s390x/css: add s390-squash-mcss machine option

We want to support real (i.e. not virtual) channel devices
even for guests that do not support MCSS-E (where guests may
see devices from any channel subsystem image at once). As all
virtio-ccw devices are in css 0xfe (and show up in the default
css 0 for guests not activating MCSS-E), we need an option to
squash both the virtio subchannels and e.g. passed-through
subchannels from their real css (0-3, or 0 for hosts not
activating MCSS-E) into the default css. This will be
exploited in a later patch.

Signed-off-by: Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170517004813.58227-4-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
This commit is contained in:
Xiao Feng Ren 2017-05-17 02:48:03 +02:00 committed by Cornelia Huck
parent 74c98e20a6
commit 274250c301
4 changed files with 37 additions and 1 deletions

View file

@ -42,7 +42,8 @@ DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
" dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
" suppress-vmdesc=on|off disables self-describing migration (default=off)\n"
" nvdimm=on|off controls NVDIMM support (default=off)\n"
" enforce-config-section=on|off enforce configuration section migration (default=off)\n",
" enforce-config-section=on|off enforce configuration section migration (default=off)\n"
" s390-squash-mcss=on|off controls support for squashing into default css (default=off)\n",
QEMU_ARCH_ALL)
STEXI
@item -machine [type=]@var{name}[,prop=@var{value}[,...]]
@ -81,6 +82,9 @@ controls whether DEA wrapping keys will be created to allow
execution of DEA cryptographic functions. The default is on.
@item nvdimm=on|off
Enables or disables NVDIMM support. The default is off.
@item s390-squash-mcss=on|off
Enables or disables squashing subchannels into the default css.
The default is off.
@end table
ETEXI