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On Wed, Jun 29, 2016 at 6:59 PM, Fam Zheng <famz at redhat.com> wrote: > It is documented that KOBJ_ADD should be generated after the object's > attributes and children are ready. We can achieve this with the new > disk_gen_uevents interface. > > Signed-off-by: Fam Zheng <famz at redhat.com> > --- > arch/powerp...

On Wed, Jun 29, 2016 at 6:59 PM, Fam Zheng <famz at redhat.com> wrote: > It is documented that KOBJ_ADD should be generated after the object's > attributes and children are ready. We can achieve this with the new > disk_gen_uevents interface. > > Signed-off-by: Fam Zheng <famz at redhat.com> > --- > arch/powerp...

On Wed, 17 Aug 2016 16:48:23 +0800 Fam Zheng <famz at redhat.com> wrote: > On Wed, 08/17 10:49, Cornelia Huck wrote: > > On Wed, 17 Aug 2016 15:15:06 +0800 > > Fam Zheng <famz at redhat.com> wrote: > > > > > @@ -613,10 +614,8 @@ void device_add_disk(struct device *parent, struct gendisk *disk) > > >...

On Wed, 17 Aug 2016 16:48:23 +0800 Fam Zheng <famz at redhat.com> wrote: > On Wed, 08/17 10:49, Cornelia Huck wrote: > > On Wed, 17 Aug 2016 15:15:06 +0800 > > Fam Zheng <famz at redhat.com> wrote: > > > > > @@ -613,10 +614,8 @@ void device_add_disk(struct device *parent, struct gendisk *disk) > > >...

On Wed, 17 Aug 2016 15:15:06 +0800 Fam Zheng <famz at redhat.com> wrote: > @@ -613,10 +614,8 @@ void device_add_disk(struct device *parent, struct gendisk *disk) > disk->flags |= GENHD_FL_UP; > > retval = blk_alloc_devt(&disk->part0, &devt); > - if (retval) { > - WARN_ON(1); > - return; > - } > +...

On Wed, 17 Aug 2016 15:15:06 +0800 Fam Zheng <famz at redhat.com> wrote: > @@ -613,10 +614,8 @@ void device_add_disk(struct device *parent, struct gendisk *disk) > disk->flags |= GENHD_FL_UP; > > retval = blk_alloc_devt(&disk->part0, &devt); > - if (retval) { > - WARN_ON(1); > - return; > - } > +...

...case of virtio-scsi-pci, the device may still try to send interupts, which will be on IRQ lines seeing MSI-X disabled. Those interrupts will be unhandled, and may cause flood. Remove the device in "shutdown" callback to allow device drivers clean up things. Signed-off-by: Fam Zheng <famz at redhat.com> --- drivers/virtio/virtio.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index 5ce2aa4..12f1f1e 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -269,6 +269,19 @@ static int virtio_dev_r...

...case of virtio-scsi-pci, the device may still try to send interupts, which will be on IRQ lines seeing MSI-X disabled. Those interrupts will be unhandled, and may cause flood. Remove the device in "shutdown" callback to allow device drivers clean up things. Signed-off-by: Fam Zheng <famz at redhat.com> --- drivers/virtio/virtio.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index 5ce2aa4..12f1f1e 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -269,6 +269,19 @@ static int virtio_dev_r...

v2: Fix endianness of WWNN/WWPN. [Paolo] This series implements the proposed fc_host feature of virtio-scsi. The first patch updates the data structure changes according to the spec proposal; the second patch actually implements the operations. Fam Zheng (2): virtio_scsi: Add fc_host definitions virtio_scsi: Implement fc_host drivers/scsi/virtio_scsi.c | 60

v2: Fix endianness of WWNN/WWPN. [Paolo] This series implements the proposed fc_host feature of virtio-scsi. The first patch updates the data structure changes according to the spec proposal; the second patch actually implements the operations. Fam Zheng (2): virtio_scsi: Add fc_host definitions virtio_scsi: Implement fc_host drivers/scsi/virtio_scsi.c | 60

The race condition is noticed between disk_add() and disk attributes, on virtio-blk hotplug. Userspace listens to the KOBJ_ADD uevent generated in add_disk(). At that point we haven't created the serial attribute file, therefore depending on how fast udev reacts, the /dev/disk/by-id/ entry doesn't always get created. As pointed out by Christoph Hellwig in the specific fix [1], virtio-blk

