1 files changed, 164 insertions, 45 deletions

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index c4a0a35e02c7..9996a989b52e 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -35,10 +35,11 @@
 #include <asm/virt.h>
 #include <asm/kvm_arm.h>
 #include <asm/kvm_asm.h>
+#include <asm/kvm_emulate.h>
 #include <asm/kvm_mmu.h>
 #include <asm/kvm_nested.h>
 #include <asm/kvm_pkvm.h>
-#include <asm/kvm_emulate.h>
+#include <asm/kvm_ptrauth.h>
 #include <asm/sections.h>
 
 #include <kvm/arm_hypercalls.h>
@@ -69,15 +70,42 @@ int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
 	return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
 }
 
+/*
+ * This functions as an allow-list of protected VM capabilities.
+ * Features not explicitly allowed by this function are denied.
+ */
+static bool pkvm_ext_allowed(struct kvm *kvm, long ext)
+{
+	switch (ext) {
+	case KVM_CAP_IRQCHIP:
+	case KVM_CAP_ARM_PSCI:
+	case KVM_CAP_ARM_PSCI_0_2:
+	case KVM_CAP_NR_VCPUS:
+	case KVM_CAP_MAX_VCPUS:
+	case KVM_CAP_MAX_VCPU_ID:
+	case KVM_CAP_MSI_DEVID:
+	case KVM_CAP_ARM_VM_IPA_SIZE:
+	case KVM_CAP_ARM_PMU_V3:
+	case KVM_CAP_ARM_SVE:
+	case KVM_CAP_ARM_PTRAUTH_ADDRESS:
+	case KVM_CAP_ARM_PTRAUTH_GENERIC:
+		return true;
+	default:
+		return false;
+	}
+}
+
 int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
 			    struct kvm_enable_cap *cap)
 {
-	int r;
-	u64 new_cap;
+	int r = -EINVAL;
 
 	if (cap->flags)
 		return -EINVAL;
 
+	if (kvm_vm_is_protected(kvm) && !pkvm_ext_allowed(kvm, cap->cap))
+		return -EINVAL;
+
 	switch (cap->cap) {
 	case KVM_CAP_ARM_NISV_TO_USER:
 		r = 0;
@@ -86,9 +114,7 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
 		break;
 	case KVM_CAP_ARM_MTE:
 		mutex_lock(&kvm->lock);
-		if (!system_supports_mte() || kvm->created_vcpus) {
-			r = -EINVAL;
-		} else {
+		if (system_supports_mte() && !kvm->created_vcpus) {
 			r = 0;
 			set_bit(KVM_ARCH_FLAG_MTE_ENABLED, &kvm->arch.flags);
 		}
@@ -99,25 +125,22 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
 		set_bit(KVM_ARCH_FLAG_SYSTEM_SUSPEND_ENABLED, &kvm->arch.flags);
 		break;
 	case KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE:
-		new_cap = cap->args[0];
-
 		mutex_lock(&kvm->slots_lock);
 		/*
 		 * To keep things simple, allow changing the chunk
 		 * size only when no memory slots have been created.
 		 */
-		if (!kvm_are_all_memslots_empty(kvm)) {
-			r = -EINVAL;
-		} else if (new_cap && !kvm_is_block_size_supported(new_cap)) {
-			r = -EINVAL;
-		} else {
-			r = 0;
-			kvm->arch.mmu.split_page_chunk_size = new_cap;
+		if (kvm_are_all_memslots_empty(kvm)) {
+			u64 new_cap = cap->args[0];
+
+			if (!new_cap || kvm_is_block_size_supported(new_cap)) {
+				r = 0;
+				kvm->arch.mmu.split_page_chunk_size = new_cap;
+			}
 		}
 		mutex_unlock(&kvm->slots_lock);
 		break;
 	default:
-		r = -EINVAL;
 		break;
 	}
 
@@ -195,6 +218,23 @@ void kvm_arch_create_vm_debugfs(struct kvm *kvm)
 	kvm_sys_regs_create_debugfs(kvm);
 }
 
+static void kvm_destroy_mpidr_data(struct kvm *kvm)
+{
+	struct kvm_mpidr_data *data;
+
+	mutex_lock(&kvm->arch.config_lock);
+
+	data = rcu_dereference_protected(kvm->arch.mpidr_data,
+					 lockdep_is_held(&kvm->arch.config_lock));
+	if (data) {
+		rcu_assign_pointer(kvm->arch.mpidr_data, NULL);
+		synchronize_rcu();
+		kfree(data);
+	}
+
+	mutex_unlock(&kvm->arch.config_lock);
+}
+
 /**
  * kvm_arch_destroy_vm - destroy the VM data structure
  * @kvm:	pointer to the KVM struct
@@ -209,7 +249,8 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 	if (is_protected_kvm_enabled())
 		pkvm_destroy_hyp_vm(kvm);
 
-	kfree(kvm->arch.mpidr_data);
+	kvm_destroy_mpidr_data(kvm);
+
 	kfree(kvm->arch.sysreg_masks);
 	kvm_destroy_vcpus(kvm);
 
