Subject: Re: [PATCH 5/7 v2] KVM: PPC: e500: Remove E.PT and E.HV.LRAT categories from VCPUs

From: Scott Wood <[email-masked]>
Date: Wed, 27 Mar 2013 12:50:34 -0500

On 03/26/2013 05:05:10 PM, Mihai Caraman wrote:
> Embedded.Page Table (E.PT) category in VMs requires indirect tlb =20
> entries
> emulation which is not supported yet. Configure TLBnCFG to remove E.PT
> and E.HV.LRAT categories from VCPUs.
>=20
> Signed-off-by: Mihai Caraman <[email-masked]>
> ---
> v2:
>  - Remove E.HV.LRAT from vcpus
>=20
>  arch/powerpc/kvm/e500_mmu.c |    6 ++++++
>  1 files changed, 6 insertions(+), 0 deletions(-)
>=20
> diff --git a/arch/powerpc/kvm/e500_mmu.c b/arch/powerpc/kvm/e500_mmu.c
> index cf60db1..0d2a293 100644
> --- a/arch/powerpc/kvm/e500_mmu.c
> +++ b/arch/powerpc/kvm/e500_mmu.c
> @@ -867,11 +867,17 @@ static int vcpu_mmu_init(struct kvm_vcpu *vcpu,
>  	vcpu->arch.tlbcfg[1] |=3D params[1].ways << TLBnCFG_ASSOC_SHIFT;
>=20
>  	if (has_feature(vcpu, VCPU_FTR_MMU_V2)) {
> +		vcpu->arch.mmucfg &=3D ~MMUCFG_LRAT;
> +
>  		if (has_feature(vcpu, VCPU_FTR_E_PT))
>  			vcpu->arch.eptcfg =3D mfspr(SPRN_EPTCFG);
>  		else
>  			vcpu->arch.eptcfg =3D 0;
>=20
> +		/* Guest mmu emulation currently doesn't handle E.PT */
> +		vcpu->arch.tlbcfg[0] &=3D ~TLBnCFG_PT;
> +		vcpu->arch.tlbcfg[1] &=3D ~TLBnCFG_IND;

You're clearing these bits *after* calling has_feature() -- doesn't =20
has_feature() depend on those bits being cleared to not advertise E_PT =20
support?

-Scott=