From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NmQhm-000789-0z for qemu-devel@nongnu.org; Tue, 02 Mar 2010 06:56:02 -0500 Received: from [199.232.76.173] (port=42090 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NmQhk-000761-DD for qemu-devel@nongnu.org; Tue, 02 Mar 2010 06:56:00 -0500 Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim 4.60) (envelope-from ) id 1NmQhh-0003H4-64 for qemu-devel@nongnu.org; Tue, 02 Mar 2010 06:56:00 -0500 Received: from mx1.redhat.com ([209.132.183.28]:19253) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NmQhg-0003Gq-Qu for qemu-devel@nongnu.org; Tue, 02 Mar 2010 06:55:57 -0500 Date: Tue, 2 Mar 2010 08:55:31 -0300 From: Marcelo Tosatti Message-ID: <20100302115531.GA19713@amt.cnet> References: <2257cac7474705fc35d74fcdff0566fb7dc0770e.1267467030.git.jan.kiszka@siemens.com> <20100302001415.GA22627@amt.cnet> <4B8CC584.1060106@web.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4B8CC584.1060106@web.de> Subject: [Qemu-devel] Re: [PATCH 2/4] KVM: Rework VCPU state writeback API List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Avi Kivity , kvm@vger.kernel.org, qemu-devel@nongnu.org On Tue, Mar 02, 2010 at 09:00:04AM +0100, Jan Kiszka wrote: > Marcelo Tosatti wrote: > > On Mon, Mar 01, 2010 at 07:10:30PM +0100, Jan Kiszka wrote: > >> This grand cleanup drops all reset and vmsave/load related > >> synchronization points in favor of four(!) generic hooks: > >> > >> - cpu_synchronize_all_states in qemu_savevm_state_complete > >> (initial sync from kernel before vmsave) > >> - cpu_synchronize_all_post_init in qemu_loadvm_state > >> (writeback after vmload) > >> - cpu_synchronize_all_post_init in main after machine init > >> - cpu_synchronize_all_post_reset in qemu_system_reset > >> (writeback after system reset) > >> > >> These writeback points + the existing one of VCPU exec after > >> cpu_synchronize_state map on three levels of writeback: > >> > >> - KVM_PUT_RUNTIME_STATE (during runtime, other VCPUs continue to run) > >> - KVM_PUT_RESET_STATE (on synchronous system reset, all VCPUs stopped) > >> - KVM_PUT_FULL_STATE (on init or vmload, all VCPUs stopped as well) > >> > >> This level is passed to the arch-specific VCPU state writing function > >> that will decide which concrete substates need to be written. That way, > >> no writer of load, save or reset functions that interact with in-kernel > >> KVM states will ever have to worry about synchronization again. That > >> also means that a lot of reasons for races, segfaults and deadlocks are > >> eliminated. > >> > >> cpu_synchronize_state remains untouched, just as Anthony suggested. We > >> continue to need it before reading or writing of VCPU states that are > >> also tracked by in-kernel KVM subsystems. > >> > >> Consequently, this patch removes many cpu_synchronize_state calls that > >> are now redundant, just like remaining explicit register syncs. > >> > >> Signed-off-by: Jan Kiszka > > > > Jan, > > > > This patch breaks system reset of WinXP.32 install (more easily > > reproducible without iothread enabled). > > > > Screenshot attached. > > > > Strange - no issues with qemu-kvm? Any special command line switch? /me > goes scrounging for some installation XP32 CD in the meantime... No issues with qemu-kvm. Could not spot anything obvious. > > Jan >