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Reply-To: Gavin Shan <gshan@redhat.com>
Subject: Re: [PATCH v6 4/9] KVM: arm64: Add vendor hypervisor firmware
 register
To:     Raghavendra Rao Ananta <rananta@google.com>,
        Marc Zyngier <maz@kernel.org>,
        Andrew Jones <drjones@redhat.com>,
        James Morse <james.morse@arm.com>,
        Alexandru Elisei <alexandru.elisei@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>
Cc:     kvm@vger.kernel.org, Catalin Marinas <catalin.marinas@arm.com>,
        Peter Shier <pshier@google.com>, linux-kernel@vger.kernel.org,
        Paolo Bonzini <pbonzini@redhat.com>,
        Will Deacon <will@kernel.org>, kvmarm@lists.cs.columbia.edu,
        linux-arm-kernel@lists.infradead.org
References: <20220423000328.2103733-1-rananta@google.com>
 <20220423000328.2103733-5-rananta@google.com>
From:   Gavin Shan <gshan@redhat.com>
Message-ID: <a5c43c41-8981-07f7-8bc7-6aabbaa05436@redhat.com>
Date:   Tue, 26 Apr 2022 14:40:47 +0800
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On 4/23/22 8:03 AM, Raghavendra Rao Ananta wrote:
> Introduce the firmware register to hold the vendor specific
> hypervisor service calls (owner value 6) as a bitmap. The
> bitmap represents the features that'll be enabled for the
> guest, as configured by the user-space. Currently, this
> includes support for KVM-vendor features along with
> reading the UID, represented by bit-0, and Precision Time
> Protocol (PTP), represented by bit-1.
> 
> Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
> ---
>   arch/arm64/include/asm/kvm_host.h |  2 ++
>   arch/arm64/include/uapi/asm/kvm.h |  4 ++++
>   arch/arm64/kvm/hypercalls.c       | 23 ++++++++++++++++++-----
>   include/kvm/arm_hypercalls.h      |  2 ++
>   4 files changed, 26 insertions(+), 5 deletions(-)
> 

Reviewed-by: Gavin Shan <gshan@redhat.com>

> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 27d4b2a7970e..a025c2ba012a 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -106,10 +106,12 @@ struct kvm_arch_memory_slot {
>    *
>    * @std_bmap: Bitmap of standard secure service calls
>    * @std_hyp_bmap: Bitmap of standard hypervisor service calls
> + * @vendor_hyp_bmap: Bitmap of vendor specific hypervisor service calls
>    */
>   struct kvm_smccc_features {
>   	unsigned long std_bmap;
>   	unsigned long std_hyp_bmap;
> +	unsigned long vendor_hyp_bmap;
>   };
>   
>   struct kvm_arch {
> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> index 9eecc7ee8c14..e7d5ae222684 100644
> --- a/arch/arm64/include/uapi/asm/kvm.h
> +++ b/arch/arm64/include/uapi/asm/kvm.h
> @@ -344,6 +344,10 @@ struct kvm_arm_copy_mte_tags {
>   #define KVM_REG_ARM_STD_HYP_BMAP		KVM_REG_ARM_FW_FEAT_BMAP_REG(1)
>   #define KVM_REG_ARM_STD_HYP_BIT_PV_TIME		0
>   
> +#define KVM_REG_ARM_VENDOR_HYP_BMAP		KVM_REG_ARM_FW_FEAT_BMAP_REG(2)
> +#define KVM_REG_ARM_VENDOR_HYP_BIT_FUNC_FEAT	0
> +#define KVM_REG_ARM_VENDOR_HYP_BIT_PTP		1
> +
>   /* Device Control API: ARM VGIC */
>   #define KVM_DEV_ARM_VGIC_GRP_ADDR	0
>   #define KVM_DEV_ARM_VGIC_GRP_DIST_REGS	1
> diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c
> index f097bebdad39..76e626d0e699 100644
> --- a/arch/arm64/kvm/hypercalls.c
> +++ b/arch/arm64/kvm/hypercalls.c
> @@ -72,9 +72,6 @@ static bool kvm_hvc_call_default_allowed(struct kvm_vcpu *vcpu, u32 func_id)
>   	 */
>   	case ARM_SMCCC_VERSION_FUNC_ID:
>   	case ARM_SMCCC_ARCH_FEATURES_FUNC_ID:
> -	case ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID:
> -	case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID:
> -	case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
>   		return true;
>   	default:
