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Re: [Qemu-devel] [PATCH] vhost: fix crash on virtio_error while device s
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [PATCH] vhost: fix crash on virtio_error while device stop |
Date: |
Wed, 13 Dec 2017 21:48:50 +0200 |
On Wed, Dec 13, 2017 at 04:45:20PM +0300, Ilya Maximets wrote:
> >> That
> >> looks very strange. Some of the functions gets 'old_status', others
> >> the 'new_status'. I'm a bit confused.
> >
> > OK, fair enough. Fixed - let's pass old status everywhere,
> > users that need the new one can get it from the vdev.
> >
> >> And it's not functional in current state:
> >>
> >> hw/net/virtio-net.c:264:28: error: ‘status’ undeclared
> >
> > Fixed too. new version below.
>
> This doesn't fix the segmentation fault.
Hmm you are right. Looking into it.
> I have exactly same crash stacktrace:
>
> #0 vhost_memory_unmap hw/virtio/vhost.c:446
> #1 vhost_virtqueue_stop hw/virtio/vhost.c:1155
> #2 vhost_dev_stop hw/virtio/vhost.c:1594
> #3 vhost_net_stop_one hw/net/vhost_net.c:289
> #4 vhost_net_stop hw/net/vhost_net.c:368
> #5 virtio_net_vhost_status (old_status=15 '\017', n=0x5625f3901100) at
> hw/net/virtio-net.c:180
> #6 virtio_net_set_status (vdev=0x5625f3901100, old_status=<optimized out>)
> at hw/net/virtio-net.c:254
> #7 virtio_set_status (address@hidden, val=<optimized out>) at
> hw/virtio/virtio.c:1152
> #8 virtio_error (vdev=0x5625f3901100, address@hidden "Guest says index %u is
> available") at hw/virtio/virtio.c:2460
BTW what is causing this? Why is guest avail index corrupted?
> #9 virtqueue_get_head at hw/virtio/virtio.c:543
> #10 virtqueue_drop_all hw/virtio/virtio.c:984
> #11 virtio_net_drop_tx_queue_data hw/net/virtio-net.c:240
> #12 virtio_bus_set_host_notifier at hw/virtio/virtio-bus.c:297
> #13 vhost_dev_disable_notifiers at hw/virtio/vhost.c:1431
> #14 vhost_net_stop_one at hw/net/vhost_net.c:290
> #15 vhost_net_stop at hw/net/vhost_net.c:368
> #16 virtio_net_vhost_status (old_status=15 '\017', n=0x5625f3901100) at
> hw/net/virtio-net.c:180
> #17 virtio_net_set_status (vdev=0x5625f3901100, old_status=<optimized out>)
> at hw/net/virtio-net.c:254
> #18 qmp_set_link at net/net.c:1430
> #19 chr_closed_bh at net/vhost-user.c:214
> #20 aio_bh_call at util/async.c:90
> #21 aio_bh_poll at util/async.c:118
> #22 aio_dispatch at util/aio-posix.c:429
> #23 aio_ctx_dispatch at util/async.c:261
> #24 g_main_context_dispatch () from /lib64/libglib-2.0.so.0
> #25 glib_pollfds_poll () at util/main-loop.c:213
> #26 os_host_main_loop_wait at util/main-loop.c:261
> #27 main_loop_wait at util/main-loop.c:515
> #28 main_loop () at vl.c:1917
> #29 main
>
>
> Actually the logic doesn't change. In function virtio_net_vhost_status():
>
> - if ((virtio_net_started(n, status) && !nc->peer->link_down) ==
> + if ((virtio_net_started(n, vdev->status) && !nc->peer->link_down) ==
> !!n->vhost_started) {
> return;
> }
>
> previously new 'status' was checked and the new 'vdev->status' checked now.
> It's the same condition that doesn't work because vhost_started flag is still
> set to 1.
> Anyway, nc->peer->link_down is true in our case, so there is no difference if
> we'll change the vdev->status.
>
> >>>
> >>> Signed-off-by: Michael S. Tsirkin <address@hidden>
> >
> > Still completely untested, sorry about that - hope you can help here.
> >
> > diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
> > index 098bdaa..f5d0ee1 100644
> > --- a/include/hw/virtio/virtio.h
> > +++ b/include/hw/virtio/virtio.h
> > @@ -115,7 +115,7 @@ typedef struct VirtioDeviceClass {
> > void (*get_config)(VirtIODevice *vdev, uint8_t *config);
> > void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
> > void (*reset)(VirtIODevice *vdev);
> > - void (*set_status)(VirtIODevice *vdev, uint8_t val);
> > + void (*set_status)(VirtIODevice *vdev, uint8_t old_status);
> > /* For transitional devices, this is a bitmap of features
> > * that are only exposed on the legacy interface but not
> > * the modern one.
> > diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
> > index 05d1440..b8b07ba 100644
> > --- a/hw/block/virtio-blk.c
> > +++ b/hw/block/virtio-blk.c
> > @@ -814,15 +814,15 @@ static uint64_t virtio_blk_get_features(VirtIODevice
> > *vdev, uint64_t features,
> > return features;
> > }
> >
> > -static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status)
> > +static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t old_status)
> > {
> > VirtIOBlock *s = VIRTIO_BLK(vdev);
> >
> > - if (!(status & (VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_DRIVER_OK))) {
> > + if (!(vdev->status & (VIRTIO_CONFIG_S_DRIVER |
> > VIRTIO_CONFIG_S_DRIVER_OK))) {
> > assert(!s->dataplane_started);
> > }
> >
> > - if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
> > + if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
> > return;
> > }
> >
> > diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c
> > index 9470bd7..881b1ff 100644
> > --- a/hw/char/virtio-serial-bus.c
> > +++ b/hw/char/virtio-serial-bus.c
> > @@ -616,7 +616,7 @@ static void guest_reset(VirtIOSerial *vser)
> > }
> > }
> >
> > -static void set_status(VirtIODevice *vdev, uint8_t status)
> > +static void set_status(VirtIODevice *vdev, uint8_t old_status)
> > {
> > VirtIOSerial *vser;
> > VirtIOSerialPort *port;
> > @@ -625,7 +625,7 @@ static void set_status(VirtIODevice *vdev, uint8_t
> > status)
> > port = find_port_by_id(vser, 0);
> >
> > if (port && !use_multiport(port->vser)
> > - && (status & VIRTIO_CONFIG_S_DRIVER_OK)) {
> > + && (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
> > /*
> > * Non-multiport guests won't be able to tell us guest
> > * open/close status. Such guests can only have a port at id
> > @@ -634,7 +634,7 @@ static void set_status(VirtIODevice *vdev, uint8_t
> > status)
> > */
> > port->guest_connected = true;
> > }
> > - if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
> > + if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
> > guest_reset(vser);
> > }
> >
> > diff --git a/hw/input/virtio-input.c b/hw/input/virtio-input.c
> > index 0e42f0d..abb817b 100644
> > --- a/hw/input/virtio-input.c
> > +++ b/hw/input/virtio-input.c
> > @@ -188,12 +188,12 @@ static uint64_t
> > virtio_input_get_features(VirtIODevice *vdev, uint64_t f,
> > return f;
> > }
> >
> > -static void virtio_input_set_status(VirtIODevice *vdev, uint8_t val)
> > +static void virtio_input_set_status(VirtIODevice *vdev, uint8_t old_val)
> > {
> > VirtIOInputClass *vic = VIRTIO_INPUT_GET_CLASS(vdev);
> > VirtIOInput *vinput = VIRTIO_INPUT(vdev);
> >
> > - if (val & VIRTIO_CONFIG_S_DRIVER_OK) {
> > + if (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) {
> > if (!vinput->active) {
> > vinput->active = true;
> > if (vic->change_active) {
> > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> > index 38674b0..7851968 100644
> > --- a/hw/net/virtio-net.c
> > +++ b/hw/net/virtio-net.c
> > @@ -124,7 +124,7 @@ static void virtio_net_announce_timer(void *opaque)
> > virtio_notify_config(vdev);
> > }
> >
> > -static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
> > +static void virtio_net_vhost_status(VirtIONet *n, uint8_t old_status)
> > {
> > VirtIODevice *vdev = VIRTIO_DEVICE(n);
> > NetClientState *nc = qemu_get_queue(n->nic);
> > @@ -134,7 +134,7 @@ static void virtio_net_vhost_status(VirtIONet *n,
> > uint8_t status)
> > return;
> > }
> >
> > - if ((virtio_net_started(n, status) && !nc->peer->link_down) ==
> > + if ((virtio_net_started(n, vdev->status) && !nc->peer->link_down) ==
> > !!n->vhost_started) {
> > return;
> > }
> > @@ -212,12 +212,12 @@ static bool virtio_net_set_vnet_endian(VirtIODevice
> > *vdev, NetClientState *ncs,
> > return false;
> > }
> >
> > -static void virtio_net_vnet_endian_status(VirtIONet *n, uint8_t status)
> > +static void virtio_net_vnet_endian_status(VirtIONet *n, uint8_t old_status)
> > {
> > VirtIODevice *vdev = VIRTIO_DEVICE(n);
> > int queues = n->multiqueue ? n->max_queues : 1;
> >
> > - if (virtio_net_started(n, status)) {
