Merge branch kvm-arm64/6.6/generic-vcpu into kvmarm-master/next

* kvm-arm64/6.6/generic-vcpu:
  : .
  : Cleanup the obsolete vcpu target abstraction, courtesy of Oliver.
  : From the cover letter:
  :
  : "kvm_vcpu_init::target is quite useless at this point. We don't do any
  : uarch-specific emulation in the first place, and require userspace
  : select the 'generic' vCPU target on all but a few implementations.
  :
  : Small series to (1) clean up usage of the target value in the kernel and
  : (2) switch to the 'generic' target on implementations that previously
  : had their own target values. The implementation-specific values are
  : still tolerated, though, to avoid UAPI breakage."
  : .
  KVM: arm64: Always return generic v8 as the preferred target
  KVM: arm64: Replace vCPU target with a configuration flag
  KVM: arm64: Remove pointless check for changed init target
  KVM: arm64: Delete pointless switch statement in kvm_reset_vcpu()

Signed-off-by: Marc Zyngier <maz@kernel.org>

Author: Marc Zyngier

arch/arm64/include/asm/kvm_host.h

@@ -567,8 +567,7 @@ struct kvm_vcpu_arch {
 	/* Cache some mmu pages needed inside spinlock regions */
 	struct kvm_mmu_memory_cache mmu_page_cache;
 
-	/* Target CPU and feature flags */
-	int target;
+	/* feature flags */
 	DECLARE_BITMAP(features, KVM_VCPU_MAX_FEATURES);
 
 	/* Virtual SError ESR to restore when HCR_EL2.VSE is set */
@@ -669,6 +668,8 @@ struct kvm_vcpu_arch {
 #define VCPU_SVE_FINALIZED	__vcpu_single_flag(cflags, BIT(1))
 /* PTRAUTH exposed to guest */
 #define GUEST_HAS_PTRAUTH	__vcpu_single_flag(cflags, BIT(2))
+/* KVM_ARM_VCPU_INIT completed */
+#define VCPU_INITIALIZED	__vcpu_single_flag(cflags, BIT(3))
 
 /* Exception pending */
 #define PENDING_EXCEPTION	__vcpu_single_flag(iflags, BIT(0))
@@ -899,7 +900,6 @@ struct kvm_vcpu_stat {
 	u64 exits;
 };
 
-void kvm_vcpu_preferred_target(struct kvm_vcpu_init *init);
 unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu);
 int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices);
 int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);

arch/arm64/kvm/arm.c

@@ -365,7 +365,7 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 #endif
 
 	/* Force users to call KVM_ARM_VCPU_INIT */
-	vcpu->arch.target = -1;
+	vcpu_clear_flag(vcpu, VCPU_INITIALIZED);
 	bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
 
 	vcpu->arch.mmu_page_cache.gfp_zero = __GFP_ZERO;
@@ -574,7 +574,7 @@ unsigned long kvm_arch_vcpu_get_ip(struct kvm_vcpu *vcpu)
 
 static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
 {
-	return vcpu->arch.target >= 0;
+	return vcpu_get_flag(vcpu, VCPU_INITIALIZED);
 }
 
 /*
@@ -1058,7 +1058,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 			 * invalid. The VMM can try and fix it by issuing  a
 			 * KVM_ARM_VCPU_INIT if it really wants to.
 			 */
-			vcpu->arch.target = -1;
+			vcpu_clear_flag(vcpu, VCPU_INITIALIZED);
 			ret = ARM_EXCEPTION_IL;
 		}
 
@@ -1219,8 +1219,7 @@ static bool kvm_vcpu_init_changed(struct kvm_vcpu *vcpu,
 {
 	unsigned long features = init->features[0];
 
-	return !bitmap_equal(vcpu->arch.features, &features, KVM_VCPU_MAX_FEATURES) ||
-			vcpu->arch.target != init->target;
+	return !bitmap_equal(vcpu->arch.features, &features, KVM_VCPU_MAX_FEATURES);
 }
 
 static int __kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
@@ -1236,20 +1235,18 @@ static int __kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
 	    !bitmap_equal(kvm->arch.vcpu_features, &features, KVM_VCPU_MAX_FEATURES))
 		goto out_unlock;
 
-	vcpu->arch.target = init->target;
 	bitmap_copy(vcpu->arch.features, &features, KVM_VCPU_MAX_FEATURES);
 
