hw/scsi/virtio-scsi-dataplane.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-)
After the AioContext lock push down, there is a race between
virtio_scsi_dataplane_start and those "assert(s->ctx &&
s->dataplane_started)", because the latter doesn't isn't wrapped in
aio_context_acquire.
Reproducer is simply booting a Fedora guest with an empty
virtio-scsi-dataplane controller:
qemu-system-x86_64 \
-drive if=none,id=root,format=raw,file=Fedora-Cloud-Base-25-1.3.x86_64.raw \
-device virtio-scsi \
-device scsi-disk,drive=root,bootindex=1 \
-object iothread,id=io \
-device virtio-scsi-pci,iothread=io \
-net user,hostfwd=tcp::10022-:22 -net nic,model=virtio -m 2048 \
--enable-kvm
Signed-off-by: Fam Zheng <famz@redhat.com>
---
hw/scsi/virtio-scsi-dataplane.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c
index 74c95e0..12b44b7 100644
--- a/hw/scsi/virtio-scsi-dataplane.c
+++ b/hw/scsi/virtio-scsi-dataplane.c
@@ -52,28 +52,40 @@ void virtio_scsi_dataplane_setup(VirtIOSCSI *s, Error **errp)
static bool virtio_scsi_data_plane_handle_cmd(VirtIODevice *vdev,
VirtQueue *vq)
{
- VirtIOSCSI *s = (VirtIOSCSI *)vdev;
+ bool progress;
+ VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+ aio_context_acquire(s->ctx);
assert(s->ctx && s->dataplane_started);
- return virtio_scsi_handle_cmd_vq(s, vq);
+ progress = virtio_scsi_handle_cmd_vq(s, vq);
+ aio_context_release(s->ctx);
+ return progress;
}
static bool virtio_scsi_data_plane_handle_ctrl(VirtIODevice *vdev,
VirtQueue *vq)
{
+ bool progress;
VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+ aio_context_acquire(s->ctx);
assert(s->ctx && s->dataplane_started);
- return virtio_scsi_handle_ctrl_vq(s, vq);
+ progress = virtio_scsi_handle_ctrl_vq(s, vq);
+ aio_context_release(s->ctx);
+ return progress;
}
static bool virtio_scsi_data_plane_handle_event(VirtIODevice *vdev,
VirtQueue *vq)
{
+ bool progress;
VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+ aio_context_acquire(s->ctx);
assert(s->ctx && s->dataplane_started);
- return virtio_scsi_handle_event_vq(s, vq);
+ progress = virtio_scsi_handle_event_vq(s, vq);
+ aio_context_release(s->ctx);
+ return progress;
}
static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n,
--
2.9.3
On 14/03/2017 14:26, Fam Zheng wrote: > After the AioContext lock push down, there is a race between > virtio_scsi_dataplane_start and those "assert(s->ctx && > s->dataplane_started)", because the latter doesn't isn't wrapped in > aio_context_acquire. > > Reproducer is simply booting a Fedora guest with an empty > virtio-scsi-dataplane controller: > > qemu-system-x86_64 \ > -drive if=none,id=root,format=raw,file=Fedora-Cloud-Base-25-1.3.x86_64.raw \ > -device virtio-scsi \ > -device scsi-disk,drive=root,bootindex=1 \ > -object iothread,id=io \ > -device virtio-scsi-pci,iothread=io \ > -net user,hostfwd=tcp::10022-:22 -net nic,model=virtio -m 2048 \ > --enable-kvm > > Signed-off-by: Fam Zheng <famz@redhat.com> > --- > hw/scsi/virtio-scsi-dataplane.c | 20 ++++++++++++++++---- > 1 file changed, 16 insertions(+), 4 deletions(-) > > diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c > index 74c95e0..12b44b7 100644 > --- a/hw/scsi/virtio-scsi-dataplane.c > +++ b/hw/scsi/virtio-scsi-dataplane.c > @@ -52,28 +52,40 @@ void virtio_scsi_dataplane_setup(VirtIOSCSI *s, Error **errp) > static bool virtio_scsi_data_plane_handle_cmd(VirtIODevice *vdev, > VirtQueue *vq) > { > - VirtIOSCSI *s = (VirtIOSCSI *)vdev; > + bool progress; > + VirtIOSCSI *s = VIRTIO_SCSI(vdev); > > + aio_context_acquire(s->ctx); > assert(s->ctx && s->dataplane_started); > - return virtio_scsi_handle_cmd_vq(s, vq); > + progress = virtio_scsi_handle_cmd_vq(s, vq); > + aio_context_release(s->ctx); Can you use virtio_scsi_acquire/release, and remove it from virtio_scsi_handle_*_vq? Paolo > + return progress; > } > > static bool virtio_scsi_data_plane_handle_ctrl(VirtIODevice *vdev, > VirtQueue *vq) > { > + bool progress; > VirtIOSCSI *s = VIRTIO_SCSI(vdev); > > + aio_context_acquire(s->ctx); > assert(s->ctx && s->dataplane_started); > - return virtio_scsi_handle_ctrl_vq(s, vq); > + progress = virtio_scsi_handle_ctrl_vq(s, vq); > + aio_context_release(s->ctx); > + return progress; > } > > static bool virtio_scsi_data_plane_handle_event(VirtIODevice *vdev, > VirtQueue *vq) > { > + bool progress; > VirtIOSCSI *s = VIRTIO_SCSI(vdev); > > + aio_context_acquire(s->ctx); > assert(s->ctx && s->dataplane_started); > - return virtio_scsi_handle_event_vq(s, vq); > + progress = virtio_scsi_handle_event_vq(s, vq); > + aio_context_release(s->ctx); > + return progress; > } > > static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n, >
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