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 F40AC199934; Thu, 1 May 2025 13:31:19 +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=1746106282; cv=none; b=b7l34jFuiA2otvGijg5oLV18+qv1crHBYPeh0afH3URdHm8uGaHWxYfdTJ3n2+sfP5b7cV1D5/jTUuxIJdLoBXc92VlxMfVozsMZEetYoRVDxYRfTwiPMzwXR8hD1lYVWwsbWS9XttR1PxiF+vz/WIH/Z5W9YBZ+m++TEOA6Ar0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746106282; c=relaxed/simple; bh=etO68qKb2gZAy7IEQvfp46hAtSkStH1cUiCh5zZ2IYg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=oloHpCokLgr1mxN3X0N8YC75F7pm52VgjxqJieUTuYBFAdl1EJ0jxyuivEkwyWYzyMVyV+oT3UedNATawJU6x1lBWdmq7SCkgVg5A2ovy+sM+brAt7qrrLzhkw4bCEKFoDvdFEdaTFlwnaNaesjfZl19f5Ap4ipeBdS75kiPwf0= 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 7407A168F; Thu, 1 May 2025 06:31:11 -0700 (PDT) Received: from [10.1.33.27] (e122027.cambridge.arm.com [10.1.33.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BCB6E3F5A1; Thu, 1 May 2025 06:31:14 -0700 (PDT) Message-ID: <93477779-bec8-4e6b-b6e5-edb82f664df7@arm.com> Date: Thu, 1 May 2025 14:31:12 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v8 05/43] arm64: RME: Check for RME support at KVM init To: Suzuki K Poulose , 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> <20250416134208.383984-6-steven.price@arm.com> From: Steven Price Content-Language: en-GB In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 25/04/2025 12:08, Suzuki K Poulose wrote: > On 16/04/2025 14:41, Steven Price wrote: >> Query the RMI version number and check if it is a compatible version. A >> static key is also provided to signal that a supported RMM is available. >> >> Functions are provided to query if a VM or VCPU is a realm (or rec) >> which currently will always return false. >> >> Later patches make use of struct realm and the states as the ioctls >> interfaces are added to support realm and REC creation and destruction. >> >> Signed-off-by: Steven Price >> Reviewed-by: Gavin Shan >> --- >> Changes since v6: >>   * Improved message for an unsupported RMI ABI version. >> Changes since v5: >>   * Reword "unsupported" message from "host supports" to "we want" to >>     clarify that 'we' are the 'host'. >> Changes since v2: >>   * Drop return value from kvm_init_rme(), it was always 0. >>   * Rely on the RMM return value to identify whether the RSI ABI is >>     compatible. >> --- >>   arch/arm64/include/asm/kvm_emulate.h | 18 +++++++++ >>   arch/arm64/include/asm/kvm_host.h    |  4 ++ >>   arch/arm64/include/asm/kvm_rme.h     | 56 ++++++++++++++++++++++++++++ >>   arch/arm64/include/asm/virt.h        |  1 + >>   arch/arm64/kvm/Makefile              |  3 +- >>   arch/arm64/kvm/arm.c                 |  6 +++ >>   arch/arm64/kvm/rme.c                 | 56 ++++++++++++++++++++++++++++ >>   7 files changed, 143 insertions(+), 1 deletion(-) >>   create mode 100644 arch/arm64/include/asm/kvm_rme.h >>   create mode 100644 arch/arm64/kvm/rme.c >> >> diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/ >> include/asm/kvm_emulate.h >> index d7cf66573aca..1c43a4fc25dd 100644 >> --- a/arch/arm64/include/asm/kvm_emulate.h >> +++ b/arch/arm64/include/asm/kvm_emulate.h >> @@ -686,4 +686,22 @@ static inline void vcpu_set_hcrx(struct kvm_vcpu >> *vcpu) >>               vcpu->arch.hcrx_el2 |= HCRX_EL2_EnFPM; >>       } >>   } >> + >> +static inline bool kvm_is_realm(struct kvm *kvm) >> +{ >> +    if (static_branch_unlikely(&kvm_rme_is_available) && kvm) >> +        return kvm->arch.is_realm; >> +    return false; >> +} >> + >> +static inline enum realm_state kvm_realm_state(struct kvm *kvm) >> +{ >> +    return READ_ONCE(kvm->arch.realm.state); >> +} >> + >> +static inline bool vcpu_is_rec(struct kvm_vcpu *vcpu) >> +{ >> +    return false; >> +} >> + >>   #endif /* __ARM64_KVM_EMULATE_H__ */ >> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/ >> asm/kvm_host.h >> index e98cfe7855a6..7bd81b86eab0 100644 >> --- a/arch/arm64/include/asm/kvm_host.h >> +++ b/arch/arm64/include/asm/kvm_host.h >> @@ -27,6 +27,7 @@ >>   #include >>   #include >>   #include >> +#include >>   #include >>     #define __KVM_HAVE_ARCH_INTC_INITIALIZED >> @@ -394,6 +395,9 @@ struct kvm_arch { >>        * the associated pKVM instance in the hypervisor. >>        */ >>       struct kvm_protected_vm pkvm; >> + >> +    bool is_realm; >> +    struct realm realm; >>   }; >>     struct