 	/* Now we know what it is, we can reset it. */
 	ret = kvm_reset_vcpu(vcpu);
 	if (ret) {
-		vcpu->arch.target = -1;
 		bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
 		goto out_unlock;
 	}
 
 	bitmap_copy(kvm->arch.vcpu_features, &features, KVM_VCPU_MAX_FEATURES);
 	set_bit(KVM_ARCH_FLAG_VCPU_FEATURES_CONFIGURED, &kvm->arch.flags);
-
+	vcpu_set_flag(vcpu, VCPU_INITIALIZED);
 out_unlock:
 	mutex_unlock(&kvm->arch.config_lock);
 	return ret;
@@ -1260,14 +1257,15 @@ static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
 {
 	int ret;
 
-	if (init->target != kvm_target_cpu())
+	if (init->target != KVM_ARM_TARGET_GENERIC_V8 &&
+	    init->target != kvm_target_cpu())
 		return -EINVAL;
 
 	ret = kvm_vcpu_init_check_features(vcpu, init);
 	if (ret)
 		return ret;
 
-	if (vcpu->arch.target == -1)
+	if (!kvm_vcpu_initialized(vcpu))
 		return __kvm_vcpu_set_target(vcpu, init);
 
 	if (kvm_vcpu_init_changed(vcpu, init))
@@ -1595,9 +1593,9 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
 		return kvm_vm_ioctl_set_device_addr(kvm, &dev_addr);
 	}
 	case KVM_ARM_PREFERRED_TARGET: {
-		struct kvm_vcpu_init init;
-
-		kvm_vcpu_preferred_target(&init);
+		struct kvm_vcpu_init init = {
+			.target = KVM_ARM_TARGET_GENERIC_V8,
+		};
 
 		if (copy_to_user(argp, &init, sizeof(init)))
 			return -EFAULT;

arch/arm64/kvm/guest.c

@@ -884,21 +884,6 @@ u32 __attribute_const__ kvm_target_cpu(void)
 	return KVM_ARM_TARGET_GENERIC_V8;
 }
 
-void kvm_vcpu_preferred_target(struct kvm_vcpu_init *init)
-{
-	u32 target = kvm_target_cpu();
-
-	memset(init, 0, sizeof(*init));
-
-	/*
-	 * For now, we don't return any features.
-	 * In future, we might use features to return target
-	 * specific features available for the preferred
-	 * target type.
-	 */
-	init->target = (__u32)target;
-}
-
 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 {
 	return -EINVAL;

arch/arm64/kvm/hyp/nvhe/switch.c

@@ -236,7 +236,7 @@ static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code)
 		 * KVM_ARM_VCPU_INIT, however, this is likely not possible for
 		 * protected VMs.
 		 */
-		vcpu->arch.target = -1;
+		vcpu_clear_flag(vcpu, VCPU_INITIALIZED);
 		*exit_code &= BIT(ARM_EXIT_WITH_SERROR_BIT);
 		*exit_code |= ARM_EXCEPTION_IL;
 	}

arch/arm64/kvm/reset.c

@@ -248,21 +248,16 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
 		}
 	}
 
-	switch (vcpu->arch.target) {
-	default:
-		if (vcpu_el1_is_32bit(vcpu)) {
-			pstate = VCPU_RESET_PSTATE_SVC;
-		} else if (vcpu_has_nv(vcpu)) {
-			pstate = VCPU_RESET_PSTATE_EL2;
-		} else {
-			pstate = VCPU_RESET_PSTATE_EL1;
-		}
-
-		if (kvm_vcpu_has_pmu(vcpu) && !kvm_arm_support_pmu_v3()) {
-			ret = -EINVAL;
-			goto out;
-		}
-		break;
+	if (vcpu_el1_is_32bit(vcpu))
+		pstate = VCPU_RESET_PSTATE_SVC;
+	else if (vcpu_has_nv(vcpu))
+		pstate = VCPU_RESET_PSTATE_EL2;
+	else
+		pstate = VCPU_RESET_PSTATE_EL1;
+
+	if (kvm_vcpu_has_pmu(vcpu) && !kvm_arm_support_pmu_v3()) {
+		ret = -EINVAL;
+		goto out;
 	}
 
 	/* Reset core registers */