1 files changed, 87 insertions, 47 deletions

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ba66c171d951..0dbf94eb954f 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1363,6 +1363,11 @@ void vmx_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
 		vmx->emulation_required = vmx_emulation_required(vcpu);
 }
 
+static bool vmx_get_if_flag(struct kvm_vcpu *vcpu)
+{
+	return vmx_get_rflags(vcpu) & X86_EFLAGS_IF;
+}
+
 u32 vmx_get_interrupt_shadow(struct kvm_vcpu *vcpu)
 {
 	u32 interruptibility = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);
@@ -2646,15 +2651,6 @@ int alloc_loaded_vmcs(struct loaded_vmcs *loaded_vmcs)
 		if (!loaded_vmcs->msr_bitmap)
 			goto out_vmcs;
 		memset(loaded_vmcs->msr_bitmap, 0xff, PAGE_SIZE);
-
-		if (IS_ENABLED(CONFIG_HYPERV) &&
-		    static_branch_unlikely(&enable_evmcs) &&
-		    (ms_hyperv.nested_features & HV_X64_NESTED_MSR_BITMAP)) {
-			struct hv_enlightened_vmcs *evmcs =
-				(struct hv_enlightened_vmcs *)loaded_vmcs->vmcs;
-
-			evmcs->hv_enlightenments_control.msr_bitmap = 1;
-		}
 	}
 
 	memset(&loaded_vmcs->host_state, 0, sizeof(struct vmcs_host_state));
@@ -2918,6 +2914,13 @@ static void vmx_flush_tlb_all(struct kvm_vcpu *vcpu)
 	}
 }
 
+static inline int vmx_get_current_vpid(struct kvm_vcpu *vcpu)
+{
+	if (is_guest_mode(vcpu))
+		return nested_get_vpid02(vcpu);
+	return to_vmx(vcpu)->vpid;
+}
+
 static void vmx_flush_tlb_current(struct kvm_vcpu *vcpu)
 {
 	struct kvm_mmu *mmu = vcpu->arch.mmu;
@@ -2930,31 +2933,29 @@ static void vmx_flush_tlb_current(struct kvm_vcpu *vcpu)
 	if (enable_ept)
 		ept_sync_context(construct_eptp(vcpu, root_hpa,
 						mmu->shadow_root_level));
-	else if (!is_guest_mode(vcpu))
-		vpid_sync_context(to_vmx(vcpu)->vpid);
 	else
-		vpid_sync_context(nested_get_vpid02(vcpu));
+		vpid_sync_context(vmx_get_current_vpid(vcpu));
 }
 
 static void vmx_flush_tlb_gva(struct kvm_vcpu *vcpu, gva_t addr)
 {
 	/*
-	 * vpid_sync_vcpu_addr() is a nop if vmx->vpid==0, see the comment in
+	 * vpid_sync_vcpu_addr() is a nop if vpid==0, see the comment in
 	 * vmx_flush_tlb_guest() for an explanation of why this is ok.
 	 */
-	vpid_sync_vcpu_addr(to_vmx(vcpu)->vpid, addr);
+	vpid_sync_vcpu_addr(vmx_get_current_vpid(vcpu), addr);
 }
 
 static void vmx_flush_tlb_guest(struct kvm_vcpu *vcpu)
 {
 	/*
-	 * vpid_sync_context() is a nop if vmx->vpid==0, e.g. if enable_vpid==0
-	 * or a vpid couldn't be allocated for this vCPU.  VM-Enter and VM-Exit
-	 * are required to flush GVA->{G,H}PA mappings from the TLB if vpid is
+	 * vpid_sync_context() is a nop if vpid==0, e.g. if enable_vpid==0 or a
+	 * vpid couldn't be allocated for this vCPU.  VM-Enter and VM-Exit are
+	 * required to flush GVA->{G,H}PA mappings from the TLB if vpid is
 	 * disabled (VM-Enter with vpid enabled and vpid==0 is disallowed),
 	 * i.e. no explicit INVVPID is necessary.
 	 */
-	vpid_sync_context(to_vmx(vcpu)->vpid);
+	vpid_sync_context(vmx_get_current_vpid(vcpu));
 }
 
 void vmx_ept_load_pdptrs(struct kvm_vcpu *vcpu)
@@ -3963,8 +3964,7 @@ static int vmx_deliver_posted_interrupt(struct kvm_vcpu *vcpu, int vector)
 	if (pi_test_and_set_on(&vmx->pi_desc))
 		return 0;
 
