From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 23666C433E1 for ; Tue, 4 Aug 2020 17:06:30 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id DCBE92086A for ; Tue, 4 Aug 2020 17:06:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="aUf2HULJ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DCBE92086A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 7D9AA4B57A; Tue, 4 Aug 2020 13:06:29 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@redhat.com Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id tYStRxQfY6UY; Tue, 4 Aug 2020 13:06:28 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 380FC4B795; Tue, 4 Aug 2020 13:06:28 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 7A0644B584 for ; Tue, 4 Aug 2020 13:06:26 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 4yS+KlSkKf9o for ; Tue, 4 Aug 2020 13:06:25 -0400 (EDT) Received: from us-smtp-1.mimecast.com (us-smtp-1.mimecast.com [205.139.110.61]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 7ECF84B72C for ; Tue, 4 Aug 2020 13:06:25 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1596560785; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=sAkg/Iwx4xnjg6Rnu+uqLzEQ6JwtFTxMfaav6AgT7dU=; b=aUf2HULJrvi4X0c6DuuzV1T4Hjs5kfHoo76GSnOa8LGAUNqnfw9nlNuT+WtgggggrrAU6H ouS8BiBMQ6Arr1hQ9uSXMoyjW01n8jYxOxx/YyWul3XE0Co7E0+cutjPPXdsrdimPtEXX+ 2dlIwkJspsePptmD+9eUbClJsJnY11k= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-66-HN4gs_NwNji8AcnAAw6L6A-1; Tue, 04 Aug 2020 13:06:21 -0400 X-MC-Unique: HN4gs_NwNji8AcnAAw6L6A-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E15E2800475; Tue, 4 Aug 2020 17:06:19 +0000 (UTC) Received: from kamzik.brq.redhat.com (unknown [10.40.192.120]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3F97272E48; Tue, 4 Aug 2020 17:06:18 +0000 (UTC) From: Andrew Jones To: kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu Subject: [PATCH v2 6/6] arm64/x86: KVM: Introduce steal-time cap Date: Tue, 4 Aug 2020 19:06:04 +0200 Message-Id: <20200804170604.42662-7-drjones@redhat.com> In-Reply-To: <20200804170604.42662-1-drjones@redhat.com> References: <20200804170604.42662-1-drjones@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Cc: maz@kernel.org, pbonzini@redhat.com, steven.price@arm.com X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu arm64 requires a vcpu fd (KVM_HAS_DEVICE_ATTR vcpu ioctl) to probe support for steal-time. However this is unnecessary, as only a KVM fd is required, and it complicates userspace (userspace may prefer delaying vcpu creation until after feature probing). Introduce a cap that can be checked instead. While x86 can already probe steal-time support with a kvm fd (KVM_GET_SUPPORTED_CPUID), we add the cap there too for consistency. Reviewed-by: Steven Price Signed-off-by: Andrew Jones --- Documentation/virt/kvm/api.rst | 13 +++++++++++++ arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/kvm/arm.c | 3 +++ arch/arm64/kvm/pvtime.c | 2 +- arch/x86/kvm/x86.c | 3 +++ include/uapi/linux/kvm.h | 1 + 6 files changed, 22 insertions(+), 1 deletion(-) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 3bd96c1a3962..51208c5d6ac2 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6152,3 +6152,16 @@ KVM can therefore start protected VMs. This capability governs the KVM_S390_PV_COMMAND ioctl and the KVM_MP_STATE_LOAD MP_STATE. KVM_SET_MP_STATE can fail for protected guests when the state change is invalid. + +8.24 KVM_CAP_STEAL_TIME +----------------------- + +:Architectures: arm64, x86 + +This capability indicates that KVM supports steal time accounting. +When steal time accounting is supported it may be enabled with +architecture-specific interfaces. This capability and the architecture- +specific interfaces must be consistent, i.e. if one says the feature +is supported, than the other should as well and vice versa. For arm64 +see Documentation/virt/kvm/devices/vcpu.rst "KVM_ARM_VCPU_PVTIME_CTRL". +For x86 see Documentation/virt/kvm/msr.rst "MSR_KVM_STEAL_TIME". diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 1b65dfeb6fed..57c44bc56087 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -505,6 +505,7 @@ long kvm_hypercall_pv_features(struct kvm_vcpu *vcpu); gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu); void kvm_update_stolen_time(struct kvm_vcpu *vcpu); +bool kvm_arm_pvtime_supported(void); int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); int kvm_arm_pvtime_get_attr(struct kvm_vcpu *vcpu, diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 90cb90561446..0f7f8cd2f341 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -222,6 +222,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) */ r = 1; break; + case KVM_CAP_STEAL_TIME: + r = kvm_arm_pvtime_supported(); + break; default: r = kvm_arch_vm_ioctl_check_extension(kvm, ext); break; diff --git a/arch/arm64/kvm/pvtime.c b/arch/arm64/kvm/pvtime.c index 75234321d896..920ac43077ad 100644 --- a/arch/arm64/kvm/pvtime.c +++ b/arch/arm64/kvm/pvtime.c @@ -71,7 +71,7 @@ gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu) return base; } -static bool kvm_arm_pvtime_supported(void) +bool kvm_arm_pvtime_supported(void) { return !!sched_info_on(); } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 88c593f83b28..27fc86bb28c4 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3538,6 +3538,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_HYPERV_ENLIGHTENED_VMCS: r = kvm_x86_ops.nested_ops->enable_evmcs != NULL; break; + case KVM_CAP_STEAL_TIME: + r = sched_info_on(); + break; default: break; } diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 4fdf30316582..121fb29ac004 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1031,6 +1031,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_PPC_SECURE_GUEST 181 #define KVM_CAP_HALT_POLL 182 #define KVM_CAP_ASYNC_PF_INT 183 +#define KVM_CAP_STEAL_TIME 184 #ifdef KVM_CAP_IRQ_ROUTING -- 2.25.4 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm