From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 0A36418CC15; Mon, 28 Apr 2025 08:58:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745830705; cv=none; b=BxMrYPdcNKWowUe1HtGsAbdEHu4bdfVO0K81Fqns/CxBtYKrYR2JPl+sRZ32zY4I7rn06SzrJ8/rD53+879PKDQNJdMH+KVxzJMvhQLdwY1kkbfVYvjjXuQnI8K8YgLYrV53dRFr/nlUK0fly8Cw1VW4nq4CMysfleKoz4xQ+Yc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745830705; c=relaxed/simple; bh=hBhlveHVYfdqh7hjf/loO1kscPH9CqqgworRHqmeYSs=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=YvoSqZGNXnM3hkXzmMSy+YUsLsF0cS6rJhYy4H1tyUCY4uYYKdWuzv3N2anTYz/K98g62yhy3k05Y313lezLlzuCBIcOaeO1jCDBi36TIoJ7PM/HCu5SsuZSyVDOFYFXr9woKP/vCMGL/JlqWXHDTLxwlYX41OgGRjCTH8FzkFU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9F6591595; Mon, 28 Apr 2025 01:58:15 -0700 (PDT) Received: from [10.1.37.44] (Suzukis-MBP.cambridge.arm.com [10.1.37.44]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 29A013F673; Mon, 28 Apr 2025 01:58:19 -0700 (PDT) Message-ID: <35a91f8c-cdf6-4595-9ed2-c792a8e9d679@arm.com> Date: Mon, 28 Apr 2025 09:58:18 +0100 Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v8 06/43] arm64: RME: Define the user ABI Content-Language: en-GB To: Steven Price , kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev, Ganapatrao Kulkarni , Gavin Shan , Shanker Donthineni , Alper Gun , "Aneesh Kumar K . V" References: <20250416134208.383984-1-steven.price@arm.com> <20250416134208.383984-7-steven.price@arm.com> From: Suzuki K Poulose In-Reply-To: <20250416134208.383984-7-steven.price@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Steven On 16/04/2025 14:41, Steven Price wrote: > There is one (multiplexed) CAP which can be used to create, populate and > then activate the realm. > > Co-developed-by: Suzuki K Poulose > Signed-off-by: Suzuki K Poulose > Signed-off-by: Steven Price > --- > Changes since v7: > * Add documentation of new ioctls > * Bump the magic numbers to avoid conflicts > Changes since v6: > * Rename some of the symbols to make their usage clearer and avoid > repetition. > Changes from v5: > * Actually expose the new VCPU capability (KVM_ARM_VCPU_REC) by bumping > KVM_VCPU_MAX_FEATURES - note this also exposes KVM_ARM_VCPU_HAS_EL2! > --- > Documentation/virt/kvm/api.rst | 70 +++++++++++++++++++++++++++++++ > arch/arm64/include/uapi/asm/kvm.h | 49 ++++++++++++++++++++++ > include/uapi/linux/kvm.h | 10 +++++ > 3 files changed, 129 insertions(+) > > diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst > index 1f8625b7646a..99ba6c82cf37 100644 > --- a/Documentation/virt/kvm/api.rst > +++ b/Documentation/virt/kvm/api.rst > @@ -3527,6 +3527,11 @@ Possible features: > - the KVM_REG_ARM64_SVE_VLS pseudo-register is immutable, and can > no longer be written using KVM_SET_ONE_REG. > > + - KVM_ARM_VCPU_REC: Allocate a REC (Realm Execution Context) for this > + VCPU. This must be specified on all VCPUs created in a Realm VM. > + Depends on KVM_CAP_ARM_RME. > + Requires KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_REC). > + > 4.83 KVM_ARM_PREFERRED_TARGET > ----------------------------- > > @@ -5098,6 +5103,7 @@ 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. > @@ -6452,6 +6458,30 @@ the capability to be present. > > `flags` must currently be zero. > > +4.144 KVM_ARM_VCPU_RMM_PSCI_COMPLETE > +------------------------------------ > + > +:Capability: KVM_CAP_ARM_RME > +:Architectures: arm64 > +:Type: vcpu ioctl > +:Parameters: struct kvm_arm_rmm_psci_complete (in) > +:Returns: 0 if successful, < 0 on error > + > +:: > + > + struct kvm_arm_rmm_psci_complete { > + __u64 target_mpidr; > + __u32 psci_status; > + __u32 padding[3]; > + }; > + > +Where PSCI functions are handled by user space, the RMM needs to be informed of > +the target of the operation using `target_mpidr`, along with the status > +(`psci_status`). The RMM v1.0 specification defines two functions that require > +this call: PSCI_CPU_ON and PSCI_AFFINITY_INFO. > + > +If the kernel is handling PSCI then this is done automatically and the VMM > +doesn't need to call this ioctl. > > .. _kvm_run: > > @@ -8280,6 +8310,46 @@ aforementioned registers before the first KVM_RUN. These registers are VM > scoped, meaning that the same set of values are presented on all vCPUs in a > given VM. > > +7.38 KVM_CAP_ARM_RME > +-------------------- > + > +:Architectures: arm64 > +:Target: VM > +:Parameters: args[0] provides an action, args[1] points to a structure in > + memory for some actions. > +:Returns: 0 on success, negative