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Diffstat (limited to 'Documentation/virtual')
| -rw-r--r-- | Documentation/virtual/kvm/devices/vm.txt | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/devices/vm.txt b/Documentation/virtual/kvm/devices/vm.txt index 0ed6808b9965..8a458f42ded2 100644 --- a/Documentation/virtual/kvm/devices/vm.txt +++ b/Documentation/virtual/kvm/devices/vm.txt @@ -112,6 +112,63 @@ Returns: -EFAULT if the given address is not accessible from kernel space. -EBUSY if at least one VCPU has already been defined. 0 in case of success. +2.5. ATTRIBUTE: KVM_S390_VM_CPU_MACHINE_SUBFUNC (r/o) + +Allows user space to retrieve available cpu subfunctions without any filtering +done by a set IBC. These subfunctions are indicated to the guest VCPU via +query or "test bit" subfunctions and used e.g. by cpacf functions, plo and ptff. + +A subfunction block is only valid if KVM_S390_VM_CPU_MACHINE contains the +STFL(E) bit introducing the affected instruction. If the affected instruction +indicates subfunctions via a "query subfunction", the response block is +contained in the returned struct. If the affected instruction +indicates subfunctions via a "test bit" mechanism, the subfunction codes are +contained in the returned struct in MSB 0 bit numbering. + +struct kvm_s390_vm_cpu_subfunc { + u8 plo[32]; # always valid (ESA/390 feature) + u8 ptff[16]; # valid with TOD-clock steering + u8 kmac[16]; # valid with Message-Security-Assist + u8 kmc[16]; # valid with Message-Security-Assist + u8 km[16]; # valid with Message-Security-Assist + u8 kimd[16]; # valid with Message-Security-Assist + u8 klmd[16]; # valid with Message-Security-Assist + u8 pckmo[16]; # valid with Message-Security-Assist-Extension 3 + u8 kmctr[16]; # valid with Message-Security-Assist-Extension 4 + u8 kmf[16]; # valid with Message-Security-Assist-Extension 4 + u8 kmo[16]; # valid with Message-Security-Assist-Extension 4 + u8 pcc[16]; # valid with Message-Security-Assist-Extension 4 + u8 ppno[16]; # valid with Message-Security-Assist-Extension 5 + u8 reserved[1824]; # reserved for future instructions +}; + +Parameters: address of a buffer to load the subfunction blocks from. +Returns: -EFAULT if the given address is not accessible from kernel space. + 0 in case of success. + +2.6. ATTRIBUTE: KVM_S390_VM_CPU_PROCESSOR_SUBFUNC (r/w) + +Allows user space to retrieve or change cpu subfunctions to be indicated for +all VCPUs of a VM. This attribute will only be available if kernel and +hardware support are in place. + +The kernel uses the configured subfunction blocks for indication to +the guest. A subfunction block will only be used if the associated STFL(E) bit +has not been disabled by user space (so the instruction to be queried is +actually available for the guest). + +As long as no data has been written, a read will fail. The IBC will be used +to determine available subfunctions in this case, this will guarantee backward +compatibility. + +See 2.5. for a description of the parameter struct. + +Parameters: address of a buffer to store/load the subfunction blocks from. +Returns: -EFAULT if the given address is not accessible from kernel space. + -EINVAL when reading, if there was no write yet. + -EBUSY if at least one VCPU has already been defined. + 0 in case of success. + 3. GROUP: KVM_S390_VM_TOD Architectures: s390 |