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[34.68.225.194]) by smtp.gmail.com with ESMTPSA id y3-20020a92c983000000b002c7dce8329fsm10292511iln.72.2022.03.22.16.06.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Mar 2022 16:06:07 -0700 (PDT) Date: Tue, 22 Mar 2022 23:06:04 +0000 From: Oliver Upton To: Gavin Shan Cc: kvmarm@lists.cs.columbia.edu, maz@kernel.org, linux-kernel@vger.kernel.org, eauger@redhat.com, shan.gavin@gmail.com, Jonathan.Cameron@huawei.com, pbonzini@redhat.com, vkuznets@redhat.com, will@kernel.org Subject: Re: [PATCH v5 15/22] KVM: arm64: Support SDEI_EVENT_SIGNAL hypercall Message-ID: References: <20220322080710.51727-1-gshan@redhat.com> <20220322080710.51727-16-gshan@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220322080710.51727-16-gshan@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Gavin, On Tue, Mar 22, 2022 at 04:07:03PM +0800, Gavin Shan wrote: > This supports SDEI_EVENT_SIGNAL hypercall. It's used by the guest > to inject SDEI event, whose number must be zero to the specified > vCPU. As the routing mode and affinity isn't supported yet, the > calling vCPU is assumed to be the target. > > The SDEI event 0x0 is a private one, with normal priority. It's > usually used for testing. I don't know if that is actually the case. One real use that immediately comes to mind is doing an NMI on a wedged CPU. KVM probably shouldn't glean at how the guest may use a particular call, so at most we should just point at the spec and state that event 0 is for software signaled events. > Signed-off-by: Gavin Shan > --- > arch/arm64/kvm/sdei.c | 64 ++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 63 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c > index a24270378305..ba2ca65c871b 100644 > --- a/arch/arm64/kvm/sdei.c > +++ b/arch/arm64/kvm/sdei.c > @@ -726,6 +726,66 @@ static int do_inject_event(struct kvm_vcpu *vcpu, > return 0; > } > > +static unsigned long hypercall_signal(struct kvm_vcpu *vcpu) > +{ > + struct kvm *kvm = vcpu->kvm; > + struct kvm_sdei_kvm *ksdei = kvm->arch.sdei; > + struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei; > + struct kvm_sdei_exposed_event *exposed_event; > + struct kvm_sdei_registered_event *registered_event; > + unsigned long event_num = smccc_get_arg1(vcpu); > + int index; > + unsigned long ret = SDEI_SUCCESS; > + > + /* @event_num must be zero */ > + if (!kvm_sdei_is_default(event_num)) { 0 isn't KVM's default event. I'd argue KVM doesn't have a default event to begin with. This has a precise definition coming from the spec. In fact, 'KVM_SDEI_DEFAULT_EVENT' should probably be eliminated, and any missing SDEI definitions should be added to include/uapi/linux/arm_sdei.h. That goes for any values coming from the specification. KVM's implementation details belong in a KVM header :) -- Thanks, Oliver 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 Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57956C433F5 for ; Tue, 22 Mar 2022 23:06:13 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id C473149F4E; Tue, 22 Mar 2022 19:06:12 -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=@google.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 DOAi7kKXAiFL; Tue, 22 Mar 2022 19:06:11 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 9844349F07; Tue, 22 Mar 2022 19:06:11 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 6AD8449EFC for ; Tue, 22 Mar 2022 19:06:10 -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 9oC5iSKhDMKj for ; Tue, 22 Mar 2022 19:06:09 -0400 (EDT) Received: from mail-io1-f44.google.com (mail-io1-f44.google.com [209.85.166.44]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 4A9CC49ED7 for ; Tue, 22 Mar 2022 19:06:09 -0400 (EDT) Received: by mail-io1-f44.google.com with SMTP id c23so22015297ioi.4 for ; Tue, 22 Mar 2022 16:06:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=21fg6XWhU71tdjvtfle0AJij7OP2A2tXWl2jGQhNfvU=; b=WmVfjk0ZQjejqSijckp6Pw+yiFEK2WgK97TPc650R9vz61ruco/HdtN/loRXvj/fZY