From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [uq/master patch 1/2] kvm-all.c: use recommended max vcpus limit Date: Sun, 18 Aug 2013 17:28:28 +0200 Message-ID: <5210E81C.7030109@redhat.com> References: <20130812195629.350634011@redhat.com> <20130812195730.079414823@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, gleb@redhat.com To: Marcelo Tosatti Return-path: Received: from mx1.redhat.com ([209.132.183.28]:62940 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751301Ab3HRP3Q (ORCPT ); Sun, 18 Aug 2013 11:29:16 -0400 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r7IFTGQF006530 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Sun, 18 Aug 2013 11:29:16 -0400 In-Reply-To: <20130812195730.079414823@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Il 12/08/2013 21:56, Marcelo Tosatti ha scritto: > Commit 8c3ba334f8588e1d5099f8602cf01897720e0eca, "KVM: x86: Raise the > hard VCPU count limit", upstream introduced the notion of a recommended > vcpu max limit. > > Switch the order so the recommended vcpu max limit is used instead of > the actual max vcpu limit. > > Signed-off-by: Marcelo Tosatti > > Index: qemu/kvm-all.c > =================================================================== > --- qemu.orig/kvm-all.c > +++ qemu/kvm-all.c > @@ -1321,11 +1321,11 @@ static int kvm_max_vcpus(KVMState *s) > * procedure from the kernel API documentation to cope with > * older kernels that may be missing capabilities. > */ > - ret = kvm_check_extension(s, KVM_CAP_MAX_VCPUS); > + ret = kvm_check_extension(s, KVM_CAP_NR_VCPUS); > if (ret) { > return ret; > } > - ret = kvm_check_extension(s, KVM_CAP_NR_VCPUS); > + ret = kvm_check_extension(s, KVM_CAP_MAX_VCPUS); > if (ret) { > return ret; > } > > This would break "working" configurations. Perhaps we should just warn if the VCPU limit exceeds KVM_CAP_NR_VCPUS, and fail if the VCPU limit exceeds KVM_CAP_MAX_VCPUS. Patch 2 is fine, ok to apply it (since it fixes a real bug) and then you can work on top of it? Paolo