[PATCH 4/5] KVM: PPC: e500: Emulate EPTCFG register

[Alexander Graf]

On 30.01.2013, at 14:29, Mihai Caraman wrote:

> EPTCFG register defined by E.PT is accessed unconditionally by Linux guests
> in the presence of MAV 2.0. Emulate EPTCFG register now.
> 
> Signed-off-by: Mihai Caraman <mihai.caraman at freescale.com>
> ---
> arch/powerpc/include/asm/kvm_host.h |    1 +
> arch/powerpc/kvm/e500.h             |    6 ++++++
> arch/powerpc/kvm/e500_emulate.c     |    9 +++++++++
> arch/powerpc/kvm/e500_mmu.c         |    5 +++++
> 4 files changed, 21 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
> index 88fcfe6..f480b20 100644
> --- a/arch/powerpc/include/asm/kvm_host.h
> +++ b/arch/powerpc/include/asm/kvm_host.h
> @@ -503,6 +503,7 @@ struct kvm_vcpu_arch {
> 	u32 tlbcfg[4];
> 	u32 tlbps[4];
> 	u32 mmucfg;
> +	u32 eptcfg;

This too needs to be settable through SW_TLB.

> 	u32 epr;
> 	struct kvmppc_booke_debug_reg dbg_reg;
> #endif
> diff --git a/arch/powerpc/kvm/e500.h b/arch/powerpc/kvm/e500.h
> index b9f76d8..983eb95 100644
> --- a/arch/powerpc/kvm/e500.h
> +++ b/arch/powerpc/kvm/e500.h
> @@ -308,4 +308,10 @@ static inline unsigned int has_mmu_v2(const struct kvm_vcpu *vcpu)
> 	return ((vcpu->arch.mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V2);
> }
> 
> +static inline unsigned int supports_page_tables(const struct kvm_vcpu *vcpu)

bool again. Can we generalize this a bit more? How about a small framework that allows us to differentiate across e.XX features?

if (has_feature(vcpu, FEATURE_E_PT))
   ...


> +{
> +	return ((vcpu->arch.tlbcfg[0] & TLBnCFG_IND)
> +		|| (vcpu->arch.tlbcfg[1] & TLBnCFG_IND));
> +}
> +
> #endif /* KVM_E500_H */
> diff --git a/arch/powerpc/kvm/e500_emulate.c b/arch/powerpc/kvm/e500_emulate.c
> index 5515dc5..493e231 100644
> --- a/arch/powerpc/kvm/e500_emulate.c
> +++ b/arch/powerpc/kvm/e500_emulate.c
> @@ -339,6 +339,15 @@ int kvmppc_core_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, ulong *spr_val)
> 			return EMULATE_FAIL;
> 		*spr_val = vcpu->arch.tlbps[1];
> 		break;
> +	case SPRN_EPTCFG:
> +		if (!has_mmu_v2(vcpu))
> +			return EMULATE_FAIL;
> +		/*
> +		 * Legacy Linux guests access EPTCFG register even if the E.PT
> +		 * category is disabled in the VM. Give them a chance to live.
> +		 */
> +		*spr_val = vcpu->arch.eptcfg;
> +		break;
> 	default:
> 		emulated = kvmppc_booke_emulate_mfspr(vcpu, sprn, spr_val);
> 	}
> diff --git a/arch/powerpc/kvm/e500_mmu.c b/arch/powerpc/kvm/e500_mmu.c
> index 9a1f7b7..199c11e 100644
> --- a/arch/powerpc/kvm/e500_mmu.c
> +++ b/arch/powerpc/kvm/e500_mmu.c
> @@ -799,6 +799,11 @@ int kvmppc_e500_tlb_init(struct kvmppc_vcpu_e500 *vcpu_e500)
> 	if (has_mmu_v2(vcpu)) {
> 		vcpu->arch.tlbps[0] = mfspr(SPRN_TLB0PS);
> 		vcpu->arch.tlbps[1] = mfspr(SPRN_TLB1PS);
> +
> +		if (supports_page_tables(vcpu))
> +			vcpu->arch.eptcfg = mfspr(SPRN_EPTCFG);

Please don't introduce new mfspr()s here :). Just have user space set it.


Alex

> +		else
> +			vcpu->arch.eptcfg = 0;
> 	}
> 
> 	kvmppc_recalc_tlb1map_range(vcpu_e500);
> -- 
> 1.7.4.1
> 
> 
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