch of unnecessary
boilerplate code, this sets the stage for aging rmap SPTEs outside of
mmu_lock.

Note, there's a small functional change, as kvm_test_age_gfn() will now
return immediately if a young SPTE is found, whereas previously KVM would
continue iterating over other levels.

Link: https://lore.kernel.org/r/20240809194335.1726916-15-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Sean Christopherson
2024-08-09 12:43:26 -07:00
parent 548f87f667
commit c17f150000
1 changed files with 22 additions and 46 deletions
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68
arch/x86/kvm/mmu/mmu.c
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@@ -1577,25 +1577,6 @@ static bool __kvm_rmap_zap_gfn_range(struct kvm *kvm,
start, end - 1, can_yield, true, flush);
}
typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
struct kvm_memory_slot *slot, gfn_t gfn,
int level);
static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm,
struct kvm_gfn_range *range,
rmap_handler_t handler)
{
struct slot_rmap_walk_iterator iterator;
bool ret = false;
for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL,
range->start, range->end - 1, &iterator)
ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn,
iterator.level);
return ret;
}
bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
{
bool flush = false;
@@ -1615,31 +1596,6 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
return flush;
}
static bool kvm_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
struct kvm_memory_slot *slot, gfn_t gfn, int level)
{
u64 *sptep;
struct rmap_iterator iter;
int young = 0;
for_each_rmap_spte(rmap_head, &iter, sptep)
young |= mmu_spte_age(sptep);
return young;
}
static bool kvm_test_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
struct kvm_memory_slot *slot, gfn_t gfn, int level)
{
u64 *sptep;
struct rmap_iterator iter;
for_each_rmap_spte(rmap_head, &iter, sptep)
if (is_accessed_spte(*sptep))
return true;
return false;
}
#define RMAP_RECYCLE_THRESHOLD 1000
static void __rmap_add(struct kvm *kvm,
@@ -1674,12 +1630,32 @@ static void rmap_add(struct kvm_vcpu *vcpu, const struct kvm_memory_slot *slot,
__rmap_add(vcpu->kvm, cache, slot, spte, gfn, access);
}
static bool kvm_rmap_age_gfn_range(struct kvm *kvm,
struct kvm_gfn_range *range, bool test_only)
{
struct slot_rmap_walk_iterator iterator;
struct rmap_iterator iter;
bool young = false;
u64 *sptep;
for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL,
range->start, range->end - 1, &iterator) {
for_each_rmap_spte(iterator.rmap, &iter, sptep) {
if (test_only && is_accessed_spte(*sptep))
return true;
young = mmu_spte_age(sptep);
}
}
return young;
}
bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
{
bool young = false;
if (kvm_memslots_have_rmaps(kvm))
young = kvm_handle_gfn_range(kvm, range, kvm_age_rmap);
young = kvm_rmap_age_gfn_range(kvm, range, false);
if (tdp_mmu_enabled)
young |= kvm_tdp_mmu_age_gfn_range(kvm, range);
@@ -1692,7 +1668,7 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
bool young = false;
if (kvm_memslots_have_rmaps(kvm))
young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmap);
young = kvm_rmap_age_gfn_range(kvm, range, true);
if (tdp_mmu_enabled)
young |= kvm_tdp_mmu_test_age_gfn(kvm, range);