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path: root/Documentation/virtual/kvm/devices/vm.txt
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2017-08-29KVM: s390: Multiple Epoch Facility supportCollin L. Walling1-1/+13
Allow for the enablement of MEF and the support for the extended epoch in SIE and VSIE for the extended guest TOD-Clock. A new interface is used for getting/setting a guest's extended TOD-Clock that uses a single ioctl invocation, KVM_S390_VM_TOD_EXT. Since the host time is a moving target that might see an epoch switch or STP sync checks we need an atomic ioctl and cannot use the exisiting two interfaces. The old method of getting and setting the guest TOD-Clock is still retained and is used when the old ioctls are called. Signed-off-by: Collin L. Walling <walling@linux.vnet.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.vnet.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> Reviewed-by: Jason J. Herne <jjherne@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2017-06-22KVM: s390: CMMA tracking, ESSA emulation, migration modeClaudio Imbrenda1-0/+33
* Add a migration state bitmap to keep track of which pages have dirty CMMA information. * Disable CMMA by default, so we can track if it's used or not. Enable it on first use like we do for storage keys (unless we are doing a migration). * Creates a VM attribute to enter and leave migration mode. * In migration mode, CMMA is disabled in the SIE block, so ESSA is always interpreted and emulated in software. * Free the migration state on VM destroy. Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2017-04-26s390: kvm: Cpu model support for msa6, msa7 and msa8Jason J. Herne1-1/+2
msa6 and msa7 require no changes. msa8 adds kma instruction and feature area. Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: provide CMMA attributes only if availableDavid Hildenbrand1-1/+2
Let's not provide the device attribute for cmma enabling and clearing if the hardware doesn't support it. This also helps getting rid of the undocumented return value "-EINVAL" in case CMMA is not available when trying to enable it. Also properly document the meaning of -EINVAL for CMMA clearing. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: interface to query and configure cpu subfunctionsDavid Hildenbrand1-0/+57
We have certain instructions that indicate available subfunctions via a query subfunction (crypto functions and ptff), or via a test bit function (plo). By exposing these "subfunction blocks" to user space, we allow user space to 1) query available subfunctions and make sure subfunctions won't get lost during migration - e.g. properly indicate them via a CPU model 2) change the subfunctions to be reported to the guest (even adding unavailable ones) This mechanism works just like the way we indicate the stfl(e) list to user space. This way, user space could even emulate some subfunctions in QEMU in the future. If this is ever applicable, we have to make sure later on, that unsupported subfunctions result in an intercept to QEMU. Please note that support to indicate them to the guest is still missing and requires hardware support. Usually, the IBC takes already care of these subfunctions for migration safety. QEMU should make sure to always set these bits properly according to the machine generation to be emulated. Available subfunctions are only valid in combination with STFLE bits retrieved via KVM_S390_VM_CPU_MACHINE and enabled via KVM_S390_VM_CPU_PROCESSOR. If the applicable bits are available, the indicated subfunctions are guaranteed to be correct. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: interface to query and configure cpu featuresDavid Hildenbrand1-0/+27
For now, we only have an interface to query and configure facilities indicated via STFL(E). However, we also have features indicated via SCLP, that have to be indicated to the guest by user space and usually require KVM support. This patch allows user space to query and configure available cpu features for the guest. Please note that disabling a feature doesn't necessarily mean that it is completely disabled (e.g. ESOP is mostly handled by the SIE). We will try our best to disable it. Most features (e.g. SCLP) can't directly be forwarded, as most of them need in addition to hardware support, support in KVM. As we later on want to turn these features in KVM explicitly on/off (to simulate different behavior), we have to filter all features provided by the hardware and make them configurable. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-02-10KVM: s390: add documentation of KVM_S390_VM_CRYPTODavid Hildenbrand1-0/+33
Let's properly document KVM_S390_VM_CRYPTO and its attributes. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-02-10KVM: s390: add documentation of KVM_S390_VM_TODDavid Hildenbrand1-0/+19
Let's properly document KVM_S390_VM_TOD and its attributes. Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-12-15KVM: s390: fix mismatch between user and in-kernel guest limitDominik Dingel1-1/+2
While the userspace interface requests the maximum size the gmap code expects to get a maximum address. This error resulted in bigger page tables than necessary for some guest sizes, e.g. a 2GB guest used 3 levels instead of 2. At the same time we introduce KVM_S390_NO_MEM_LIMIT, which allows in a bright future that a guest spans the complete 64 bit address space. We also switch to TASK_MAX_SIZE for the initial memory size, this is a cosmetic change as the previous size also resulted in a 4 level pagetable creation. Reported-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-10-12Doc:kvm: Fix typo in Doc/virtual/kvmMasanari Iida1-1/+1
This patch fix spelling typos in Documentation/virtual/kvm. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2015-02-09KVM: s390: add cpu model supportMichael Mueller1-0/+45
This patch enables cpu model support in kvm/s390 via the vm attribute interface. During KVM initialization, the host properties cpuid, IBC value and the facility list are stored in the architecture specific cpu model structure. During vcpu setup, these properties are taken to initialize the related SIE state. This mechanism allows to adjust the properties from user space and thus to implement different selectable cpu models. This patch uses the IBC functionality to block instructions that have not been implemented at the requested CPU type and GA level compared to the full host capability. Userspace has to initialize the cpu model before vcpu creation. A cpu model change of running vcpus is not possible. Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: Allow userspace to limit guest memory sizeDominik Dingel1-0/+14
With commit c6c956b80bdf ("KVM: s390/mm: support gmap page tables with less than 5 levels") we are able to define a limit for the guest memory size. As we round up the guest size in respect to the levels of page tables we get to guest limits of: 2048 MB, 4096 GB, 8192 TB and 16384 PB. We currently limit the guest size to 16 TB, which means we end up creating a page table structure supporting guest sizes up to 8192 TB. This patch introduces an interface that allows userspace to tune this limit. This may bring performance improvements for small guests. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-11-07KVM: fix vm device attribute documentationDominik Dingel1-5/+5
Documentation uses incorrect attribute names for some vm device attributes: fix this. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22KVM: s390: Exploiting generic userspace interface for cmmaDominik Dingel1-0/+16
To enable CMMA and to reset its state we use the vm kvm_device ioctls, encapsulating attributes within the KVM_S390_VM_MEM_CTRL group. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22KVM: s390: Per-vm kvm device controlsDominik Dingel1-0/+10
We sometimes need to get/set attributes specific to a virtual machine and so need something else than ONE_REG. Let's copy the KVM_DEVICE approach, and define the respective ioctls for the vm file descriptor. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Acked-by: Alexander Graf <agraf@suse.de> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>