* [PATCH] virtio-rng: complete have_data completion in removing device @ 2014-08-05 17:35 ` Amos Kong 0 siblings, 0 replies; 10+ messages in thread From: Amos Kong @ 2014-08-05 17:35 UTC (permalink / raw) To: virtualization; +Cc: amit.shah, rusty, kvm, stable When we try to hot-remove a busy virtio-rng device from QEMU monitor, the device can't be hot-removed. Because virtio-rng driver hangs at wait_for_completion_killable(). This patch fixed the hang by completing have_data completion before unregistering a virtio-rng device. Signed-off-by: Amos Kong <akong@redhat.com> Cc: stable@vger.kernel.org --- drivers/char/hw_random/virtio-rng.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c index 0027137..416b15c 100644 --- a/drivers/char/hw_random/virtio-rng.c +++ b/drivers/char/hw_random/virtio-rng.c @@ -137,6 +137,7 @@ static void remove_common(struct virtio_device *vdev) struct virtrng_info *vi = vdev->priv; vdev->config->reset(vdev); + complete(&vi->have_data); vi->busy = false; if (vi->hwrng_register_done) hwrng_unregister(&vi->hwrng); -- 1.9.3 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH] virtio-rng: complete have_data completion in removing device @ 2014-08-05 17:35 ` Amos Kong 0 siblings, 0 replies; 10+ messages in thread From: Amos Kong @ 2014-08-05 17:35 UTC (permalink / raw) To: virtualization; +Cc: amit.shah, stable, kvm When we try to hot-remove a busy virtio-rng device from QEMU monitor, the device can't be hot-removed. Because virtio-rng driver hangs at wait_for_completion_killable(). This patch fixed the hang by completing have_data completion before unregistering a virtio-rng device. Signed-off-by: Amos Kong <akong@redhat.com> Cc: stable@vger.kernel.org --- drivers/char/hw_random/virtio-rng.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c index 0027137..416b15c 100644 --- a/drivers/char/hw_random/virtio-rng.c +++ b/drivers/char/hw_random/virtio-rng.c @@ -137,6 +137,7 @@ static void remove_common(struct virtio_device *vdev) struct virtrng_info *vi = vdev->priv; vdev->config->reset(vdev); + complete(&vi->have_data); vi->busy = false; if (vi->hwrng_register_done) hwrng_unregister(&vi->hwrng); -- 1.9.3 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH] virtio-rng: complete have_data completion in removing device 2014-08-05 17:35 ` Amos Kong @ 2014-08-06 8:05 ` Amos Kong -1 siblings, 0 replies; 10+ messages in thread From: Amos Kong @ 2014-08-06 8:05 UTC (permalink / raw) To: virtualization; +Cc: amit.shah, stable, kvm On Wed, Aug 06, 2014 at 01:35:15AM +0800, Amos Kong wrote: > When we try to hot-remove a busy virtio-rng device from QEMU monitor, > the device can't be hot-removed. Because virtio-rng driver hangs at > wait_for_completion_killable(). > > This patch fixed the hang by completing have_data completion before > unregistering a virtio-rng device. Hi Amit, Before applying this patch, it's blocking insider wait_for_completion_killable() Applied this patch, wait_for_completion_killable() returns 0, and vi->data_avail becomes 0, then rng_get_date() will return 0. Is it expected result? > Signed-off-by: Amos Kong <akong@redhat.com> > Cc: stable@vger.kernel.org > --- > drivers/char/hw_random/virtio-rng.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c > index 0027137..416b15c 100644 > --- a/drivers/char/hw_random/virtio-rng.c > +++ b/drivers/char/hw_random/virtio-rng.c > @@ -137,6 +137,7 @@ static void remove_common(struct virtio_device *vdev) > struct virtrng_info *vi = vdev->priv; > > vdev->config->reset(vdev); > + complete(&vi->have_data); > vi->busy = false; > if (vi->hwrng_register_done) > hwrng_unregister(&vi->hwrng); > -- > 1.9.3 > > _______________________________________________ > Virtualization mailing list > Virtualization@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/virtualization -- Amos. ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] virtio-rng: complete have_data completion in removing device @ 2014-08-06 8:05 ` Amos Kong 0 siblings, 0 replies; 10+ messages in thread From: Amos Kong @ 2014-08-06 8:05 UTC (permalink / raw) To: virtualization; +Cc: amit.shah, kvm, stable On Wed, Aug 06, 2014 at 01:35:15AM +0800, Amos Kong wrote: > When we try to hot-remove a busy virtio-rng device from QEMU monitor, > the device can't be hot-removed. Because virtio-rng driver hangs at > wait_for_completion_killable(). > > This patch fixed the hang by completing have_data completion before > unregistering a virtio-rng device. Hi Amit, Before applying this patch, it's blocking insider wait_for_completion_killable() Applied this patch, wait_for_completion_killable() returns 0, and vi->data_avail becomes 0, then rng_get_date() will return 0. Is it expected result? > Signed-off-by: Amos Kong <akong@redhat.com> > Cc: stable@vger.kernel.org > --- > drivers/char/hw_random/virtio-rng.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c > index 0027137..416b15c 100644 > --- a/drivers/char/hw_random/virtio-rng.c > +++ b/drivers/char/hw_random/virtio-rng.c > @@ -137,6 +137,7 @@ static void remove_common(struct virtio_device *vdev) > struct virtrng_info *vi = vdev->priv; > > vdev->config->reset(vdev); > + complete(&vi->have_data); > vi->busy = false; > if (vi->hwrng_register_done) > hwrng_unregister(&vi->hwrng); > -- > 1.9.3 > > _______________________________________________ > Virtualization mailing list > Virtualization@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/virtualization -- Amos. ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] virtio-rng: complete have_data completion in removing device 2014-08-06 8:05 ` Amos Kong @ 2014-08-06 8:25 ` Amit Shah -1 siblings, 0 replies; 10+ messages in thread From: Amit Shah @ 2014-08-06 8:25 UTC (permalink / raw) To: Amos Kong; +Cc: virtualization, stable, kvm On (Wed) 06 Aug 2014 [16:05:41], Amos Kong wrote: > On Wed, Aug 06, 2014 at 01:35:15AM +0800, Amos Kong wrote: > > When we try to hot-remove a busy virtio-rng device from QEMU monitor, > > the device can't be hot-removed. Because virtio-rng driver hangs at > > wait_for_completion_killable(). > > > > This patch fixed the hang by completing have_data completion before > > unregistering a virtio-rng device. > > Hi Amit, > > Before applying this patch, it's blocking insider wait_for_completion_killable() > Applied this patch, wait_for_completion_killable() returns 0, > and vi->data_avail becomes 0, then rng_get_date() will return 0. Thanks for checking this. > Is it expected result? I think what will happen is vi->data_avail will be set to whatever it was set last. In case of a previous successful read request, the data_avail will be set to whatever number of bytes the host gave. On doing a hot-unplug on the succeeding wait, the value in data_avail will be re-used, and the hwrng core will wrongly take some bytes in the buffer as input from the host. So, I think we need to set vi->data_avail = 0; before calling wait_event_completion_killable(). Amit ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] virtio-rng: complete have_data completion in removing device @ 2014-08-06 8:25 ` Amit Shah 0 siblings, 0 replies; 10+ messages in thread From: Amit Shah @ 2014-08-06 8:25 UTC (permalink / raw) To: Amos Kong; +Cc: kvm, stable, virtualization On (Wed) 06 Aug 2014 [16:05:41], Amos Kong wrote: > On Wed, Aug 06, 2014 at 01:35:15AM +0800, Amos Kong wrote: > > When we try to hot-remove a busy virtio-rng device from QEMU monitor, > > the device can't be hot-removed. Because virtio-rng driver hangs at > > wait_for_completion_killable(). > > > > This patch fixed the hang by completing have_data completion before > > unregistering a virtio-rng device. > > Hi Amit, > > Before applying this patch, it's blocking insider wait_for_completion_killable() > Applied this patch, wait_for_completion_killable() returns 0, > and vi->data_avail becomes 0, then rng_get_date() will return 0. Thanks for checking this. > Is it expected result? I think what will happen is vi->data_avail will be set to whatever it was set last. In case of a previous successful read request, the data_avail will be set to whatever number of bytes the host gave. On doing a hot-unplug on the succeeding wait, the value in data_avail will be re-used, and the hwrng core will wrongly take some bytes in the buffer as input from the host. So, I