From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A650B1A0728; Fri, 30 May 2025 07:39:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.156.1 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748590786; cv=none; b=TetqeMW4fvSF7KCx+z+zp/WI+Cb/POvqNFfWSBkgnVBGf714MkU8CGu0fqbxg1GnCDR4NRhIOZCpmen3u0Ue1lYQggYunQ/86BUMD4n1Dih9Dltpyu4eSkVm/MJPEjp+eEcOdIF1Fz3o02dlerC1wafcvuPUW4jE/dc6QBYenNA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748590786; c=relaxed/simple; bh=wB1SE95KN7NJHuM8MAkkQhq66vP7wmN6W0MbPCDarbU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=o1VFfAnaDb7q3oUgWsRaHxs5UrUXrmBlZuWypMWDYe61QSM4jS1ywDOQIzJ7wucWGARB1napNWN2kjR8geXV3Yj2pKpuovZil7Cgpk0gJQeUuVEDxWKM7NZ7tWqosXbsqbNzDheoOB/K3AAXFtjcfgy5OT9d3S9U0eCd9sKZfgs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=AWBnHOO8; arc=none smtp.client-ip=148.163.156.1 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="AWBnHOO8" Received: from pps.filterd (m0356517.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 54U3moaa025476; Fri, 30 May 2025 07:39:41 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=pp1; bh=BqFfgN VCREIIj9Mnd2DOPwtUGsL8Sf0vQL1t8Nt/4cg=; b=AWBnHOO8moonQCMhZo2Dgz A+ho15PnbvtE4f1PfcfmHZQb3MocCwM+3lBPgTy/XXskJBvwTB9eWyygA2l17M4b uK3Lr9SvpxF5j8/RFcIY+EQjZWa8r/ml0VAOAferELC2tEnUFVtD4gYNGnVeTAji gxH9xNQZ8v3xY90jQeTySfQXedHmHYYjIow9zTR0ao9xwJ9RUAwzSr2xG4HmJlyf ZLlWdToXlUHp1H/h9QL2wb0tIPyb/8yL0bHYaFEhzV/lPxbctg+01190qvVNEYhG Xs2GFj+gEUBOb0X7dXjpmCBUoBMKso+HRYACOlewzQdARfNdFeFLLiVK5MNy1PmQ == Received: from ppma22.wdc07v.mail.ibm.com (5c.69.3da9.ip4.static.sl-reverse.com [169.61.105.92]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 46x40k25xu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 30 May 2025 07:39:40 +0000 (GMT) Received: from pps.filterd (ppma22.wdc07v.mail.ibm.com [127.0.0.1]) by ppma22.wdc07v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 54U6meBe030849; Fri, 30 May 2025 07:39:39 GMT Received: from smtprelay04.fra02v.mail.ibm.com ([9.218.2.228]) by ppma22.wdc07v.mail.ibm.com (PPS) with ESMTPS id 46uru10eqg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 30 May 2025 07:39:39 +0000 Received: from smtpav05.fra02v.mail.ibm.com (smtpav05.fra02v.mail.ibm.com [10.20.54.104]) by smtprelay04.