From patchwork Mon Mar 4 21:41:43 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kiszka X-Patchwork-Id: 2214781 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id D2AEBDF5B1 for ; Mon, 4 Mar 2013 21:41:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932669Ab3CDVlt (ORCPT ); Mon, 4 Mar 2013 16:41:49 -0500 Received: from mout.web.de ([212.227.17.12]:63998 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932254Ab3CDVlt (ORCPT ); Mon, 4 Mar 2013 16:41:49 -0500 Received: from mchn199C.mchp.siemens.de ([95.157.56.37]) by smtp.web.de (mrweb102) with ESMTPSA (Nemesis) id 0MbhRh-1USuyL1u5t-00Ipu8; Mon, 04 Mar 2013 22:41:44 +0100 Message-ID: <51351517.3090600@web.de> Date: Mon, 04 Mar 2013 22:41:43 +0100 From: Jan Kiszka User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 MIME-Version: 1.0 To: Gleb Natapov , Marcelo Tosatti CC: kvm , Paolo Bonzini Subject: [PATCH v2] KVM: x86: Convert INIT and SIPI signals into synchronously handled requests X-Enigmail-Version: 1.5 X-Provags-ID: V02:K0:eqoNkLrXmKFozKlb6TYRC44F8kIv/O2+3fhEQFuORTh yHBv5H68Ts3tcsCNyu4oxjXYQ7bGXSIX+uJ9+b5C9diJWz/C7s OCVD+VvD7EpOVxwuWICcvzlck+Aqe9SmctxfmTB4yN1w25bOZj 2g1jO5A+dPEa9lc8fKqBE0sGkKLEZOak2evzDG+wg7o+Rjq5bX m+345q/yZrjNiQT3Oun/g== Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Jan Kiszka A VCPU sending INIT or SIPI to some other VCPU races for setting the remote VCPU's mp_state. When we were unlucky, KVM_MP_STATE_INIT_RECEIVED was overwritten by kvm_emulate_halt and, thus, got lost. Fix this by raising requests on the sender side that will then be handled synchronously over the target VCPU context. Signed-off-by: Jan Kiszka --- Changes in v2: - check transition to INIT_RECEIVED in vcpu_enter_guest - removed return value of kvm_check_init_and_sipi - caller has to check for relevant transition afterward - add write barrier after setting sipi_vector arch/x86/kvm/lapic.c | 11 ++++++----- arch/x86/kvm/x86.c | 15 +++++++++++++++ include/linux/kvm_host.h | 2 ++ 3 files changed, 23 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 02b51dd..7986c9f 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -731,8 +731,7 @@ 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; - kvm_make_request(KVM_REQ_EVENT, vcpu); + kvm_make_request(KVM_REQ_INIT, vcpu); kvm_vcpu_kick(vcpu); } else { apic_debug("Ignoring de-assert INIT to vcpu %d\n", @@ -743,11 +742,13 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode, case APIC_DM_STARTUP: apic_debug("SIPI to vcpu %d vector 0x%02x\n", vcpu->vcpu_id, vector); - if (vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) { + if (vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED || + test_bit(KVM_REQ_INIT, &vcpu->requests)) { result = 1; vcpu->arch.sipi_vector = vector; - vcpu->arch.mp_state = KVM_MP_STATE_SIPI_RECEIVED; - kvm_make_request(KVM_REQ_EVENT, vcpu); + /* make sure sipi_vector is visible for the receiver */ + smp_wmb(); + kvm_make_request(KVM_REQ_SIPI, vcpu); kvm_vcpu_kick(vcpu); } break; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d0cf737..0be04b9 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5641,6 +5641,15 @@ static void update_eoi_exitmap(struct kvm_vcpu *vcpu) kvm_x86_ops->load_eoi_exitmap(vcpu, eoi_exit_bitmap); } +static void kvm_check_init_and_sipi(struct kvm_vcpu *vcpu) +{ + if (kvm_check_request(KVM_REQ_INIT, vcpu)) + vcpu->arch.mp_state = KVM_MP_STATE_INIT_RECEIVED; + if (kvm_check_request(KVM_REQ_SIPI, vcpu) && + vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) + vcpu->arch.mp_state = KVM_MP_STATE_SIPI_RECEIVED; +} + static int vcpu_enter_guest(struct kvm_vcpu *vcpu) { int r; @@ -5649,6 +5658,11 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) bool req_immediate_exit = 0; if (vcpu->requests) { + kvm_check_init_and_sipi(vcpu); + if (vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) { + r = 1; + goto out; + } if (kvm_check_request(KVM_REQ_MMU_RELOAD, vcpu)) kvm_mmu_unload(vcpu); if (kvm_check_request(KVM_REQ_MIGRATE_TIMER, vcpu)) @@ -6977,6 +6991,7 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm, int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu) { + kvm_check_init_and_sipi(vcpu); return (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE && !vcpu->arch.apf.halted) || !list_empty_careful(&vcpu->async_pf.done) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 722cae7..1a191c9 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -124,6 +124,8 @@ static inline bool is_error_page(struct page *page) #define KVM_REQ_MCLOCK_INPROGRESS 20 #define KVM_REQ_EPR_EXIT 21 #define KVM_REQ_EOIBITMAP 22 +#define KVM_REQ_INIT 23 +#define KVM_REQ_SIPI 24 #define KVM_USERSPACE_IRQ_SOURCE_ID 0 #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID 1