@@ -218,9 +259,47 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 	kvm_arm_teardown_hypercalls(kvm);
 }
 
+static bool kvm_has_full_ptr_auth(void)
+{
+	bool apa, gpa, api, gpi, apa3, gpa3;
+	u64 isar1, isar2, val;
+
+	/*
+	 * Check that:
+	 *
+	 * - both Address and Generic auth are implemented for a given
+         *   algorithm (Q5, IMPDEF or Q3)
+	 * - only a single algorithm is implemented.
+	 */
+	if (!system_has_full_ptr_auth())
+		return false;
+
+	isar1 = read_sanitised_ftr_reg(SYS_ID_AA64ISAR1_EL1);
+	isar2 = read_sanitised_ftr_reg(SYS_ID_AA64ISAR2_EL1);
+
+	apa = !!FIELD_GET(ID_AA64ISAR1_EL1_APA_MASK, isar1);
+	val = FIELD_GET(ID_AA64ISAR1_EL1_GPA_MASK, isar1);
+	gpa = (val == ID_AA64ISAR1_EL1_GPA_IMP);
+
+	api = !!FIELD_GET(ID_AA64ISAR1_EL1_API_MASK, isar1);
+	val = FIELD_GET(ID_AA64ISAR1_EL1_GPI_MASK, isar1);
+	gpi = (val == ID_AA64ISAR1_EL1_GPI_IMP);
+
+	apa3 = !!FIELD_GET(ID_AA64ISAR2_EL1_APA3_MASK, isar2);
+	val  = FIELD_GET(ID_AA64ISAR2_EL1_GPA3_MASK, isar2);
+	gpa3 = (val == ID_AA64ISAR2_EL1_GPA3_IMP);
+
+	return (apa == gpa && api == gpi && apa3 == gpa3 &&
+		(apa + api + apa3) == 1);
+}
+
 int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 {
 	int r;
+
+	if (kvm && kvm_vm_is_protected(kvm) && !pkvm_ext_allowed(kvm, ext))
+		return 0;
+
 	switch (ext) {
 	case KVM_CAP_IRQCHIP:
 		r = vgic_present;
@@ -311,7 +390,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 		break;
 	case KVM_CAP_ARM_PTRAUTH_ADDRESS:
 	case KVM_CAP_ARM_PTRAUTH_GENERIC:
-		r = system_has_full_ptr_auth();
+		r = kvm_has_full_ptr_auth();
 		break;
 	case KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE:
 		if (kvm)
@@ -378,12 +457,6 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 
 	vcpu->arch.mmu_page_cache.gfp_zero = __GFP_ZERO;
 
-	/*
-	 * Default value for the FP state, will be overloaded at load
-	 * time if we support FP (pretty likely)
-	 */
-	vcpu->arch.fp_state = FP_STATE_FREE;
-
 	/* Set up the timer */
 	kvm_timer_vcpu_init(vcpu);
 
@@ -395,6 +468,13 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 
 	vcpu->arch.hw_mmu = &vcpu->kvm->arch.mmu;
 
+	/*
+	 * This vCPU may have been created after mpidr_data was initialized.
+	 * Throw out the pre-computed mappings if that is the case which forces
+	 * KVM to fall back to iteratively searching the vCPUs.
+	 */
+	kvm_destroy_mpidr_data(vcpu->kvm);
+
 	err = kvm_vgic_vcpu_init(vcpu);
 	if (err)
 		return err;
@@ -428,6 +508,44 @@ void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu)
 
 }
 
+static void vcpu_set_pauth_traps(struct kvm_vcpu *vcpu)
+{
+	if (vcpu_has_ptrauth(vcpu)) {
+		/*
+		 * Either we're running running an L2 guest, and the API/APK
+		 * bits come from L1's HCR_EL2, or API/APK are both set.
+		 */
+		if (unlikely(vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu))) {
+			u64 val;
+
+			val = __vcpu_sys_reg(vcpu, HCR_EL2);
+			val &= (HCR_API | HCR_APK);
+			vcpu->arch.hcr_el2 &= ~(HCR_API | HCR_APK);
+			vcpu->arch.hcr_el2 |= val;
+		} else {
+			vcpu->arch.hcr_el2 |= (HCR_API | HCR_APK);
+		}
+
+		/*
+		 * Save the host keys if there is any chance for the guest
+		 * to use pauth, as the entry code will reload the guest
+		 * keys in that case.
+		 * Protected mode is the exception to that rule, as the
+		 * entry into the EL2 code eagerly switch back and forth
+		 * between host and hyp keys (and kvm_hyp_ctxt is out of
+		 * reach anyway).
+		 */
+		if (is_protected_kvm_enabled())
+			return;
+
+		if (vcpu->arch.hcr_el2 & (HCR_API | HCR_APK)) {
+			struct kvm_cpu_context *ctxt;
+			ctxt = this_cpu_ptr_hyp_sym(kvm_hyp_ctxt);
+			ptrauth_save_keys(ctxt);
+		}
+	}
+}
+
 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	struct kvm_s2_mmu *mmu;
@@ -466,8 +584,8 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 	else
 		vcpu_set_wfx_traps(vcpu);
 
