KVM: MMU: mark page dirty in make_spte

This simplifies set_spte, which we want to remove, and unifies code
between the shadow MMU and the TDP MMU.  The warning will be added
back later to make_spte as well.

There is a small disadvantage in the TDP MMU; it may unnecessarily mark
a page as dirty twice if two vCPUs end up mapping the same page twice.
However, this is a very small cost for a case that is already rare.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 8b6dc27..5a75795 100644 (file)
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -2688,9 +2688,6 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
        ret = make_spte(vcpu, pte_access, level, gfn, pfn, *sptep, speculative,
                        can_unsync, host_writable, sp_ad_disabled(sp), &spte);
 
-       if (spte & PT_WRITABLE_MASK)
-               kvm_vcpu_mark_page_dirty(vcpu, gfn);
-
        if (*sptep == spte)
                ret |= SET_SPTE_SPURIOUS;
        else if (mmu_spte_update(sptep, spte))

diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c
index a33c581..66be945 100644 (file)
--- a/arch/x86/kvm/mmu/spte.c
+++ b/arch/x86/kvm/mmu/spte.c
@@ -179,6 +179,9 @@ out:
                  "spte = 0x%llx, level = %d, rsvd bits = 0x%llx", spte, level,
                  get_rsvd_bits(&vcpu->arch.mmu->shadow_zero_check, spte, level));
 
+       if (spte & PT_WRITABLE_MASK)
+               kvm_vcpu_mark_page_dirty(vcpu, gfn);
+
        *new_spte = spte;
        return ret;
 }

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 3bf85a8..b41b6f5 100644 (file)
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -542,26 +542,7 @@ static inline bool tdp_mmu_map_set_spte_atomic(struct kvm_vcpu *vcpu,
                                               struct tdp_iter *iter,
                                               u64 new_spte)
 {
-       struct kvm *kvm = vcpu->kvm;
-
-       if (!tdp_mmu_set_spte_atomic_no_dirty_log(kvm, iter, new_spte))
-               return false;
-
-       /*
-        * Use kvm_vcpu_gfn_to_memslot() instead of going through
-        * handle_changed_spte_dirty_log() to leverage vcpu->last_used_slot.
-        */
-       if (is_writable_pte(new_spte)) {
-               struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, iter->gfn);
-
-               if (slot && kvm_slot_dirty_track_enabled(slot)) {
-                       /* Enforced by kvm_mmu_hugepage_adjust. */
-                       WARN_ON_ONCE(iter->level > PG_LEVEL_4K);
-                       mark_page_dirty_in_slot(kvm, slot, iter->gfn);
-               }
-       }
-
-       return true;
+       return tdp_mmu_set_spte_atomic_no_dirty_log(vcpu->kvm, iter, new_spte);
 }
 
 static inline bool tdp_mmu_zap_spte_atomic(struct kvm *kvm,