Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752133AbaGBJN5 (ORCPT ); Wed, 2 Jul 2014 05:13:57 -0400 Received: from mga11.intel.com ([192.55.52.93]:17219 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751412AbaGBJNz convert rfc822-to-8bit (ORCPT ); Wed, 2 Jul 2014 05:13:55 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,587,1400050800"; d="scan'208";a="556307899" From: "Hu, Robert" To: Jan Kiszka , Wanpeng Li , Paolo Bonzini , "Gleb Natapov" CC: "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH] KVM: nVMX: Fix IRQs inject to L2 which belong to L1 since race Thread-Topic: [PATCH] KVM: nVMX: Fix IRQs inject to L2 which belong to L1 since race Thread-Index: AQHPldSKdY2V8Q1LP0KBuNcMMbpgWpuMf9GQ Date: Wed, 2 Jul 2014 09:13:53 +0000 Message-ID: <9E79D1C9A97CFD4097BCE431828FDD3198359C@SHSMSX103.ccr.corp.intel.com> References: <1404284054-51863-1-git-send-email-wanpeng.li@linux.intel.com> <9E79D1C9A97CFD4097BCE431828FDD31983416@SHSMSX103.ccr.corp.intel.com> <53B3CADD.3000504@siemens.com> In-Reply-To: <53B3CADD.3000504@siemens.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: Jan Kiszka [mailto:jan.kiszka@siemens.com] > Sent: Wednesday, July 2, 2014 5:03 PM > To: Hu, Robert; Wanpeng Li; Paolo Bonzini; Gleb Natapov > Cc: kvm@vger.kernel.org; linux-kernel@vger.kernel.org > Subject: Re: [PATCH] KVM: nVMX: Fix IRQs inject to L2 which belong to L1 since > race > > On 2014-07-02 09:20, Hu, Robert wrote: > >> -----Original Message----- > >> From: Wanpeng Li [mailto:wanpeng.li@linux.intel.com] > >> Sent: Wednesday, July 2, 2014 2:54 PM > >> To: Paolo Bonzini; Jan Kiszka; Gleb Natapov > >> Cc: Hu, Robert; kvm@vger.kernel.org; linux-kernel@vger.kernel.org; Wanpeng > Li > >> Subject: [PATCH] KVM: nVMX: Fix IRQs inject to L2 which belong to L1 since > race > >> > >> This patch fix bug https://bugzilla.kernel.org/show_bug.cgi?id=72381 > >> > >> If we didn't inject a still-pending event to L1 since nested_run_pending, > >> KVM_REQ_EVENT should be requested after the vmexit in order to inject the > >> event to L1. However, current log blindly request a KVM_REQ_EVENT even if > >> there is no still-pending event to L1 which blocked by nested_run_pending. > >> There is a race which lead to an interrupt will be injected to L2 which > >> belong to L1 if L0 send an interrupt to L1 during this window. > >> > >> VCPU0 another thread > >> > >> L1 intr not blocked on L2 first entry > >> vmx_vcpu_run req event > >> kvm check request req event > >> check_nested_events don't have any intr > >> not nested exit > >> intr occur (8254, lapic timer > >> etc) > >> inject_pending_event now have intr > >> inject interrupt > >> > >> This patch fix this race by introduced a l1_events_blocked field in nested_vmx > >> which indicates there is still-pending event which blocked by > >> nested_run_pending, > >> and smart request a KVM_REQ_EVENT if there is a still-pending event which > >> blocked > >> by nested_run_pending. > >> > >> Signed-off-by: Wanpeng Li > > Tested-by: Robert Hu > > Do you happen to have a kvm-unit-test for this race? Or how did you > test? Just curious, and if there is a test, it would be good to > integrate it. I just apply the patch and test the reported scenario. > > Jan > > -- > Siemens AG, Corporate Technology, CT RTC ITP SES-DE > Corporate Competence Center Embedded Linux -- 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/