diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
index b1eb46e26b2e..36a8786db291 100644
--- a/arch/x86/kvm/kvm_cache_regs.h
+++ b/arch/x86/kvm/kvm_cache_regs.h
@@ -43,6 +43,18 @@ BUILD_KVM_GPR_ACCESSORS(r14, R14)
 BUILD_KVM_GPR_ACCESSORS(r15, R15)
 #endif
 
+/*
+ * Using the register cache from interrupt context is generally not allowed, as
+ * caching a register and marking it available/dirty can't be done atomically,
+ * i.e. accesses from interrupt context may clobber state or read stale data if
+ * the vCPU task is in the process of updating the cache.  The exception is if
+ * KVM is handling a PMI IRQ/NMI VM-Exit, as that bound code sequence doesn't
+ * touch the cache, it runs after the cache is reset (post VM-Exit), and PMIs
+ * need to access several registers that are cacheable.
+ */
+#define kvm_assert_register_caching_allowed(vcpu)		\
+	lockdep_assert_once(in_task() || kvm_arch_pmi_in_guest(vcpu))
+
 /*
  * avail  dirty
  * 0	  0	  register in VMCS/VMCB
@@ -53,24 +65,28 @@ BUILD_KVM_GPR_ACCESSORS(r15, R15)
 static inline bool kvm_register_is_available(struct kvm_vcpu *vcpu,
 					     enum kvm_reg reg)
 {
+	kvm_assert_register_caching_allowed(vcpu);
 	return test_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
 }
 
 static inline bool kvm_register_is_dirty(struct kvm_vcpu *vcpu,
 					 enum kvm_reg reg)
 {
+	kvm_assert_register_caching_allowed(vcpu);
 	return test_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
 }
 
 static inline void kvm_register_mark_available(struct kvm_vcpu *vcpu,
 					       enum kvm_reg reg)
 {
+	kvm_assert_register_caching_allowed(vcpu);
 	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
 }
 
 static inline void kvm_register_mark_dirty(struct kvm_vcpu *vcpu,
 					   enum kvm_reg reg)
 {
+	kvm_assert_register_caching_allowed(vcpu);
 	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
 	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
 }
@@ -84,6 +100,7 @@ static inline void kvm_register_mark_dirty(struct kvm_vcpu *vcpu,
 static __always_inline bool kvm_register_test_and_mark_available(struct kvm_vcpu *vcpu,
 								 enum kvm_reg reg)
 {
+	kvm_assert_register_caching_allowed(vcpu);
 	return arch___test_and_set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
 }