search for: virtio_ccw_get_config

...98: ebdff0800024 stmg %r13,%r15,128(%r15) 000000000015bf9e: a7f13fe0 tmll %r15,16352 [ 0.839749] Call Trace: [ 0.839751] ([<000000000015bf8a>] __might_sleep+0x8a/0x98) [ 0.839756] [<000000000028a562>] __kmalloc+0x272/0x350 [ 0.839759] [<000000000058f824>] virtio_ccw_get_config+0x3c/0x100 [ 0.839762] [<000000000049fcb0>] balloon+0x1b8/0x330 [ 0.839765] [<00000000001529c8>] kthread+0x120/0x138 [ 0.839767] [<0000000000683c22>] kernel_thread_starter+0x6/0xc [ 0.839770] [<0000000000683c1c>] kernel_thread_starter+0x0/0xc [ 0.839772] n...

...98: ebdff0800024 stmg %r13,%r15,128(%r15) 000000000015bf9e: a7f13fe0 tmll %r15,16352 [ 0.839749] Call Trace: [ 0.839751] ([<000000000015bf8a>] __might_sleep+0x8a/0x98) [ 0.839756] [<000000000028a562>] __kmalloc+0x272/0x350 [ 0.839759] [<000000000058f824>] virtio_ccw_get_config+0x3c/0x100 [ 0.839762] [<000000000049fcb0>] balloon+0x1b8/0x330 [ 0.839765] [<00000000001529c8>] kthread+0x120/0x138 [ 0.839767] [<0000000000683c22>] kernel_thread_starter+0x6/0xc [ 0.839770] [<0000000000683c1c>] kernel_thread_starter+0x0/0xc [ 0.839772] n...

...:50:42AM +1030, Rusty Russell wrote: > Thomas Huth <thuth at linux.vnet.ibm.com> writes: > > Hi all, > > > > with the recent kernel 3.19, I get a kernel warning when I start my > > KVM guest on s390 with virtio balloon enabled: > > The deeper problem is that virtio_ccw_get_config just silently fails on > OOM. Same problem with virtio_ccw_reset. But avoiding kmalloc calls in virtio_ccw_get_config isn't enough I think, it might still sleep. > > Neither get_config nor set_config are expected to fail. > > Cornelia, I think ccw and config_area should be a...

...:50:42AM +1030, Rusty Russell wrote: > Thomas Huth <thuth at linux.vnet.ibm.com> writes: > > Hi all, > > > > with the recent kernel 3.19, I get a kernel warning when I start my > > KVM guest on s390 with virtio balloon enabled: > > The deeper problem is that virtio_ccw_get_config just silently fails on > OOM. Same problem with virtio_ccw_reset. But avoiding kmalloc calls in virtio_ccw_get_config isn't enough I think, it might still sleep. > > Neither get_config nor set_config are expected to fail. > > Cornelia, I think ccw and config_area should be a...

Thomas Huth <thuth at linux.vnet.ibm.com> writes: > Hi all, > > with the recent kernel 3.19, I get a kernel warning when I start my > KVM guest on s390 with virtio balloon enabled: The deeper problem is that virtio_ccw_get_config just silently fails on OOM. Neither get_config nor set_config are expected to fail. Cornelia, I think ccw and config_area should be allocated inside vcdev. You could either use pointers, or simply allocate vcdev with GDP_DMA. This would avoid the kmalloc inside these calls. Thanks, Rusty. >...

Thomas Huth <thuth at linux.vnet.ibm.com> writes: > Hi all, > > with the recent kernel 3.19, I get a kernel warning when I start my > KVM guest on s390 with virtio balloon enabled: The deeper problem is that virtio_ccw_get_config just silently fails on OOM. Neither get_config nor set_config are expected to fail. Cornelia, I think ccw and config_area should be allocated inside vcdev. You could either use pointers, or simply allocate vcdev with GDP_DMA. This would avoid the kmalloc inside these calls. Thanks, Rusty. >...

On Wed, 12 Sep 2018 16:02:01 +0200 Halil Pasic <pasic at linux.ibm.com> wrote: > Currently we have a race on vcdev->config in virtio_ccw_get_config() and > in virtio_ccw_set_config(). > > This normally does not cause problems, as these are usually infrequent > operations. But occasionally sysfs attributes are directly dependent on > pieces of virio config and trigger a get on each read. This gives us at > least one trigger....

...018 00:52:14 +0200 Halil Pasic <pasic at linux.ibm.com> wrote: > On 09/18/2018 08:29 PM, Cornelia Huck wrote: > > On Wed, 12 Sep 2018 16:02:01 +0200 > > Halil Pasic <pasic at linux.ibm.com> wrote: > > > >> Currently we have a race on vcdev->config in virtio_ccw_get_config() and > >> in virtio_ccw_set_config(). > >> > >> This normally does not cause problems, as these are usually infrequent > >> operations. But occasionally sysfs attributes are directly dependent on > >> pieces of virio config and trigger a get on each rea...