The race condition is noticed between disk_add() and disk attributes, on virtio-blk hotplug. Userspace listens to the KOBJ_ADD uevent generated in add_disk(). At that point we haven't created the serial attribute file, therefore depending on how fast udev reacts, the /dev/disk/by-id/ entry doesn't always get created. As pointed out by Christoph Hellwig in the specific fix [1], virtio-blk

...Q, which is totally unexpected thus will not be handled. In this case the guest hangs. Let's reset the device so that it will not generate any interrupts. Link: https://bugzilla.redhat.com/show_bug.cgi?id=1128424 Cc: Ulrich Obergfell <uobergfe at redhat.com> Signed-off-by: Fam Zheng <famz at redhat.com> --- drivers/virtio/virtio_pci.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index d34ebfa..cd7be6f 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -743,6 +743,14 @@ out: ret...

...Q, which is totally unexpected thus will not be handled. In this case the guest hangs. Let's reset the device so that it will not generate any interrupts. Link: https://bugzilla.redhat.com/show_bug.cgi?id=1128424 Cc: Ulrich Obergfell <uobergfe at redhat.com> Signed-off-by: Fam Zheng <famz at redhat.com> --- drivers/virtio/virtio_pci.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index d34ebfa..cd7be6f 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -743,6 +743,14 @@ out: ret...

On Wed, 08/17 11:06, Cornelia Huck wrote: > On Wed, 17 Aug 2016 16:48:23 +0800 > Fam Zheng <famz at redhat.com> wrote: > > > On Wed, 08/17 10:49, Cornelia Huck wrote: > > > On Wed, 17 Aug 2016 15:15:06 +0800 > > > Fam Zheng <famz at redhat.com> wrote: > > > > > > > @@ -613,10 +614,8 @@ void device_add_disk(struct device *parent, struct...

...> change handler is added here because primary_active will toggle during > migration. Looks like there's active discussion on virtio tc mailing list. It's ok to post patches meanwhile but best as RFC, and repost after controversy is resolved. > > Signed-off-by: Fam Zheng <famz at redhat.com> > --- > drivers/scsi/virtio_scsi.c | 60 +++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 59 insertions(+), 1 deletion(-) > > diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c > index ec91bd0..1bb330c 100644 > --- a/drivers...

...> change handler is added here because primary_active will toggle during > migration. Looks like there's active discussion on virtio tc mailing list. It's ok to post patches meanwhile but best as RFC, and repost after controversy is resolved. > > Signed-off-by: Fam Zheng <famz at redhat.com> > --- > drivers/scsi/virtio_scsi.c | 60 +++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 59 insertions(+), 1 deletion(-) > > diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c > index ec91bd0..1bb330c 100644 > --- a/drivers...

...ci doesn't implement shutdown, and > after we disable MSI-X, futher notifications from device will be > delivered to IRQ, which is unexpected. This IRQ will not be cleared, and > may prevent us from making progress, by keep triggering interrupts. > > Signed-off-by: Fam Zheng <famz at redhat.com> > --- > drivers/pci/pci-driver.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > index 3cb2210..fb29c96 100644 > --- a/drivers/pci/pci-driver.c > +++ b/drivers/pci/pci-d...

...ci doesn't implement shutdown, and > after we disable MSI-X, futher notifications from device will be > delivered to IRQ, which is unexpected. This IRQ will not be cleared, and > may prevent us from making progress, by keep triggering interrupts. > > Signed-off-by: Fam Zheng <famz at redhat.com> > --- > drivers/pci/pci-driver.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > index 3cb2210..fb29c96 100644 > --- a/drivers/pci/pci-driver.c > +++ b/drivers/pci/pci-d...

..., observe some problems > with virtio scsi? How to reproduce them? this needs to go > into the commit messages. OK, my bad. > > > Remove the device in "shutdown" callback to allow device drivers clean > > up things. > > > > Signed-off-by: Fam Zheng <famz at redhat.com> > > I'm concerned this will cause more hangs on shutdown: one > of the reasons for reboot is device mal-functioning. > How about we just reset devices instead? Something like > the below (untested). > > Signed-off-by: Michael S. Tsirkin <mst at redhat...