This defines 5 new facilities and the new 3931 and 3932 machines.
As before the name is not yet known and we do use gen16a and gen16b.
The new features are part of the full model.
The default model is still empty (same as z15) and will be added
in a separate patch at a later point in time.
Also add the dependencies of new facilities and as a fix for z15 add
a dependency from S390_FEAT_VECTOR_PACKED_DECIMAL_ENH to
S390_VECTOR_PACKED_DECIMAL.
[merged <20210701084348.26556-1-borntraeger@de.ibm.com>]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-Id: <20210622201923.150205-2-borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
DIAGNOSE 0x318 (diag318) is an s390 instruction that allows the storage
of diagnostic information that is collected by the firmware in the case
of hardware/firmware service events.
QEMU handles the instruction by storing the info in the CPU state. A
subsequent register sync will communicate the data to the hypervisor.
QEMU handles the migration via a VM State Description.
This feature depends on the Extended-Length SCCB (els) feature. If
els is not present, then a warning will be printed and the SCLP bit
that allows the Linux kernel to execute the instruction will not be
set.
Availability of this instruction is determined by byte 134 (aka fac134)
bit 0 of the SCLP Read Info block. This coincidentally expands into the
space used for CPU entries, which means VMs running with the diag318
capability may not be able to read information regarding all CPUs
unless the guest kernel supports an extended-length SCCB.
This feature is not supported in protected virtualization mode.
Signed-off-by: Collin Walling <walling@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Acked-by: Thomas Huth <thuth@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-Id: <20200915194416.107460-9-walling@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
As more features and facilities are added to the Read SCP Info (RSCPI)
response, more space is required to store them. The space used to store
these new features intrudes on the space originally used to store CPU
entries. This means as more features and facilities are added to the
RSCPI response, less space can be used to store CPU entries.
With the Extended-Length SCCB (ELS) facility, a KVM guest can execute
the RSCPI command and determine if the SCCB is large enough to store a
complete reponse. If it is not large enough, then the required length
will be set in the SCCB header.
The caller of the SCLP command is responsible for creating a
large-enough SCCB to store a complete response. Proper checking should
be in place, and the caller should execute the command once-more with
the large-enough SCCB.
This facility also enables an extended SCCB for the Read CPU Info
(RCPUI) command.
When this facility is enabled, the boundary violation response cannot
be a result from the RSCPI, RSCPI Forced, or RCPUI commands.
In order to tolerate kernels that do not yet have full support for this
feature, a "fixed" offset to the start of the CPU Entries within the
Read SCP Info struct is set to allow for the original 248 max entries
when this feature is disabled.
Additionally, this is introduced as a CPU feature to protect the guest
from migrating to a machine that does not support storing an extended
SCCB. This could otherwise hinder the VM from being able to read all
available CPU entries after migration (such as during re-ipl).
Signed-off-by: Collin Walling <walling@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-Id: <20200915194416.107460-7-walling@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
