KVM fixes for v4.13-rc2

A bunch of small fixes for x86.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Radim Krčmář:
 "A bunch of small fixes for x86"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm: x86: hyperv: avoid livelock in oneshot SynIC timers
  KVM: VMX: Fix invalid guest state detection after task-switch emulation
  x86: add MULTIUSER dependency for KVM
  KVM: nVMX: Disallow VM-entry in MOV-SS shadow
  KVM: nVMX: track NMI blocking state separately for each VMCS
  KVM: x86: masking out upper bits

arch/x86/kvm/Kconfig

@@ -22,7 +22,7 @@ config KVM
 	depends on HAVE_KVM
 	depends on HIGH_RES_TIMERS
 	# for TASKSTATS/TASK_DELAY_ACCT:
-	depends on NET
+	depends on NET && MULTIUSER
 	select PREEMPT_NOTIFIERS
 	select MMU_NOTIFIER
 	select ANON_INODES

arch/x86/kvm/hyperv.c

@@ -649,9 +649,10 @@ void kvm_hv_process_stimers(struct kvm_vcpu *vcpu)
 				}
 
 				if ((stimer->config & HV_STIMER_ENABLE) &&
-				    stimer->count)
+				    stimer->count) {
-					stimer_start(stimer);
+					if (!stimer->msg_pending)
-				else
+						stimer_start(stimer);
+				} else
 					stimer_cleanup(stimer);
 			}
 		}

arch/x86/kvm/vmx.c

@@ -198,7 +198,8 @@ struct loaded_vmcs {
 	struct vmcs *vmcs;
 	struct vmcs *shadow_vmcs;
 	int cpu;
-	int launched;
+	bool launched;
+	bool nmi_known_unmasked;
 	struct list_head loaded_vmcss_on_cpu_link;
 };
 
@@ -2326,6 +2327,11 @@ static void vmx_vcpu_put(struct kvm_vcpu *vcpu)
 	__vmx_load_host_state(to_vmx(vcpu));
 }
 
+static bool emulation_required(struct kvm_vcpu *vcpu)
+{
+	return emulate_invalid_guest_state && !guest_state_valid(vcpu);
+}
+
 static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu);
 
 /*
@@ -2363,6 +2369,8 @@ static unsigned long vmx_get_rflags(struct kvm_vcpu *vcpu)
 
 static void vmx_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
 {
+	unsigned long old_rflags = vmx_get_rflags(vcpu);
+
 	__set_bit(VCPU_EXREG_RFLAGS, (ulong *)&vcpu->arch.regs_avail);
 	to_vmx(vcpu)->rflags = rflags;
 	if (to_vmx(vcpu)->rmode.vm86_active) {
@@ -2370,6 +2378,9 @@ static void vmx_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
 		rflags |= X86_EFLAGS_IOPL | X86_EFLAGS_VM;
 	}
 	vmcs_writel(GUEST_RFLAGS, rflags);
+
+	if ((old_rflags ^ to_vmx(vcpu)->rflags) & X86_EFLAGS_VM)
+		to_vmx(vcpu)->emulation_required = emulation_required(vcpu);
 }
 
 static u32 vmx_get_pkru(struct kvm_vcpu *vcpu)
@@ -3857,11 +3868,6 @@ static __init int alloc_kvm_area(void)
 	return 0;
 }
 
-static bool emulation_required(struct kvm_vcpu *vcpu)
-{
-	return emulate_invalid_guest_state && !guest_state_valid(vcpu);
-}
-
 static void fix_pmode_seg(struct kvm_vcpu *vcpu, int seg,
 		struct kvm_segment *save)
 {
@@ -5510,10 +5516,8 @@ static void vmx_inject_nmi(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 
-	if (!is_guest_mode(vcpu)) {
+	++vcpu->stat.nmi_injections;
-		++vcpu->stat.nmi_injections;
+	vmx->loaded_vmcs->nmi_known_unmasked = false;
-		vmx->nmi_known_unmasked = false;
-	}
 
