Marcelo Tosatti wrote: > 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.kiszka@xxxxxxxxxxx> >>> 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. > And, of course, my WinXP installation did not trigger any reset issue, even in non-iothreaded mode. :( Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
