Commit 19c654bf authored by Steffen Eiden's avatar Steffen Eiden Committed by Janosch Frank
Browse files

KVM: s390: Add UV feature negotiation 



Add a uv_feature list for pv-guests to the KVM cpu-model.
The feature bits 'AP-interpretation for secure guests' and
'AP-interrupt for secure guests' are available.

Signed-off-by: default avatarSteffen Eiden <seiden@linux.ibm.com>
Reviewed-by: default avatarJanosch Frank <frankja@linux.ibm.com>
Reviewed-by: default avatarMichael Mueller <mimu@linux.ibm.com>
Signed-off-by: default avatarJanosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20230815151415.379760-4-seiden@linux.ibm.com
Message-Id: <20230815151415.379760-4-seiden@linux.ibm.com>
parent 59a88140

arch/s390/include/asm/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -817,6 +817,8 @@ struct kvm_s390_cpu_model { 
	__u64 *fac_list;

	u64 cpuid;

	unsigned short ibc;

	/* subset of available UV-features for pv-guests enabled by user space */

	struct kvm_s390_vm_cpu_uv_feat uv_feat_guest;

};



typedef int (*crypto_hook)(struct kvm_vcpu *vcpu);

arch/s390/include/uapi/asm/kvm.h

+16 −0
Original line number Diff line number Diff line
@@ -159,6 +159,22 @@ struct kvm_s390_vm_cpu_subfunc { 
	__u8 reserved[1728];

};



#define KVM_S390_VM_CPU_PROCESSOR_UV_FEAT_GUEST	6

#define KVM_S390_VM_CPU_MACHINE_UV_FEAT_GUEST	7



#define KVM_S390_VM_CPU_UV_FEAT_NR_BITS	64

struct kvm_s390_vm_cpu_uv_feat {

	union {

		struct {

			__u64 : 4;

			__u64 ap : 1;		/* bit 4 */

			__u64 ap_intr : 1;	/* bit 5 */

			__u64 : 58;

		};

		__u64 feat;

	};

};



/* kvm attributes for crypto */

#define KVM_S390_VM_CRYPTO_ENABLE_AES_KW	0

#define KVM_S390_VM_CRYPTO_ENABLE_DEA_KW	1

arch/s390/kvm/kvm-s390.c

+73 −0
Original line number Diff line number Diff line
@@ -1531,6 +1531,39 @@ static int kvm_s390_set_processor_subfunc(struct kvm *kvm, 
	return 0;

}



#define KVM_S390_VM_CPU_UV_FEAT_GUEST_MASK	\

(						\

	((struct kvm_s390_vm_cpu_uv_feat){	\

		.ap = 1,			\

		.ap_intr = 1,			\

	})					\

	.feat					\

)



static int kvm_s390_set_uv_feat(struct kvm *kvm, struct kvm_device_attr *attr)

{

	struct kvm_s390_vm_cpu_uv_feat __user *ptr = (void __user *)attr->addr;

	unsigned long data, filter;



	filter = uv_info.uv_feature_indications & KVM_S390_VM_CPU_UV_FEAT_GUEST_MASK;

	if (get_user(data, &ptr->feat))

		return -EFAULT;

	if (!bitmap_subset(&data, &filter, KVM_S390_VM_CPU_UV_FEAT_NR_BITS))

		return -EINVAL;



	mutex_lock(&kvm->lock);

	if (kvm->created_vcpus) {

		mutex_unlock(&kvm->lock);

		return -EBUSY;

	}

	kvm->arch.model.uv_feat_guest.feat = data;

	mutex_unlock(&kvm->lock);



	VM_EVENT(kvm, 3, "SET: guest UV-feat: 0x%16.16lx", data);



	return 0;

}



static int kvm_s390_set_cpu_model(struct kvm *kvm, struct kvm_device_attr *attr)

{

	int ret = -ENXIO;
@@ -1545,6 +1578,9 @@ static int kvm_s390_set_cpu_model(struct kvm *kvm, struct kvm_device_attr *attr) 
	case KVM_S390_VM_CPU_PROCESSOR_SUBFUNC:

		ret = kvm_s390_set_processor_subfunc(kvm, attr);

		break;

	case KVM_S390_VM_CPU_PROCESSOR_UV_FEAT_GUEST:

		ret = kvm_s390_set_uv_feat(kvm, attr);

		break;

	}

	return ret;

}
@@ -1777,6 +1813,33 @@ static int kvm_s390_get_machine_subfunc(struct kvm *kvm, 
	return 0;

}



static int kvm_s390_get_processor_uv_feat(struct kvm *kvm, struct kvm_device_attr *attr)

{

	struct kvm_s390_vm_cpu_uv_feat __user *dst = (void __user *)attr->addr;

	unsigned long feat = kvm->arch.model.uv_feat_guest.feat;



	if (put_user(feat, &dst->feat))

		return -EFAULT;

	VM_EVENT(kvm, 3, "GET: guest UV-feat: 0x%16.16lx", feat);



	return 0;

}



static int kvm_s390_get_machine_uv_feat(struct kvm *kvm, struct kvm_device_attr *attr)

{

	struct kvm_s390_vm_cpu_uv_feat __user *dst = (void __user *)attr->addr;

	unsigned long feat;



	BUILD_BUG_ON(sizeof(*dst) != sizeof(uv_info.uv_feature_indications));



	feat = uv_info.uv_feature_indications & KVM_S390_VM_CPU_UV_FEAT_GUEST_MASK;

	if (put_user(feat, &dst->feat))

		return -EFAULT;

	VM_EVENT(kvm, 3, "GET: guest UV-feat: 0x%16.16lx", feat);



	return 0;

}



static int kvm_s390_get_cpu_model(struct kvm *kvm, struct kvm_device_attr *attr)

{

	int ret = -ENXIO;
@@ -1800,6 +1863,12 @@ static int kvm_s390_get_cpu_model(struct kvm *kvm, struct kvm_device_attr *attr) 
	case KVM_S390_VM_CPU_MACHINE_SUBFUNC:

		ret = kvm_s390_get_machine_subfunc(kvm, attr);

		break;

	case KVM_S390_VM_CPU_PROCESSOR_UV_FEAT_GUEST:

		ret = kvm_s390_get_processor_uv_feat(kvm, attr);

		break;

	case KVM_S390_VM_CPU_MACHINE_UV_FEAT_GUEST:

		ret = kvm_s390_get_machine_uv_feat(kvm, attr);

		break;

	}

	return ret;

}
@@ -1952,6 +2021,8 @@ static int kvm_s390_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr) 
		case KVM_S390_VM_CPU_MACHINE_FEAT:

		case KVM_S390_VM_CPU_MACHINE_SUBFUNC:

		case KVM_S390_VM_CPU_PROCESSOR_SUBFUNC:

		case KVM_S390_VM_CPU_MACHINE_UV_FEAT_GUEST:

		case KVM_S390_VM_CPU_PROCESSOR_UV_FEAT_GUEST:

			ret = 0;

			break;

		default:
@@ -3296,6 +3367,8 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) 
	kvm->arch.model.cpuid = kvm_s390_get_initial_cpuid();

	kvm->arch.model.ibc = sclp.ibc & 0x0fff;



	kvm->arch.model.uv_feat_guest.feat = 0;



	kvm_s390_crypto_init(kvm);



	if (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM)) {