KVM: s390: Storage key manipulation IOCTL (0ee4ddc1) · Commits · git / linux-net

Documentation/virt/kvm/api.rst

+42 −0

Original line number	Diff line number	Diff line
		@@ -6517,6 +6517,40 @@ the capability to be present.

		`flags` must currently be zero.

		4.144 KVM_S390_KEYOP
		--------------------

		:Capability: KVM_CAP_S390_KEYOP
		:Architectures: s390
		:Type: vm ioctl
		:Parameters: struct kvm_s390_keyop (in/out)
		:Returns: 0 in case of success, < 0 on error

		The specified key operation is performed on the given guest address. The
		previous storage key (or the relevant part thereof) will be returned in
		`key`.

		::

		struct kvm_s390_keyop {
		__u64 guest_addr;
		__u8 key;
		__u8 operation;
		};

		Currently supported values for ``operation``:

		KVM_S390_KEYOP_ISKE
		Returns the storage key for the guest address ``guest_addr`` in ``key``.

		KVM_S390_KEYOP_RRBE
		Resets the reference bit for the guest address ``guest_addr``, returning the
		R and C bits of the old storage key in ``key``; the remaining fields of
		the storage key will be set to 0.

		KVM_S390_KEYOP_SSKE
		Sets the storage key for the guest address ``guest_addr`` to the key
		specified in ``key``, returning the previous value in ``key``.

		.. _kvm_run:

		@@ -9287,6 +9321,14 @@ The presence of this capability indicates that KVM_RUN will update the
		KVM_RUN_X86_GUEST_MODE bit in kvm_run.flags to indicate whether the
		vCPU was executing nested guest code when it exited.

		8.46 KVM_CAP_S390_KEYOP
		-----------------------

		:Architectures: s390

		The presence of this capability indicates that the KVM_S390_KEYOP ioctl is
		available.

		KVM exits with the register state of either the L1 or L2 guest
		depending on which executed at the time of an exit. Userspace must
		take care to differentiate between these cases.

arch/s390/kvm/kvm-s390.c

+58 −0

Original line number	Diff line number	Diff line
		@@ -554,6 +554,37 @@ static void __kvm_s390_exit(void)
		debug_unregister(kvm_s390_dbf_uv);
		}

		static int kvm_s390_keyop(struct kvm_s390_mmu_cache mc, struct kvm kvm, int op,
		unsigned long addr, union skey skey)
		{
		union asce asce = kvm->arch.gmap->asce;
		gfn_t gfn = gpa_to_gfn(addr);
		int r;

		guard(read_lock)(&kvm->mmu_lock);

		switch (op) {
		case KVM_S390_KEYOP_SSKE:
		r = dat_cond_set_storage_key(mc, asce, gfn, skey, &skey, 0, 0, 0);
		if (r >= 0)
		return skey.skey;
		break;
		case KVM_S390_KEYOP_ISKE:
		r = dat_get_storage_key(asce, gfn, &skey);
		if (!r)
		return skey.skey;
		break;
		case KVM_S390_KEYOP_RRBE:
		r = dat_reset_reference_bit(asce, gfn);
		if (r > 0)
		return r << 1;
		break;
		default:
		return -EINVAL;
		}
		return r;
		}

		/* Section: device related */
		long kvm_arch_dev_ioctl(struct file *filp,
		unsigned int ioctl, unsigned long arg)
		@@ -598,6 +629,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
		case KVM_CAP_S390_DIAG318:
		case KVM_CAP_IRQFD_RESAMPLE:
		case KVM_CAP_S390_USER_OPEREXEC:
		case KVM_CAP_S390_KEYOP:
		r = 1;
		break;
		case KVM_CAP_SET_GUEST_DEBUG2:
		@@ -2931,6 +2963,32 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
		r = -EFAULT;
		break;
		}
		case KVM_S390_KEYOP: {
		struct kvm_s390_mmu_cache *mc;
		struct kvm_s390_keyop kop;
		union skey skey;

		if (copy_from_user(&kop, argp, sizeof(kop))) {
		r = -EFAULT;
		break;
		}
		skey.skey = kop.key;

		mc = kvm_s390_new_mmu_cache();
		if (!mc)
		return -ENOMEM;

		r = kvm_s390_keyop(mc, kvm, kop.operation, kop.guest_addr, skey);
		kvm_s390_free_mmu_cache(mc);
		if (r < 0)
		break;

		kop.key = r;
		r = 0;
		if (copy_to_user(argp, &kop, sizeof(kop)))
		r = -EFAULT;
		break;
		}
		case KVM_S390_ZPCI_OP: {
		struct kvm_s390_zpci_op args;

include/uapi/linux/kvm.h

+11 −0

Original line number	Diff line number	Diff line
		@@ -974,6 +974,7 @@ struct kvm_enable_cap {
		#define KVM_CAP_GUEST_MEMFD_FLAGS 244
		#define KVM_CAP_ARM_SEA_TO_USER 245
		#define KVM_CAP_S390_USER_OPEREXEC 246
		#define KVM_CAP_S390_KEYOP 247

		struct kvm_irq_routing_irqchip {
		__u32 irqchip;
		@@ -1219,6 +1220,15 @@ struct kvm_vfio_spapr_tce {
		__s32 tablefd;
		};

		#define KVM_S390_KEYOP_ISKE 0x01
		#define KVM_S390_KEYOP_RRBE 0x02
		#define KVM_S390_KEYOP_SSKE 0x03
		struct kvm_s390_keyop {
		__u64 guest_addr;
		__u8 key;
		__u8 operation;
		};

		/*
		* KVM_CREATE_VCPU receives as a parameter the vcpu slot, and returns
		* a vcpu fd.
		@@ -1238,6 +1248,7 @@ struct kvm_vfio_spapr_tce {
		#define KVM_S390_UCAS_MAP _IOW(KVMIO, 0x50, struct kvm_s390_ucas_mapping)
		#define KVM_S390_UCAS_UNMAP _IOW(KVMIO, 0x51, struct kvm_s390_ucas_mapping)
		#define KVM_S390_VCPU_FAULT _IOW(KVMIO, 0x52, unsigned long)
		#define KVM_S390_KEYOP _IOWR(KVMIO, 0x53, struct kvm_s390_keyop)

		/* Device model IOC */
		#define KVM_CREATE_IRQCHIP _IO(KVMIO, 0x60)