Date:   Mon, 13 Feb 2023 18:04:13 +0200
From:   Zhi Wang <zhi.wang.linux@gmail.com>
To:     Steven Price <steven.price@arm.com>
Cc:     kvm@vger.kernel.org, kvmarm@lists.linux.dev,
        Catalin Marinas <catalin.marinas@arm.com>,
        Marc Zyngier <maz@kernel.org>, Will Deacon <will@kernel.org>,
        James Morse <james.morse@arm.com>,
        Oliver Upton <oliver.upton@linux.dev>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Zenghui Yu <yuzenghui@huawei.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Joey Gouly <joey.gouly@arm.com>,
        Alexandru Elisei <alexandru.elisei@arm.com>,
        Christoffer Dall <christoffer.dall@arm.com>,
        Fuad Tabba <tabba@google.com>, linux-coco@lists.linux.dev
Subject: Re: [RFC PATCH 05/28] arm64: RME: Define the user ABI
Message-ID: <20230213180413.00000392@gmail.com>
In-Reply-To: <20230127112932.38045-6-steven.price@arm.com>
References: <20230127112248.136810-1-suzuki.poulose@arm.com>
        <20230127112932.38045-1-steven.price@arm.com>
        <20230127112932.38045-6-steven.price@arm.com>
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On Fri, 27 Jan 2023 11:29:09 +0000
Steven Price <steven.price@arm.com> wrote:

> There is one (multiplexed) CAP which can be used to create, populate and
> then activate the realm.
> 
> Signed-off-by: Steven Price <steven.price@arm.com>
> ---
>  Documentation/virt/kvm/api.rst    |  1 +
>  arch/arm64/include/uapi/asm/kvm.h | 63 +++++++++++++++++++++++++++++++
>  include/uapi/linux/kvm.h          |  2 +
>  3 files changed, 66 insertions(+)
> 
> diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
> index 0dd5d8733dd5..f1a59d6fb7fc 100644
> --- a/Documentation/virt/kvm/api.rst
> +++ b/Documentation/virt/kvm/api.rst
> @@ -4965,6 +4965,7 @@ Recognised values for feature:
>  
>    =====      ===========================================
>    arm64      KVM_ARM_VCPU_SVE (requires KVM_CAP_ARM_SVE)
> +  arm64      KVM_ARM_VCPU_REC (requires KVM_CAP_ARM_RME)
>    =====      ===========================================
>  
>  Finalizes the configuration of the specified vcpu feature.
> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> index a7a857f1784d..fcc0b8dce29b 100644
> --- a/arch/arm64/include/uapi/asm/kvm.h
> +++ b/arch/arm64/include/uapi/asm/kvm.h
> @@ -109,6 +109,7 @@ struct kvm_regs {
>  #define KVM_ARM_VCPU_SVE		4 /* enable SVE for this CPU */
>  #define KVM_ARM_VCPU_PTRAUTH_ADDRESS	5 /* VCPU uses address authentication */
>  #define KVM_ARM_VCPU_PTRAUTH_GENERIC	6 /* VCPU uses generic authentication */
> +#define KVM_ARM_VCPU_REC		7 /* VCPU REC state as part of Realm */
>  
>  struct kvm_vcpu_init {
>  	__u32 target;
> @@ -401,6 +402,68 @@ enum {
>  #define   KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES	3
>  #define   KVM_DEV_ARM_ITS_CTRL_RESET		4
>  
> +/* KVM_CAP_ARM_RME on VM fd */
> +#define KVM_CAP_ARM_RME_CONFIG_REALM		0
> +#define KVM_CAP_ARM_RME_CREATE_RD		1
> +#define KVM_CAP_ARM_RME_INIT_IPA_REALM		2
> +#define KVM_CAP_ARM_RME_POPULATE_REALM		3
> +#define KVM_CAP_ARM_RME_ACTIVATE_REALM		4
> +

It is a little bit confusing here. These seems more like 'commands' not caps.
Will leave more comments after reviewing the later patches.
 
> +#define KVM_CAP_ARM_RME_MEASUREMENT_ALGO_SHA256		0
> +#define KVM_CAP_ARM_RME_MEASUREMENT_ALGO_SHA512		1
> +
> +#define KVM_CAP_ARM_RME_RPV_SIZE 64
> +
> +/* List of configuration items accepted for KVM_CAP_ARM_RME_CONFIG_REALM */
> +#define KVM_CAP_ARM_RME_CFG_RPV			0
> +#define KVM_CAP_ARM_RME_CFG_HASH_ALGO		1
> +#define KVM_CAP_ARM_RME_CFG_SVE			2
> +#define KVM_CAP_ARM_RME_CFG_DBG			3
> +#define KVM_CAP_ARM_RME_CFG_PMU			4
> +
> +struct kvm_cap_arm_rme_config_item {
> +	__u32 cfg;
> +	union {
> +		/* cfg == KVM_CAP_ARM_RME_CFG_RPV */
> +		struct {
> +			__u8	rpv[KVM_CAP_ARM_RME_RPV_SIZE];
> +		};
> +
> +		/* cfg == KVM_CAP_ARM_RME_CFG_HASH_ALGO */
> +		struct {
> +			__u32	hash_algo;
> +		};
> +
> +		/* cfg == KVM_CAP_ARM_RME_CFG_SVE */
> +		struct {
> +			__u32	sve_vq;
> +		};
> +
> +		/* cfg == KVM_CAP_ARM_RME_CFG_DBG */
> +		struct {
> +			__u32	num_brps;
> +			__u32	num_wrps;
> +		};
> +
> +		/* cfg == KVM_CAP_ARM_RME_CFG_PMU */
> +		struct {
> +			__u32	num_pmu_cntrs;
> +		};
> +		/* Fix the size of the union */
> +		__u8	reserved[256];
> +	};
> +};
> +
> +struct kvm_cap_arm_rme_populate_realm_args {
> +	__u64 populate_ipa_base;
> +	__u64 populate_ipa_size;
> +};
> +
> +struct kvm_cap_arm_rme_init_ipa_args {
> +	__u64 init_ipa_base;
> +	__u64 init_ipa_size;
> +};
> +
>  /* Device Control API on vcpu fd */
>  #define KVM_ARM_VCPU_PMU_V3_CTRL	0
>  #define   KVM_ARM_VCPU_PMU_V3_IRQ	0
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index 20522d4ba1e0..fec1909e8b73 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -1176,6 +1176,8 @@ struct kvm_ppc_resize_hpt {
>  #define KVM_CAP_S390_PROTECTED_ASYNC_DISABLE 224
>  #define KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP 225
>  
> +#define KVM_CAP_ARM_RME 300 // FIXME: Large number to prevent conflicts
> +
>  #ifdef KVM_CAP_IRQ_ROUTING
>  
>  struct kvm_irq_routing_irqchip {