think we need to set vi->data_avail = 0; before calling wait_event_completion_killable(). Amit ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] virtio-rng: complete have_data completion in removing device 2014-08-06 8:25 ` Amit Shah @ 2014-09-08 15:29 ` Amos Kong -1 siblings, 0 replies; 10+ messages in thread From: Amos Kong @ 2014-09-08 15:29 UTC (permalink / raw) To: Amit Shah; +Cc: virtualization, stable, kvm On Wed, Aug 06, 2014 at 01:55:29PM +0530, Amit Shah wrote: > On (Wed) 06 Aug 2014 [16:05:41], Amos Kong wrote: > > On Wed, Aug 06, 2014 at 01:35:15AM +0800, Amos Kong wrote: > > > When we try to hot-remove a busy virtio-rng device from QEMU monitor, > > > the device can't be hot-removed. Because virtio-rng driver hangs at > > > wait_for_completion_killable(). > > > > > > This patch fixed the hang by completing have_data completion before > > > unregistering a virtio-rng device. > > > > Hi Amit, > > > > Before applying this patch, it's blocking insider wait_for_completion_killable() > > Applied this patch, wait_for_completion_killable() returns 0, > > and vi->data_avail becomes 0, then rng_get_date() will return 0. > > Thanks for checking this. > > > Is it expected result? > > I think what will happen is vi->data_avail will be set to whatever it > was set last. In case of a previous successful read request, the > data_avail will be set to whatever number of bytes the host gave. On > doing a hot-unplug on the succeeding wait, the value in data_avail > will be re-used, and the hwrng core will wrongly take some bytes in > the buffer as input from the host. > > So, I think we need to set vi->data_avail = 0; before calling > wait_event_completion_killable(). > > Amit In my latest debugging, I found the hang is caused by unexpected reading when we started to remove the device. I have two draft fix, 1) is skip unexpected reading by checking a remove flag. 2) is unregistering device at the beginning of remove_common(). I think second patch is better if it won't cause new problem. The original patch (complete in remove_common()) is still necessary. Test results: hotplug issue disappeared (dd process will quit). diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c index 2e3139e..028797c 100644 --- a/drivers/char/hw_random/virtio-rng.c +++ b/drivers/char/hw_random/virtio-rng.c @@ -35,6 +35,7 @@ struct virtrng_info { unsigned int data_avail; int index; bool busy; + bool remove; bool hwrng_register_done; }; @@ -68,6 +69,9 @@ static int virtio_read(struct hwrng *rng, void *buf, size_t size, bool wait) int ret; struct virtrng_info *vi = (struct virtrng_info *)rng->priv; + if (vi->remove) + return 0; + if (!vi->busy) { vi->busy = true; init_completion(&vi->have_data); @@ -137,6 +141,8 @@ static void remove_common(struct virtio_device *vdev) { struct virtrng_info *vi = vdev->priv; + vi->remove = true; + complete(&vi->have_data); vdev->config->reset(vdev); vi->busy = false; if (vi->hwrng_register_done) diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c index 2e3139e..9b8c2ce 100644 --- a/drivers/char/hw_random/virtio-rng.c +++ b/drivers/char/hw_random/virtio-rng.c @@ -137,10 +137,11 @@ static void remove_common(struct virtio_device *vdev) { struct virtrng_info *vi = vdev->priv; - vdev->config->reset(vdev); - vi->busy = false; if (vi->hwrng_register_done) hwrng_unregister(&vi->hwrng); + complete(&vi->have_data); + vdev->config->reset(vdev); + vi->busy = false; vdev->config->del_vqs(vdev); ida_simple_remove(&rng_index_ida, vi->index); kfree(vi); ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH] virtio-rng: complete have_data completion in removing device @ 2014-09-08 15:29 ` Amos Kong 0 siblings, 0 replies; 10+ messages in thread From: Amos Kong @ 2014-09-08 15:29 UTC (permalink / raw) To: Amit Shah; +Cc: kvm, stable, virtualization On Wed, Aug 06, 2014 at 01:55:29PM +0530, Amit Shah wrote: > On (Wed) 06 Aug 2014 [16:05:41], Amos Kong wrote: > > On Wed, Aug 06, 2014 at 01:35:15AM +0800, Amos Kong wrote: > > > When we try to hot-remove a busy virtio-rng device from QEMU monitor, > > > the device can't be hot-removed. Because virtio-rng driver hangs at > > > wait_for_completion_killable(). > > > > > > This patch fixed the hang by completing have_data completion before > > > unregistering a virtio-rng device. > > > > Hi Amit, > > > > Before applying this patch, it's blocking insider wait_for_completion_killable() > > Applied this patch, wait_for_completion_killable() returns 0, > > and vi->data_avail becomes 0, then rng_get_date() will return 0. > > Thanks for checking this. > > > Is it expected result? > > I think what will happen is vi->data_avail will be set to whatever it > was set last. In case of a previous successful read request, the > data_avail will be set to whatever number of bytes the host gave. On > doing a hot-unplug on the succeeding wait, the value in data_avail > will be re-used, and the hwrng core will wrongly take some bytes in > the buffer as input from the host. > > So, I think we need to set vi->data_avail = 0; before calling > wait_event_completion_killable(). > > Amit In my latest debugging, I found the hang is caused by unexpected reading when we started to remove the device. I have two draft fix, 1) is skip unexpected reading by checking a remove flag. 2) is unregistering device at the beginning of remove_common(). I think second patch is better if it won't cause new problem. The original patch (complete in remove_common()) is still necessary. Test results: hotplug issue disappeared (dd process will quit). diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c index 2e3139e..028797c 100644 --- a/drivers/char/hw_random/virtio-rng.c +++ b/drivers/char/hw_random/virtio-rng.c @@ -35,6 +35,7 @@ struct virtrng_info { unsigned int data_avail; int index; bool busy; + bool remove; bool hwrng_register_done; }; @@ -68,6 +69,9 @@ static int virtio_read(struct hwrng *rng, void *buf, size_t size, bool wait) int ret; struct virtrng_info *vi = (struct virtrng_info *)rng->priv; + if (vi->remove) + return 0; + if (!vi->busy) { vi->busy = true; init_completion(&vi->have_data); @@ -137,6 +141,8 @@ static void remove_common(struct virtio_device *vdev) { struct virtrng_info *vi = vdev->priv; + vi->remove = true; + complete(&vi->have_data); vdev->config->reset(vdev); vi->busy = false; if (vi->hwrng_register_done) diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c index 2e3139e..9b8c2ce 100644 --- a/drivers/char/hw_random/virtio-rng.c +++ b/drivers/char/hw_random/virtio-rng.c @@ -137,10 +137,11 @@ static void remove_common(struct virtio_device *vdev) { struct virtrng_info *vi = vdev->priv; - vdev->config->reset(vdev); - vi->busy = false; if (vi->hwrng_register_done) hwrng_unregister(&vi->hwrng); + complete(&vi->have_data); + vdev->config->reset(vdev); + vi->busy = false; vdev->config->del_vqs(vdev); ida_simple_remove(&rng_index_ida, vi->index); kfree(vi); ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH] virtio-rng: complete have_data completion in removing device 2014-09-08 15:29 ` Amos Kong @ 2014-09-09 10:47 ` Amos Kong -1 siblings, 0 replies; 10+ messages in thread From: Amos Kong @ 2014-09-09 10:47 UTC (permalink / raw) To: Amit Shah; +Cc: kvm, stable, virtualization On Mon, Sep 08, 2014 at 11:29:51PM +0800, Amos Kong wrote: > On Wed, Aug 06, 2014 at 01:55:29PM +0530, Amit Shah wrote: > > On (Wed) 06 Aug 2014 [16:05:41], Amos Kong wrote: > > > On Wed, Aug 06, 2014 at 01:35:15AM +0800, Amos Kong wrote: > > > > When we try to hot-remove a busy virtio-rng device from QEMU monitor, > > > > the device can't be hot-removed. Because virtio-rng driver hangs at > > > > wait_for_completion_killable(). > > > > > > > > This patch fixed the hang by completing have_data completion before > > > > unregistering a virtio-rng device. > > > > > > Hi Amit, > > > > > > Before applying this patch, it's blocking insider wait_for_completion_killable() > > > Applied this patch, wait_for_completion_killable() returns 0, > > > and vi->data_avail becomes 0, then rng_get_date() will return 0. > > > > Thanks for checking this. > > > > > Is it expected result? > > Hi Amit > > I think what will happen is vi->data_avail will be set to whatever it > > was set last. In case of a previous successful read request, the > > data_avail will