* [PATCH v2 0/2] virtio: console: add locking around control out-vq @ 2013-03-29 11:00 Amit Shah 2013-03-29 11:00 ` [PATCH v2 1/2] virtio: console: rename cvq_lock to c_ivq_lock Amit Shah 2013-03-29 11:00 ` [PATCH v2 2/2] virtio: console: add locking around c_ovq operations Amit Shah 0 siblings, 2 replies; 7+ messages in thread From: Amit Shah @ 2013-03-29 11:00 UTC (permalink / raw) To: Rusty Russell; +Cc: Amit Shah, Virtualization List The in-vq operations were protected by a lock, but the out-vq operations were not. This caused panics / errors as described in patch 2. Fix that. The first patch renames the existing cvq_lock to c_ivq_lock to match c_ivq. The second patch introduces the c_ovq_lock for the c_ovq. Please apply. I also believe this is a candidate for stable. v2: * Use spin_lock instead of spin_lock_irq. Pointed out by Wanlong Gao. Amit Shah (2): virtio: console: rename cvq_lock to c_ivq_lock virtio: console: add locking around c_ovq operations drivers/char/virtio_console.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) -- 1.8.1.4 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v2 1/2] virtio: console: rename cvq_lock to c_ivq_lock 2013-03-29 11:00 [PATCH v2 0/2] virtio: console: add locking around control out-vq Amit Shah @ 2013-03-29 11:00 ` Amit Shah 2013-03-29 11:04 ` Wanlong Gao 2013-03-29 11:00 ` [PATCH v2 2/2] virtio: console: add locking around c_ovq operations Amit Shah 1 sibling, 1 reply; 7+ messages in thread From: Amit Shah @ 2013-03-29 11:00 UTC (permalink / raw) To: Rusty Russell; +Cc: Amit Shah, Virtualization List The cvq_lock was taken for the c_ivq. Rename the lock to make that obvious. We'll also add a lock around the c_ovq in the next commit, so there's no ambiguity. Signed-off-by: Amit Shah <amit.shah@redhat.com> --- drivers/char/virtio_console.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index e905d5f..7e9bc1d 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -149,7 +149,7 @@ struct ports_device { spinlock_t ports_lock; /* To protect the vq operations for the control channel */ - spinlock_t cvq_lock; + spinlock_t c_ivq_lock; /* The current config space is stored here */ struct virtio_console_config config; @@ -1709,23 +1709,23 @@ static void control_work_handler(struct work_struct *work) portdev = container_of(work, struct ports_device, control_work); vq = portdev->c_ivq; - spin_lock(&portdev->cvq_lock); + spin_lock(&portdev->c_ivq_lock); while ((buf = virtqueue_get_buf(vq, &len))) { - spin_unlock(&portdev->cvq_lock); + spin_unlock(&portdev->c_ivq_lock); buf->len = len; buf->offset = 0; handle_control_message(portdev, buf); - spin_lock(&portdev->cvq_lock); + spin_lock(&portdev->c_ivq_lock); if (add_inbuf(portdev->c_ivq, buf) < 0) { dev_warn(&portdev->vdev->dev, "Error adding buffer to queue\n"); free_buf(buf, false); } } - spin_unlock(&portdev->cvq_lock); + spin_unlock(&portdev->c_ivq_lock); } static void out_intr(struct virtqueue *vq) @@ -1986,10 +1986,11 @@ static int virtcons_probe(struct virtio_device *vdev) if (multiport) { unsigned int nr_added_bufs; - spin_lock_init(&portdev->cvq_lock); + spin_lock_init(&portdev->c_ivq_lock); INIT_WORK(&portdev->control_work, &control_work_handler); - nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock); + nr_added_bufs = fill_queue(portdev->c_ivq, + &portdev->c_ivq_lock); if (!nr_added_bufs) { dev_err(&vdev->dev, "Error allocating buffers for control queue\n"); @@ -2140,7 +2141,7 @@ static int virtcons_restore(struct virtio_device *vdev) return ret; if (use_multiport(portdev)) - fill_queue(portdev->c_ivq, &portdev->cvq_lock); + fill_queue(portdev->c_ivq, &portdev->c_ivq_lock); list_for_each_entry(port, &portdev->ports, list) { port->in_vq = portdev->in_vqs[port->id]; -- 1.8.1.4 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v2 1/2] virtio: console: rename cvq_lock to c_ivq_lock 2013-03-29 11:00 ` [PATCH v2 1/2] virtio: console: rename cvq_lock to c_ivq_lock Amit Shah @ 2013-03-29 11:04 ` Wanlong Gao 0 siblings, 0 replies; 7+ messages in thread From: Wanlong Gao @ 2013-03-29 11:04 UTC (permalink / raw) To: Amit Shah; +Cc: Virtualization List On 03/29/2013 07:00 PM, Amit Shah wrote: > The cvq_lock was taken for the c_ivq. Rename the lock to make that > obvious. > > We'll also add a lock around the c_ovq in the next commit, so there's no > ambiguity. > > Signed-off-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com> > --- > drivers/char/virtio_console.c | 17 +++++++++-------- > 1 file changed, 9 insertions(+), 8 deletions(-) > > diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c > index e905d5f..7e9bc1d 100644 > --- a/drivers/char/virtio_console.c > +++ b/drivers/char/virtio_console.c > @@ -149,7 +149,7 @@ struct ports_device { > spinlock_t ports_lock; > > /* To protect the vq operations for the control channel */ > - spinlock_t cvq_lock; > + spinlock_t c_ivq_lock; > > /* The current config space is stored here */ > struct virtio_console_config config; > @@ -1709,23 +1709,23 @@ static void control_work_handler(struct work_struct *work) > portdev = container_of(work, struct ports_device, control_work); > vq = portdev->c_ivq; > > - spin_lock(&portdev->cvq_lock); > + spin_lock(&portdev->c_ivq_lock); > while ((buf = virtqueue_get_buf(vq, &len))) { > - spin_unlock(&portdev->cvq_lock); > + spin_unlock(&portdev->c_ivq_lock); > > buf->len = len; > buf->offset = 0; > > handle_control_message(portdev, buf); > > - spin_lock(&portdev->cvq_lock); > + spin_lock(&portdev->c_ivq_lock); > if (add_inbuf(portdev->c_ivq, buf) < 0) { > dev_warn(&portdev->vdev->dev, > "Error adding buffer to queue\n"); > free_buf(buf, false); > } > } > - spin_unlock(&portdev->cvq_lock); > + spin_unlock(&portdev->c_ivq_lock); > } > > static void out_intr(struct virtqueue *vq) > @@ -1986,10 +1986,11 @@ static int virtcons_probe(struct virtio_device *vdev) > if (multiport) { > unsigned int nr_added_bufs; > > - spin_lock_init(&portdev->cvq_lock); > + spin_lock_init(&portdev->c_ivq_lock); > INIT_WORK(&portdev->control_work, &control_work_handler); > > - nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock); > + nr_added_bufs = fill_queue(portdev->c_ivq, > + &portdev->c_ivq_lock); > if (!nr_added_bufs) { > dev_err(&vdev->dev, > "Error allocating buffers for control queue\n"); > @@ -2140,7 +2141,7 @@ static int virtcons_restore(struct virtio_device *vdev) > return ret; > > if (use_multiport(portdev)) > - fill_queue(portdev->c_ivq, &portdev->cvq_lock); > + fill_queue(portdev->c_ivq, &portdev->c_ivq_lock); > > list_for_each_entry(port, &portdev->ports, list) { > port->in_vq = portdev->in_vqs[port->id]; > ^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v2 2/2] virtio: console: add locking around c_ovq operations 2013-03-29 11:00 [PATCH v2 0/2] virtio: console: add locking around control out-vq Amit Shah 2013-03-29 11:00 ` [PATCH v2 1/2] virtio: console: rename cvq_lock to c_ivq_lock Amit Shah @ 2013-03-29 11:00 ` Amit Shah 2013-03-29 11:05 ` Wanlong Gao 2013-03-30 3:58 ` Rusty Russell 1 sibling, 2 replies; 7+ messages in thread From: Amit Shah @ 2013-03-29 11:00 UTC (permalink / raw) To: Rusty Russell; +Cc: Amit Shah, Virtualization List When multiple ovq operations are being performed (lots of open/close operations on virtio_console