value on error > + > +Used to configure and set up the memory for a Realm. The available actions are: > + > +================================= ============================================= > + KVM_CAP_ARM_RME_CONFIG_REALM Takes struct arm_rme_config as args[1] and > + configures realm parameters prior to it being > + created. > + > + Options are ARM_RME_CONFIG_RPV to set the > + "Realm Personalization Value" and > + ARM_RME_CONFIG_HASH_ALGO to set the hash > + algorithm. > + > + KVM_CAP_ARM_RME_CREATE_REALM Request the RMM create the realm. The realm's minor nit: s/RMM create/RMM to create/ Or may be rephrase it: Request the RMM to create the Realm with the configured parameters. > + configuration parameters must be set first. > + > + KVM_CAP_ARM_RME_INIT_RIPAS_REALM Takes struct arm_rme_init_ripas as args[1] > + and sets the RIPAS (Realm IPA State) to > + RIPAS_RAM of a specified area of the realm's > + IPA. > + > + KVM_CAP_ARM_RME_POPULATE_REALM Takes struct arm_rme_init_ripas as args[1] nit: struct arm_rme_populate_realm > + and populates a region of protected address > + space by copying the data from the shared > + alias. > + > + KVM_CAP_ARM_RME_ACTIVATE_REALM Request the RMM activate the realm. No s/the RMM/the RMM to/ > + further changes can be made to the realm's > + configuration, and VCPUs are not permitted to > + enter the realm until it has been activated. minor nit: this sounds as if "configurations" (of parameters) are possible after the CREATE_REALM and before ACTIVATE_REALM ? Could we also make it clear that the VCPUs must have been created before ACTIVATE ? May be rephrase it to: No changes can be made to Realm's memory (including the IPA state). No new VCPUs can be created after this step. > +================================= ============================================= > + > 8. Other capabilities. > ====================== > > diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h > index af9d9acaf997..b57712880605 100644 > --- a/arch/arm64/include/uapi/asm/kvm.h > +++ b/arch/arm64/include/uapi/asm/kvm.h > @@ -106,6 +106,7 @@ struct kvm_regs { > #define KVM_ARM_VCPU_PTRAUTH_GENERIC 6 /* VCPU uses generic authentication */ > #define KVM_ARM_VCPU_HAS_EL2 7 /* Support nested virtualization */ > #define KVM_ARM_VCPU_HAS_EL2_E2H0 8 /* Limit NV support to E2H RES0 */ > +#define KVM_ARM_VCPU_REC 9 /* VCPU REC state as part of Realm */ > > struct kvm_vcpu_init { > __u32 target; > @@ -429,6 +430,54 @@ 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_REALM 1 > +#define KVM_CAP_ARM_RME_INIT_RIPAS_REALM 2 > +#define KVM_CAP_ARM_RME_POPULATE_REALM 3 > +#define KVM_CAP_ARM_RME_ACTIVATE_REALM 4 > + > +/* List of configuration items accepted for KVM_CAP_ARM_RME_CONFIG_REALM */ > +#define ARM_RME_CONFIG_RPV 0 > +#define ARM_RME_CONFIG_HASH_ALGO 1 > + > +#define ARM_RME_CONFIG_MEASUREMENT_ALGO_SHA256 0 > +#define ARM_RME_CONFIG_MEASUREMENT_ALGO_SHA512 1 minor nit: May be we could rename this to CONFIG_HASH_ALGO_* to align with the RMM spec (btw which also moved from measurement to hash) and the parameter. Suzuki > + > +#define ARM_RME_CONFIG_RPV_SIZE 64 > + > +struct arm_rme_config { > + __u32 cfg; > + union { > + /* cfg == ARM_RME_CONFIG_RPV */ > + struct { > + __u8 rpv[ARM_RME_CONFIG_RPV_SIZE]; > + }; > + > + /* cfg == ARM_RME_CONFIG_HASH_ALGO */ > + struct { > + __u32 hash_algo; > + }; > + > + /* Fix the size of the union */ > + __u8 reserved[256]; > + }; > +}; > + > +#define KVM_ARM_RME_POPULATE_FLAGS_MEASURE (1 << 0) > +struct arm_rme_populate_realm { > + __u64 base; > + __u64 size; > + __u32 flags; > + __u32 reserved[3]; > +}; > + > +struct arm_rme_init_ripas { > + __u64 base; > + __u64 size; > + __u64 reserved[2]; > +}; > + > /* 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 b6ae8ad8934b..0b8479985581 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -930,6 +930,7 @@ struct kvm_enable_cap { > #define KVM_CAP_X86_APIC_BUS_CYCLES_NS 237 > #define KVM_CAP_X86_GUEST_MODE 238 > #define KVM_CAP_ARM_WRITABLE_IMP_ID_REGS 239 > +#define KVM_CAP_ARM_RME 240 > > struct kvm_irq_routing_irqchip { > __u32 irqchip; > @@ -1582,4 +1583,13 @@ struct kvm_pre_fault_memory { > __u64 padding[5]; > }; > > +/* Available with KVM_CAP_ARM_RME, only for VMs with KVM_VM_TYPE_ARM_REALM */ > +struct kvm_arm_rmm_psci_complete { > + __u64 target_mpidr; > + __u32 psci_status; > + __u32 padding[3]; > +}; > + > +#define KVM_ARM_VCPU_RMM_PSCI_COMPLETE _IOW(KVMIO, 0xd6, struct kvm_arm_rmm_psci_complete) > + > #endif /* __LINUX_KVM_H */