| Generic vm interface |
| ==================================== |
| |
| The virtual machine "device" also accepts the ioctls KVM_SET_DEVICE_ATTR, |
| KVM_GET_DEVICE_ATTR, and KVM_HAS_DEVICE_ATTR. The interface uses the same |
| struct kvm_device_attr as other devices, but targets VM-wide settings |
| and controls. |
| |
| The groups and attributes per virtual machine, if any, are architecture |
| specific. |
| |
| 1. GROUP: KVM_S390_VM_MEM_CTRL |
| Architectures: s390 |
| |
| 1.1. ATTRIBUTE: KVM_S390_VM_MEM_ENABLE_CMMA |
| Parameters: none |
| Returns: -EBUSY if a vcpu is already defined, otherwise 0 |
| |
| Enables Collaborative Memory Management Assist (CMMA) for the virtual machine. |
| |
| 1.2. ATTRIBUTE: KVM_S390_VM_MEM_CLR_CMMA |
| Parameters: none |
| Returns: 0 |
| |
| Clear the CMMA status for all guest pages, so any pages the guest marked |
| as unused are again used any may not be reclaimed by the host. |
| |
| 1.3. ATTRIBUTE KVM_S390_VM_MEM_LIMIT_SIZE |
| Parameters: in attr->addr the address for the new limit of guest memory |
| Returns: -EFAULT if the given address is not accessible |
| -EINVAL if the virtual machine is of type UCONTROL |
| -E2BIG if the given guest memory is to big for that machine |
| -EBUSY if a vcpu is already defined |
| -ENOMEM if not enough memory is available for a new shadow guest mapping |
| 0 otherwise |
| |
| Allows userspace to query the actual limit and set a new limit for |
| the maximum guest memory size. The limit will be rounded up to |
| 2048 MB, 4096 GB, 8192 TB respectively, as this limit is governed by |
| the number of page table levels. In the case that there is no limit we will set |
| the limit to KVM_S390_NO_MEM_LIMIT (U64_MAX). |
| |
| 2. GROUP: KVM_S390_VM_CPU_MODEL |
| Architectures: s390 |
| |
| 2.1. ATTRIBUTE: KVM_S390_VM_CPU_MACHINE (r/o) |
| |
| Allows user space to retrieve machine and kvm specific cpu related information: |
| |
| struct kvm_s390_vm_cpu_machine { |
| __u64 cpuid; # CPUID of host |
| __u32 ibc; # IBC level range offered by host |
| __u8 pad[4]; |
| __u64 fac_mask[256]; # set of cpu facilities enabled by KVM |
| __u64 fac_list[256]; # set of cpu facilities offered by host |
| } |
| |
| Parameters: address of buffer to store the machine related cpu data |
| of type struct kvm_s390_vm_cpu_machine* |
| Returns: -EFAULT if the given address is not accessible from kernel space |
| -ENOMEM if not enough memory is available to process the ioctl |
| 0 in case of success |
| |
| 2.2. ATTRIBUTE: KVM_S390_VM_CPU_PROCESSOR (r/w) |
| |
| Allows user space to retrieve or request to change cpu related information for a vcpu: |
| |
| struct kvm_s390_vm_cpu_processor { |
| __u64 cpuid; # CPUID currently (to be) used by this vcpu |
| __u16 ibc; # IBC level currently (to be) used by this vcpu |
| __u8 pad[6]; |
| __u64 fac_list[256]; # set of cpu facilities currently (to be) used |
| # by this vcpu |
| } |
| |
| KVM does not enforce or limit the cpu model data in any form. Take the information |
| retrieved by means of KVM_S390_VM_CPU_MACHINE as hint for reasonable configuration |
| setups. Instruction interceptions triggered by additionally set facility bits that |
| are not handled by KVM need to by imlemented in the VM driver code. |
| |
| Parameters: address of buffer to store/set the processor related cpu |
| data of type struct kvm_s390_vm_cpu_processor*. |
| Returns: -EBUSY in case 1 or more vcpus are already activated (only in write case) |
| -EFAULT if the given address is not accessible from kernel space |
| -ENOMEM if not enough memory is available to process the ioctl |
| 0 in case of success |
| |
| 3. GROUP: KVM_S390_VM_TOD |
| Architectures: s390 |
| |
| 3.1. ATTRIBUTE: KVM_S390_VM_TOD_HIGH |
| |
| Allows user space to set/get the TOD clock extension (u8). |
| |
| Parameters: address of a buffer in user space to store the data (u8) to |
| Returns: -EFAULT if the given address is not accessible from kernel space |
| -EINVAL if setting the TOD clock extension to != 0 is not supported |
| |
| 3.2. ATTRIBUTE: KVM_S390_VM_TOD_LOW |
| |
| Allows user space to set/get bits 0-63 of the TOD clock register as defined in |
| the POP (u64). |
| |
| Parameters: address of a buffer in user space to store the data (u64) to |
| Returns: -EFAULT if the given address is not accessible from kernel space |
| |
| 4. GROUP: KVM_S390_VM_CRYPTO |
| Architectures: s390 |
| |
| 4.1. ATTRIBUTE: KVM_S390_VM_CRYPTO_ENABLE_AES_KW (w/o) |
| |
| Allows user space to enable aes key wrapping, including generating a new |
| wrapping key. |
| |
| Parameters: none |
| Returns: 0 |
| |
| 4.2. ATTRIBUTE: KVM_S390_VM_CRYPTO_ENABLE_DEA_KW (w/o) |
| |
| Allows user space to enable dea key wrapping, including generating a new |
| wrapping key. |
| |
| Parameters: none |
| Returns: 0 |
| |
| 4.3. ATTRIBUTE: KVM_S390_VM_CRYPTO_DISABLE_AES_KW (w/o) |
| |
| Allows user space to disable aes key wrapping, clearing the wrapping key. |
| |
| Parameters: none |
| Returns: 0 |
| |
| 4.4. ATTRIBUTE: KVM_S390_VM_CRYPTO_DISABLE_DEA_KW (w/o) |
| |
| Allows user space to disable dea key wrapping, clearing the wrapping key. |
| |
| Parameters: none |
| Returns: 0 |