From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH 4/4] KVM: Rework of guest debug state writing Date: Mon, 08 Feb 2010 17:07:04 +0100 Message-ID: <4B7036A8.5080108@siemens.com> References: <372238c800e0d57815f472502fdf78e53463bbb6.1265232579.git.jan.kiszka@siemens.com> <20100203234929.GA11012@amt.cnet> <4B6A15EE.4050501@web.de> <20100204130038.GA15671@amt.cnet> <4B6AE1E6.9040805@siemens.com> <4B6AEAB8.3030509@siemens.com> <20100204180555.GA3861@amt.cnet> <4B6B179A.3080704@siemens.com> <4B6B194A.90009@siemens.com> <20100208155226.GC2887@amt.cnet> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Anthony Liguori , "qemu-devel@nongnu.org" , Avi Kivity , "kvm@vger.kernel.org" To: Marcelo Tosatti Return-path: Received: from david.siemens.de ([192.35.17.14]:21274 "EHLO david.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752157Ab0BHQHa (ORCPT ); Mon, 8 Feb 2010 11:07:30 -0500 In-Reply-To: <20100208155226.GC2887@amt.cnet> Sender: kvm-owner@vger.kernel.org List-ID: Marcelo Tosatti wrote: > On Thu, Feb 04, 2010 at 08:00:26PM +0100, Jan Kiszka wrote: >> Jan Kiszka wrote: >>> Marcelo Tosatti wrote: >>>> Unrelated to this problem, won't put_vcpu_events, which is executed >>>> after KVM_SET_GUEST_DEBUG, overwrite any queued debug exceptions? >>> Good point, SET_GUEST_DEBUG should be last in the writeback for that reason. >> Actually, we no longer need the exception injection via SET_GUEST_DEBUG >> now that we have full access via vcpu_events. > >> So this needs a cleanup, and I'm afraid quite a few cases are broken >> ATM with vcpu_events writeback overwriting the reinjected exceptions. > > Don't see what you mean here. Can you be more explicit? What breakage? SET_GUEST_DEBUG and SET_VCPU_EVENTS are mutually exclusive. If we have the latter, don't use the former for exception injection anymore. And this is broken already without any of my patches applied, that was my point. Will work on this soon. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NeW8k-0000N3-RF for qemu-devel@nongnu.org; Mon, 08 Feb 2010 11:07:10 -0500 Received: from [199.232.76.173] (port=52788 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NeW8k-0000Mv-EO for qemu-devel@nongnu.org; Mon, 08 Feb 2010 11:07:10 -0500 Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim 4.60) (envelope-from ) id 1NeW8i-00080e-VI for qemu-devel@nongnu.org; Mon, 08 Feb 2010 11:07:10 -0500 Received: from david.siemens.de ([192.35.17.14]:21105) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1NeW8i-0007zn-C8 for qemu-devel@nongnu.org; Mon, 08 Feb 2010 11:07:08 -0500 Message-ID: <4B7036A8.5080108@siemens.com> Date: Mon, 08 Feb 2010 17:07:04 +0100 From: Jan Kiszka MIME-Version: 1.0 References: <372238c800e0d57815f472502fdf78e53463bbb6.1265232579.git.jan.kiszka@siemens.com> <20100203234929.GA11012@amt.cnet> <4B6A15EE.4050501@web.de> <20100204130038.GA15671@amt.cnet> <4B6AE1E6.9040805@siemens.com> <4B6AEAB8.3030509@siemens.com> <20100204180555.GA3861@amt.cnet> <4B6B179A.3080704@siemens.com> <4B6B194A.90009@siemens.com> <20100208155226.GC2887@amt.cnet> In-Reply-To: <20100208155226.GC2887@amt.cnet> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: [PATCH 4/4] KVM: Rework of guest debug state writing List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Marcelo Tosatti Cc: Anthony Liguori , "qemu-devel@nongnu.org" , "kvm@vger.kernel.org" , Avi Kivity Marcelo Tosatti wrote: > On Thu, Feb 04, 2010 at 08:00:26PM +0100, Jan Kiszka wrote: >> Jan Kiszka wrote: >>> Marcelo Tosatti wrote: >>>> Unrelated to this problem, won't put_vcpu_events, which is executed >>>> after KVM_SET_GUEST_DEBUG, overwrite any queued debug exceptions? >>> Good point, SET_GUEST_DEBUG should be last in the writeback for that reason. >> Actually, we no longer need the exception injection via SET_GUEST_DEBUG >> now that we have full access via vcpu_events. > >> So this needs a cleanup, and I'm afraid quite a few cases are broken >> ATM with vcpu_events writeback overwriting the reinjected exceptions. > > Don't see what you mean here. Can you be more explicit? What breakage? SET_GUEST_DEBUG and SET_VCPU_EVENTS are mutually exclusive. If we have the latter, don't use the former for exception injection anymore. And this is broken already without any of my patches applied, that was my point. Will work on this soon. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux