From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932628AbeCOUmj (ORCPT ); Thu, 15 Mar 2018 16:42:39 -0400 Received: from foss.arm.com ([217.140.101.70]:47728 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752847AbeCOUmh (ORCPT ); Thu, 15 Mar 2018 16:42:37 -0400 Message-ID: <5AAADA1B.2030601@arm.com> Date: Thu, 15 Mar 2018 20:39:55 +0000 From: James Morse User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.6.0 MIME-Version: 1.0 To: Dongjiu Geng CC: rkrcmar@redhat.com, corbet@lwn.net, christoffer.dall@linaro.org, marc.zyngier@arm.com, linux@armlinux.org.uk, catalin.marinas@arm.com, rjw@rjwysocki.net, bp@alien8.de, lenb@kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-acpi@vger.kernel.org, devel@acpica.org, huangshaoyu@huawei.com Subject: Re: [PATCH v10 2/5] arm64: KVM: export the capability to set guest SError syndrome References: <1520093380-42577-1-git-send-email-gengdongjiu@huawei.com> <1520093380-42577-3-git-send-email-gengdongjiu@huawei.com> In-Reply-To: <1520093380-42577-3-git-send-email-gengdongjiu@huawei.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Dongjiu Geng, On 03/03/18 16:09, Dongjiu Geng wrote: > Before user space injects a SError, it needs to know whether it can > specify the guest Exception Syndrome, so KVM should tell user space > whether it has such capability. > diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt > index fc3ae95..8a3d708 100644 > --- a/Documentation/virtual/kvm/api.txt > +++ b/Documentation/virtual/kvm/api.txt > @@ -4415,3 +4415,14 @@ Parameters: none > This capability indicates if the flic device will be able to get/set the > AIS states for migration via the KVM_DEV_FLIC_AISM_ALL attribute and allows > to discover this without having to create a flic device. > + > +8.14 KVM_CAP_ARM_SET_SERROR_ESR > + > +Architectures: arm, arm64 > + > +This capability indicates that userspace can specify syndrome value reported to > +guest OS when guest takes a virtual SError interrupt exception. "when userspace triggers a virtual SError"... how? > +If KVM has this capability, userspace can only specify the ISS field for the ESR > +syndrome, can not specify the EC field which is not under control by KVM. Where do I put the ESR? If you re-order this after the patch that adds the API, you can describe how this can be used. Thanks, James > +If this virtual SError is taken to EL1 using AArch64, this value will be reported > +into ISS filed of ESR_EL1. > diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c > index 3256b92..38c8a64 100644 > --- a/arch/arm64/kvm/reset.c > +++ b/arch/arm64/kvm/reset.c > @@ -77,6 +77,9 @@ int kvm_arch_dev_ioctl_check_extension(struct kvm *kvm, long ext) > case KVM_CAP_ARM_PMU_V3: > r = kvm_arm_support_pmu_v3(); > break; > + case KVM_CAP_ARM_INJECT_SERROR_ESR: > + r = cpus_have_const_cap(ARM64_HAS_RAS_EXTN); > + break; > case KVM_CAP_SET_GUEST_DEBUG: > case KVM_CAP_VCPU_ATTRIBUTES: > r = 1; > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index 8fb90a0..3587b33 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -934,6 +934,7 @@ struct kvm_ppc_resize_hpt { > #define KVM_CAP_S390_AIS_MIGRATION 150 > #define KVM_CAP_PPC_GET_CPU_CHAR 151 > #define KVM_CAP_S390_BPB 152 > +#define KVM_CAP_ARM_INJECT_SERROR_ESR 153 > > #ifdef KVM_CAP_IRQ_ROUTING > >