Merge tag 'kvm-x86-hyperv-6.8' of https://github.com/kvm-x86/linux into HEAD

KVM x86 Hyper-V changes for 6.8:

 - Guard KVM-on-HyperV's range-based TLB flush hooks with an #ifdef on
   CONFIG_HYPERV as a minor optimization, and to self-document the code.

 - Add CONFIG_KVM_HYPERV to allow disabling KVM support for HyperV "emulation"
   at build time.

4 files changed, 30 insertions, 21 deletions

diff --git a/arch/x86/kvm/svm/hyperv.h b/arch/x86/kvm/svm/hyperv.h
index 02f4784b5d44..d3f8bfc05832 100644
--- a/arch/x86/kvm/svm/hyperv.h
+++ b/arch/x86/kvm/svm/hyperv.h
@@ -11,6 +11,7 @@
 #include "../hyperv.h"
 #include "svm.h"
 
+#ifdef CONFIG_KVM_HYPERV
 static inline void nested_svm_hv_update_vm_vp_ids(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
@@ -41,5 +42,13 @@ static inline bool nested_svm_l2_tlb_flush_enabled(struct kvm_vcpu *vcpu)
 }
 
 void svm_hv_inject_synthetic_vmexit_post_tlb_flush(struct kvm_vcpu *vcpu);
+#else /* CONFIG_KVM_HYPERV */
+static inline void nested_svm_hv_update_vm_vp_ids(struct kvm_vcpu *vcpu) {}
+static inline bool nested_svm_l2_tlb_flush_enabled(struct kvm_vcpu *vcpu)
+{
+	return false;
+}
+static inline void svm_hv_inject_synthetic_vmexit_post_tlb_flush(struct kvm_vcpu *vcpu) {}
+#endif /* CONFIG_KVM_HYPERV */
 
 #endif /* __ARCH_X86_KVM_SVM_HYPERV_H__ */
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 3fea8c47679e..20212aac050b 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -187,7 +187,6 @@ void recalc_intercepts(struct vcpu_svm *svm)
  */
 static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
 {
-	struct hv_vmcb_enlightenments *hve = &svm->nested.ctl.hv_enlightenments;
 	int i;
 
 	/*
@@ -198,11 +197,16 @@ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
 	 * - Nested hypervisor (L1) is using Hyper-V emulation interface and
 	 * tells KVM (L0) there were no changes in MSR bitmap for L2.
 	 */
-	if (!svm->nested.force_msr_bitmap_recalc &&
-	    kvm_hv_hypercall_enabled(&svm->vcpu) &&
-	    hve->hv_enlightenments_control.msr_bitmap &&
-	    (svm->nested.ctl.clean & BIT(HV_VMCB_NESTED_ENLIGHTENMENTS)))
-		goto set_msrpm_base_pa;
+#ifdef CONFIG_KVM_HYPERV
+	if (!svm->nested.force_msr_bitmap_recalc) {
+		struct hv_vmcb_enlightenments *hve = &svm->nested.ctl.hv_enlightenments;
+
+		if (kvm_hv_hypercall_enabled(&svm->vcpu) &&
+		    hve->hv_enlightenments_control.msr_bitmap &&
+		    (svm->nested.ctl.clean & BIT(HV_VMCB_NESTED_ENLIGHTENMENTS)))
+			goto set_msrpm_base_pa;
+	}
+#endif
 
 	if (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT)))
 		return true;
@@ -230,7 +234,9 @@ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
 
 	svm->nested.force_msr_bitmap_recalc = false;
 
+#ifdef CONFIG_KVM_HYPERV
 set_msrpm_base_pa:
+#endif
 	svm->vmcb->control.msrpm_base_pa = __sme_set(__pa(svm->nested.msrpm));
 
 	return true;
@@ -378,12 +384,14 @@ void __nested_copy_vmcb_control_to_cache(struct kvm_vcpu *vcpu,
 	to->msrpm_base_pa &= ~0x0fffULL;
 	to->iopm_base_pa  &= ~0x0fffULL;
 
+#ifdef CONFIG_KVM_HYPERV
 	/* Hyper-V extensions (Enlightened VMCB) */
 	if (kvm_hv_hypercall_enabled(vcpu)) {
 		to->clean = from->clean;
 		memcpy(&to->hv_enlightenments, &from->hv_enlightenments,
 		       sizeof(to->hv_enlightenments));
 	}
+#endif
 }
 
 void nested_copy_vmcb_control_to_cache(struct vcpu_svm *svm,
@@ -487,14 +495,8 @@ static void nested_save_pending_event_to_vmcb12(struct vcpu_svm *svm,
 
 static void nested_svm_transition_tlb_flush(struct kvm_vcpu *vcpu)
 {
-	/*
-	 * KVM_REQ_HV_TLB_FLUSH flushes entries from either L1's VP_ID or
-	 * L2's VP_ID upon request from the guest. Make sure we check for
-	 * pending entries in the right FIFO upon L1/L2 transition as these
-	 * requests are put by other vCPUs asynchronously.
-	 */
-	if (to_hv_vcpu(vcpu) && npt_enabled)
-		kvm_make_request(KVM_REQ_HV_TLB_FLUSH, vcpu);
+	/* Handle pending Hyper-V TLB flush requests */
+	kvm_hv_nested_transtion_tlb_flush(vcpu, npt_enabled);
 
 	/*
 	 * TODO: optimize unconditional TLB flush/MMU sync.  A partial list of
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index c409f934c377..8ef95139cd24 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -148,7 +148,9 @@ struct vmcb_ctrl_area_cached {
 	u64 virt_ext;
 	u32 clean;
 	union {
+#if IS_ENABLED(CONFIG_HYPERV) || IS_ENABLED(CONFIG_KVM_HYPERV)
 		struct hv_vmcb_enlightenments hv_enlightenments;
+#endif
 		u8 reserved_sw[32];
 	};
 };
diff --git a/arch/x86/kvm/svm/svm_onhyperv.c b/arch/x86/kvm/svm/svm_onhyperv.c
index 7af8422d3382..3971b3ea5d04 100644
--- a/arch/x86/kvm/svm/svm_onhyperv.c
+++ b/arch/x86/kvm/svm/svm_onhyperv.c
@@ -18,18 +18,14 @@
 int svm_hv_enable_l2_tlb_flush(struct kvm_vcpu *vcpu)
 {
 	struct hv_vmcb_enlightenments *hve;
-	struct hv_partition_assist_pg **p_hv_pa_pg =
-			&to_kvm_hv(vcpu->kvm)->hv_pa_pg;
+	hpa_t partition_assist_page = hv_get_partition_assist_page(vcpu);
 
-	if (!*p_hv_pa_pg)
-		*p_hv_pa_pg = kzalloc(PAGE_SIZE, GFP_KERNEL);
-
-	if (!*p_hv_pa_pg)
+	if (partition_assist_page == INVALID_PAGE)
 		return -ENOMEM;
 
 	hve = &to_svm(vcpu)->vmcb->control.hv_enlightenments;
 
-	hve->partition_assist_page = __pa(*p_hv_pa_pg);
+	hve->partition_assist_page = partition_assist_page;
 	hve->hv_vm_id = (unsigned long)vcpu->kvm;
 	if (!hve->hv_enlightenments_control.nested_flush_hypercall) {
 		hve->hv_enlightenments_control.nested_flush_hypercall = 1;