...rusty at rustcorp.com.au> wrote: > Thomas Huth <thuth at linux.vnet.ibm.com> writes: > > Hi all, > > > > with the recent kernel 3.19, I get a kernel warning when I start my > > KVM guest on s390 with virtio balloon enabled: > > The deeper problem is that virtio_ccw_get_config just silently fails on > OOM. > > Neither get_config nor set_config are expected to fail. AFAIK this is currently not a problem. According to http://lwn.net/Articles/627419/ these kmalloc calls never fail because they allocate less than a page. Thomas

...rusty at rustcorp.com.au> wrote: > Thomas Huth <thuth at linux.vnet.ibm.com> writes: > > Hi all, > > > > with the recent kernel 3.19, I get a kernel warning when I start my > > KVM guest on s390 with virtio balloon enabled: > > The deeper problem is that virtio_ccw_get_config just silently fails on > OOM. > > Neither get_config nor set_config are expected to fail. AFAIK this is currently not a problem. According to http://lwn.net/Articles/627419/ these kmalloc calls never fail because they allocate less than a page. Thomas

The following changes since commit 8c0f9f5b309d627182d5da72a69246f58bde1026: Revert "uapi/linux/keyctl.h: don't use C++ reserved keyword as a struct member name" (2018-09-25 13:28:58 +0200) are available in the Git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git tags/virtio-ccw-20180926 for you to fetch changes up to

...<thuth at linux.vnet.ibm.com> writes: > >> > Hi all, > >> > > >> > with the recent kernel 3.19, I get a kernel warning when I start my > >> > KVM guest on s390 with virtio balloon enabled: > >> > >> The deeper problem is that virtio_ccw_get_config just silently fails on > >> OOM. > >> > >> Neither get_config nor set_config are expected to fail. > > > > AFAIK this is currently not a problem. According to > > http://lwn.net/Articles/627419/ these kmalloc calls never > > fail because they allo...

...<thuth at linux.vnet.ibm.com> writes: > >> > Hi all, > >> > > >> > with the recent kernel 3.19, I get a kernel warning when I start my > >> > KVM guest on s390 with virtio balloon enabled: > >> > >> The deeper problem is that virtio_ccw_get_config just silently fails on > >> OOM. > >> > >> Neither get_config nor set_config are expected to fail. > > > > AFAIK this is currently not a problem. According to > > http://lwn.net/Articles/627419/ these kmalloc calls never > > fail because they allo...

...u8 status) > kfree(ccw); > } > > -static struct virtio_config_ops virtio_ccw_config_ops = { > +static const struct virtio_config_ops virtio_ccw_config_ops = { > .get_features = virtio_ccw_get_features, > .finalize_features = virtio_ccw_finalize_features, > .get = virtio_ccw_get_config, > -- > 2.11.0

...u8 status) > kfree(ccw); > } > > -static struct virtio_config_ops virtio_ccw_config_ops = { > +static const struct virtio_config_ops virtio_ccw_config_ops = { > .get_features = virtio_ccw_get_features, > .finalize_features = virtio_ccw_finalize_features, > .get = virtio_ccw_get_config, > -- > 2.11.0

...gt;> > Hi all, > > > >> > > > > >> > with the recent kernel 3.19, I get a kernel warning when I start my > > > >> > KVM guest on s390 with virtio balloon enabled: > > > >> > > > >> The deeper problem is that virtio_ccw_get_config just silently fails on > > > >> OOM. > > > >> > > > >> Neither get_config nor set_config are expected to fail. > > > > > > > > AFAIK this is currently not a problem. According to > > > > http://lwn.net/Articles/627419...

...gt;> > Hi all, > > > >> > > > > >> > with the recent kernel 3.19, I get a kernel warning when I start my > > > >> > KVM guest on s390 with virtio balloon enabled: > > > >> > > > >> The deeper problem is that virtio_ccw_get_config just silently fails on > > > >> OOM. > > > >> > > > >> Neither get_config nor set_config are expected to fail. > > > > > > > > AFAIK this is currently not a problem. According to > > > > http://lwn.net/Articles/627419...

...:50:42AM +1030, Rusty Russell wrote: > Thomas Huth <thuth at linux.vnet.ibm.com> writes: > > Hi all, > > > > with the recent kernel 3.19, I get a kernel warning when I start my > > KVM guest on s390 with virtio balloon enabled: > > The deeper problem is that virtio_ccw_get_config just silently fails on > OOM. > > Neither get_config nor set_config are expected to fail. > > Cornelia, I think ccw and config_area should be allocated inside vcdev. > You could either use pointers, or simply allocate vcdev with GDP_DMA. > > This would avoid the kmalloc i...

...:50:42AM +1030, Rusty Russell wrote: > Thomas Huth <thuth at linux.vnet.ibm.com> writes: > > Hi all, > > > > with the recent kernel 3.19, I get a kernel warning when I start my > > KVM guest on s390 with virtio balloon enabled: > > The deeper problem is that virtio_ccw_get_config just silently fails on > OOM. > > Neither get_config nor set_config are expected to fail. > > Cornelia, I think ccw and config_area should be allocated inside vcdev. > You could either use pointers, or simply allocate vcdev with GDP_DMA. > > This would avoid the kmalloc i...

...w_set_status(struct virtio_device *vdev, u8 status) kfree(ccw); } -static struct virtio_config_ops virtio_ccw_config_ops = { +static const struct virtio_config_ops virtio_ccw_config_ops = { .get_features = virtio_ccw_get_features, .finalize_features = virtio_ccw_finalize_features, .get = virtio_ccw_get_config, -- 1.9.1