diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 52bbbb553ce1..59469495c8d3 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -8553,6 +8553,20 @@ KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMM   By default, KVM relaxes the consisten
                                            bit to be cleared.  Note that the vmcs02
                                            bit is still completely controlled by the
                                            host, regardless of the quirk setting.
+
+KVM_X86_QUIRK_NESTED_SVM_SHARED_PAT        By default, KVM for nested SVM guests
+                                           shares the IA32_PAT MSR between L1 and
+                                           L2. This is legacy behavior and does
+                                           not match the AMD architecture
+                                           specification. When this quirk is
+                                           disabled and nested paging (NPT) is
+                                           enabled for L2, KVM correctly
+                                           virtualizes a separate guest PAT
+                                           register for L2, using the g_pat
+                                           field in the VMCB. When NPT is
+                                           disabled for L2, L1 and L2 continue
+                                           to share the IA32_PAT MSR regardless
+                                           of the quirk setting.
 ========================================   ================================================
 
 7.32 KVM_CAP_MAX_VCPU_ID
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 8a53ca619570..ef353daeacc9 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -2550,7 +2550,8 @@ int memslot_rmap_alloc(struct kvm_memory_slot *slot, unsigned long npages);
 	 KVM_X86_QUIRK_SLOT_ZAP_ALL |		\
 	 KVM_X86_QUIRK_STUFF_FEATURE_MSRS |	\
 	 KVM_X86_QUIRK_IGNORE_GUEST_PAT |	\
-	 KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMM)
+	 KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMM |	\
+	 KVM_X86_QUIRK_NESTED_SVM_SHARED_PAT)
 
 #define KVM_X86_CONDITIONAL_QUIRKS		\
 	(KVM_X86_QUIRK_CD_NW_CLEARED |		\
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index 5f2b30d0405c..3ada2fa9ca86 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -477,6 +477,7 @@ struct kvm_sync_regs {
 #define KVM_X86_QUIRK_STUFF_FEATURE_MSRS	(1 << 8)
 #define KVM_X86_QUIRK_IGNORE_GUEST_PAT		(1 << 9)
 #define KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMM (1 << 10)
+#define KVM_X86_QUIRK_NESTED_SVM_SHARED_PAT	(1 << 11)
 
 #define KVM_STATE_NESTED_FORMAT_VMX	0
 #define KVM_STATE_NESTED_FORMAT_SVM	1
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 19b80ef56e2b..9fd2232aa8d1 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -24,6 +24,7 @@
 
 #include "cpuid.h"
 #include "kvm_cache_regs.h"
+#include "x86.h"
 
 /*
  * Helpers to convert to/from physical addresses for pages whose address is
@@ -641,6 +642,16 @@ static inline bool nested_npt_enabled(struct vcpu_svm *svm)
 	return svm->nested.ctl.misc_ctl & SVM_MISC_ENABLE_NP;
 }
 
+static inline bool l2_has_separate_pat(struct kvm_vcpu *vcpu)
+{
+	/*
+	 * If KVM_X86_QUIRK_NESTED_SVM_SHARED_PAT is disabled while a vCPU
+	 * is running, the L2 IA32_PAT semantics for that vCPU are undefined.
+	 */
+	return nested_npt_enabled(to_svm(vcpu)) &&
+	       !kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_NESTED_SVM_SHARED_PAT);
+}
+
 static inline bool nested_vnmi_enabled(struct vcpu_svm *svm)
 {
 	return guest_cpu_cap_has(&svm->vcpu, X86_FEATURE_VNMI) &&