be set to whatever number of bytes the host gave. On > > doing a hot-unplug on the succeeding wait, the value in data_avail > > will be re-used, and the hwrng core will wrongly take some bytes in > > the buffer as input from the host. > > > > So, I think we need to set vi->data_avail = 0; before calling > > wait_event_completion_killable(). I finally understand content, we need to set vi->data_avail to 0 before returning virtio_read(), it might enter wait_event_completion_killable() when we try to remove the device. We call complete() in remove_common(), then wait_event_completion_killable() will exit, but virtio_read() will be re-entered if the device still isn't unregistered, then re-stuck inside wait_event_completion_killable(). I tested some complex condition (both quick/slow backend), I found some problem in below two patches. I will post another fix later. The test result is expected. 1. Hotplug remove virtio-rng0, dd process will exit with an error: "dd: error reading ‘/dev/hwrng’: Operation not permitted" virtio-rng0 disappear from 'info pci' 2. Re-read by dd, hotplug virtio-rng1, dd process exit with same error, virtio-rng1 disappear Thanks, Amos > > > > Amit > > In my latest debugging, I found the hang is caused by unexpected reading > when we started to remove the device. > > I have two draft fix, 1) is skip unexpected reading by checking a > remove flag. 2) is unregistering device at the beginning of > remove_common(). I think second patch is better if it won't cause > new problem. > > The original patch (complete in remove_common()) is still necessary. > > Test results: hotplug issue disappeared (dd process will quit). > > > diff --git a/drivers/char/hw_random/virtio-rng.c > b/drivers/char/hw_random/virtio-rng.c > index 2e3139e..028797c 100644 > --- a/drivers/char/hw_random/virtio-rng.c > +++ b/drivers/char/hw_random/virtio-rng.c > @@ -35,6 +35,7 @@ struct virtrng_info { > unsigned int data_avail; > int index; > bool busy; > + bool remove; > bool hwrng_register_done; > }; > > @@ -68,6 +69,9 @@ static int virtio_read(struct hwrng *rng, void *buf, > size_t size, bool wait) > int ret; > struct virtrng_info *vi = (struct virtrng_info *)rng->priv; > > + if (vi->remove) > + return 0; > + > if (!vi->busy) { > vi->busy = true; > init_completion(&vi->have_data); > @@ -137,6 +141,8 @@ static void remove_common(struct virtio_device > *vdev) > { > struct virtrng_info *vi = vdev->priv; > > + vi->remove = true; > + complete(&vi->have_data); > vdev->config->reset(vdev); > vi->busy = false; > if (vi->hwrng_register_done) > > > diff --git a/drivers/char/hw_random/virtio-rng.c > b/drivers/char/hw_random/virtio-rng.c > index 2e3139e..9b8c2ce 100644 > --- a/drivers/char/hw_random/virtio-rng.c > +++ b/drivers/char/hw_random/virtio-rng.c > @@ -137,10 +137,11 @@ static void remove_common(struct virtio_device > *vdev) > { > struct virtrng_info *vi = vdev->priv; > > - vdev->config->reset(vdev); > - vi->busy = false; > if (vi->hwrng_register_done) > hwrng_unregister(&vi->hwrng); > + complete(&vi->have_data); > + vdev->config->reset(vdev); > + vi->busy = false; > vdev->config->del_vqs(vdev); > ida_simple_remove(&rng_index_ida, vi->index); > kfree(vi); ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] virtio-rng: complete have_data completion in removing device @ 2014-09-09 10:47 ` Amos Kong 0 siblings, 0 replies; 10+ messages in thread From: Amos Kong @ 2014-09-09 10:47 UTC (permalink / raw) To: Amit Shah; +Cc: stable, kvm, virtualization On Mon, Sep 08, 2014 at 11:29:51PM +0800, Amos Kong wrote: > On Wed, Aug 06, 2014 at 01:55:29PM +0530, Amit Shah wrote: > > On (Wed) 06 Aug 2014 [16:05:41], Amos Kong wrote: > > > On Wed, Aug 06, 2014 at 01:35:15AM +0800, Amos Kong wrote: > > > > When we try to hot-remove a busy virtio-rng device from QEMU monitor, > > > > the device can't be hot-removed. Because virtio-rng driver hangs at > > > > wait_for_completion_killable(). > > > > > > > > This patch fixed the hang by completing have_data completion before > > > > unregistering a virtio-rng device. > > > > > > Hi Amit, > > > > > > Before applying this patch, it's blocking insider