TpoYto7Qkfc1WWv0Kti0nvVS1+cIHPLHqziHvknk/NGBdxjXGOKeJWQ6fv/cimzX4qSU uTZtPGjqDZ2AJlTc0y0m2g0n/rlQHpTeeDGGRjAqhE/F4aWTp/km/QlYmiEUMjDGBwpt AOU+vDFwhqaG7US7+OvkH+hM6ITRrhBhvOWg9CqaHdcMwBAYyOWx8zN+DUL9eAFkIo/F smHrN1GRopkkH4wgH+6RD3BzpK6hfOMC8wSDZWFguX3hupusBLvAls19QuRtGUoaTIqK SUIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=21fg6XWhU71tdjvtfle0AJij7OP2A2tXWl2jGQhNfvU=; b=fk10Q7FhrrsW5iv/FPbHAIb0pKmTj21H7pQye1H69QM6mLn4+pA8x1BZHoSE6J+5Tb XV6h5u8y78c+3rwNq/UBgCrTAcUyuPLo/EusmAiCh94ng4xfOInR8Oqq3puItRO4Q9jA /oyvH+3vi2IFsLaS/szZC9VC8GJUTlg/c1ikQy+CT7IlaP1HLEu8SHoOM7NSIX55X4b0 Re78czs52eMJU/6jJDxxoVJOzEDLmSo/Uo18uz0v4S/4gD1JOM8eD9Fqx2t291QavEBK 5zTajAKIrq3wKF0Qq68mPHJ6VscbX+r63jYcJLkut4+iQUd+sTaTCKk73JDTu2C/xiTo Pi/Q== X-Gm-Message-State: AOAM530NvYWc5DNxw2OVH/w8ssKL12GDDmyqlOWStsyar1jR6crvafCk XrSF/bEMIDthPS3YPvQLqKgiHw== X-Google-Smtp-Source: ABdhPJzGCE6EzVZman8fSiUohf3D8+V2/3CWoBE09YGE21g6Vy6+LY5kvFh/StgAYK6rV9NtGAC5Xg== X-Received: by 2002:a05:6638:1511:b0:319:fde7:501c with SMTP id b17-20020a056638151100b00319fde7501cmr14282398jat.13.1647990368349; Tue, 22 Mar 2022 16:06:08 -0700 (PDT) Received: from google.com (194.225.68.34.bc.googleusercontent.com. [34.68.225.194]) by smtp.gmail.com with ESMTPSA id y3-20020a92c983000000b002c7dce8329fsm10292511iln.72.2022.03.22.16.06.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Mar 2022 16:06:07 -0700 (PDT) Date: Tue, 22 Mar 2022 23:06:04 +0000 From: Oliver Upton To: Gavin Shan Subject: Re: [PATCH v5 15/22] KVM: arm64: Support SDEI_EVENT_SIGNAL hypercall Message-ID: References: <20220322080710.51727-1-gshan@redhat.com> <20220322080710.51727-16-gshan@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220322080710.51727-16-gshan@redhat.com> Cc: maz@kernel.org, linux-kernel@vger.kernel.org, eauger@redhat.com, shan.gavin@gmail.com, Jonathan.Cameron@huawei.com, pbonzini@redhat.com, vkuznets@redhat.com, will@kernel.org, kvmarm@lists.cs.columbia.edu 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 Hi Gavin, On Tue, Mar 22, 2022 at 04:07:03PM +0800, Gavin Shan wrote: > This supports SDEI_EVENT_SIGNAL hypercall. It's used by the guest > to inject SDEI event, whose number must be zero to the specified > vCPU. As the routing mode and affinity isn't supported yet, the > calling vCPU is assumed to be the target. > > The SDEI event 0x0 is a private one, with normal priority. It's > usually used for testing. I don't know if that is actually the case. One real use that immediately comes to mind is doing an NMI on a wedged CPU. KVM probably shouldn't glean at how the guest may use a particular call, so at most we should just point at the spec and state that event 0 is for software signaled events. > Signed-off-by: Gavin Shan > --- > arch/arm64/kvm/sdei.c | 64 ++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 63 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c > index a24270378305..ba2ca65c871b 100644 > --- a/arch/arm64/kvm/sdei.c > +++ b/arch/arm64/kvm/sdei.c > @@ -726,6 +726,66 @@ static int do_inject_event(struct kvm_vcpu *vcpu, > return 0; > } > > +static unsigned long hypercall_signal(struct kvm_vcpu *vcpu) > +{ > + struct kvm *kvm = vcpu->kvm; > + struct kvm_sdei_kvm *ksdei = kvm->arch.sdei; > + struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei; > + struct kvm_sdei_exposed_event *exposed_event; > + struct kvm_sdei_registered_event *registered_event; > + unsigned long event_num = smccc_get_arg1(vcpu); > + int index; > + unsigned long ret = SDEI_SUCCESS; > + > + /* @event_num must be zero */ > + if (!kvm_sdei_is_default(event_num)) { 0 isn't KVM's default event. I'd argue KVM doesn't have a default event to begin with. This has a precise definition coming from the spec. In fact, 'KVM_SDEI_DEFAULT_EVENT' should probably be eliminated, and any missing SDEI definitions should be added to include/uapi/linux/arm_sdei.h. That goes for any values coming from the specification. KVM's implementation details belong in a KVM header :) -- Thanks, Oliver _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm