From patchwork Mon Mar 18 16:14:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Woodhouse X-Patchwork-Id: 13595585 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5EF7DC54E5D for ; Mon, 18 Mar 2024 16:47:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=kU9fv6hn+PIuwF4rmJz7/WSq10zHqdHUmXiqIKmbGhY=; b=RopaKnPbzsobtV lyPAJuL9hU72zW6R6FGVhsCtvY2Ua1Pp1RcVPr1DohUaTl9Sq18oK9gwnj9902RAJ0Wkrp4dQwLN3 tAq+gjxf44NYHza/9nnWZ0YEKbs6Vdh2V5qQ3OAsEsV//TYGu6qiYYba2BjrBw3hBGmDI6IFhwcCT EDUWTbtUFFNH0FP8T4cHUWgfyKi2UCHUB6P9Dc51jcn0C6Dstt4XOSxi34BebEf9QA5ZZaevlVpbN Uw+f8w1tjj1yA+tzinlcYQb4xtO4Yan4nI4nAjg47RIkGTSFIU+6YOJneMt4OEbhUi9Sa5ntS+duN l+zfGao2OoQzWpmhWZcg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rmG8m-00000009I5Q-40iZ; Mon, 18 Mar 2024 16:47:12 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rmG8i-00000009I3u-2htm for linux-arm-kernel@bombadil.infradead.org; Mon, 18 Mar 2024 16:47:08 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=Xyw6pk7zn4iFLKziLAKf5sK11Uu17VrJE78dXX+5XEk=; b=Yfi4kdXFo5ww+yFo2Q7L746RO3 hXmuv4GJNX1gSMcu8d4JM2BIxo4Tv57TKIHP3sLhORGEVEpNrnRcgy6XJrWwv6e6B5mlMSB8d8ld8 oCJL5M45rPGtGqABzd69bZzMnl7ahUwZ88dbMbwNy5Ha94r6xqk2tJQjHA3dugoOAD3pLrlyxi4BC BpRugeUSo6NDW85TPieORghou9/cVyJOW8H6tQi3U2ciyMrQKWqgIbaWmlaB/8ozEqMXH8ojBtrw6 Xm9ffYFVCQHJ9yJ7TVWayK59u4IqEmUvtQRjxjnYIo8oqMNF4yE78m7CqlGjxFK38aN1qm4IWagVi 4UM2cRBQ==; Received: from [2001:8b0:10b:1::ebe] (helo=i7.infradead.org) by desiato.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1rmG8Z-0000000CjyB-1jje; Mon, 18 Mar 2024 16:46:59 +0000 Received: from dwoodhou by i7.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1rmG8W-00000004F1G-16xY; Mon, 18 Mar 2024 16:46:56 +0000 From: David Woodhouse To: linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org Cc: Paolo Bonzini , Jonathan Corbet , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon , Mark Rutland , Lorenzo Pieralisi , "Rafael J. Wysocki" , Len Brown , Pavel Machek , David Woodhouse , Mostafa Saleh , Jean-Philippe Brucker , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-pm@vger.kernel.org Subject: [RFC PATCH v2 2/4] KVM: arm64: Add PSCI SYSTEM_OFF2 function for hibernation Date: Mon, 18 Mar 2024 16:14:24 +0000 Message-ID: <20240318164646.1010092-3-dwmw2@infradead.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240318164646.1010092-1-dwmw2@infradead.org> References: <20240318164646.1010092-1-dwmw2@infradead.org> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by desiato.infradead.org. See http://www.infradead.org/rpr.html X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: David Woodhouse The PSCI v1.3 specification (alpha) adds support for a SYSTEM_OFF2 function which is analogous to ACPI S4 state. This will allow hosting environments to determine that a guest is hibernated rather than just powered off, and ensure that they preserve the virtual environment appropriately to allow the guest to resume safely (or bump the hardware_signature in the FACS to trigger a clean reboot instead). The beta version will be changed to say that PSCI_FEATURES returns a bit mask of the supported hibernate types, which is implemented here. Signed-off-by: David Woodhouse --- Documentation/virt/kvm/api.rst | 11 +++++++++ arch/arm64/include/asm/kvm_host.h | 2 ++ arch/arm64/include/uapi/asm/kvm.h | 6 +++++ arch/arm64/kvm/arm.c | 5 +++++ arch/arm64/kvm/psci.c | 37 +++++++++++++++++++++++++++++++ include/uapi/linux/kvm.h | 1 + 6 files changed, 62 insertions(+) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 0b5a33ee71ee..ff061b6a2393 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6761,6 +6761,10 @@ the first `ndata` items (possibly zero) of the data array are valid. the guest issued a SYSTEM_RESET2 call according to v1.1 of the PSCI specification. + - for arm64, data[0] is set to KVM_SYSTEM_EVENT_SHUTDOWN_FLAG_PSCI_OFF2 + if the guest issued a SYSTEM_OFF2 call according to v1.3 of the PSCI + specification. + - for RISC-V, data[0] is set to the value of the second argument of the ``sbi_system_reset`` call. @@ -6794,6 +6798,13 @@ either: - Deny the guest request to suspend the VM. See ARM DEN0022D.b 5.19.2 "Caller responsibilities" for possible return values. +Hibernation using the PSCI SYSTEM_OFF2 call is enabled with the +KVM_CAP_ARM_SYSTEM_OFF2 VM capability. If a guest invokes