On Mon, Nov 07, 2022 at 06:31:00PM +0100, Christian A. Ehrhardt wrote: > On Mon, Nov 07, 2022 at 08:30:32AM -0500, Michael S. Tsirkin wrote: > > On Sun, Nov 06, 2022 at 07:00:33PM +0100, Christian A. Ehrhardt wrote: > > > > > > Hi, > > > > > > On Sat, Nov 05, 2022 at 12:43:05PM -0400, Michael S. Tsirkin wrote: > > > > On Sat, Nov 05, 2022 at 05:35:57PM +0100, Bernhard Beschow wrote: > > > > > > > > > > > > > > > On Wed, Nov 2, 2022 at 5:24 PM Michael S. Tsirkin <m...@redhat.com> > > > > > wrote: > > > > > > > > > > From: Yajun Wu <yaj...@nvidia.com> > > > > > > > > > > This patch is part of adding vhost-user vhost_dev_start support. > > > > > The > > > > > motivation is to improve backend configuration speed and reduce > > > > > live > > > > > migration VM downtime. > > > > > > > > > > Moving the device start routines after finishing all the > > > > > necessary device > > > > > and VQ configuration, further aligning to the virtio > > > > > specification for > > > > > "device initialization sequence". > > > > > > > > > > Following patch will add vhost-user vhost_dev_start support. > > > > > > > > > > Signed-off-by: Yajun Wu <yaj...@nvidia.com> > > > > > Acked-by: Parav Pandit <pa...@nvidia.com> > > > > > > > > > > Message-Id: <20221017064452.1226514-2-yaj...@nvidia.com> > > > > > Reviewed-by: Michael S. Tsirkin <m...@redhat.com> > > > > > Signed-off-by: Michael S. Tsirkin <m...@redhat.com> > > > > > --- > > > > > hw/block/vhost-user-blk.c | 18 +++++++++++------- > > > > > hw/net/vhost_net.c | 12 ++++++------ > > > > > 2 files changed, 17 insertions(+), 13 deletions(-) > > > > > > > > > > > > > > > A git bisect tells me that this is the first bad commit for failing > > > > > qos-tests > > > > > which only fail when parallel jobs are enabled, e.g. `make > > > > > check-qtest -j8`: > > > > > > Parallel test run is not required provided that the test machine is > > > sufficiently busy (load > number of CPU threads). In this case a single > > > invocation of the qos test will fail reliably with this change. > > > > > > However, the change is not really the root cause of the failures. > > > > > > > > Summary of Failures: > > > > > > > > > > 76/541 qemu:qtest+qtest-aarch64 / qtest-aarch64/qos-test > > > > > > > > > > ERROR 18.68s killed by signal 6 SIGABRT > > > > > 77/541 qemu:qtest+qtest-arm / qtest-arm/qos-test > > > > > > > > > > ERROR 17.60s killed by signal 6 SIGABRT > > > > > 93/541 qemu:qtest+qtest-i386 / qtest-i386/qos-test > > > > > > > > > > ERROR 18.98s killed by signal 6 SIGABRT > > > > > 108/541 qemu:qtest+qtest-ppc64 / qtest-ppc64/qos-test > > > > > > > > > > ERROR 16.40s killed by signal 6 SIGABRT > > > > > 112/541 qemu:qtest+qtest-i386 / qtest-i386/bios-tables-test > > > > > > > > > > ERROR 145.94s killed by signal 6 SIGABRT > > > > > 130/541 qemu:qtest+qtest-x86_64 / qtest-x86_64/qos-test > > > > > > > > > > ERROR 17.32s killed by signal 6 SIGABRT > > > > > 243/541 qemu:qtest+qtest-x86_64 / qtest-x86_64/bios-tables-test > > > > > > > > > > ERROR 127.70s killed by signal 6 SIGABRT > > > > > > > > > > Ok: 500 > > > > > Expected Fail: 0 > > > > > Fail: 7 > > > > > Unexpected Pass: 0 > > > > > Skipped: 34 > > > > > Timeout: 0 > > > > > > > > > > Can anyone else reproduce this? > > > > > > > > Could you pls try latest for_upstream in my tree? > > > > That should have this fixed. > > > > > > Your new pull request simply drops this change and this does fix > > > make check-qtest. However, this looks accidental to me and the real > > > bug is there in plain origin/master, too. > > > > > > What happens is this backtrace a recursive call to vu_gpio_stop > > > via the backtrace below. It is caused by a delayed of the TCP > > > connection (the delayed part only triggers with heavy load on the > > > machine). > > > > > > You can get the failure back (probably in upstream) if the test is > > > forced to us "use-started=off" which can be set on the command line. > > > E.g. like this: > > > > > > diff --git a/tests/qtest/libqos/virtio-gpio.c > > > b/tests/qtest/libqos/virtio-gpio.c > > > index 762aa6695b..17c6b71e8b 100644 > > > --- a/tests/qtest/libqos/virtio-gpio.c > > > +++ b/tests/qtest/libqos/virtio-gpio.c > > > @@ -154,14 +154,14 @@ static void virtio_gpio_register_nodes(void) > > > QOSGraphEdgeOptions edge_opts = { }; > > > > > > /* vhost-user-gpio-device */ > > > - edge_opts.extra_device_opts = "id=gpio0,chardev=chr-vhost-user-test"; > > > + edge_opts.extra_device_opts = > > > "id=gpio0,chardev=chr-vhost-user-test,use-started=off"; > > > qos_node_create_driver("vhost-user-gpio-device", > > > virtio_gpio_device_create); > > > qos_node_consumes("vhost-user-gpio-device", "virtio-bus", > > > &edge_opts); > > > qos_node_produces("vhost-user-gpio-device", "vhost-user-gpio"); > > > > > > /* virtio-gpio-pci */ > > > - edge_opts.extra_device_opts = > > > "id=gpio0,addr=04.0,chardev=chr-vhost-user-test"; > > > + edge_opts.extra_device_opts = > > > "id=gpio0,addr=04.0,chardev=chr-vhost-user-test,use-started=on"; > > > add_qpci_address(&edge_opts, &addr); > > > qos_node_create_driver("vhost-user-gpio-pci", > > > virtio_gpio_pci_create); > > > qos_node_consumes("vhost-user-gpio-pci", "pci-bus", &edge_opts); > > > > > > > > > I haven't verified this but from looking at the code other types of > > > vhost devices seem to have the same problem (e.g. vhost-user-i2c looks > > > suspicious). > > > > > > Ok, here's the backtrace: > > > > > > #0 vu_gpio_stop (vdev=vdev@entry=0x560e0ae449d0) at > > > ../hw/virtio/vhost-user-gpio.c:143 > > > #1 0x0000560e0768fb1f in vu_gpio_disconnect (dev=<optimized out>) at > > > ../hw/virtio/vhost-user-gpio.c:260 > > > #2 vu_gpio_event (opaque=<optimized out>, event=<optimized out>) at > > > ../hw/virtio/vhost-user-gpio.c:279 > > > #3 0x0000560e078057b5 in tcp_chr_disconnect_locked (chr=0x560e0a00f800) > > > at ../chardev/char-socket.c:470 > > > #4 0x0000560e078058d3 in tcp_chr_write (chr=0x560e0a00f800, > > > buf=<optimized out>, len=<optimized out>) at ../chardev/char-socket.c:129 > > > #5 0x0000560e07808a63 in qemu_chr_write_buffer > > > (s=s@entry=0x560e0a00f800, buf=buf@entry=0x7ffc76812ac0 <error: Cannot > > > access memory at address 