Setting up KVM host support
Depending on how the kvm module is compiled, use kernel or module parameters to configure the KVM host support. The parameter that adds support for guests in IBM® Secure Execution mode is always a kernel parameter.
Kernel parameters
The kvm.nested= and kvm.hpage= apply only if the kvm module is compiled into the kernel. Regardless of how the kvm module is compiled, prot_virt= is a kernel parameter.
- kvm.nested=
- If set to
1
, passes the SIE capability on to its guests. Thus, the guests can be hosts for higher-level guests.Nested KVM hosts are intended for test environments and not for production systems.
- kvm.hpage=
- If set to
1
, supports guest-configurations with huge-page memory backing.Enough 1 MB huge pages must be set up to satisfy the needs of the guests. For details about setting up huge pages, see Huge-page support.
Nested hosts cannot back their guests with huge pages. You cannot set both
kvm.nested= and kvm.hpage= to 1.
- prot_virt=
- applies to KVM hosts in LPAR mode. If set to 1, the host can support guests in IBM Secure Execution mode.
To make kernel parameters persistent, include them in the boot configuration. See Including kernel parameters in a boot configuration.
Module parameters
Configure the KVM host support with module parameters if it is compiled as a separate module, kvm.
- nested=
- If set to
1
, passes the SIE capability on to its guests. Thus, the guests can be hosts for higher-level guests.Nested KVM hosts are intended for test environments and not for production systems.
- hpage=
- If set to
1
, supports guest-configurations with huge-page memory backing.Enough 1 MB huge pages must be set up to satisfy the needs of the guests. For details about setting up huge pages, see Huge-page support.
Nested hosts cannot back their guests with huge pages. You cannot set both
nested= and hpage= to 1.
To make module parameters persistent, use the modprobe configuration file. See also Specifying module parameters with modprobe.