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| author | Collin Walling <walling@linux.ibm.com> | 2020-06-25 11:07:23 -0400 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2020-09-14 09:08:10 +0200 |
| commit | f20d4e924b4465822c4a35290b85aadf88ddf466 (patch) | |
| tree | c9bc31bf6fc122706bda7e7198c2b5a70edb49cc /Documentation/virt | |
| parent | 37f66bbef0920429b8cb5eddba849ec4308a9f8e (diff) | |
docs: kvm: add documentation for KVM_CAP_S390_DIAG318
Documentation for the s390 DIAGNOSE 0x318 instruction handling.
Signed-off-by: Collin Walling <walling@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/kvm/20200625150724.10021-2-walling@linux.ibm.com/
Message-Id: <20200625150724.10021-2-walling@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'Documentation/virt')
| -rw-r--r-- | Documentation/virt/kvm/api.rst | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index d2b733dc7892..51191b56e61c 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6173,3 +6173,23 @@ specific interfaces must be consistent, i.e. if one says the feature is supported, than the other should as well and vice versa. For arm64 see Documentation/virt/kvm/devices/vcpu.rst "KVM_ARM_VCPU_PVTIME_CTRL". For x86 see Documentation/virt/kvm/msr.rst "MSR_KVM_STEAL_TIME". + +8.25 KVM_CAP_S390_DIAG318 +------------------------- + +:Architectures: s390 + +This capability enables a guest to set information about its control program +(i.e. guest kernel type and version). The information is helpful during +system/firmware service events, providing additional data about the guest +environments running on the machine. + +The information is associated with the DIAGNOSE 0x318 instruction, which sets +an 8-byte value consisting of a one-byte Control Program Name Code (CPNC) and +a 7-byte Control Program Version Code (CPVC). The CPNC determines what +environment the control program is running in (e.g. Linux, z/VM...), and the +CPVC is used for information specific to OS (e.g. Linux version, Linux +distribution...) + +If this capability is available, then the CPNC and CPVC can be synchronized +between KVM and userspace via the sync regs mechanism (KVM_SYNC_DIAG318). |