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 54U7dZ6t26935870 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 30 May 2025 07:39:35 GMT Received: from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 64EF02004B; Fri, 30 May 2025 07:39:35 +0000 (GMT) Received: from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C487E20043; Fri, 30 May 2025 07:39:34 +0000 (GMT) Received: from [9.111.57.132] (unknown [9.111.57.132]) by smtpav05.fra02v.mail.ibm.com (Postfix) with ESMTP; Fri, 30 May 2025 07:39:34 +0000 (GMT) Message-ID: <2b9f0a39-2a97-45ab-a59e-bba0e1e3b2f0@linux.ibm.com> Date: Fri, 30 May 2025 09:39:34 +0200 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 1/3] KVM: s390: Set KVM_MAX_VCPUS to 256 To: Christoph Schlameuss , kvm@vger.kernel.org Cc: linux-s390@vger.kernel.org, Christian Borntraeger , Claudio Imbrenda , David Hildenbrand , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Sven Schnelle , Thomas Huth References: <20250522-rm-bsca-v3-0-51d169738fcf@linux.ibm.com> <20250522-rm-bsca-v3-1-51d169738fcf@linux.ibm.com> Content-Language: en-US From: Janosch Frank Autocrypt: addr=frankja@linux.ibm.com; keydata= xsFNBFubpD4BEADX0uhkRhkj2AVn7kI4IuPY3A8xKat0ihuPDXbynUC77mNox7yvK3X5QBO6 qLqYr+qrG3buymJJRD9xkp4mqgasHdB5WR9MhXWKH08EvtvAMkEJLnqxgbqf8td3pCQ2cEpv 15mH49iKSmlTcJ+PvJpGZcq/jE42u9/0YFHhozm8GfQdb9SOI/wBSsOqcXcLTUeAvbdqSBZe zuMRBivJQQI1esD9HuADmxdE7c4AeMlap9MvxvUtWk4ZJ/1Z3swMVCGzZb2Xg/9jZpLsyQzb lDbbTlEeyBACeED7DYLZI3d0SFKeJZ1SUyMmSOcr9zeSh4S4h4w8xgDDGmeDVygBQZa1HaoL Esb8Y4avOYIgYDhgkCh0nol7XQ5i/yKLtnNThubAcxNyryw1xSstnKlxPRoxtqTsxMAiSekk 0m3WJwvwd1s878HrQNK0orWd8BzzlSswzjNfQYLF466JOjHPWFOok9pzRs+ucrs6MUwDJj0S cITWU9Rxb04XyigY4XmZ8dywaxwi2ZVTEg+MD+sPmRrTw+5F+sU83cUstuymF3w1GmyofgsU Z+/ldjToHnq21MNa1wx0lCEipCCyE/8K9B9bg9pUwy5lfx7yORP3JuAUfCYb8DVSHWBPHKNj HTOLb2g2UT65AjZEQE95U2AY9iYm5usMqaWD39pAHfhC09/7NQARAQABzSVKYW5vc2NoIEZy YW5rIDxmcmFua2phQGxpbnV4LmlibS5jb20+wsF3BBMBCAAhBQJbm6Q+AhsjBQsJCAcCBhUI CQoLAgQWAgMBAh4BAheAAAoJEONU5rjiOLn4p9gQALjkdj5euJVI2nNT3/IAxAhQSmRhPEt0 AmnCYnuTcHRWPujNr5kqgtyER9+EMQ0ZkX44JU2q7OWxTdSNSAN/5Z7qmOR9JySvDOf4d3mS bMB5zxL9d8SbnSs1uW96H9ZBTlTQnmLfsiM9TetAjSrR8nUmjGhe2YUhJLR1v1LguME+YseT eXnLzIzqqpu311/eYiiIGcmaOjPCE+vFjcXL5oLnGUE73qSYiujwhfPCCUK0850o1fUAYq5p CNBCoKT4OddZR+0itKc/cT6NwEDwdokeg0+rAhxb4Rv5oFO70lziBplEjOxu3dqgIKbHbjza EXTb+mr7VI9O4tTdqrwJo2q9zLqqOfDBi7NDvZFLzaCewhbdEpDYVu6/WxprAY94hY3F4trT rQMHJKQENtF6ZTQc9fcT5I3gAmP+OEvDE5hcTALpWm6Z6SzxO7gEYCnF+qGXqp8sJVrweMub