wait_for_completion_killable() > > > Applied this patch, wait_for_completion_killable() returns 0, > > > and vi->data_avail becomes 0, then rng_get_date() will return 0. > > > > Thanks for checking this. > > > > > Is it expected result? > > Hi Amit > > I think what will happen is vi->data_avail will be set to whatever it > > was set last. In case of a previous successful read request, the > > data_avail will be set to whatever number of bytes the host gave. On > > doing a hot-unplug on the succeeding wait, the value in data_avail > > will be re-used, and the hwrng core will wrongly take some bytes in > > the buffer as input from the host. > > > > So, I think we need to set vi->data_avail = 0; before calling > > wait_event_completion_killable(). I finally understand content, we need to set vi->data_avail to 0 before returning virtio_read(), it might enter wait_event_completion_killable() when we try to remove the device. We call complete() in remove_common(), then wait_event_completion_killable() will exit, but virtio_read() will be re-entered if the device still isn't unregistered, then re-stuck inside wait_event_completion_killable(). I tested some complex condition (both quick/slow backend), I found some problem in below two patches. I will post another fix later. The test result is expected. 1. Hotplug remove virtio-rng0, dd process will exit with an error: "dd: error reading ‘/dev/hwrng’: Operation not permitted" virtio-rng0 disappear from 'info pci' 2. Re-read by dd, hotplug virtio-rng1, dd process exit with same error, virtio-rng1 disappear Thanks, Amos > > > > Amit > > In my latest debugging, I found the hang is caused by unexpected reading > when we started to remove the device. > > I have two draft fix, 1) is skip unexpected reading by checking a > remove flag. 2) is unregistering device at the beginning of > remove_common(). I think second patch is better if it won't cause > new problem. > > The original patch (complete in remove_common()) is still necessary. > > Test results: hotplug issue disappeared (dd process will quit). > > > diff --git a/drivers/char/hw_random/virtio-rng.c > b/drivers/char/hw_random/virtio-rng.c > index 2e3139e..028797c 100644 > --- a/drivers/char/hw_random/virtio-rng.c > +++ b/drivers/char/hw_random/virtio-rng.c > @@ -35,6 +35,7 @@ struct virtrng_info { > unsigned int data_avail; > int index; > bool busy; > + bool remove; > bool hwrng_register_done; > }; > > @@ -68,6 +69,9 @@ static int virtio_read(struct hwrng *rng, void *buf, > size_t size, bool wait) > int ret; > struct virtrng_info *vi = (struct virtrng_info *)rng->priv; > > + if (vi->remove) > + return 0; > + > if (!vi->busy) { > vi->busy = true; > init_completion(&vi->have_data); > @@ -137,6 +141,8 @@ static void remove_common(struct virtio_device > *vdev) > { > struct virtrng_info *vi = vdev->priv; > > + vi->remove = true; > + complete(&vi->have_data); > vdev->config->reset(vdev); > vi->busy = false; > if (vi->hwrng_register_done) > > > diff --git a/drivers/char/hw_random/virtio-rng.c > b/drivers/char/hw_random/virtio-rng.c > index 2e3139e..9b8c2ce 100644 > --- a/drivers/char/hw_random/virtio-rng.c > +++ b/drivers/char/hw_random/virtio-rng.c > @@ -137,10 +137,11 @@ static void remove_common(struct virtio_device > *vdev) > { > struct virtrng_info *vi = vdev->priv; > > - vdev->config->reset(vdev); > - vi->busy = false; > if (vi->hwrng_register_done) > hwrng_unregister(&vi->hwrng); > + complete(&vi->have_data); > + vdev->config->reset(vdev); > + vi->busy = false; > vdev->config->del_vqs(vdev); > ida_simple_remove(&rng_index_ida, vi->index); > kfree(vi); _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2014-09-09 10:47 UTC | newest] Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2014-08-05 17:35 [PATCH] virtio-rng: complete have_data completion in removing device Amos Kong 2014-08-05 17:35 ` Amos Kong 2014-08-06 8:05 ` Amos Kong 2014-08-06 8:05 ` Amos Kong 2014-08-06 8:25 ` Amit Shah 2014-08-06 8:25 ` Amit Shah 2014-09-08 15:29 ` Amos Kong 2014-09-08 15:29 ` Amos Kong 2014-09-09 10:47 ` Amos Kong 2014-09-09 10:47 ` Amos Kong
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.