Michael Mueller
cc674ef252
The boolean module parameter "kvm.use_gisa" controls if newly created guests will use the GISA facility if provided by the host system. The default is yes. # cat /sys/module/kvm/parameters/use_gisa Y The parameter can be changed on the fly. # echo N > /sys/module/kvm/parameters/use_gisa Already running guests are not affected by this change. The kvm s390 debug feature shows if a guest is running with GISA. # grep gisa /sys/kernel/debug/s390dbf/kvm-$pid/sprintf 00 01582725059:843303 3 - 08 00000000e119bc01 gisa 0x00000000c9ac2642 initialized 00 01582725059:903840 3 - 11 000000004391ee22 00[0000000000000000-0000000000000000]: AIV gisa format-1 enabled for cpu 000 ... 00 01582725059:916847 3 - 08 0000000094fff572 gisa 0x00000000c9ac2642 cleared In general, that value should not be changed as the GISA facility enhances interruption delivery performance. A reason to switch the GISA facility off might be a performance comparison run or debugging. Signed-off-by: Michael Mueller <mimu@linux.ibm.com> Link: https://lore.kernel.org/r/20200227091031.102993-1-mimu@linux.ibm.com Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.