Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752241Ab3CJLqw (ORCPT ); Sun, 10 Mar 2013 07:46:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:10219 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751764Ab3CJLqv (ORCPT ); Sun, 10 Mar 2013 07:46:51 -0400 Date: Sun, 10 Mar 2013 13:46:46 +0200 From: Gleb Natapov To: Paolo Bonzini Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, mtosatti@redhat.com, jan.kiszka@siemens.com Subject: Re: [PATCH] x86: kvm: reset the bootstrap processor when it gets an INIT Message-ID: <20130310114646.GM11223@redhat.com> References: <1362811713-25830-1-git-send-email-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1362811713-25830-1-git-send-email-pbonzini@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1554 Lines: 37 On Sat, Mar 09, 2013 at 07:48:33AM +0100, Paolo Bonzini wrote: > After receiving an INIT signal (either via the local APIC, or through > KVM_SET_MP_STATE), the bootstrap processor should reset immediately > and start execution at 0xfffffff0. Also, SIPIs have no effect on the > bootstrap processor. However, KVM currently does not differentiate > between the BSP and APs. > Userspace is capable of resetting vcpu by itself, so adding code to handle KVM_SET_MP_STATE(INIT) looks unnecessary to me. I think the simple patch below (not tested) should handle INIT for in-kernel irq chip and userspace does not need special handling for cpu reset. It already knows how to reset cpu on system_reset, so reseting only cpus should not be different. diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 02b51dd..6cb3c21 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -731,7 +731,9 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode, case APIC_DM_INIT: if (!trig_mode || level) { result = 1; - vcpu->arch.mp_state = KVM_MP_STATE_INIT_RECEIVED; + vcpu->arch.mp_state = kvm_vcpu_is_bsp(vcpu) ? + KVM_MP_STATE_SIPI_RECEIVED : + KVM_MP_STATE_INIT_RECEIVED; kvm_make_request(KVM_REQ_EVENT, vcpu); kvm_vcpu_kick(vcpu); } else { -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/