From aa069a996951f3e2e38437ef0316685a5893fc7e Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Fri, 21 Sep 2018 20:02:01 +1000 Subject: KVM: PPC: Book3S HV: Add a VM capability to enable nested virtualization With this, userspace can enable a KVM-HV guest to run nested guests under it. The administrator can control whether any nested guests can be run; setting the "nested" module parameter to false prevents any guests becoming nested hypervisors (that is, any attempt to enable the nested capability on a guest will fail). Guests which are already nested hypervisors will continue to be so. Reviewed-by: David Gibson Signed-off-by: Paul Mackerras --- Documentation/virtual/kvm/api.txt | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'Documentation/virtual/kvm') diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 2f5f9b743bff..fde48b6708f1 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -4532,6 +4532,20 @@ With this capability, a guest may read the MSR_PLATFORM_INFO MSR. Otherwise, a #GP would be raised when the guest tries to access. Currently, this capability does not enable write permissions of this MSR for the guest. +7.16 KVM_CAP_PPC_NESTED_HV + +Architectures: ppc +Parameters: none +Returns: 0 on success, -EINVAL when the implementation doesn't support + nested-HV virtualization. + +HV-KVM on POWER9 and later systems allows for "nested-HV" +virtualization, which provides a way for a guest VM to run guests that +can run using the CPU's supervisor mode (privileged non-hypervisor +state). Enabling this capability on a VM depends on the CPU having +the necessary functionality and on the facility being enabled with a +kvm-hv module parameter. + 8. Other capabilities. ---------------------- -- cgit v1.2.3