the PSCI +SYSTEM_OFF2 function, KVM will exit to userspace with the +KVM_SYSTEM_EVENT_SHUTDOWN event type and with data[0] set to +KVM_SYSTEM_EVENT_SHUTDOWN_FLAG_PSCI_OFF2. The only supported hibernate +type for the SYSTEM_OFF2 function is HIBERNATE_OFF (0x0). + :: /* KVM_EXIT_IOAPIC_EOI */ diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 6883963bbc3a..6ed05791afdb 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -299,6 +299,8 @@ struct kvm_arch { #define KVM_ARCH_FLAG_ID_REGS_INITIALIZED 7 /* Fine-Grained UNDEF initialised */ #define KVM_ARCH_FLAG_FGU_INITIALIZED 8 + /* PSCI SYSTEM_OFF2 (hibernate) enabled for the guest */ +#define KVM_ARCH_FLAG_SYSTEM_OFF2_ENABLED 9 unsigned long flags; /* VM-wide vCPU feature set */ diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index 964df31da975..66736ff04011 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -484,6 +484,12 @@ enum { */ #define KVM_SYSTEM_EVENT_RESET_FLAG_PSCI_RESET2 (1ULL << 0) +/* + * Shutdown caused by a PSCI v1.3 SYSTEM_OFF2 call. + * Valid only when the system event has a type of KVM_SYSTEM_EVENT_SHUTDOWN. + */ +#define KVM_SYSTEM_EVENT_SHUTDOWN_FLAG_PSCI_OFF2 (1ULL << 0) + /* run->fail_entry.hardware_entry_failure_reason codes. */ #define KVM_EXIT_FAIL_ENTRY_CPU_UNSUPPORTED (1ULL << 0) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 3dee5490eea9..47d23064d6f7 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -98,6 +98,10 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, r = 0; set_bit(KVM_ARCH_FLAG_SYSTEM_SUSPEND_ENABLED, &kvm->arch.flags); break; + case KVM_CAP_ARM_SYSTEM_OFF2: + r = 0; + set_bit(KVM_ARCH_FLAG_SYSTEM_OFF2_ENABLED, &kvm->arch.flags); + break; case KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE: new_cap = cap->args[0]; @@ -243,6 +247,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_VCPU_ATTRIBUTES: case KVM_CAP_PTP_KVM: case KVM_CAP_ARM_SYSTEM_SUSPEND: + case KVM_CAP_ARM_SYSTEM_OFF2: case KVM_CAP_IRQFD_RESAMPLE: case KVM_CAP_COUNTER_OFFSET: r = 1; diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c index 1f69b667332b..59570eea8aa7 100644 --- a/arch/arm64/kvm/psci.c +++ b/arch/arm64/kvm/psci.c @@ -194,6 +194,12 @@ static void kvm_psci_system_off(struct kvm_vcpu *vcpu) kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN, 0); } +static void kvm_psci_system_off2(struct kvm_vcpu *vcpu) +{ + kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN, + KVM_SYSTEM_EVENT_SHUTDOWN_FLAG_PSCI_OFF2); +} + static void kvm_psci_system_reset(struct kvm_vcpu *vcpu) { kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET, 0); @@ -353,6 +359,11 @@ static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor) if (test_bit(KVM_ARCH_FLAG_SYSTEM_SUSPEND_ENABLED, &kvm->arch.flags)) val = 0; break; + case PSCI_1_3_FN_SYSTEM_OFF2: + case PSCI_1_3_FN64_SYSTEM_OFF2: + if (test_bit(KVM_ARCH_FLAG_SYSTEM_OFF2_ENABLED, &kvm->arch.flags)) + val = 1UL << PSCI_1_3_HIBERNATE_TYPE_OFF; + break; case PSCI_1_1_FN_SYSTEM_RESET2: case PSCI_1_1_FN64_SYSTEM_RESET2: if (minor >= 1) @@ -374,6 +385,32 @@ static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor) return 0; } break; + case PSCI_1_3_FN_SYSTEM_OFF2: + kvm_psci_narrow_to_32bit(vcpu); + fallthrough; + case PSCI_1_3_FN64_SYSTEM_OFF2: + if (!test_bit(KVM_ARCH_FLAG_SYSTEM_OFF2_ENABLED, &kvm->arch.flags)) + break; + + arg = smccc_get_arg1(vcpu); + if (arg != PSCI_1_3_HIBERNATE_TYPE_OFF) { + val = PSCI_RET_INVALID_PARAMS; + break; + } + kvm_psci_system_off2(vcpu); + /* + * We shouldn't be going back to guest VCPU after + * receiving SYSTEM_OFF2 request. + * + * If user space accidentally/deliberately resumes + * guest VCPU after SYSTEM_OFF request then guest + * VCPU should see internal failure from PSCI return + * value. To achieve this, we preload r0 (or x0) with + * PSCI return value INTERNAL_FAILURE. + */ + val = PSCI_RET_INTERNAL_FAILURE; + ret = 0; + break; case PSCI_1_1_FN_SYSTEM_RESET2: kvm_psci_narrow_to_32bit(vcpu); fallthrough; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 2190adbe3002..caa3845b80d6 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -917,6 +917,7 @@ struct kvm_enable_cap { #define KVM_CAP_MEMORY_ATTRIBUTES 233 #define KVM_CAP_GUEST_MEMFD 234 #define KVM_CAP_VM_TYPES 235 +#define KVM_CAP_ARM_SYSTEM_OFF2 236 struct kvm_irq_routing_irqchip { __u32 irqchip;