>   		return kvm_psci_func_id_is_valid(vcpu, func_id);
> @@ -97,6 +94,13 @@ static bool kvm_hvc_call_allowed(struct kvm_vcpu *vcpu, u32 func_id)
>   	case ARM_SMCCC_HV_PV_TIME_ST:
>   		return kvm_arm_fw_reg_feat_enabled(&smccc_feat->std_hyp_bmap,
>   					KVM_REG_ARM_STD_HYP_BIT_PV_TIME);
> +	case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID:
> +	case ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID:
> +		return kvm_arm_fw_reg_feat_enabled(&smccc_feat->vendor_hyp_bmap,
> +					KVM_REG_ARM_VENDOR_HYP_BIT_FUNC_FEAT);
> +	case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
> +		return kvm_arm_fw_reg_feat_enabled(&smccc_feat->vendor_hyp_bmap,
> +					KVM_REG_ARM_VENDOR_HYP_BIT_PTP);
>   	default:
>   		return kvm_hvc_call_default_allowed(vcpu, func_id);
>   	}
> @@ -189,8 +193,7 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
>   		val[3] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_3;
>   		break;
>   	case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID:
> -		val[0] = BIT(ARM_SMCCC_KVM_FUNC_FEATURES);
> -		val[0] |= BIT(ARM_SMCCC_KVM_FUNC_PTP);
> +		val[0] = smccc_feat->vendor_hyp_bmap;
>   		break;
>   	case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
>   		kvm_ptp_get_time(vcpu, val);
> @@ -217,6 +220,7 @@ static const u64 kvm_arm_fw_reg_ids[] = {
>   	KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3,
>   	KVM_REG_ARM_STD_BMAP,
>   	KVM_REG_ARM_STD_HYP_BMAP,
> +	KVM_REG_ARM_VENDOR_HYP_BMAP,
>   };
>   
>   void kvm_arm_init_hypercalls(struct kvm *kvm)
> @@ -225,6 +229,7 @@ void kvm_arm_init_hypercalls(struct kvm *kvm)
>   
>   	smccc_feat->std_bmap = KVM_ARM_SMCCC_STD_FEATURES;
>   	smccc_feat->std_hyp_bmap = KVM_ARM_SMCCC_STD_HYP_FEATURES;
> +	smccc_feat->vendor_hyp_bmap = KVM_ARM_SMCCC_VENDOR_HYP_FEATURES;
>   }
>   
>   int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu)
> @@ -317,6 +322,9 @@ int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
>   	case KVM_REG_ARM_STD_HYP_BMAP:
>   		val = READ_ONCE(smccc_feat->std_hyp_bmap);
>   		break;
> +	case KVM_REG_ARM_VENDOR_HYP_BMAP:
> +		val = READ_ONCE(smccc_feat->vendor_hyp_bmap);
> +		break;
>   	default:
>   		return -ENOENT;
>   	}
> @@ -343,6 +351,10 @@ static int kvm_arm_set_fw_reg_bmap(struct kvm_vcpu *vcpu, u64 reg_id, u64 val)
>   		fw_reg_bmap = &smccc_feat->std_hyp_bmap;
>   		fw_reg_features = KVM_ARM_SMCCC_STD_HYP_FEATURES;
>   		break;
> +	case KVM_REG_ARM_VENDOR_HYP_BMAP:
> +		fw_reg_bmap = &smccc_feat->vendor_hyp_bmap;
> +		fw_reg_features = KVM_ARM_SMCCC_VENDOR_HYP_FEATURES;
> +		break;
>   	default:
>   		return -ENOENT;
>   	}
> @@ -445,6 +457,7 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
>   		return 0;
>   	case KVM_REG_ARM_STD_BMAP:
>   	case KVM_REG_ARM_STD_HYP_BMAP:
> +	case KVM_REG_ARM_VENDOR_HYP_BMAP:
>   		return kvm_arm_set_fw_reg_bmap(vcpu, reg->id, val);
>   	default:
>   		return -ENOENT;
> diff --git a/include/kvm/arm_hypercalls.h b/include/kvm/arm_hypercalls.h
> index aadd6ae3ab72..4ebfdd26e486 100644
> --- a/include/kvm/arm_hypercalls.h
> +++ b/include/kvm/arm_hypercalls.h
> @@ -9,9 +9,11 @@
>   /* Last valid bits of the bitmapped firmware registers */
>   #define KVM_REG_ARM_STD_BMAP_BIT_MAX		0
>   #define KVM_REG_ARM_STD_HYP_BMAP_BIT_MAX	0
> +#define KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_MAX	1
>   
>   #define KVM_ARM_SMCCC_STD_FEATURES		GENMASK(KVM_REG_ARM_STD_BMAP_BIT_MAX, 0)
>   #define KVM_ARM_SMCCC_STD_HYP_FEATURES		GENMASK(KVM_REG_ARM_STD_HYP_BMAP_BIT_MAX, 0)
> +#define KVM_ARM_SMCCC_VENDOR_HYP_FEATURES	GENMASK(KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_MAX, 0)
>   
>   int kvm_hvc_call_handler(struct kvm_vcpu *vcpu);
>   
>