From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756261Ab3D1BcL (ORCPT ); Sat, 27 Apr 2013 21:32:11 -0400 Received: from g1t0029.austin.hp.com ([15.216.28.36]:8847 "EHLO g1t0029.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755352Ab3D1BcJ (ORCPT ); Sat, 27 Apr 2013 21:32:09 -0400 From: Chegu Vinod To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: gleb@redhat.com, Chegu Vinod Subject: [PATCH] KVM: x86: Increase the "hard" max VCPU limit Date: Sat, 27 Apr 2013 18:31:04 -0700 Message-Id: <1367112664-19862-1-git-send-email-chegu_vinod@hp.com> X-Mailer: git-send-email 1.7.5.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org KVM guests today use 8bit APIC ids allowing for 256 ID's. Reserving one ID for Broadcast interrupts should leave 255 ID's. In case of KVM there is no need for reserving another ID for IO-APIC so the hard max limit for VCPUS can be increased from 254 to 255. (This was confirmed by Gleb Natapov http://article.gmane.org/gmane.comp.emulators.kvm.devel/99713 ) Signed-off-by: Chegu Vinod --- arch/x86/include/asm/kvm_host.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 4979778..bc57bfa 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -31,7 +31,7 @@ #include #include -#define KVM_MAX_VCPUS 254 +#define KVM_MAX_VCPUS 255 #define KVM_SOFT_MAX_VCPUS 160 #define KVM_USER_MEM_SLOTS 125 /* memory slots that are not exposed to userspace */ -- 1.7.1