 	if (vmx->rmode.vm86_active) {
 		if (kvm_inject_realmode_interrupt(vcpu, NMI_VECTOR, 0) != EMULATE_DONE)
@@ -5527,16 +5531,21 @@ static void vmx_inject_nmi(struct kvm_vcpu *vcpu)
 
 static bool vmx_get_nmi_mask(struct kvm_vcpu *vcpu)
 {
-	if (to_vmx(vcpu)->nmi_known_unmasked)
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	bool masked;
+
+	if (vmx->loaded_vmcs->nmi_known_unmasked)
 		return false;
-	return vmcs_read32(GUEST_INTERRUPTIBILITY_INFO)	& GUEST_INTR_STATE_NMI;
+	masked = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & GUEST_INTR_STATE_NMI;
+	vmx->loaded_vmcs->nmi_known_unmasked = !masked;
+	return masked;
 }
 
 static void vmx_set_nmi_mask(struct kvm_vcpu *vcpu, bool masked)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 
-	vmx->nmi_known_unmasked = !masked;
+	vmx->loaded_vmcs->nmi_known_unmasked = !masked;
 	if (masked)
 		vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO,
 			      GUEST_INTR_STATE_NMI);
@@ -8736,7 +8745,7 @@ static void vmx_recover_nmi_blocking(struct vcpu_vmx *vmx)
 
 	idtv_info_valid = vmx->idt_vectoring_info & VECTORING_INFO_VALID_MASK;
 
-	if (vmx->nmi_known_unmasked)
+	if (vmx->loaded_vmcs->nmi_known_unmasked)
 		return;
 	/*
 	 * Can't use vmx->exit_intr_info since we're not sure what
@@ -8760,7 +8769,7 @@ static void vmx_recover_nmi_blocking(struct vcpu_vmx *vmx)
 		vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO,
 			      GUEST_INTR_STATE_NMI);
 	else
-		vmx->nmi_known_unmasked =
+		vmx->loaded_vmcs->nmi_known_unmasked =
 			!(vmcs_read32(GUEST_INTERRUPTIBILITY_INFO)
 			  & GUEST_INTR_STATE_NMI);
 }
@@ -10488,6 +10497,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
 {
 	struct vmcs12 *vmcs12;
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	u32 interrupt_shadow = vmx_get_interrupt_shadow(vcpu);
 	u32 exit_qual;
 	int ret;
 
@@ -10512,6 +10522,12 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
 	 * for misconfigurations which will anyway be caught by the processor
 	 * when using the merged vmcs02.
 	 */
+	if (interrupt_shadow & KVM_X86_SHADOW_INT_MOV_SS) {
+		nested_vmx_failValid(vcpu,
+				     VMXERR_ENTRY_EVENTS_BLOCKED_BY_MOV_SS);
+		goto out;
+	}
+
 	if (vmcs12->launch_state == launch) {
 		nested_vmx_failValid(vcpu,
 			launch ? VMXERR_VMLAUNCH_NONCLEAR_VMCS

arch/x86/kvm/x86.c

@@ -597,8 +597,8 @@ bool pdptrs_changed(struct kvm_vcpu *vcpu)
 		      (unsigned long *)&vcpu->arch.regs_avail))
 		return true;
 
-	gfn = (kvm_read_cr3(vcpu) & ~31u) >> PAGE_SHIFT;
+	gfn = (kvm_read_cr3(vcpu) & ~31ul) >> PAGE_SHIFT;
-	offset = (kvm_read_cr3(vcpu) & ~31u) & (PAGE_SIZE - 1);
+	offset = (kvm_read_cr3(vcpu) & ~31ul) & (PAGE_SIZE - 1);
 	r = kvm_read_nested_guest_page(vcpu, gfn, pdpte, offset, sizeof(pdpte),
 				       PFERR_USER_MASK | PFERR_WRITE_MASK);
 	if (r < 0)