fds), the __send_control_msg() function can get confused without locking. A simple recipe to cause badness is: * create a QEMU VM with two virtio-serial ports * in the guest, do while true;do echo abc >/dev/vport0p1;done while true;do echo edf >/dev/vport0p2;done In one run, this caused a panic in __send_control_msg(). In another, I got virtio_console virtio0: control-o:id 0 is not a head! This also results repeated messages similar to these on the host: qemu-kvm: virtio-serial-bus: Unexpected port id 478762112 for device virtio-serial-bus.0 qemu-kvm: virtio-serial-bus: Unexpected port id 478762368 for device virtio-serial-bus.0 Reported-by: FuXiangChun <xfu@redhat.com> Signed-off-by: Amit Shah <amit.shah@redhat.com> --- drivers/char/virtio_console.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 7e9bc1d..a91488c 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -150,6 +150,7 @@ struct ports_device { /* To protect the vq operations for the control channel */ spinlock_t c_ivq_lock; + spinlock_t c_ovq_lock; /* The current config space is stored here */ struct virtio_console_config config; @@ -569,11 +570,14 @@ static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id, vq = portdev->c_ovq; sg_init_one(sg, &cpkt, sizeof(cpkt)); + + spin_lock(&portdev->c_ovq_lock); if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt, GFP_ATOMIC) == 0) { virtqueue_kick(vq); while (!virtqueue_get_buf(vq, &len)) cpu_relax(); } + spin_unlock(&portdev->c_ovq_lock); return 0; } @@ -1987,6 +1991,7 @@ static int virtcons_probe(struct virtio_device *vdev) unsigned int nr_added_bufs; spin_lock_init(&portdev->c_ivq_lock); + spin_lock_init(&portdev->c_ovq_lock); INIT_WORK(&portdev->control_work, &control_work_handler); nr_added_bufs = fill_queue(portdev->c_ivq, -- 1.8.1.4 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v2 2/2] virtio: console: add locking around c_ovq operations 2013-03-29 11:00 ` [PATCH v2 2/2] virtio: console: add locking around c_ovq operations Amit Shah @ 2013-03-29 11:05 ` Wanlong Gao 2013-03-30 3:58 ` Rusty Russell 1 sibling, 0 replies; 7+ messages in thread From: Wanlong Gao @ 2013-03-29 11:05 UTC (permalink / raw) To: Amit Shah; +Cc: Virtualization List On 03/29/2013 07:00 PM, Amit Shah wrote: > When multiple ovq operations are being performed (lots of open/close > operations on virtio_console fds), the __send_control_msg() function can > get confused without locking. > > A simple recipe to cause badness is: > * create a QEMU VM with two virtio-serial ports > * in the guest, do > while true;do echo abc >/dev/vport0p1;done > while true;do echo edf >/dev/vport0p2;done > > In one run, this caused a panic in __send_control_msg(). In another, I > got > > virtio_console virtio0: control-o:id 0 is not a head! > > This also results repeated messages similar to these on the host: > > qemu-kvm: virtio-serial-bus: Unexpected port id 478762112 for device virtio-serial-bus.0 > qemu-kvm: virtio-serial-bus: Unexpected port id 478762368 for device virtio-serial-bus.0 > > Reported-by: FuXiangChun <xfu@redhat.com> > Signed-off-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com> > --- > drivers/char/virtio_console.