-	if (vcpu != kvm_get_running_vcpu() &&
-	    !kvm_vcpu_trigger_posted_interrupt(vcpu, false))
+	if (!kvm_vcpu_trigger_posted_interrupt(vcpu, false))
 		kvm_vcpu_kick(vcpu);
 
 	return 0;
@@ -5881,18 +5881,14 @@ static int __vmx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
 		vmx_flush_pml_buffer(vcpu);
 
 	/*
-	 * We should never reach this point with a pending nested VM-Enter, and
-	 * more specifically emulation of L2 due to invalid guest state (see
-	 * below) should never happen as that means we incorrectly allowed a
-	 * nested VM-Enter with an invalid vmcs12.
+	 * KVM should never reach this point with a pending nested VM-Enter.
+	 * More specifically, short-circuiting VM-Entry to emulate L2 due to
+	 * invalid guest state should never happen as that means KVM knowingly
+	 * allowed a nested VM-Enter with an invalid vmcs12.  More below.
 	 */
 	if (KVM_BUG_ON(vmx->nested.nested_run_pending, vcpu->kvm))
 		return -EIO;
 
-	/* If guest state is invalid, start emulating */
-	if (vmx->emulation_required)
-		return handle_invalid_guest_state(vcpu);
-
 	if (is_guest_mode(vcpu)) {
 		/*
 		 * PML is never enabled when running L2, bail immediately if a
@@ -5914,10 +5910,30 @@ static int __vmx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
 		 */
 		nested_mark_vmcs12_pages_dirty(vcpu);
 
+		/*
+		 * Synthesize a triple fault if L2 state is invalid.  In normal
+		 * operation, nested VM-Enter rejects any attempt to enter L2
+		 * with invalid state.  However, those checks are skipped if
+		 * state is being stuffed via RSM or KVM_SET_NESTED_STATE.  If
+		 * L2 state is invalid, it means either L1 modified SMRAM state
+		 * or userspace provided bad state.  Synthesize TRIPLE_FAULT as
+		 * doing so is architecturally allowed in the RSM case, and is
+		 * the least awful solution for the userspace case without
+		 * risking false positives.
+		 */
+		if (vmx->emulation_required) {
+			nested_vmx_vmexit(vcpu, EXIT_REASON_TRIPLE_FAULT, 0, 0);
+			return 1;
+		}
+
 		if (nested_vmx_reflect_vmexit(vcpu))
 			return 1;
 	}
 
+	/* If guest state is invalid, start emulating.  L2 is handled above. */
+	if (vmx->emulation_required)
+		return handle_invalid_guest_state(vcpu);
+
 	if (exit_reason.failed_vmentry) {
 		dump_vmcs(vcpu);
 		vcpu->run->exit_reason = KVM_EXIT_FAIL_ENTRY;
@@ -6262,9 +6278,9 @@ static int vmx_sync_pir_to_irr(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	int max_irr;
-	bool max_irr_updated;
+	bool got_posted_interrupt;
 
-	if (KVM_BUG_ON(!vcpu->arch.apicv_active, vcpu->kvm))
+	if (KVM_BUG_ON(!enable_apicv, vcpu->kvm))
 		return -EIO;
 
