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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 C0134C6778C for ; Wed, 4 Jul 2018 09:13:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 85C7823C45 for ; Wed, 4 Jul 2018 09:13:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 85C7823C45 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934089AbeGDJNs (ORCPT ); Wed, 4 Jul 2018 05:13:48 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:39732 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932648AbeGDJNn (ORCPT ); Wed, 4 Jul 2018 05:13:43 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 10AF840704A7; Wed, 4 Jul 2018 09:13:43 +0000 (UTC) Received: from vitty.brq.redhat.com.redhat.com (unknown [10.43.2.155]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2F3BB1C59E; Wed, 4 Jul 2018 09:13:39 +0000 (UTC) From: Vitaly Kuznetsov To: kys@linuxonhyperv.com Cc: x86@kernel.org, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, jasowang@redhat.com, tglx@linutronix.de, hpa@zytor.com, sthemmin@microsoft.com, Michael.H.Kelley@microsoft.com, kys@microsoft.com Subject: Re: [PATCH 1/1] X86/Hyper-V:: Fix the circular dependency in IPI enlightenment. References: <20180703230155.15160-1-kys@linuxonhyperv.com> Date: Wed, 04 Jul 2018 11:13:38 +0200 In-Reply-To: <20180703230155.15160-1-kys@linuxonhyperv.com> (kys@linuxonhyperv.com's message of "Tue, 3 Jul 2018 16:01:55 -0700") Message-ID: <87bmbnbby5.fsf@vitty.brq.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Wed, 04 Jul 2018 09:13:43 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Wed, 04 Jul 2018 09:13:43 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'vkuznets@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org kys@linuxonhyperv.com writes: > From: "K. Y. Srinivasan" > > The IPI hypercalls depend on being able to map the Linux notion of CPU ID > to the hypervisor's notion of the CPU ID. The array hv_vp_index[] provides > this mapping. Code for populating this array depends on the IPI functionality. > Break this circular dependency. > > Fixes: 68bb7bfb7985 ("X86/Hyper-V: Enable IPI enlightenments") > > Signed-off-by: K. Y. Srinivasan > Tested-by: Michael Kelley > --- > arch/x86/hyperv/hv_apic.c | 5 +++++ > arch/x86/hyperv/hv_init.c | 5 ++++- > arch/x86/include/asm/mshyperv.h | 2 ++ > 3 files changed, 11 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c > index f68855499391..63d7c196739f 100644 > --- a/arch/x86/hyperv/hv_apic.c > +++ b/arch/x86/hyperv/hv_apic.c > @@ -114,6 +114,8 @@ static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector) > ipi_arg->vp_set.format = HV_GENERIC_SET_SPARSE_4K; > nr_bank = cpumask_to_vpset(&(ipi_arg->vp_set), mask); > } > + if (nr_bank == -1) > + goto ipi_mask_ex_done; > if (!nr_bank) > ipi_arg->vp_set.format = HV_GENERIC_SET_ALL; > > @@ -158,6 +160,9 @@ static bool __send_ipi_mask(const struct cpumask *mask, int vector) > > for_each_cpu(cur_cpu, mask) { > vcpu = hv_cpu_number_to_vp_number(cur_cpu); > + if (vcpu == -1) > + goto ipi_mask_done; > + Nit: hv_vp_index is u32 *, it would make sense to use U32_MAX instead of '-1' everywhere in this patch. > /* > * This particular version of the IPI hypercall can > * only target upto 64 CPUs. > diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c > index 4c431e1c1eff..04159893702e 100644 > --- a/arch/x86/hyperv/hv_init.c > +++ b/arch/x86/hyperv/hv_init.c > @@ -265,7 +265,7 @@ void __init hyperv_init(void) > { > u64 guest_id, required_msrs; > union hv_x64_msr_hypercall_contents hypercall_msr; > - int cpuhp; > + int cpuhp, i; > > if (x86_hyper_type != X86_HYPER_MS_HYPERV) > return; > @@ -293,6 +293,9 @@ void __init hyperv_init(void) > if (!hv_vp_index) > return; > > + for (i = 0; i < num_possible_cpus(); i++) > + hv_vp_index[i] = -1; > + > hv_vp_assist_page = kcalloc(num_possible_cpus(), > sizeof(*hv_vp_assist_page), GFP_KERNEL); > if (!hv_vp_assist_page) { > diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h > index 3cd14311edfa..dee3f7347253 100644 > --- a/arch/x86/include/asm/mshyperv.h > +++ b/arch/x86/include/asm/mshyperv.h > @@ -281,6 +281,8 @@ static inline int cpumask_to_vpset(struct hv_vpset *vpset, > */ > for_each_cpu(cpu, cpus) { > vcpu = hv_cpu_number_to_vp_number(cpu); > + if (vcpu == -1) > + return -1; > vcpu_bank = vcpu / 64; > vcpu_offset = vcpu % 64; > __set_bit(vcpu_offset, (unsigned long *) -- Vitaly