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c > index 7e9bc1d..a91488c 100644 > --- a/drivers/char/virtio_console.c > +++ b/drivers/char/virtio_console.c > @@ -150,6 +150,7 @@ struct ports_device { > > /* To protect the vq operations for the control channel */ > spinlock_t c_ivq_lock; > + spinlock_t c_ovq_lock; > > /* The current config space is stored here */ > struct virtio_console_config config; > @@ -569,11 +570,14 @@ static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id, > vq = portdev->c_ovq; > > sg_init_one(sg, &cpkt, sizeof(cpkt)); > + > + spin_lock(&portdev->c_ovq_lock); > if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt, GFP_ATOMIC) == 0) { > virtqueue_kick(vq); > while (!virtqueue_get_buf(vq, &len)) > cpu_relax(); > } > + spin_unlock(&portdev->c_ovq_lock); > return 0; > } > > @@ -1987,6 +1991,7 @@ static int virtcons_probe(struct virtio_device *vdev) > unsigned int nr_added_bufs; > > spin_lock_init(&portdev->c_ivq_lock); > + spin_lock_init(&portdev->c_ovq_lock); > INIT_WORK(&portdev->control_work, &control_work_handler); > > nr_added_bufs = fill_queue(portdev->c_ivq, > ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 2/2] virtio: console: add locking around c_ovq operations 2013-03-29 11:00 ` [PATCH v2 2/2] virtio: console: add locking around c_ovq operations Amit Shah 2013-03-29 11:05 ` Wanlong Gao @ 2013-03-30 3:58 ` Rusty Russell 2013-04-02 5:26 ` Amit Shah 1 sibling, 1 reply; 7+ messages in thread From: Rusty Russell @ 2013-03-30 3:58 UTC (permalink / raw) Cc: Amit Shah, Virtualization List Amit Shah <amit.shah@redhat.com> writes: > When multiple ovq operations are being performed (lots of open/close > operations on virtio_console fds), the __send_control_msg() function can > get confused without locking. > > A simple recipe to cause badness is: > * create a QEMU VM with two virtio-serial ports > * in the guest, do > while true;do echo abc >/dev/vport0p1;done > while true;do echo edf >/dev/vport0p2;done > > In one run, this caused a panic in __send_control_msg(). In another, I > got > > virtio_console virtio0: control-o:id 0 is not a head! Both applied to my fixes branch, with CC: stable added. For future reference, I prefer you to put the CC: stable@kernel.org tag in if you think it's a stable candidate. Thanks, Rusty. ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 2/2] virtio: console: add locking around c_ovq operations 2013-03-30 3:58 ` Rusty Russell @ 2013-04-02 5:26 ` Amit Shah 0 siblings, 0 replies; 7+ messages in thread From: Amit Shah @ 2013-04-02 5:26 UTC (permalink / raw) To: Rusty Russell; +Cc: Virtualization List On (Sat) 30 Mar 2013 [14:28:28], Rusty Russell wrote: > Amit Shah <amit.shah@redhat.com> writes: > > When multiple ovq operations are being performed (lots of open/close > > operations on virtio_console fds), the __send_control_msg() function can > > get confused without locking. > > > > A simple recipe to cause badness is: > > * create a QEMU VM with two virtio-serial ports > > * in the guest, do > > while true;do echo abc >/dev/vport0p1;done > > while true;do echo edf >/dev/vport0p2;done > > > > In one run, this caused a panic in __send_control_msg(). In another, I > > got > > > > virtio_console virtio0: control-o:id 0 is not a head! > > Both applied to my fixes branch, with CC: stable added. > > For future reference, I prefer you to put the CC: stable@kernel.org tag > in if you think it's a stable candidate. Will do, Thanks Amit ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2013-04-02 5:26 UTC | newest] Thread overview: 7+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2013-03-29 11:00 [PATCH v2 0/2] virtio: console: add locking around control out-vq Amit Shah 2013-03-29 11:00 ` [PATCH v2 1/2] virtio: console: rename cvq_lock to c_ivq_lock Amit Shah 2013-03-29 11:04 ` Wanlong Gao 2013-03-29 11:00 ` [PATCH v2 2/2] virtio: console: add locking around c_ovq operations Amit Shah 2013-03-29 11:05 ` Wanlong Gao 2013-03-30 3:58 ` Rusty Russell 2013-04-02 5:26 ` Amit Shah
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