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 B3B87C433EF for ; Tue, 23 Nov 2021 16:38:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239680AbhKWQlZ (ORCPT ); Tue, 23 Nov 2021 11:41:25 -0500 Received: from mail.kernel.org ([198.145.29.99]:46236 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238679AbhKWQko (ORCPT ); Tue, 23 Nov 2021 11:40:44 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5641360FC1; Tue, 23 Nov 2021 16:37:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1637685456; bh=prfRBXHT11HlDy6/ki/x5/yNTAkx8jJUHgj1Ha8Fo/g=; h=From:To:Cc:Subject:Date:From; b=osNx2g9R5xqbRFq0Uq1I5Gyg+Y9itDUq5FODxPzaBSDE3NzVfcVnXErJ6HTZTFOYw PAzrTb5gmih20S6JS3pvRxShrTmNqrDbDbxgP7Z2dVUxyXMLOXxpbr4Lg7nb2BBYcS uw1ieWJFY2jP6RMGENNCbHRkm8c/3WmOo5tTCgnVN6ykOxXx6dOnN5bio6sMYvlUCy GquKZgp61ZlQ6piylYpebzuLxkJjnt3w4a3RIsnbwb/a0h2iKyT1UQYze6JfrwceG6 wYmZKS0xBQrNU8kUwzwVtpBWv/kB4afVLMpE9SbWLZ05DmYhIJAFi2xbYj89InRy97 9QoHFak/8pfdQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vitaly Kuznetsov , Christian Borntraeger , Christian Borntraeger , Paolo Bonzini , Sasha Levin , frankja@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, kvm@vger.kernel.org, linux-s390@vger.kernel.org Subject: [PATCH MANUALSEL 4.9 1/2] KVM: s390: Cap KVM_CAP_NR_VCPUS by num_online_cpus() Date: Tue, 23 Nov 2021 11:37:32 -0500 Message-Id: <20211123163733.289925-1-sashal@kernel.org> X-Mailer: git-send-email 2.33.0 MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vitaly Kuznetsov [ Upstream commit 82cc27eff4486f8e79ef8faac1af1f5573039aa4 ] KVM_CAP_NR_VCPUS is a legacy advisory value which on other architectures return num_online_cpus() caped by KVM_CAP_NR_VCPUS or something else (ppc and arm64 are special cases). On s390, KVM_CAP_NR_VCPUS returns the same as KVM_CAP_MAX_VCPUS and this may turn out to be a bad 'advice'. Switch s390 to returning caped num_online_cpus() too. Acked-by: Christian Borntraeger Signed-off-by: Vitaly Kuznetsov Reviewed-by: Christian Borntraeger Message-Id: <20211116163443.88707-6-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- arch/s390/kvm/kvm-s390.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index d8fd2eadcda7f..b8f67d19e132d 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -399,6 +399,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = KVM_MAX_VCPUS; else if (sclp.has_esca && sclp.has_64bscao) r = KVM_S390_ESCA_CPU_SLOTS; + if (ext == KVM_CAP_NR_VCPUS) + r = min_t(unsigned int, num_online_cpus(), r); break; case KVM_CAP_NR_MEMSLOTS: r = KVM_USER_MEM_SLOTS; -- 2.33.0