3 files changed, 65 insertions, 1 deletions
diff --git a/arch/loongarch/include/uapi/asm/kvm.h b/arch/loongarch/include/uapi/asm/kvm.h
index ddc5cab0ffd0..49bafac8b22d 100644
--- a/arch/loongarch/include/uapi/asm/kvm.h
+++ b/arch/loongarch/include/uapi/asm/kvm.h
@@ -82,6 +82,14 @@ struct kvm_fpu {
 #define KVM_IOC_CSRID(REG)		LOONGARCH_REG_64(KVM_REG_LOONGARCH_CSR, REG)
 #define KVM_IOC_CPUCFG(REG)		LOONGARCH_REG_64(KVM_REG_LOONGARCH_CPUCFG, REG)
 
+/* Device Control API on vm fd */
+#define KVM_LOONGARCH_VM_FEAT_CTRL	0
+#define  KVM_LOONGARCH_VM_FEAT_LSX	0
+#define  KVM_LOONGARCH_VM_FEAT_LASX	1
+#define  KVM_LOONGARCH_VM_FEAT_X86BT	2
+#define  KVM_LOONGARCH_VM_FEAT_ARMBT	3
+#define  KVM_LOONGARCH_VM_FEAT_MIPSBT	4
+
 /* Device Control API on vcpu fd */
 #define KVM_LOONGARCH_VCPU_CPUCFG	0
 #define KVM_LOONGARCH_VCPU_PVTIME_CTRL	1
diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
index 6905283f535b..ae991b3fda79 100644
--- a/arch/loongarch/kvm/vcpu.c
+++ b/arch/loongarch/kvm/vcpu.c
@@ -497,6 +497,12 @@ static int _kvm_get_cpucfg_mask(int id, u64 *v)
 			*v |= CPUCFG2_LSX;
 		if (cpu_has_lasx)
 			*v |= CPUCFG2_LASX;
+		if (cpu_has_lbt_x86)
+			*v |= CPUCFG2_X86BT;
+		if (cpu_has_lbt_arm)
+			*v |= CPUCFG2_ARMBT;
+		if (cpu_has_lbt_mips)
+			*v |= CPUCFG2_MIPSBT;
 
 		return 0;
 	case LOONGARCH_CPUCFG3:
diff --git a/arch/loongarch/kvm/vm.c b/arch/loongarch/kvm/vm.c
index 6b2e4f66ad26..33398a151e71 100644
--- a/arch/loongarch/kvm/vm.c
+++ b/arch/loongarch/kvm/vm.c
@@ -99,7 +99,57 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	return r;
 }
 
+static int kvm_vm_feature_has_attr(struct kvm *kvm, struct kvm_device_attr *attr)
+{
+	switch (attr->attr) {
+	case KVM_LOONGARCH_VM_FEAT_LSX:
+		if (cpu_has_lsx)
+			return 0;
+		return -ENXIO;
+	case KVM_LOONGARCH_VM_FEAT_LASX:
+		if (cpu_has_lasx)
+			return 0;
+		return -ENXIO;
+	case KVM_LOONGARCH_VM_FEAT_X86BT:
+		if (cpu_has_lbt_x86)
+			return 0;
+		return -ENXIO;
+	case KVM_LOONGARCH_VM_FEAT_ARMBT:
+		if (cpu_has_lbt_arm)
+			return 0;
+		return -ENXIO;
+	case KVM_LOONGARCH_VM_FEAT_MIPSBT:
+		if (cpu_has_lbt_mips)
+			return 0;
+		return -ENXIO;
+	default:
+		return -ENXIO;
+	}
+}
+
+static int kvm_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr)
+{
+	switch (attr->group) {
+	case KVM_LOONGARCH_VM_FEAT_CTRL:
+		return kvm_vm_feature_has_attr(kvm, attr);
+	default:
+		return -ENXIO;
+	}
+}
+
 int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
 {
-	return -ENOIOCTLCMD;
+	void __user *argp = (void __user *)arg;
+	struct kvm *kvm = filp->private_data;
+	struct kvm_device_attr attr;
+
+	switch (ioctl) {
+	case KVM_HAS_DEVICE_ATTR:
+		if (copy_from_user(&attr, argp, sizeof(attr)))
+			return -EFAULT;
+
+		return kvm_vm_has_attr(kvm, &attr);
+	default:
+		return -ENOIOCTLCMD;
+	}
 }