> > + if (virtio_net_started(n, vdev->status)) {
> > /* Before using the device, we tell the network backend about the
> > * endianness to use when parsing vnet headers. If the backend
> > * can't do it, we fallback onto fixing the headers in the core
> > @@ -225,7 +225,7 @@ static void virtio_net_vnet_endian_status(VirtIONet *n,
> > uint8_t status)
> > */
> > n->needs_vnet_hdr_swap = virtio_net_set_vnet_endian(vdev,
> > n->nic->ncs,
> > queues, true);
> > - } else if (virtio_net_started(n, vdev->status)) {
> > + } else if (virtio_net_started(n, old_status)) {
> > /* After using the device, we need to reset the network backend to
> > * the default (guest native endianness), otherwise the guest may
> > * lose network connectivity if it is rebooted into a different
> > @@ -243,15 +243,15 @@ static void
> > virtio_net_drop_tx_queue_data(VirtIODevice *vdev, VirtQueue *vq)
> > }
> > }
> >
> > -static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t
> > status)
> > +static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t
> > old_status)
> > {
> > VirtIONet *n = VIRTIO_NET(vdev);
> > VirtIONetQueue *q;
> > int i;
> > uint8_t queue_status;
> >
> > - virtio_net_vnet_endian_status(n, status);
> > - virtio_net_vhost_status(n, status);
> > + virtio_net_vnet_endian_status(n, old_status);
> > + virtio_net_vhost_status(n, old_status);
> >
> > for (i = 0; i < n->max_queues; i++) {
> > NetClientState *ncs = qemu_get_subqueue(n->nic, i);
> > @@ -261,7 +261,7 @@ static void virtio_net_set_status(struct VirtIODevice
> > *vdev, uint8_t status)
> > if ((!n->multiqueue && i != 0) || i >= n->curr_queues) {
> > queue_status = 0;
> > } else {
> > - queue_status = status;
> > + queue_status = vdev->status;
> > }
> > queue_started =
> > virtio_net_started(n, queue_status) && !n->vhost_started;
> > @@ -2048,9 +2048,11 @@ static void virtio_net_device_unrealize(DeviceState
> > *dev, Error **errp)
> > VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> > VirtIONet *n = VIRTIO_NET(dev);
> > int i, max_queues;
> > + uint8_t old_status = vdev->status;
> >
> > /* This will stop vhost backend if appropriate. */
> > - virtio_net_set_status(vdev, 0);
> > + vdev->status = 0;
> > + virtio_net_set_status(vdev, old_status);
> >
> > g_free(n->netclient_name);
> > n->netclient_name = NULL;
> > diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c
> > index 9c1bea8..5a561e4 100644
> > --- a/hw/scsi/vhost-scsi.c
> > +++ b/hw/scsi/vhost-scsi.c
> > @@ -108,11 +108,11 @@ static void vhost_scsi_stop(VHostSCSI *s)
> > vhost_scsi_common_stop(vsc);
> > }
> >
> > -static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
> > +static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t old_val)
> > {
> > VHostSCSI *s = VHOST_SCSI(vdev);
> > VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
> > - bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);
> > + bool start = vdev->status & VIRTIO_CONFIG_S_DRIVER_OK;
> >
> > if (vsc->dev.started == start) {
> > return;
> > diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
> > index f7561e2..289a27e 100644
> > --- a/hw/scsi/vhost-user-scsi.c
> > +++ b/hw/scsi/vhost-user-scsi.c
> > @@ -38,11 +38,11 @@ static const int user_feature_bits[] = {
> > VHOST_INVALID_FEATURE_BIT
> > };
> >
> > -static void vhost_user_scsi_set_status(VirtIODevice *vdev, uint8_t status)
> > +static void vhost_user_scsi_set_status(VirtIODevice *vdev, uint8_t
> > old_status)
> > {
> > VHostUserSCSI *s = (VHostUserSCSI *)vdev;
> > VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
> > - bool start = (status & VIRTIO_CONFIG_S_DRIVER_OK) && vdev->vm_running;
> > + bool start = (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) &&
> > vdev->vm_running;
> >
> > if (vsc->dev.started == start) {
> > return;
> > diff --git a/hw/virtio/vhost-vsock.c b/hw/virtio/vhost-vsock.c
> > index 5ec1c6a..d3f445b 100644
> > --- a/hw/virtio/vhost-vsock.c
> > +++ b/hw/virtio/vhost-vsock.c
> > @@ -154,10 +154,10 @@ static void vhost_vsock_stop(VirtIODevice *vdev)
> > vhost_dev_disable_notifiers(&vsock->vhost_dev, vdev);
> > }
