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2019-03-23s390/virtio: handle find on invalid queue gracefullyHalil Pasic1-1/+3
commit 3438b2c039b4bf26881786a1f3450f016d66ad11 upstream. A queue with a capacity of zero is clearly not a valid virtio queue. Some emulators report zero queue size if queried with an invalid queue index. Instead of crashing in this case let us just return -ENOENT. To make that work properly, let us fix the notifier cleanup logic as well. Cc: stable@vger.kernel.org Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-13virtio/s390: fix race in ccw_io_helper()Halil Pasic1-1/+6
commit 78b1a52e05c9db11d293342e8d6d8a230a04b4e7 upstream. While ccw_io_helper() seems like intended to be exclusive in a sense that it is supposed to facilitate I/O for at most one thread at any given time, there is actually nothing ensuring that threads won't pile up at vcdev->wait_q. If they do, all threads get woken up and see the status that belongs to some other request than their own. This can lead to bugs. For an example see: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1788432 This race normally does not cause any problems. The operations provided by struct virtio_config_ops are usually invoked in a well defined sequence, normally don't fail, and are normally used quite infrequent too. Yet, if some of the these operations are directly triggered via sysfs attributes, like in the case described by the referenced bug, userspace is given an opportunity to force races by increasing the frequency of the given operations. Let us fix the problem by ensuring, that for each device, we finish processing the previous request before starting with a new one. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Reported-by: Colin Ian King <colin.king@canonical.com> Cc: stable@vger.kernel.org Message-Id: <20180925121309.58524-3-pasic@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-13virtio/s390: avoid race on vcdev->configHalil Pasic1-2/+8
commit 2448a299ec416a80f699940a86f4a6d9a4f643b1 upstream. 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. However, for some devices writing to/reading from the config space can be triggered through sysfs attributes. For these, userspace can force the race by increasing the frequency. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Cc: stable@vger.kernel.org Message-Id: <20180925121309.58524-2-pasic@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17virtio/s390: handle error values in irbCornelia Huck1-25/+37
The common I/O layer may pass an error value as the irb in the device's interrupt handler (for classic channel I/O). This won't happen in current virtio-ccw implementations, but it's better to be safe than sorry. Let's just return the error conveyed by the irb and clear any possible pending I/O indications. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Guenther Hutzl <hutzl@linux.vnet.ibm.com> Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-10-14s390/diag: add a statistic for diagnose callsMartin Schwidefsky1-3/+12
Introduce /sys/debug/kernel/diag_stat with a statistic how many diagnose calls have been done by each CPU in the system. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-09-16virtio/s390: handle failures of READ_VQ_CONF ccwPierre Morel1-1/+9
In virtio_ccw_read_vq_conf() the return value of ccw_io_helper() was not checked. If the configuration could not be read properly, we'd wrongly assume a queue size of 0. Let's propagate any I/O error to virtio_ccw_setup_vq() so it may properly fail. Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-07-23Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds3-0/+1906
Pull virtio/vhost fixes from Michael Tsirkin: "Bugfixes and documentation fixes. Igor's patch that allows users to tweak memory table size is borderline, but it does fix known crashes, so I merged it" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: vhost: add max_mem_regions module parameter vhost: extend memory regions allocation to vmalloc 9p/trans_virtio: reset virtio device on remove virtio/s390: rename drivers/s390/kvm -> drivers/s390/virtio MAINTAINERS: separate section for s390 virtio drivers virtio: define virtio_pci_cfg_cap in header. virtio: Fix typecast of pointer in vring_init() virtio scsi: fix unused variable warning vhost: use binary search instead of linear in find_region() virtio_net: document VIRTIO_NET_CTRL_GUEST_OFFLOADS
2015-07-07virtio/s390: rename drivers/s390/kvm -> drivers/s390/virtioCornelia Huck3-0/+1899
This more accurately reflects what these drivers actually do. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>