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.
----------------------
MODULE_PARM_DESC(h_ipi_redirect, "Redirect H_IPI wakeup to a free host core");
#endif
+/* If set, guests are allowed to create and control nested guests */
+static bool nested = true;
+module_param(nested, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(nested, "Enable nested virtualization (only on POWER9)");
+
+static inline bool nesting_enabled(struct kvm *kvm)
+{
+ return kvm->arch.nested_enable && kvm_is_radix(kvm);
+}
+
/* If set, the threads on each CPU core have to be in the same MMU mode */
static bool no_mixing_hpt_and_radix;
case H_SET_PARTITION_TABLE:
ret = H_FUNCTION;
- if (vcpu->kvm->arch.nested_enable)
+ if (nesting_enabled(vcpu->kvm))
ret = kvmhv_set_partition_table(vcpu);
break;
case H_ENTER_NESTED:
ret = H_FUNCTION;
- if (!vcpu->kvm->arch.nested_enable)
+ if (!nesting_enabled(vcpu->kvm))
break;
ret = kvmhv_enter_nested_guest(vcpu);
if (ret == H_INTERRUPT) {
break;
case H_TLB_INVALIDATE:
ret = H_FUNCTION;
- if (!vcpu->kvm->arch.nested_enable)
- break;
- ret = kvmhv_do_nested_tlbie(vcpu);
+ if (nesting_enabled(vcpu->kvm))
+ ret = kvmhv_do_nested_tlbie(vcpu);
break;
default:
/* Must be called with kvm->lock held and mmu_ready = 0 and no vcpus running */
int kvmppc_switch_mmu_to_hpt(struct kvm *kvm)
{
- if (kvm->arch.nested_enable) {
- kvm->arch.nested_enable = false;
+ if (nesting_enabled(kvm))
kvmhv_release_all_nested(kvm);
- }
kvmppc_free_radix(kvm);
kvmppc_update_lpcr(kvm, LPCR_VPM1,
LPCR_VPM1 | LPCR_UPRT | LPCR_GTSE | LPCR_HR);
/* Perform global invalidation and return lpid to the pool */
if (cpu_has_feature(CPU_FTR_ARCH_300)) {
- if (kvm->arch.nested_enable)
+ if (nesting_enabled(kvm))
kvmhv_release_all_nested(kvm);
kvm->arch.process_table = 0;
kvmhv_set_ptbl_entry(kvm->arch.lpid, 0, 0);
return err;
}
+static int kvmhv_enable_nested(struct kvm *kvm)
+{
+ if (!nested)
+ return -EPERM;
+ if (!cpu_has_feature(CPU_FTR_ARCH_300))
+ return -ENODEV;
+
+ /* kvm == NULL means the caller is testing if the capability exists */
+ if (kvm)
+ kvm->arch.nested_enable = true;
+ return 0;
+}
+
static struct kvmppc_ops kvm_ops_hv = {
.get_sregs = kvm_arch_vcpu_ioctl_get_sregs_hv,
.set_sregs = kvm_arch_vcpu_ioctl_set_sregs_hv,
.configure_mmu = kvmhv_configure_mmu,
.get_rmmu_info = kvmhv_get_rmmu_info,
.set_smt_mode = kvmhv_set_smt_mode,
+ .enable_nested = kvmhv_enable_nested,
};
static int kvm_init_subcore_bitmap(void)
r = !!(hv_enabled && cpu_has_feature(CPU_FTR_ARCH_300) &&
cpu_has_feature(CPU_FTR_HVMODE));
break;
+ case KVM_CAP_PPC_NESTED_HV:
+ r = !!(hv_enabled && kvmppc_hv_ops->enable_nested &&
+ !kvmppc_hv_ops->enable_nested(NULL));
+ break;
#endif
case KVM_CAP_SYNC_MMU:
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
r = kvm->arch.kvm_ops->set_smt_mode(kvm, mode, flags);
break;
}
+
+ case KVM_CAP_PPC_NESTED_HV:
+ r = -EINVAL;
+ if (!is_kvmppc_hv_enabled(kvm) ||
+ !kvm->arch.kvm_ops->enable_nested)
+ break;
+ r = kvm->arch.kvm_ops->enable_nested(kvm);
+ break;
#endif
default:
r = -EINVAL;