diff options
| author | Claudio Fontana <cfontana@suse.de> | 2024-03-14 18:22:18 +0100 |
|---|---|---|
| committer | Thomas Huth <thuth@redhat.com> | 2024-03-15 07:19:01 +0100 |
| commit | b17693453ef4d06f732295c2e70128a7cf20bf30 (patch) | |
| tree | 55f506b33d038d13a5320602fddac6ebbd6dac18 /docs | |
| parent | ba49d760eb04630e7b15f423ebecf6c871b8f77b (diff) | |
docs/s390: clarify even more that cpu-topology is KVM-only
At least for now cpu-topology is implemented only for KVM.
We already say this, but this tries to be more explicit,
and also show it in the examples.
This adds a new reference in the introduction that we can point to,
whenever we need to reference accelerators and how to select them.
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Message-ID: <20240314172218.16478-1-cfontana@suse.de>
Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Tested-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/system/introduction.rst | 2 | ||||
| -rw-r--r-- | docs/system/s390x/cpu-topology.rst | 14 |
2 files changed, 10 insertions, 6 deletions
diff --git a/docs/system/introduction.rst b/docs/system/introduction.rst index 51ac132d6c..746707eb00 100644 --- a/docs/system/introduction.rst +++ b/docs/system/introduction.rst @@ -1,6 +1,8 @@ Introduction ============ +.. _Accelerators: + Virtualisation Accelerators --------------------------- diff --git a/docs/system/s390x/cpu-topology.rst b/docs/system/s390x/cpu-topology.rst index 5133fdc362..d5b506ee5c 100644 --- a/docs/system/s390x/cpu-topology.rst +++ b/docs/system/s390x/cpu-topology.rst @@ -25,17 +25,19 @@ monitor polarization changes, see ``docs/devel/s390-cpu-topology.rst``. Prerequisites ------------- -To use the CPU topology, you need to run with KVM on a s390x host that -uses the Linux kernel v6.0 or newer (which provide the so-called +To use the CPU topology, you currently need to choose the KVM accelerator. +See :ref:`Accelerators` for more details about accelerators and how to select them. + +The s390x host needs to use a Linux kernel v6.0 or newer (which provides the so-called ``KVM_CAP_S390_CPU_TOPOLOGY`` capability that allows QEMU to signal the CPU topology facility via the so-called STFLE bit 11 to the VM). Enabling CPU topology --------------------- -Currently, CPU topology is only enabled in the host model by default. +Currently, CPU topology is enabled by default only in the "host" CPU model. -Enabling CPU topology in a CPU model is done by setting the CPU flag +Enabling CPU topology in another CPU model is done by setting the CPU flag ``ctop`` to ``on`` as in: .. code-block:: bash @@ -132,7 +134,7 @@ In the following machine we define 8 sockets with 4 cores each. .. code-block:: bash - $ qemu-system-s390x -m 2G \ + $ qemu-system-s390x -accel kvm -m 2G \ -cpu gen16b,ctop=on \ -smp cpus=5,sockets=8,cores=4,maxcpus=32 \ -device host-s390x-cpu,core-id=14 \ @@ -227,7 +229,7 @@ with vertical high entitlement. .. code-block:: bash - $ qemu-system-s390x -m 2G \ + $ qemu-system-s390x -accel kvm -m 2G \ -cpu gen16b,ctop=on \ -smp cpus=1,sockets=8,cores=4,maxcpus=32 \ \ |