Commit de760db4 authored by Paul Mackerras's avatar Paul Mackerras Committed by Michael Ellerman
Browse files

KVM: PPC: Book3S HV: Allow HV module to load without hypervisor mode 



With this, the KVM-HV module can be loaded in a guest running under
KVM-HV, and if the hypervisor supports nested virtualization, this
guest can now act as a nested hypervisor and run nested guests.

This also adds some checks to inform userspace that HPT guests are not
supported by nested hypervisors (by returning false for the
KVM_CAP_PPC_MMU_HASH_V3 capability), and to prevent userspace from
configuring a guest to use HPT mode.

Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
Reviewed-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 10b5022d

arch/powerpc/kvm/book3s_hv.c

+12 −4
Original line number Diff line number Diff line
@@ -4811,11 +4811,15 @@ static int kvmppc_core_emulate_mfspr_hv(struct kvm_vcpu *vcpu, int sprn, 


static int kvmppc_core_check_processor_compat_hv(void)

{

	if (!cpu_has_feature(CPU_FTR_HVMODE) ||

	    !cpu_has_feature(CPU_FTR_ARCH_206))

		return -EIO;

	if (cpu_has_feature(CPU_FTR_HVMODE) &&

	    cpu_has_feature(CPU_FTR_ARCH_206))

		return 0;



	/* POWER9 in radix mode is capable of being a nested hypervisor. */

	if (cpu_has_feature(CPU_FTR_ARCH_300) && radix_enabled())

		return 0;



	return -EIO;

}



#ifdef CONFIG_KVM_XICS
@@ -5133,6 +5137,10 @@ static int kvmhv_configure_mmu(struct kvm *kvm, struct kvm_ppc_mmuv3_cfg *cfg) 
	if (radix && !radix_enabled())

		return -EINVAL;



	/* If we're a nested hypervisor, we currently only support radix */

	if (kvmhv_on_pseries() && !radix)

		return -EINVAL;



	mutex_lock(&kvm->lock);

	if (radix != kvm_is_radix(kvm)) {

		if (kvm->arch.mmu_ready) {

arch/powerpc/kvm/powerpc.c

+2 −1
Original line number Diff line number Diff line
@@ -594,7 +594,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) 
		r = !!(hv_enabled && radix_enabled());

		break;

	case KVM_CAP_PPC_MMU_HASH_V3:

		r = !!(hv_enabled && cpu_has_feature(CPU_FTR_ARCH_300));

		r = !!(hv_enabled && cpu_has_feature(CPU_FTR_ARCH_300) &&

		       cpu_has_feature(CPU_FTR_HVMODE));

		break;

#endif

	case KVM_CAP_SYNC_MMU:

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