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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B5486C433EF for ; Wed, 11 May 2022 11:25:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241371AbiEKLZT (ORCPT ); Wed, 11 May 2022 07:25:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55182 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240169AbiEKLYu (ORCPT ); Wed, 11 May 2022 07:24:50 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A803A23277E for ; Wed, 11 May 2022 04:24:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1652268252; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=qyVh4yYbgKLJScnCPfU+OUbwX6+f1OtvAPiKUvEbSzQ=; b=Jp6zh4i7YNZRea71eu07vdYcD2K69pEwbHjTb6fAdFWRsadHNy1F626eqSkl4OhZCFjy5j ji0Hw2mtzEW7gbiJjT6DTI7PW+wtZ/f7+ZePKdJ4jQpjxJmATvP5WuYb/jV61ENFk/YeQw Tfvxi0NhPI/S/il6HtcjvXDNERV8yc8= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-461-j_qvobNEPxyE-MEDq4p5Ww-1; Wed, 11 May 2022 07:24:09 -0400 X-MC-Unique: j_qvobNEPxyE-MEDq4p5Ww-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4A6F32949BD7; Wed, 11 May 2022 11:24:09 +0000 (UTC) Received: from starship (unknown [10.40.192.26]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0947A14A5069; Wed, 11 May 2022 11:24:06 +0000 (UTC) Message-ID: <01b9b22398d791126c41e517816b1cd513af7326.camel@redhat.com> Subject: Re: [PATCH v3 08/34] KVM: x86: hyper-v: Use HV_MAX_SPARSE_VCPU_BANKS/HV_VCPUS_PER_SPARSE_BANK instead of raw '64' From: Maxim Levitsky To: Vitaly Kuznetsov , kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , Michael Kelley , Siddharth Chandrasekaran , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org Date: Wed, 11 May 2022 14:24:06 +0300 In-Reply-To: <20220414132013.1588929-9-vkuznets@redhat.com> References: <20220414132013.1588929-1-vkuznets@redhat.com> <20220414132013.1588929-9-vkuznets@redhat.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5 (3.36.5-2.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.85 on 10.11.54.7 Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org On Thu, 2022-04-14 at 15:19 +0200, Vitaly Kuznetsov wrote: > It may not be clear from where the '64' limit for the maximum sparse > bank number comes from, use HV_MAX_SPARSE_VCPU_BANKS define instead. > Use HV_VCPUS_PER_SPARSE_BANK in KVM_HV_MAX_SPARSE_VCPU_SET_BITS's > definition. Opportunistically adjust the comment around BUILD_BUG_ON(). > > No functional change. > > Suggested-by: Sean Christopherson > Signed-off-by: Vitaly Kuznetsov > --- > arch/x86/kvm/hyperv.c | 13 ++++++------- > 1 file changed, 6 insertions(+), 7 deletions(-) > > diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c > index fc4bb0ead9fa..3cf68645a2e6 100644 > --- a/arch/x86/kvm/hyperv.c > +++ b/arch/x86/kvm/hyperv.c > @@ -43,7 +43,7 @@ > /* "Hv#1" signature */ > #define HYPERV_CPUID_SIGNATURE_EAX 0x31237648 > > -#define KVM_HV_MAX_SPARSE_VCPU_SET_BITS DIV_ROUND_UP(KVM_MAX_VCPUS, 64) > +#define KVM_HV_MAX_SPARSE_VCPU_SET_BITS DIV_ROUND_UP(KVM_MAX_VCPUS, HV_VCPUS_PER_SPARSE_BANK) > > static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer, > bool vcpu_kick); > @@ -1798,7 +1798,7 @@ static u64 kvm_get_sparse_vp_set(struct kvm *kvm, struct kvm_hv_hcall *hc, > u64 *sparse_banks, int consumed_xmm_halves, > gpa_t offset) > { > - if (hc->var_cnt > 64) > + if (hc->var_cnt > HV_MAX_SPARSE_VCPU_BANKS) > return -EINVAL; > > /* Cap var_cnt to ignore banks that cannot contain a legal VP index. */ > @@ -1969,12 +1969,11 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) > gpa_t data_offset; > > /* > - * The Hyper-V TLFS doesn't allow more than 64 sparse banks, e.g. the > - * valid mask is a u64. Fail the build if KVM's max allowed number of > - * vCPUs (>4096) would exceed this limit, KVM will additional changes > - * for Hyper-V support to avoid setting the guest up to fail. > + * The Hyper-V TLFS doesn't allow more than HV_MAX_SPARSE_VCPU_BANKS > + * sparse banks. Fail the build if KVM's max allowed number of > + * vCPUs (>4096) exceeds this limit. > */ > - BUILD_BUG_ON(KVM_HV_MAX_SPARSE_VCPU_SET_BITS > 64); > + BUILD_BUG_ON(KVM_HV_MAX_SPARSE_VCPU_SET_BITS > HV_MAX_SPARSE_VCPU_BANKS); > > if (!hc->fast && is_guest_mode(vcpu)) { > hc->ingpa = translate_nested_gpa(vcpu, hc->ingpa, 0, NULL); Reviewed-by: Maxim Levitsky Best regards, Maxim Levitsky