From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754563AbdCBJlm (ORCPT ); Thu, 2 Mar 2017 04:41:42 -0500 Received: from foss.arm.com ([217.140.101.70]:56730 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754531AbdCBJle (ORCPT ); Thu, 2 Mar 2017 04:41:34 -0500 Subject: Re: [PATCH V11 10/10] arm/arm64: KVM: add guest SEA support To: Xiongfeng Wang , James Morse References: <1487712121-16688-1-git-send-email-tbaicar@codeaurora.org> <1487712121-16688-11-git-send-email-tbaicar@codeaurora.org> <58B43092.6040401@arm.com> <3df82a7b-1a32-e2d7-ae78-7132a4eab1a0@huawei.com> <58B57941.3000703@arm.com> <4ff98823-d6f0-eb2e-4b98-f6d5e255f6c3@huawei.com> Cc: punit.agrawal@arm.com, mark.rutland@arm.com, linux-efi@vger.kernel.org, kvm@vger.kernel.org, rkrcmar@redhat.com, matt@codeblueprint.co.uk, catalin.marinas@arm.com, Tyler Baicar , will.deacon@arm.com, linux@armlinux.org.uk, paul.gortmaker@windriver.com, lv.zheng@intel.com, kvmarm@lists.cs.columbia.edu, fu.wei@linaro.org, tn@semihalf.com, zjzhang@codeaurora.org, robert.moore@intel.com, linux-acpi@vger.kernel.org, eun.taik.lee@samsung.com, shijie.huang@arm.com, labbott@redhat.com, lenb@kernel.org, harba@codeaurora.org, Suzuki.Poulose@arm.com, john.garry@huawei.com, rostedt@goodmis.org, nkaje@codeaurora.org, sandeepa.s.prabhu@gmail.com, linux-arm-kernel@lists.infradead.org, devel@acpica.org, rjw@rjwysocki.net, rruigrok@codeaurora.org, linux-kernel@vger.kernel.org, astone@redhat.com, hanjun.guo@linaro.org, joe@perches.com, pbonzini@redhat.com, akpm@linux-foundation.org, bristot@redhat.com, christoffer.dall@linaro.org, shiju.jose@huawei.com From: Marc Zyngier Organization: ARM Ltd Message-ID: <6d0fa5a5-bcbf-38b8-45ac-d645220ee9e2@arm.com> Date: Thu, 2 Mar 2017 09:39:21 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Icedove/45.6.0 MIME-Version: 1.0 In-Reply-To: <4ff98823-d6f0-eb2e-4b98-f6d5e255f6c3@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 On 01/03/17 02:31, Xiongfeng Wang wrote: [lot of things] > If an SEA is injected into guest OS, the guest OS will jump to the SEA > exception entry when the context switched to guest OS. And the CPSR and > FAR_EL1 are recovered according to the content of vcpu. Then the guest > OS can signal a process or panic. If another guest process read the > error data, another SEA will be generated and it will be single too. > > Without QEMU involved, the drawback is that no APEI table can be mocked > up in guest OS, and no memory_failure() will be called. So the memory of > error data will be released into buddy system and assigned to another > process. If the error was caused by instantaneous radiation or > electromagnetic, the memory is usable again if it is written with a > correct data. If the memory has wore out and a correct data is written, > the ECC error may occurs again with high possibility. Before a 2-bit ECC > error is reported, much more 1-bit errors will be reported. This is > report to host os, the host os can determine the memory node has worn > out and hot-plug out the memory node, and guest os may be terminated if > its memory data can't be migrated. > > Of course, it is better to get QEMU involved, so the memory_failure can > be executed in guest OS. But before that implemented, can we add SEA > injection in kvm_handle_guest_abort()? No. I will strongly object to that. This is a platform decision to forward SEAs, not an architectural one. The core KVM code is only concerned about implementing the ARM architecture, and not something that is firmware dependent. Thanks, M. -- Jazz is not dead. It just smells funny...