-	if (vcpu_has_ptrauth(vcpu))
-		vcpu_ptrauth_disable(vcpu);
+	vcpu_set_pauth_traps(vcpu);
+
 	kvm_arch_vcpu_load_debug_state_flags(vcpu);
 
 	if (!cpumask_test_cpu(cpu, vcpu->kvm->arch.supported_cpus))
@@ -580,11 +698,6 @@ unsigned long kvm_arch_vcpu_get_ip(struct kvm_vcpu *vcpu)
 }
 #endif
 
-static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
-{
-	return vcpu_get_flag(vcpu, VCPU_INITIALIZED);
-}
-
 static void kvm_init_mpidr_data(struct kvm *kvm)
 {
 	struct kvm_mpidr_data *data = NULL;
@@ -594,7 +707,8 @@ static void kvm_init_mpidr_data(struct kvm *kvm)
 
 	mutex_lock(&kvm->arch.config_lock);
 
-	if (kvm->arch.mpidr_data || atomic_read(&kvm->online_vcpus) == 1)
+	if (rcu_access_pointer(kvm->arch.mpidr_data) ||
+	    atomic_read(&kvm->online_vcpus) == 1)
 		goto out;
 
 	kvm_for_each_vcpu(c, vcpu, kvm) {
@@ -631,7 +745,7 @@ static void kvm_init_mpidr_data(struct kvm *kvm)
 		data->cmpidr_to_idx[index] = c;
 	}
 
-	kvm->arch.mpidr_data = data;
+	rcu_assign_pointer(kvm->arch.mpidr_data, data);
 out:
 	mutex_unlock(&kvm->arch.config_lock);
 }
@@ -790,9 +904,8 @@ void kvm_vcpu_wfi(struct kvm_vcpu *vcpu)
 	 * doorbells to be signalled, should an interrupt become pending.
 	 */
 	preempt_disable();
-	kvm_vgic_vmcr_sync(vcpu);
 	vcpu_set_flag(vcpu, IN_WFI);
-	vgic_v4_put(vcpu);
+	kvm_vgic_put(vcpu);
 	preempt_enable();
 
 	kvm_vcpu_halt(vcpu);
@@ -800,7 +913,7 @@ void kvm_vcpu_wfi(struct kvm_vcpu *vcpu)
 
 	preempt_disable();
 	vcpu_clear_flag(vcpu, IN_WFI);
-	vgic_v4_load(vcpu);
+	kvm_vgic_load(vcpu);
 	preempt_enable();
 }
 
@@ -980,7 +1093,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 
 	if (run->exit_reason == KVM_EXIT_MMIO) {
 		ret = kvm_handle_mmio_return(vcpu);
-		if (ret)
+		if (ret <= 0)
 			return ret;
 	}
 
@@ -1270,7 +1383,7 @@ static unsigned long system_supported_vcpu_features(void)
 	if (!system_supports_sve())
 		clear_bit(KVM_ARM_VCPU_SVE, &features);
 
-	if (!system_has_full_ptr_auth()) {
+	if (!kvm_has_full_ptr_auth()) {
 		clear_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, &features);
 		clear_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, &features);
 	}
@@ -1971,7 +2084,7 @@ static void cpu_set_hyp_vector(void)
 
 static void cpu_hyp_init_context(void)
 {
-	kvm_init_host_cpu_context(&this_cpu_ptr_hyp_sym(kvm_host_data)->host_ctxt);
+	kvm_init_host_cpu_context(host_data_ptr(host_ctxt));
 
 	if (!is_kernel_in_hyp_mode())
 		cpu_init_hyp_mode();
@@ -2470,21 +2583,27 @@ out_err:
 
 struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr)
 {
-	struct kvm_vcpu *vcpu;
+	struct kvm_vcpu *vcpu = NULL;
+	struct kvm_mpidr_data *data;
 	unsigned long i;
 
 	mpidr &= MPIDR_HWID_BITMASK;
 
-	if (kvm->arch.mpidr_data) {
-		u16 idx = kvm_mpidr_index(kvm->arch.mpidr_data, mpidr);
+	rcu_read_lock();
+	data = rcu_dereference(kvm->arch.mpidr_data);
+
+	if (data) {
+		u16 idx = kvm_mpidr_index(data, mpidr);
 
-		vcpu = kvm_get_vcpu(kvm,
-				    kvm->arch.mpidr_data->cmpidr_to_idx[idx]);
+		vcpu = kvm_get_vcpu(kvm, data->cmpidr_to_idx[idx]);
 		if (mpidr != kvm_vcpu_get_mpidr_aff(vcpu))
 			vcpu = NULL;
+	}
 
+	rcu_read_unlock();
+
+	if (vcpu)
 		return vcpu;
-	}
 
 	kvm_for_each_vcpu(i, vcpu, kvm) {
 		if (mpidr == kvm_vcpu_get_mpidr_aff(vcpu))