UscyLqHoqdZC2UG4LQ1OJ97nzDpIRe0g6oJ9ZIYHKmfw5jjwH6rASTld5MFWajWdNsqK15k/ RZnHAGICKVIBOBsq26m4EsBlfCdt3b/6emuBjUXR1pyjHMz2awWzCq6/6OWs5eANZ0sdosNq dq2v0ULYTazJz2rlCXV89qRa7ukkNwdBSZNEwsD4eEMicj1LSrqWDZMAALw50L4jxaMD7lPL jJbazsFNBFubpD4BEADAcUTRqXF/aY53OSH7IwIK9lFKxIm0IoFkOEh7LMfp7FGzaP7ANrZd cIzhZi38xyOkcaFY+npGEWvko7rlIAn0JpBO4x3hfhmhBD/WSY8LQIFQNNjEm3vzrMo7b9Jb JAqQxfbURY3Dql3GUzeWTG9uaJ00u+EEPlY8zcVShDltIl5PLih20e8xgTnNzx5c110lQSu0 iZv2lAE6DM+2bJQTsMSYiwKlwTuv9LI9Chnoo6+tsN55NqyMxYqJgElk3VzlTXSr3+rtSCwf tq2cinETbzxc1XuhIX6pu/aCGnNfuEkM34b7G1D6CPzDMqokNFbyoO6DQ1+fW6c5gctXg/lZ 602iEl4C4rgcr3+EpfoPUWzKeM8JXv5Kpq4YDxhvbitr8Dm8gr38+UKFZKlWLlwhQ56r/zAU v6LIsm11GmFs2/cmgD1bqBTNHHcTWwWtRTLgmnqJbVisMJuYJt4KNPqphTWsPY8SEtbufIlY HXOJ2lqUzOReTrie2u0qcSvGAbSfec9apTFl2Xko/ddqPcZMpKhBiXmY8tJzSPk3+G4tqur4 6TYAm5ouitJsgAR61Cu7s+PNuq/pTLDhK+6/Njmc94NGBcRA4qTuysEGE79vYWP2oIAU4Fv6 gqaWHZ4MEI2XTqH8wiwzPdCQPYsSE0fXWiYu7ObeErT6iLSTZGx4rQARAQABwsFfBBgBCAAJ BQJbm6Q+AhsMAAoJEONU5rjiOLn4DDEP/RuyckW65SZcPG4cMfNgWxZF8rVjeVl/9PBfy01K 8R0hajU40bWtXSMiby7j0/dMjz99jN6L+AJHJvrLz4qYRzn2Ys843W+RfXj62Zde4YNBE5SL jJweRCbMWKaJLj6499fctxTyeb9+AMLQS4yRSwHuAZLmAb5AyCW1gBcTWZb8ON5BmWnRqeGm IgC1EvCnHy++aBnHTn0m+zV89BhTLTUal35tcjUFwluBY39R2ux/HNlBO1GY3Z+WYXhBvq7q katThLjaQSmnOrMhzqYmdShP1leFTVbzXUUIYv/GbynO/YrL2gaQpaP1bEUEi8lUAfXJbEWG dnHFkciryi092E8/9j89DJg4mmZqOau7TtUxjRMlBcIliXkzSLUk+QvD4LK1kWievJse4mte FBdkWHfP4BH/+8DxapRcG1UAheSnSRQ5LiO50annOB7oXF+vgKIaie2TBfZxQNGAs3RQ+bga DchCqFm5adiSP5+OT4NjkKUeGpBe/aRyQSle/RropTgCi85pje/juYEn2P9UAgkfBJrOHvQ9 Z+2Sva8FRd61NJLkCJ4LFumRn9wQlX2icFbi8UDV3do0hXJRRYTWCxrHscMhkrFWLhYiPF4i phX7UNdOWBQ90qpHyAxHmDazdo27gEjfvsgYMdveKknEOTEb5phwxWgg7BcIDoJf9UMC In-Reply-To: <20250522-rm-bsca-v3-1-51d169738fcf@linux.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Authority-Analysis: v=2.4 cv=SdL3duRu c=1 sm=1 tr=0 ts=683960bc cx=c_pps a=5BHTudwdYE3Te8bg5FgnPg==:117 a=5BHTudwdYE3Te8bg5FgnPg==:17 a=IkcTkHD0fZMA:10 a=dt9VzEwgFbYA:10 a=VnNF1IyMAAAA:8 a=20KFwNOVAAAA:8 a=t99LfBpkyTFO0i67b_EA:9 a=QEXdDO2ut3YA:10 X-Proofpoint-GUID: Gxc3jkhqxxu33ty6JLajp9yWTIVLYHNs X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwNTMwMDA2MiBTYWx0ZWRfX7lTbV55hRShX OtwnQTG4dapiDAQItYPMBXFEjmilQPk6H61kYNp3AjwCU3tzKaab4jl8b5DgEsRfWNlqVkpFTPI LUotv1XPZAx9M59OUgnHprBYaCvFVjecD/t5/v+8QMkkBHu3dEOnYl2g7oy38QAX4wInJ40iycG