From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36468) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X7DqL-0005u0-Ce for qemu-devel@nongnu.org; Tue, 15 Jul 2014 21:17:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1X7DqH-00005p-4w for qemu-devel@nongnu.org; Tue, 15 Jul 2014 21:17:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:64891) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X7DqG-0008W6-SU for qemu-devel@nongnu.org; Tue, 15 Jul 2014 21:17:09 -0400 Date: Tue, 15 Jul 2014 22:16:34 -0300 From: Marcelo Tosatti Message-ID: <20140716011634.GA30717@amt.cnet> References: <20140715050318.GD26186@grmbl.mre> <20140715210948.GA20036@amt.cnet> <53C5A4C9.80609@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] latest rc: virtio-blk hangs forever after migration List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Andrey Korolyov Cc: Amit Shah , Paolo Bonzini , Fam Zheng , "qemu-devel@nongnu.org" On Wed, Jul 16, 2014 at 03:40:47AM +0400, Andrey Korolyov wrote: > On Wed, Jul 16, 2014 at 2:01 AM, Paolo Bonzini wr= ote: > > Il 15/07/2014 23:25, Andrey Korolyov ha scritto: > > > >> On Wed, Jul 16, 2014 at 1:09 AM, Marcelo Tosatti > >> wrote: > >>> > >>> On Tue, Jul 15, 2014 at 06:01:08PM +0400, Andrey Korolyov wrote: > >>>> > >>>> On Tue, Jul 15, 2014 at 10:52 AM, Andrey Korolyov > >>>> wrote: > >>>>> > >>>>> On Tue, Jul 15, 2014 at 9:03 AM, Amit Shah > >>>>> wrote: > >>>>>> > >>>>>> On (Sun) 13 Jul 2014 [16:28:56], Andrey Korolyov wrote: > >>>>>>> > >>>>>>> Hello, > >>>>>>> > >>>>>>> the issue is not specific to the iothread code because generic > >>>>>>> virtio-blk also hangs up: > >>>>>> > >>>>>> > >>>>>> Do you know which version works well? If you could bisect, that= 'll > >>>>>> help a lot. > >>>>>> > >>>>>> Thanks, > >>>>>> Amit > >>>>> > >>>>> > >>>>> Hi, > >>>>> > >>>>> 2.0 works definitely well. I`ll try to finish bisection today, th= ough > >>>>> every step takes about 10 minutes to complete. > >>>> > >>>> > >>>> Yay! It is even outside of virtio-blk. > >>>> > >>>> commit 9b1786829aefb83f37a8f3135e3ea91c56001b56 > >>>> Author: Marcelo Tosatti > >>>> Date: Tue Jun 3 13:34:48 2014 -0300 > >>>> > >>>> kvmclock: Ensure proper env->tsc value for kvmclock_current_ns= ec > >>>> calculation > >>>> > >>>> Ensure proper env->tsc value for kvmclock_current_nsec calcula= tion. > >>>> > >>>> Reported-by: Marcin Gibu=C5=82a > >>>> Cc: qemu-stable@nongnu.org > >>>> Signed-off-by: Marcelo Tosatti > >>>> Signed-off-by: Paolo Bonzini > >>> > >>> > >>> Andrey, > >>> > >>> Can you please provide instructions on how to create reproducible > >>> environment? > >>> > >>> The following patch is equivalent to the original patch, for > >>> the purposes of fixing the kvmclock problem. > >>> > >>> Perhaps it becomes easier to spot the reason for the hang you are > >>> experiencing. > >>> > >>> > >>> diff --git a/hw/i386/kvm/clock.c b/hw/i386/kvm/clock.c > >>> index 272a88a..feb5fc5 100644 > >>> --- a/hw/i386/kvm/clock.c > >>> +++ b/hw/i386/kvm/clock.c > >>> @@ -17,7 +17,6 @@ > >>> #include "qemu/host-utils.h" > >>> #include "sysemu/sysemu.h" > >>> #include "sysemu/kvm.h" > >>> -#include "sysemu/cpus.h" > >>> #include "hw/sysbus.h" > >>> #include "hw/kvm/clock.h" > >>> > >>> @@ -66,7 +65,6 @@ static uint64_t kvmclock_current_nsec(KVMClockSta= te *s) > >>> > >>> cpu_physical_memory_read(kvmclock_struct_pa, &time, sizeof(tim= e)); > >>> > >>> - assert(time.tsc_timestamp <=3D migration_tsc); > >>> delta =3D migration_tsc - time.tsc_timestamp; > >>> if (time.tsc_shift < 0) { > >>> delta >>=3D -time.tsc_shift; > >>> @@ -125,8 +123,6 @@ static void kvmclock_vm_state_change(void *opaq= ue, > >>> int running, > >>> if (s->clock_valid) { > >>> return; > >>> } > >>> - > >>> - cpu_synchronize_all_states(); > >>> ret =3D kvm_vm_ioctl(kvm_state, KVM_GET_CLOCK, &data); > >>> if (ret < 0) { > >>> fprintf(stderr, "KVM_GET_CLOCK failed: %s\n", > >>> strerror(ret)); > >>> diff --git a/migration.c b/migration.c > >>> index 8d675b3..34f2325 100644 > >>> --- a/migration.c > >>> +++ b/migration.c > >>> @@ -608,6 +608,7 @@ static void *migration_thread(void *opaque) > >>> qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHE= R); > >>> old_vm_running =3D runstate_is_running(); > >>> > >>> + cpu_synchronize_all_states(); > >>> ret =3D vm_stop_force_state(RUN_STATE_FINISH_MIGRA= TE); > >>> if (ret >=3D 0) { > >>> qemu_file_set_rate_limit(s->file, INT64_MAX); > > > > > > It could also be useful to apply the above patch _and_ revert > > a096b3a6732f846ec57dc28b47ee9435aa0609bf, then try to reproduce. > > > > Paolo >=20 > Yes, it solved the issue for me! (it took much time to check because > most of country` debian mirrors went inconsistent by some reason) >=20 > Also trivial addition: >=20 > diff --git a/migration.c b/migration.c > index 34f2325..65d1c88 100644 > --- a/migration.c > +++ b/migration.c > @@ -25,6 +25,7 @@ > #include "qemu/thread.h" > #include "qmp-commands.h" > #include "trace.h" > +#include "sysemu/cpus.h" And what about not reverting a096b3a6732f846ec57dc28b47ee9435aa0609bf ? That is, test with a stock qemu.git tree and the patch sent today,=20 on this thread, to move cpu_synchronize_all_states ?