> >
> > -static void vhost_vsock_set_status(VirtIODevice *vdev, uint8_t status)
> > +static void vhost_vsock_set_status(VirtIODevice *vdev, uint8_t old_status)
> > {
> > VHostVSock *vsock = VHOST_VSOCK(vdev);
> > - bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK;
> > + bool should_start = vdev->status & VIRTIO_CONFIG_S_DRIVER_OK;
> >
> > if (!vdev->vm_running) {
> > should_start = false;
> > @@ -370,11 +370,14 @@ static void vhost_vsock_device_unrealize(DeviceState
> > *dev, Error **errp)
> > {
> > VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> > VHostVSock *vsock = VHOST_VSOCK(dev);
> > + uint8_t old_status;
> >
> > vhost_vsock_post_load_timer_cleanup(vsock);
> >
> > /* This will stop vhost backend if appropriate. */
> > - vhost_vsock_set_status(vdev, 0);
> > + old_status = vdev->status;
> > + vdev->status = 0;
> > + vhost_vsock_set_status(vdev, old_status);
> >
> > vhost_dev_cleanup(&vsock->vhost_dev);
> > virtio_cleanup(vdev);
> > diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
> > index 37cde38..84e897a 100644
> > --- a/hw/virtio/virtio-balloon.c
> > +++ b/hw/virtio/virtio-balloon.c
> > @@ -468,12 +468,12 @@ static void virtio_balloon_device_reset(VirtIODevice
> > *vdev)
> > }
> > }
> >
> > -static void virtio_balloon_set_status(VirtIODevice *vdev, uint8_t status)
> > +static void virtio_balloon_set_status(VirtIODevice *vdev, uint8_t
> > old_status)
> > {
> > VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
> >
> > if (!s->stats_vq_elem && vdev->vm_running &&
> > - (status & VIRTIO_CONFIG_S_DRIVER_OK) && virtqueue_rewind(s->svq,
> > 1)) {
> > + (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) &&
> > virtqueue_rewind(s->svq, 1)) {
> > /* poll stats queue for the element we have discarded when the VM
> > * was stopped */
> > virtio_balloon_receive_stats(vdev, s->svq);
> > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> > index ad564b0..4981858 100644
> > --- a/hw/virtio/virtio.c
> > +++ b/hw/virtio/virtio.c
> > @@ -1128,6 +1128,8 @@ static int virtio_validate_features(VirtIODevice
> > *vdev)
> > int virtio_set_status(VirtIODevice *vdev, uint8_t val)
> > {
> > VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
> > + uint8_t old_status;
> > +
> > trace_virtio_set_status(vdev, val);
> >
> > if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
> > @@ -1140,10 +1142,13 @@ int virtio_set_status(VirtIODevice *vdev, uint8_t
> > val)
> > }
> > }
> > }
> > +
> > + old_status = vdev->status;
> > + vdev->status = val;
> > +
> > if (k->set_status) {
> > - k->set_status(vdev, val);
> > + k->set_status(vdev, old_status);
> > }
> > - vdev->status = val;
> > return 0;
> > }
> >
> >
> >
> >
- [Qemu-devel] [PATCH] vhost: fix crash on virtio_error while device stop, Ilya Maximets, 2017/12/06
- Re: [Qemu-devel] [PATCH] vhost: fix crash on virtio_error while device stop, Michael S. Tsirkin, 2017/12/06
- Re: [Qemu-devel] [PATCH] vhost: fix crash on virtio_error while device stop, Ilya Maximets, 2017/12/07
- Re: [Qemu-devel] [PATCH] vhost: fix crash on virtio_error while device stop, Michael S. Tsirkin, 2017/12/07
- Re: [Qemu-devel] [PATCH] vhost: fix crash on virtio_error while device stop, Michael S. Tsirkin, 2017/12/07
- Re: [Qemu-devel] [PATCH] vhost: fix crash on virtio_error while device stop, Ilya Maximets, 2017/12/08
- Re: [Qemu-devel] [PATCH] vhost: fix crash on virtio_error while device stop, Michael S. Tsirkin, 2017/12/10
- Re: [Qemu-devel] [PATCH] vhost: fix crash on virtio_error while device stop, Ilya Maximets, 2017/12/13
- Re: [Qemu-devel] [PATCH] vhost: fix crash on virtio_error while device stop,
Michael S. Tsirkin <=
- Re: [Qemu-devel] [PATCH] vhost: fix crash on virtio_error while device stop, Ilya Maximets, 2017/12/14
- Re: [Qemu-devel] [PATCH] vhost: fix crash on virtio_error while device stop, Maxime Coquelin, 2017/12/14
- Re: [Qemu-devel] [PATCH] vhost: fix crash on virtio_error while device stop, Ilya Maximets, 2017/12/14
- Re: [Qemu-devel] [PATCH] vhost: fix crash on virtio_error while device stop, Ilya Maximets, 2017/12/14