Merge tag 'kvm-x86-mmu-6.7' of https://github.com/kvm-x86/linux into HEAD

[thirdparty/kernel/stable.git] / arch / x86 / kvm / x86.c

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4937aa50d40b069d0edf3730bc32d849b1945111..3584363b8fa6a50c509009eb9735bba8e442d552 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -962,7 +962,7 @@ void kvm_post_set_cr0(struct kvm_vcpu *vcpu, unsigned long old_cr0, unsigned lon
                kvm_mmu_reset_context(vcpu);
 
        if (((cr0 ^ old_cr0) & X86_CR0_CD) &&
-           kvm_arch_has_noncoherent_dma(vcpu->kvm) &&
+           kvm_mmu_honors_guest_mtrrs(vcpu->kvm) &&
            !kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_CD_NW_CLEARED))
                kvm_zap_gfn_range(vcpu->kvm, 0, ~0ULL);
 }
@@ -13313,15 +13313,30 @@ bool noinstr kvm_arch_has_assigned_device(struct kvm *kvm)
 }
 EXPORT_SYMBOL_GPL(kvm_arch_has_assigned_device);
 
+static void kvm_noncoherent_dma_assignment_start_or_stop(struct kvm *kvm)
+{
+       /*
+        * Non-coherent DMA assignment and de-assignment will affect
+        * whether KVM honors guest MTRRs and cause changes in memtypes
+        * in TDP.
+        * So, pass %true unconditionally to indicate non-coherent DMA was,
+        * or will be involved, and that zapping SPTEs might be necessary.
+        */
+       if (__kvm_mmu_honors_guest_mtrrs(true))
+               kvm_zap_gfn_range(kvm, gpa_to_gfn(0), gpa_to_gfn(~0ULL));
+}
+
 void kvm_arch_register_noncoherent_dma(struct kvm *kvm)
 {
-       atomic_inc(&kvm->arch.noncoherent_dma_count);
+       if (atomic_inc_return(&kvm->arch.noncoherent_dma_count) == 1)
+               kvm_noncoherent_dma_assignment_start_or_stop(kvm);
 }
 EXPORT_SYMBOL_GPL(kvm_arch_register_noncoherent_dma);
 
 void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm)
 {
-       atomic_dec(&kvm->arch.noncoherent_dma_count);
+       if (!atomic_dec_return(&kvm->arch.noncoherent_dma_count))
+               kvm_noncoherent_dma_assignment_start_or_stop(kvm);
 }
 EXPORT_SYMBOL_GPL(kvm_arch_unregister_noncoherent_dma);