Lines Matching +full:support +full:- +full:nesting
1 .. SPDX-License-Identifier: GPL-2.0
8 can be KVM-based or a different hypervisor). The straightforward
12 .----------------. .----------------.
17 |----------------'--'----------------|
22 .------------------------------------------------------.
25 |------------------------------------------------------|
27 '------------------------------------------------------'
31 - L0 – level-0; the bare metal host, running KVM
33 - L1 – level-1 guest; a VM running on L0; also called the "guest
36 - L2 – level-2 guest; a VM running on L1, this is the "nested guest"
40 a different design for nesting.
48 This document will stick with the three-level terminology (L0,
54 ---------
59 - As a developer, you want to test your software on different operating
62 hypervisor" (level-1 guest). This in turn allows you to create
63 multiple nested guests (level-2 guests), running different OSes, on
66 - Live migration of "guest hypervisors" and their nested guests, for
69 - VM image creation tools (e.g. ``virt-install``, etc) often run
72 - Some OSes use virtualization internally for security (e.g. to let
77 -----------------------
84 nesting, set the ``nested`` KVM module parameter to ``Y`` or ``1``. To
91 $ lsmod | grep -i kvm
97 $ modinfo kvm_intel | grep -i nested
105 options kvm-intel nested=y
107 4. Unload and re-load the KVM Intel module::
109 $ sudo rmmod kvm-intel
110 $ sudo modprobe kvm-intel
118 name is ``kvm-amd``.
121 Additional nested-related kernel parameters (x86)
122 -------------------------------------------------
145 -----------------------------
147 Once your bare metal host (L0) is configured for nesting, you should be
150 $ qemu-kvm -cpu host [...]
152 The above will pass through the host CPU's capabilities as-is to the
156 $ qemu-kvm -cpu Haswell-noTSX-IBRS,vmx=on
163 -------------------------
177 (via the command-line ``-cpu host``).
185 ------------------------------
194 or save-and-load an L1 guest while an L2 guest is running will result in
198 Migrating an L1 guest merely configured to support nesting, while not
205 - Migrating a nested guest (L2) to another L1 guest on the *same* bare
208 - Migrating a nested guest (L2) to another L1 guest on a *different*
211 - Migrating a nested guest (L2) to a bare metal host.
214 -----------------------------------
217 L0, L1 and L2; this can result in tedious back-n-forth between the bug
220 - Mention that you are in a "nested" setup. If you are running any kind
221 of "nesting" at all, say so. Unfortunately, this needs to be called
225 - Ensure you are actually running KVM on KVM. Sometimes people do not
236 - Kernel, libvirt, and QEMU version from L0
238 - Kernel, libvirt and QEMU version from L1
240 - QEMU command-line of L1 -- when using libvirt, you'll find it here:
243 - QEMU command-line of L2 -- as above, when using libvirt, get the
244 complete libvirt-generated QEMU command-line
246 - ``cat /sys/cpuinfo`` from L0
248 - ``cat /sys/cpuinfo`` from L1
250 - ``lscpu`` from L0
252 - ``lscpu`` from L1
254 - Full ``dmesg`` output from L0
256 - Full ``dmesg`` output from L1
258 x86-specific info to collect
264 - Output of: ``x86info -a`` from L0
266 - Output of: ``x86info -a`` from L1
268 - Output of: ``dmidecode`` from L0
270 - Output of: ``dmidecode`` from L1
272 s390x-specific info to collect
278 - ``/proc/sysinfo`` from L1; this will also include the info from L0