Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 269 insertions, 0 deletions

diff --git a/Documentation/virtual/kvm/devices/vm.txt b/Documentation/virtual/kvm/devices/vm.txt
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+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: -EINVAL if CMMA was not enabled
+         0 otherwise
+
+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
+
+2.3. ATTRIBUTE: KVM_S390_VM_CPU_MACHINE_FEAT (r/o)
+
+Allows user space to retrieve available cpu features. A feature is available if
+provided by the hardware and supported by kvm. In theory, cpu features could
+even be completely emulated by kvm.
+
+struct kvm_s390_vm_cpu_feat {
+        __u64 feat[16]; # Bitmap (1 = feature available), MSB 0 bit numbering
+};
+
+Parameters: address of a buffer to load the feature list from.
+Returns:    -EFAULT if the given address is not accessible from kernel space.
+	    0 in case of success.
+
+2.4. ATTRIBUTE: KVM_S390_VM_CPU_PROCESSOR_FEAT (r/w)
+
+Allows user space to retrieve or change enabled cpu features for all VCPUs of a
+VM. Features that are not available cannot be enabled.
+
+See 2.3. for a description of the parameter struct.
+
+Parameters: address of a buffer to store/load the feature list from.
+Returns:    -EFAULT if the given address is not accessible from kernel space.
+	    -EINVAL if a cpu feature that is not available is to be enabled.
+	    -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 kma[16];           # valid with Message-Security-Assist-Extension 8
+       u8 reserved[1808];    # 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
+
+3.1. ATTRIBUTE: KVM_S390_VM_TOD_HIGH
+
+Allows user space to set/get the TOD clock extension (u8) (superseded by
+KVM_S390_VM_TOD_EXT).
+
+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
+
+3.3. ATTRIBUTE: KVM_S390_VM_TOD_EXT
+Allows user space to set/get bits 0-63 of the TOD clock register as defined in
+the POP (u64). If the guest CPU model supports the TOD clock extension (u8), it
+also allows user space to get/set it. If the guest CPU model does not support
+it, it is stored as 0 and not allowed to be set to a value != 0.
+
+Parameters: address of a buffer in user space to store the data
+            (kvm_s390_vm_tod_clock) 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
+
+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
+
+5. GROUP: KVM_S390_VM_MIGRATION
+Architectures: s390
+
+5.1. ATTRIBUTE: KVM_S390_VM_MIGRATION_STOP (w/o)
+
+Allows userspace to stop migration mode, needed for PGSTE migration.
+Setting this attribute when migration mode is not active will have no
+effects.
+
+Parameters: none
+Returns:    0
+
+5.2. ATTRIBUTE: KVM_S390_VM_MIGRATION_START (w/o)
+
+Allows userspace to start migration mode, needed for PGSTE migration.
+Setting this attribute when migration mode is already active will have
+no effects.
+
+Parameters: none
+Returns:    -ENOMEM if there is not enough free memory to start migration mode
+	    -EINVAL if the state of the VM is invalid (e.g. no memory defined)
+	    0 in case of success.
+
+5.3. ATTRIBUTE: KVM_S390_VM_MIGRATION_STATUS (r/o)
+
+Allows userspace to query the status of migration mode.
+
+Parameters: address of a buffer in user space to store the data (u64) to;
+	    the data itself is either 0 if migration mode is disabled or 1
+	    if it is enabled
+Returns:    -EFAULT if the given address is not accessible from kernel space
+	    0 in case of success.