kvm_vcpu_fault_info { >> diff --git a/arch/arm64/include/asm/kvm_rme.h b/arch/arm64/include/ >> asm/kvm_rme.h >> new file mode 100644 >> index 000000000000..9c8a0b23e0e4 >> --- /dev/null >> +++ b/arch/arm64/include/asm/kvm_rme.h >> @@ -0,0 +1,56 @@ >> +/* SPDX-License-Identifier: GPL-2.0 */ >> +/* >> + * Copyright (C) 2023 ARM Ltd. >> + */ >> + >> +#ifndef __ASM_KVM_RME_H >> +#define __ASM_KVM_RME_H >> + >> +/** >> + * enum realm_state - State of a Realm >> + */ >> +enum realm_state { >> +    /** >> +     * @REALM_STATE_NONE: >> +     *      Realm has not yet been created. rmi_realm_create() may be >> +     *      called to create the realm. >> +     */ >> +    REALM_STATE_NONE, >> +    /** >> +     * @REALM_STATE_NEW: >> +     *      Realm is under construction, not eligible for execution. >> Pages >> +     *      may be populated with rmi_data_create(). >> +     */ >> +    REALM_STATE_NEW, >> +    /** >> +     * @REALM_STATE_ACTIVE: >> +     *      Realm has been created and is eligible for execution with >> +     *      rmi_rec_enter(). Pages may no longer be populated with >> +     *      rmi_data_create(). >> +     */ >> +    REALM_STATE_ACTIVE, >> +    /** >> +     * @REALM_STATE_DYING: >> +     *      Realm is in the process of being destroyed or has already >> been >> +     *      destroyed. >> +     */ >> +    REALM_STATE_DYING, >> +    /** >> +     * @REALM_STATE_DEAD: >> +     *      Realm has been destroyed. >> +     */ >> +    REALM_STATE_DEAD >> +}; >> + >> +/** >> + * struct realm - Additional per VM data for a Realm >> + * >> + * @state: The lifetime state machine for the realm >> + */ >> +struct realm { >> +    enum realm_state state; >> +}; >> + >> +void kvm_init_rme(void); >> + >> +#endif /* __ASM_KVM_RME_H */ >> diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/ >> virt.h >> index ebf4a9f943ed..e45d47156dcf 100644 >> --- a/arch/arm64/include/asm/virt.h >> +++ b/arch/arm64/include/asm/virt.h >> @@ -81,6 +81,7 @@ void __hyp_reset_vectors(void); >>   bool is_kvm_arm_initialised(void); >>     DECLARE_STATIC_KEY_FALSE(kvm_protected_mode_initialized); >> +DECLARE_STATIC_KEY_FALSE(kvm_rme_is_available); >>     static inline bool is_pkvm_initialized(void) >>   { >> diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile >> index 209bc76263f1..2ebc66812d49 100644 >> --- a/arch/arm64/kvm/Makefile >> +++ b/arch/arm64/kvm/Makefile >> @@ -23,7 +23,8 @@ kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o >> pvtime.o \ >>        vgic/vgic-v3.o vgic/vgic-v4.o \ >>        vgic/vgic-mmio.o vgic/vgic-mmio-v2.o \ >>        vgic/vgic-mmio-v3.o vgic/vgic-kvm-device.o \ >> -     vgic/vgic-its.o vgic/vgic-debug.o vgic/vgic-v3-nested.o >> +     vgic/vgic-its.o vgic/vgic-debug.o vgic/vgic-v3-nested.o \ >> +     rme.o >>     kvm-$(CONFIG_HW_PERF_EVENTS)  += pmu-emul.o pmu.o >>   kvm-$(CONFIG_ARM64_PTR_AUTH)  += pauth.o >> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c >> index 68fec8c95fee..856a721d41ac 100644 >> --- a/arch/arm64/kvm/arm.c >> +++ b/arch/arm64/kvm/arm.c >> @@ -40,6 +40,7 @@ >>   #include >>   #include >>   #include >> +#include >>   #include >>     #include >> @@ -59,6 +60,8 @@ enum kvm_wfx_trap_policy { >>   static enum kvm_wfx_trap_policy kvm_wfi_trap_policy __read_mostly = >> KVM_WFX_NOTRAP_SINGLE_TASK; >>   static enum kvm_wfx_trap_policy kvm_wfe_trap_policy __read_mostly = >> KVM_WFX_NOTRAP_SINGLE_TASK; >>   +DEFINE_STATIC_KEY_FALSE(kvm_rme_is_available); >> + >>   DECLARE_KVM_HYP_PER_CPU(unsigned long, kvm_hyp_vector); >>     DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_base); >> @@ -2819,6 +2822,9 @@ static __init int kvm_arm_init(void) >>         in_hyp_mode = is_kernel_in_hyp_mode(); >>   +    if (in_hyp_mode) >> +        kvm_init_rme(); >> + > > minor nit: > > I wondering if this check is necessary. If the host is running under a > a hypervisor, it could relay the calls to the RMM. Nothing urgent, but > it is a possibility. It doesn't matter to the host as such. The > Realm Guest will do its own verification and the host can ignore > what lies beneath ? Reasonable point - I don't think we have anything yet that can do that sort of relaying. But I guess anything which handles the RMI API we should be compatible with, so there's no need specifically to require in_hyp_mode. Thanks, Steve > > Either ways, > > Reviewed-by: Suzuki K Poulose > >