W4vckehjVsZ7b+YgqX8N6P7MN7BUpUsbAspZtMKpjMgQ6I/V2IIiIY35MbxcUJdu5AOMLzmN23f KpmpFELP5oBzpIabhpGww4y/gowukHgHM84VxenvhjL+YlyfY83QR5jODaeKp2CemoTc4HItIoK aOYwl1tQdlNo3GNAPPzEdSJXdds1zwAOhYD5n5cKXyh8ULnvgKRGUViJVuR2aTa4LBMCAaYJg2C yB7atsGivd3fGMjum4fimfsGSTvyjH9QfzY4YuOkW5rybOyAi6G0b6n0WPHrzbFiXqiO34pn X-Proofpoint-ORIG-GUID: Gxc3jkhqxxu33ty6JLajp9yWTIVLYHNs X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1099,Hydra:6.0.736,FMLib:17.12.80.40 definitions=2025-05-30_03,2025-05-29_01,2025-03-28_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 lowpriorityscore=0 mlxscore=0 adultscore=0 priorityscore=1501 impostorscore=0 malwarescore=0 mlxlogscore=999 suspectscore=0 bulkscore=0 spamscore=0 clxscore=1015 classifier=spam authscore=0 authtc=n/a authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2505160000 definitions=main-2505300062 On 5/22/25 11:31 AM, Christoph Schlameuss wrote: > The s390x architecture allows for 256 vCPUs with a max CPUID of 255. > The current KVM implementation limits this to 248 when using the > extended system control area (ESCA). So this correction should not cause > any real world problems but actually correct the values returned by the > ioctls: > > * KVM_CAP_NR_VCPUS > * KVM_CAP_MAX_VCPUS > * KVM_CAP_MAX_VCPU_ID > > KVM_MAX_VCPUS is also moved to kvm_host_types to allow using this in > future type definitions. > > Reviewed-by: Claudio Imbrenda > Reviewed-by: Thomas Huth > Signed-off-by: Christoph Schlameuss > --- > arch/s390/include/asm/kvm_host.h | 2 -- > arch/s390/include/asm/kvm_host_types.h | 2 ++ > arch/s390/kvm/kvm-s390.c | 2 ++ > 3 files changed, 4 insertions(+), 2 deletions(-) [...] > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index 3f3175193fd7a7a26658eb2e2533d8037447a0b4..b65e4cbe67cf70a7d614607ebdd679060e7d31f4 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -638,6 +638,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) > r = KVM_S390_ESCA_CPU_SLOTS; > if (ext == KVM_CAP_NR_VCPUS) > r = min_t(unsigned int, num_online_cpus(), r); > + else if (ext == KVM_CAP_MAX_VCPU_ID) > + r -= 1; I went on a wild goose chase since this change broke the max vcpu selftest. Turns out that KVM_CAP_MAX_VCPU_ID is actually KVM_CAP_MAX_VCPU_ID_S_ but we can't rename it since it's part of the API (sigh). Have a look at the KVM changes and it will make a bit more sense.