 	if (pi_test_on(&vmx->pi_desc)) {
@@ -6274,22 +6290,33 @@ static int vmx_sync_pir_to_irr(struct kvm_vcpu *vcpu)
 		 * But on x86 this is just a compiler barrier anyway.
 		 */
 		smp_mb__after_atomic();
-		max_irr_updated =
+		got_posted_interrupt =
 			kvm_apic_update_irr(vcpu, vmx->pi_desc.pir, &max_irr);
-
-		/*
-		 * If we are running L2 and L1 has a new pending interrupt
-		 * which can be injected, this may cause a vmexit or it may
-		 * be injected into L2.  Either way, this interrupt will be
-		 * processed via KVM_REQ_EVENT, not RVI, because we do not use
-		 * virtual interrupt delivery to inject L1 interrupts into L2.
-		 */
-		if (is_guest_mode(vcpu) && max_irr_updated)
-			kvm_make_request(KVM_REQ_EVENT, vcpu);
 	} else {
 		max_irr = kvm_lapic_find_highest_irr(vcpu);
+		got_posted_interrupt = false;
 	}
-	vmx_hwapic_irr_update(vcpu, max_irr);
+
+	/*
+	 * Newly recognized interrupts are injected via either virtual interrupt
+	 * delivery (RVI) or KVM_REQ_EVENT.  Virtual interrupt delivery is
+	 * disabled in two cases:
+	 *
+	 * 1) If L2 is running and the vCPU has a new pending interrupt.  If L1
+	 * wants to exit on interrupts, KVM_REQ_EVENT is needed to synthesize a
+	 * VM-Exit to L1.  If L1 doesn't want to exit, the interrupt is injected
+	 * into L2, but KVM doesn't use virtual interrupt delivery to inject
+	 * interrupts into L2, and so KVM_REQ_EVENT is again needed.
+	 *
+	 * 2) If APICv is disabled for this vCPU, assigned devices may still
+	 * attempt to post interrupts.  The posted interrupt vector will cause
+	 * a VM-Exit and the subsequent entry will call sync_pir_to_irr.
+	 */
+	if (!is_guest_mode(vcpu) && kvm_vcpu_apicv_active(vcpu))
+		vmx_set_rvi(max_irr);
+	else if (got_posted_interrupt)
+		kvm_make_request(KVM_REQ_EVENT, vcpu);
+
 	return max_irr;
 }
 
@@ -6601,9 +6628,7 @@ static fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu)
 	 * consistency check VM-Exit due to invalid guest state and bail.
 	 */
 	if (unlikely(vmx->emulation_required)) {
-
-		/* We don't emulate invalid state of a nested guest */
-		vmx->fail = is_guest_mode(vcpu);
+		vmx->fail = 0;
 
 		vmx->exit_reason.full = EXIT_REASON_INVALID_STATE;
 		vmx->exit_reason.failed_vmentry = 1;
@@ -6826,6 +6851,19 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu)
 	if (err < 0)
 		goto free_pml;
 
+	/*
+	 * Use Hyper-V 'Enlightened MSR Bitmap' feature when KVM runs as a
+	 * nested (L1) hypervisor and Hyper-V in L0 supports it. Enable the
+	 * feature only for vmcs01, KVM currently isn't equipped to realize any
+	 * performance benefits from enabling it for vmcs02.
+	 */
+	if (IS_ENABLED(CONFIG_HYPERV) && static_branch_unlikely(&enable_evmcs) &&
+	    (ms_hyperv.nested_features & HV_X64_NESTED_MSR_BITMAP)) {
+		struct hv_enlightened_vmcs *evmcs = (void *)vmx->vmcs01.vmcs;
+
+		evmcs->hv_enlightenments_control.msr_bitmap = 1;
+	}
+
 	/* The MSR bitmap starts with all ones */
 	bitmap_fill(vmx->shadow_msr_intercept.read, MAX_POSSIBLE_PASSTHROUGH_MSRS);
 	bitmap_fill(vmx->shadow_msr_intercept.write, MAX_POSSIBLE_PASSTHROUGH_MSRS);
@@ -7509,6 +7547,7 @@ static void hardware_unsetup(void)
 static bool vmx_check_apicv_inhibit_reasons(ulong bit)
 {
 	ulong supported = BIT(APICV_INHIBIT_REASON_DISABLE) |
+			  BIT(APICV_INHIBIT_REASON_ABSENT) |
 			  BIT(APICV_INHIBIT_REASON_HYPERV) |
 			  BIT(APICV_INHIBIT_REASON_BLOCKIRQ);
 
@@ -7558,6 +7597,7 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
 	.cache_reg = vmx_cache_reg,
 	.get_rflags = vmx_get_rflags,
 	.set_rflags = vmx_set_rflags,
+	.get_if_flag = vmx_get_if_flag,
 
 	.tlb_flush_all = vmx_flush_tlb_all,
 	.tlb_flush_current = vmx_flush_tlb_current,
@@ -7761,10 +7801,10 @@ static __init int hardware_setup(void)
 		ple_window_shrink = 0;
 	}
 
-	if (!cpu_has_vmx_apicv()) {
+	if (!cpu_has_vmx_apicv())
 		enable_apicv = 0;
+	if (!enable_apicv)
 		vmx_x86_ops.sync_pir_to_irr = NULL;
-	}
 
 	if (cpu_has_vmx_tsc_scaling()) {
 		kvm_has_tsc_control = true;