[Patch v2 5/5] KVM: x86/mmu: Merge all handle_changed_pte* functions.

Vipin Sharma
2023-02-03T19:28:53Z

__handle_changed_pte() and handle_changed_spte_acc_track() are always
used together. Merge these two functions and name the new function
handle_changed_pte(). Remove the existing handle_changed_pte() function
which just calls __handle_changed_pte and
handle_changed_spte_acc_track().

This converges SPTEs change handling code to a single place.

Signed-off-by: Vipin Sharma <vipinsh@google.com>
---
arch/x86/kvm/mmu/tdp_mmu.c | 42 +++++++++++---------------------------
1 file changed, 12 insertions(+), 30 deletions(-)

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index afe0dcb1859e..9b0c81a28f97 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -334,17 +334,6 @@ static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
u64 old_spte, u64 new_spte, int level,
bool shared);

-static void handle_changed_spte_acc_track(u64 old_spte, u64 new_spte, int level)
-{
- if (!is_shadow_present_pte(old_spte) || !is_last_spte(old_spte, level))
- return;
-
- if (is_accessed_spte(old_spte) &&
- (!is_shadow_present_pte(new_spte) || !is_accessed_spte(new_spte) ||
- spte_to_pfn(old_spte) != spte_to_pfn(new_spte)))
- kvm_set_pfn_accessed(spte_to_pfn(old_spte));
-}
-
static void tdp_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp)
{
kvm_account_pgtable_pages((void *)sp->spt, +1);
@@ -487,7 +476,7 @@ static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool shared)
}

/**
- * __handle_changed_spte - handle bookkeeping associated with an SPTE change
+ * handle_changed_spte - handle bookkeeping associated with an SPTE change
* @kvm: kvm instance
* @as_id: the address space of the paging structure the SPTE was a part of
* @gfn: the base GFN that was mapped by the SPTE
@@ -501,9 +490,9 @@ static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool shared)
* Handle bookkeeping that might result from the modification of a SPTE.
* This function must be called for all TDP SPTE modifications.
*/
-static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
- u64 old_spte, u64 new_spte, int level,
- bool shared)
+static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
+ u64 old_spte, u64 new_spte, int level,
+ bool shared)
{
bool was_present = is_shadow_present_pte(old_spte);
bool is_present = is_shadow_present_pte(new_spte);
@@ -587,15 +576,10 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
if (was_present && !was_leaf &&
(is_leaf || !is_present || WARN_ON_ONCE(pfn_changed)))
handle_removed_pt(kvm, spte_to_child_pt(old_spte, level), shared);
-}

-static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
- u64 old_spte, u64 new_spte, int level,
- bool shared)
-{
- __handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level,
- shared);
- handle_changed_spte_acc_track(old_spte, new_spte, level);
+ if (was_leaf && is_accessed_spte(old_spte) &&
+ (!is_present || !is_accessed_spte(new_spte) || pfn_changed))
+ kvm_set_pfn_accessed(spte_to_pfn(old_spte));
}

/*
@@ -638,9 +622,8 @@ static inline int tdp_mmu_set_spte_atomic(struct kvm *kvm,
if (!try_cmpxchg64(sptep, &iter->old_spte, new_spte))
return -EBUSY;

- __handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,
- new_spte, iter->level, true);
- handle_changed_spte_acc_track(iter->old_spte, new_spte, iter->level);
+ handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,
+ new_spte, iter->level, true);

return 0;
}
@@ -705,8 +688,7 @@ static u64 _tdp_mmu_set_spte(struct kvm *kvm, int as_id, tdp_ptep_t sptep,

old_spte = kvm_tdp_mmu_write_spte(sptep, old_spte, new_spte, level);

- __handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, false);
- handle_changed_spte_acc_track(old_spte, new_spte, level);
+ handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, false);
return old_spte;
}

@@ -1273,7 +1255,7 @@ static bool set_spte_gfn(struct kvm *kvm, struct tdp_iter *iter,
* Note, when changing a read-only SPTE, it's not strictly necessary to
* zero the SPTE before setting the new PFN, but doing so preserves the
* invariant that the PFN of a present * leaf SPTE can never change.
- * See __handle_changed_spte().
+ * See handle_changed_spte().
*/
tdp_mmu_set_spte(kvm, iter, 0);

@@ -1298,7 +1280,7 @@ bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
/*
* No need to handle the remote TLB flush under RCU protection, the
* target SPTE _must_ be a leaf SPTE, i.e. cannot result in freeing a
- * shadow page. See the WARN on pfn_changed in __handle_changed_spte().
+ * shadow page. See the WARN on pfn_changed in handle_changed_spte().
*/
return kvm_tdp_mmu_handle_gfn(kvm, range, set_spte_gfn);
}
--
2.39.1.519.gcb327c4b5f-goog