Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933540AbdDSIJS (ORCPT ); Wed, 19 Apr 2017 04:09:18 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:36757 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933524AbdDSIJL (ORCPT ); Wed, 19 Apr 2017 04:09:11 -0400 Subject: Re: [PATCH 4/4] KVM: x86: enable configurable MAX_VCPU To: =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , linux-kernel@vger.kernel.org, kvm@vger.kernel.org References: <20170413201951.11939-1-rkrcmar@redhat.com> <20170413201951.11939-5-rkrcmar@redhat.com> Cc: Christoffer Dall , Marc Zyngier , Paolo Bonzini , Cornelia Huck , James Hogan , Paul Mackerras , Alexander Graf From: Christian Borntraeger Date: Wed, 19 Apr 2017 10:08:58 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20170413201951.11939-5-rkrcmar@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 17041908-0028-0000-0000-0000076E1184 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006938; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000208; SDB=6.00849507; UDB=6.00419480; IPR=6.00628148; BA=6.00005301; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00015094; XFM=3.00000013; UTC=2017-04-19 08:09:04 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17041908-0029-0000-0000-00003536BB1E Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-04-19_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1704190076 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1443 Lines: 36 On 04/13/2017 10:19 PM, Radim Krčmář wrote: > The only user of KVM_MAX_VCPU is switched to kvm->max_vcpu. > > The limit could have been INT_MAX as it makes no difference, but there > is no point in making it bigger than KVM_MAX_VCPU_ID. > > Signed-off-by: Radim Krčmář > --- > arch/x86/include/asm/kvm_host.h | 1 + > arch/x86/kvm/irq_comm.c | 4 ++-- > 2 files changed, 3 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 2cc5ec7cc6f5..eeeb88eedabf 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -38,6 +38,7 @@ > #define KVM_MAX_VCPUS 288 > #define KVM_SOFT_MAX_VCPUS 240 > #define KVM_MAX_VCPU_ID 1023 > +#define KVM_CONFIGURABLE_MAX_VCPUS KVM_MAX_VCPU_ID > #define KVM_USER_MEM_SLOTS 509 > /* memory slots that are not exposed to userspace */ > #define KVM_PRIVATE_MEM_SLOTS 3 > diff --git a/arch/x86/kvm/irq_comm.c b/arch/x86/kvm/irq_comm.c > index 4517a4c2ac3a..a7baeb44539a 100644 > --- a/arch/x86/kvm/irq_comm.c > +++ b/arch/x86/kvm/irq_comm.c > @@ -60,7 +60,7 @@ int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src, > { > int i, r = -1; > struct kvm_vcpu *vcpu, *lowest = NULL; > - unsigned long dest_vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)]; > + unsigned long dest_vcpu_bitmap[BITS_TO_LONGS(kvm->max_vcpus)]; Doesnt that allow unlimited stack usage?