0x7ffc76812ac0>, len=20, > > > offset=offset@entry=0x7ffc76812a40, write_all=write_all@entry=true) at > > > ../chardev/char.c:121 > > > #6 0x0000560e07808e84 in qemu_chr_write (s=0x560e0a00f800, > > > buf=buf@entry=0x7ffc76812ac0 <error: Cannot access memory at address > > > 0x7ffc76812ac0>, len=len@entry=20, write_all=write_all@entry=true) at > > > ../chardev/char.c:173 > > > #7 0x0000560e078010e6 in qemu_chr_fe_write_all > > > (be=be@entry=0x560e0ae44bc0, buf=buf@entry=0x7ffc76812ac0 <error: Cannot > > > access memory at address 0x7ffc76812ac0>, len=len@entry=20) at > > > ../chardev/char-fe.c:53 > > > #8 0x0000560e07676d16 in vhost_user_write (msg=msg@entry=0x7ffc76812ac0, > > > fds=fds@entry=0x0, fd_num=fd_num@entry=0, dev=<optimized out>, > > > dev=<optimized out>) at ../hw/virtio/vhost-user.c:490 > > > #9 0x0000560e076777c0 in vhost_user_get_vring_base (dev=0x560e0ae44c08, > > > ring=0x7ffc76812d80) at ../hw/virtio/vhost-user.c:1260 > > > #10 0x0000560e0767314e in vhost_virtqueue_stop > > > (dev=dev@entry=0x560e0ae44c08, vdev=vdev@entry=0x560e0ae449d0, > > > vq=0x560e0ae7a570, idx=0) at ../hw/virtio/vhost.c:1220 > > > #11 0x0000560e07675236 in vhost_dev_stop (hdev=hdev@entry=0x560e0ae44c08, > > > vdev=vdev@entry=0x560e0ae449d0) at ../hw/virtio/vhost.c:1884 > > > #12 0x0000560e0768f2fd in vu_gpio_stop (vdev=0x560e0ae449d0) at > > > ../hw/virtio/vhost-user-gpio.c:148 > > > #13 0x0000560e0766a6a3 in virtio_set_status (vdev=0x560e0ae449d0, > > > val=<optimized out>) at ../hw/virtio/virtio.c:2442 > > > #14 0x0000560e0751a2e0 in vm_state_notify (running=running@entry=false, > > > state=state@entry=RUN_STATE_SHUTDOWN) at ../softmmu/runstate.c:334 > > > #15 0x0000560e07514d70 in do_vm_stop (send_stop=false, > > > state=RUN_STATE_SHUTDOWN) at ../softmmu/cpus.c:262 > > > #16 vm_shutdown () at ../softmmu/cpus.c:280 > > > #17 0x0000560e0751af63 in qemu_cleanup () at ../softmmu/runstate.c:827 > > > #18 0x0000560e07350f33 in qemu_default_main () at ../softmmu/main.c:38 > > > #19 0x00007f0a5655bd90 in __libc_start_call_main > > > (main=main@entry=0x560e0734c3e0 <main>, argc=argc@entry=25, > > > argv=argv@entry=0x7ffc768130a8) at > > > ../sysdeps/nptl/libc_start_call_main.h:58 > > > #20 0x00007f0a5655be40 in __libc_start_main_impl (main=0x560e0734c3e0 > > > <main>, argc=25, argv=0x7ffc768130a8, init=<optimized out>, > > > fini=<optimized out>, rtld_fini=<optimized out>, > > > stack_end=0x7ffc76813098) at ../csu/libc-start.c:392 > > > #21 0x0000560e07350e55 in _start () > > > > > > > > > Any Ideas how to fix this properly? > > > > > > regards Christian > > > > so fundamentally, any write into a socket can trigger stop? > > I don't think we realized this. > > Hmm this needs some thought there are likely more issues > > like this. > > The code in net/vhost-user.c seems to realize this and uses > aio to schedule the close. I was wondering if chardev should > do this for OPEN/CLOSE events by default (or by request). > However, I couldn't figure out how to ensure that the device > remains alive until the callback is actually called. > > regards Christian
Cc Alex who's been looking at this. -- MST