Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "Miscellaneous bugfixes.

  The main interesting one is a NULL pointer dereference reported by
  syzkaller ("KVM: x86: Immediately reset the MMU context when the SMM
  flag is cleared")"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: selftests: Fix kvm_check_cap() assertion
  KVM: x86/mmu: Calculate and check "full" mmu_role for nested MMU
  KVM: X86: Fix x86_emulator slab cache leak
  KVM: SVM: Call SEV Guest Decommission if ASID binding fails
  KVM: x86: Immediately reset the MMU context when the SMM flag is cleared
  KVM: x86: Fix fall-through warnings for Clang
  KVM: SVM: fix doc warnings
  KVM: selftests: Fix compiling errors when initializing the static structure
  kvm: LAPIC: Restore guard to prevent illegal APIC register access

7 files changed, 53 insertions, 10 deletions

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 9a48f138832d..b4da665bb892 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -655,6 +655,7 @@ static int __do_cpuid_func_emulated(struct kvm_cpuid_array *array, u32 func)
 		if (kvm_cpu_cap_has(X86_FEATURE_RDTSCP))
 			entry->ecx = F(RDPID);
 		++array->nent;
+		break;
 	default:
 		break;
 	}
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 6d72d8f43310..17fa4ab1b834 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1410,6 +1410,9 @@ int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len,
 	if (!apic_x2apic_mode(apic))
 		valid_reg_mask |= APIC_REG_MASK(APIC_ARBPRI);
 
+	if (alignment + len > 4)
+		return 1;
+
 	if (offset > 0x3f0 || !(valid_reg_mask & APIC_REG_MASK(offset)))
 		return 1;
 
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 0144c40d09c7..8d5876dfc6b7 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4739,9 +4739,33 @@ static void init_kvm_softmmu(struct kvm_vcpu *vcpu)
 	context->inject_page_fault = kvm_inject_page_fault;
 }
 
+static union kvm_mmu_role kvm_calc_nested_mmu_role(struct kvm_vcpu *vcpu)
+{
+	union kvm_mmu_role role = kvm_calc_shadow_root_page_role_common(vcpu, false);
+
+	/*
+	 * Nested MMUs are used only for walking L2's gva->gpa, they never have
+	 * shadow pages of their own and so "direct" has no meaning.   Set it
+	 * to "true" to try to detect bogus usage of the nested MMU.
+	 */
+	role.base.direct = true;
+
+	if (!is_paging(vcpu))
+		role.base.level = 0;
+	else if (is_long_mode(vcpu))
+		role.base.level = is_la57_mode(vcpu) ? PT64_ROOT_5LEVEL :
+						       PT64_ROOT_4LEVEL;
+	else if (is_pae(vcpu))
+		role.base.level = PT32E_ROOT_LEVEL;
+	else
+		role.base.level = PT32_ROOT_LEVEL;
+
+	return role;
+}
+
 static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu)
 {
-	union kvm_mmu_role new_role = kvm_calc_mmu_role_common(vcpu, false);
+	union kvm_mmu_role new_role = kvm_calc_nested_mmu_role(vcpu);
 	struct kvm_mmu *g_context = &vcpu->arch.nested_mmu;
 
 	if (new_role.as_u64 == g_context->mmu_role.as_u64)
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index 0e62e6a2438c..5e7e920113f3 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -221,7 +221,7 @@ static u64 *avic_get_physical_id_entry(struct kvm_vcpu *vcpu,
 	return &avic_physical_id_table[index];
 }
 
-/**
+/*
  * Note:
  * AVIC hardware walks the nested page table to check permissions,
  * but does not use the SPA address specified in the leaf page
@@ -764,7 +764,7 @@ out:
 	return ret;
 }
 
-/**
+/*
  * Note:
  * The HW cannot support posting multicast/broadcast
  * interrupts to a vCPU. So, we still use legacy interrupt
@@ -1005,7 +1005,7 @@ void avic_vcpu_put(struct kvm_vcpu *vcpu)
 	WRITE_ONCE(*(svm->avic_physical_id_cache), entry);
 }
 
-/**
+/*
  * This function is called during VCPU halt/unhalt.
  */
 static void avic_set_running(struct kvm_vcpu *vcpu, bool is_run)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index e0ce5da97fc2..8d36f0c73071 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -199,9 +199,19 @@ static void sev_asid_free(struct kvm_sev_info *sev)
 	sev->misc_cg = NULL;
 }
 
-static void sev_unbind_asid(struct kvm *kvm, unsigned int handle)
+static void sev_decommission(unsigned int handle)
 {
 	struct sev_data_decommission decommission;
+
+	if (!handle)
+		return;
+
+	decommission.handle = handle;
+	sev_guest_decommission(&decommission, NULL);
+}
+
+static void sev_unbind_asid(struct kvm *kvm, unsigned int handle)
+{
 	struct sev_data_deactivate deactivate;
 
 	if (!handle)
@@ -214,9 +224,7 @@ static void sev_unbind_asid(struct kvm *kvm, unsigned int handle)
 	sev_guest_deactivate(&deactivate, NULL);
 	up_read(&sev_deactivate_lock);
 
-	/* decommission handle */
-	decommission.handle = handle;
-	sev_guest_decommission(&decommission, NULL);
+	sev_decommission(handle);
 }
 
 static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
@@ -341,8 +349,10 @@ static int sev_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
 
 	/* Bind ASID to this guest */
 	ret = sev_bind_asid(kvm, start.handle, error);
-	if (ret)
+	if (ret) {
+		sev_decommission(start.handle);
 		goto e_free_session;
+	}
 
 	/* return handle to userspace */
 	params.handle = start.handle;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 50b42d7a8a11..c2a779b688e6 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6247,6 +6247,7 @@ void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu)
 	switch (kvm_get_apic_mode(vcpu)) {
 	case LAPIC_MODE_INVALID:
 		WARN_ONCE(true, "Invalid local APIC state");
+		break;
 	case LAPIC_MODE_DISABLED:
 		break;
 	case LAPIC_MODE_XAPIC:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6d3955a6a763..e0f4a46649d7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7106,7 +7106,10 @@ static unsigned emulator_get_hflags(struct x86_emulate_ctxt *ctxt)
 
 static void emulator_set_hflags(struct x86_emulate_ctxt *ctxt, unsigned emul_flags)
 {
-	emul_to_vcpu(ctxt)->arch.hflags = emul_flags;
+	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
+
+	vcpu->arch.hflags = emul_flags;
+	kvm_mmu_reset_context(vcpu);
 }
 
 static int emulator_pre_leave_smm(struct x86_emulate_ctxt *ctxt,
@@ -8258,6 +8261,7 @@ void kvm_arch_exit(void)
 	kvm_x86_ops.hardware_enable = NULL;
 	kvm_mmu_module_exit();
 	free_percpu(user_return_msrs);
+	kmem_cache_destroy(x86_emulator_cache);
 	kmem_cache_destroy(x86_fpu_cache);
 #ifdef CONFIG_KVM_XEN
 	static_key_deferred_flush(&kvm_xen_enabled);