KVM: x86/mmu: Merge flush and non-flush tdp_mmu_iter_cond_resched

The flushing and non-flushing variants of tdp_mmu_iter_cond_resched have
almost identical implementations. Merge the two functions and add a
flush parameter.

Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20210202185734.1680553-12-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index e3066d0..8f7b120 100644 (file)
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -444,32 +444,12 @@ static inline void tdp_mmu_set_spte_no_dirty_log(struct kvm *kvm,
                         _mmu->shadow_root_level, _start, _end)
 
 /*
- * Flush the TLB and yield if the MMU lock is contended or this thread needs to
- * return control to the scheduler.
- *
- * If this function yields, it will also reset the tdp_iter's walk over the
- * paging structure and the calling function should allow the iterator to
- * continue its traversal from the paging structure root.
- *
- * Return true if this function yielded, the TLBs were flushed, and the
- * iterator's traversal was reset. Return false if a yield was not needed.
- */
-static bool tdp_mmu_iter_flush_cond_resched(struct kvm *kvm, struct tdp_iter *iter)
-{
-       if (need_resched() || spin_needbreak(&kvm->mmu_lock)) {
-               kvm_flush_remote_tlbs(kvm);
-               cond_resched_lock(&kvm->mmu_lock);
-               tdp_iter_refresh_walk(iter);
-               return true;
-       }
-
-       return false;
-}
-
-/*
  * Yield if the MMU lock is contended or this thread needs to return control
  * to the scheduler.
  *
+ * If this function should yield and flush is set, it will perform a remote
+ * TLB flush before yielding.
+ *
  * If this function yields, it will also reset the tdp_iter's walk over the
  * paging structure and the calling function should allow the iterator to
  * continue its traversal from the paging structure root.
@@ -477,9 +457,13 @@ static bool tdp_mmu_iter_flush_cond_resched(struct kvm *kvm, struct tdp_iter *it
  * Return true if this function yielded and the iterator's traversal was reset.
  * Return false if a yield was not needed.
  */
-static bool tdp_mmu_iter_cond_resched(struct kvm *kvm, struct tdp_iter *iter)
+static inline bool tdp_mmu_iter_cond_resched(struct kvm *kvm,
+                                            struct tdp_iter *iter, bool flush)
 {
        if (need_resched() || spin_needbreak(&kvm->mmu_lock)) {
+               if (flush)
+                       kvm_flush_remote_tlbs(kvm);
+
                cond_resched_lock(&kvm->mmu_lock);
                tdp_iter_refresh_walk(iter);
                return true;
@@ -522,7 +506,7 @@ static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
                tdp_mmu_set_spte(kvm, &iter, 0);
 
                flush_needed = !can_yield ||
-                              !tdp_mmu_iter_flush_cond_resched(kvm, &iter);
+                              !tdp_mmu_iter_cond_resched(kvm, &iter, true);
        }
        return flush_needed;
 }
@@ -894,7 +878,7 @@ static bool wrprot_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
                tdp_mmu_set_spte_no_dirty_log(kvm, &iter, new_spte);
                spte_set = true;
 
-               tdp_mmu_iter_cond_resched(kvm, &iter);
+               tdp_mmu_iter_cond_resched(kvm, &iter, false);
        }
        return spte_set;
 }
@@ -953,7 +937,7 @@ static bool clear_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
                tdp_mmu_set_spte_no_dirty_log(kvm, &iter, new_spte);
                spte_set = true;
 
-               tdp_mmu_iter_cond_resched(kvm, &iter);
+               tdp_mmu_iter_cond_resched(kvm, &iter, false);
        }
        return spte_set;
 }
@@ -1069,7 +1053,7 @@ static bool set_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
                tdp_mmu_set_spte(kvm, &iter, new_spte);
                spte_set = true;
 
-               tdp_mmu_iter_cond_resched(kvm, &iter);
+               tdp_mmu_iter_cond_resched(kvm, &iter, false);
        }
 
        return spte_set;
@@ -1121,7 +1105,7 @@ static void zap_collapsible_spte_range(struct kvm *kvm,
 
                tdp_mmu_set_spte(kvm, &iter, 0);
 
-               spte_set = !tdp_mmu_iter_flush_cond_resched(kvm, &iter);
+               spte_set = !tdp_mmu_iter_cond_resched(kvm, &iter, true);
        }
 
        if (spte_set)