linux/drivers/virtio, branch v4.11

virtio-pci: Remove affinity hint before freeing the interrupt

2017-04-10T21:30:20Z

virtio-pci registers a per-vq affinity hint when using MSIX, but fails to remove it when freeing the interrupt, resulting in this type of splat: [ 31.111202] WARNING: CPU: 0 PID: 2823 at kernel/irq/manage.c:1503 __free_irq+0x2c4/0x2c8 [ 31.114689] Modules linked in: [ 31.116101] CPU: 0 PID: 2823 Comm: kexec Not tainted 4.10.0+ #6941 [ 31.118911] Hardware name: Generic DT based system [ 31.121319] [] (unwind_backtrace) from [] (show_stack+0x18/0x1c) [ 31.125017] [] (show_stack) from [] (dump_stack+0x84/0x98) [ 31.128427] [] (dump_stack) from [] (__warn+0xf4/0x10c) [ 31.131910] [] (__warn) from [] (warn_slowpath_null+0x28/0x30) [ 31.135543] [] (warn_slowpath_null) from [] (__free_irq+0x2c4/0x2c8) [ 31.139355] [] (__free_irq) from [] (free_irq+0x44/0x78) [ 31.142909] [] (free_irq) from [] (vp_del_vqs+0x68/0x1c0) [ 31.146299] [] (vp_del_vqs) from [] (pci_device_shutdown+0x3c/0x78) The obvious fix is to drop the affinity hint before freeing the interrupt. Signed-off-by: Marc Zyngier Signed-off-by: Michael S. Tsirkin

Revert "virtio_pci: remove struct virtio_pci_vq_info"

2017-04-10T21:29:59Z

This reverts commit 5c34d002dcc7a6dd665a19d098b4f4cd5501ba1a. Conflicts: drivers/virtio/virtio_pci_common.c The cleanup seems to be one of the changes that broke hybernation for some users. We are still not sure why but revert helps. This reverts the cleanup changes but keeps the affinity support. Tested-by: Mike Galbraith Signed-off-by: Michael S. Tsirkin

Revert "virtio_pci: use shared interrupts for virtqueues"

2017-04-10T21:28:57Z

This reverts commit 07ec51480b5eb1233f8c1b0f5d7a7c8d1247c507. Conflicts: drivers/virtio/virtio_pci_common.c Unfortunately the idea does not work with threadirqs as more than 32 queues can then map to a single interrupts. Further, the cleanup seems to be one of the changes that broke hybernation for some users. We are still not sure why but revert helps. This reverts the cleanup changes but keeps the affinity support. Tested-by: Mike Galbraith Signed-off-by: Michael S. Tsirkin

Revert "virtio_pci: don't duplicate the msix_enable flag in struct pci_dev"

2017-04-10T21:28:41Z

This reverts commit 53a020c661741f3b87ad3ac6fa545088aaebac9b. The cleanup seems to be one of the changes that broke hybernation for some users. We are still not sure why but revert helps. Tested-by: Mike Galbraith Signed-off-by: Michael S. Tsirkin

Revert "virtio_pci: simplify MSI-X setup"

2017-04-10T21:19:40Z

This reverts commit 52a61516125fa9a21b3bdf4f90928308e2e5573f. Conflicts: drivers/virtio/virtio_pci_common.c The cleanup seems to be one of the changes that broke hybernation for some users. We are still not sure why but revert helps. This reverts the cleanup changes but keeps the affinity support. Tested-by: Mike Galbraith Signed-off-by: Michael S. Tsirkin

Revert "virtio_pci: fix out of bound access for msix_names"

2017-04-10T20:27:50Z

This reverts commit de85ec8b07f82c8c84de7687f769e74bf4c26a1e. Follow-up patches will revert 07ec51480b5e ("virtio_pci: use shared interrupts for virtqueues") that triggered the problem so no need for this one anymore. Tested-by: Mike Galbraith Signed-off-by: Michael S. Tsirkin

virtio: allow drivers to validate features

2017-04-07T13:38:59Z

Some drivers can't support all features in all configurations. At the moment we blindly set FEATURES_OK and later FAILED. Support this better by adding a callback drivers can use to do some early checks. Signed-off-by: Michael S. Tsirkin

virtio_balloon: prevent uninitialized variable use

2017-03-28T17:41:28Z

The latest gcc-7.0.1 snapshot reports a new warning: virtio/virtio_balloon.c: In function 'update_balloon_stats': virtio/virtio_balloon.c:258:26: error: 'events[2]' is used uninitialized in this function [-Werror=uninitialized] virtio/virtio_balloon.c:260:26: error: 'events[3]' is used uninitialized in this function [-Werror=uninitialized] virtio/virtio_balloon.c:261:56: error: 'events[18]' is used uninitialized in this function [-Werror=uninitialized] virtio/virtio_balloon.c:262:56: error: 'events[17]' is used uninitialized in this function [-Werror=uninitialized] This seems absolutely right, so we should add an extra check to prevent copying uninitialized stack data into the statistics. >From all I can tell, this has been broken since the statistics code was originally added in 2.6.34. Fixes: 9564e138b1f6 ("virtio: Add memory statistics reporting to the balloon driver (V4)") Signed-off-by: Arnd Bergmann Signed-off-by: Ladi Prosek Signed-off-by: Michael S. Tsirkin

virtio-balloon: use actual number of stats for stats queue buffers

2017-03-28T17:41:28Z

The virtio balloon driver contained a not-so-obvious invariant that update_balloon_stats has to update exactly VIRTIO_BALLOON_S_NR counters in order to send valid stats to the host. This commit fixes it by having update_balloon_stats return the actual number of counters, and its callers use it when pushing buffers to the stats virtqueue. Note that it is still out of spec to change the number of counters at run-time. "Driver MUST supply the same subset of statistics in all buffers submitted to the statsq." Suggested-by: Arnd Bergmann Signed-off-by: Ladi Prosek Signed-off-by: Michael S. Tsirkin

virtio_balloon: init 1st buffer in stats vq

2017-03-28T17:41:27Z

When init_vqs runs, virtio_balloon.stats is either uninitialized or contains stale values. The host updates its state with garbage data because it has no way of knowing that this is just a marker buffer used for signaling. This patch updates the stats before pushing the initial buffer. Alternative fixes: * Push an empty buffer in init_vqs. Not easily done with the current virtio implementation and violates the spec "Driver MUST supply the same subset of statistics in all buffers submitted to the statsq". * Push a buffer with invalid tags in init_vqs. Violates the same spec clause, plus "invalid tag" is not really defined. Note: the spec says: When using the legacy interface, the device SHOULD ignore all values in the first buffer in the statsq supplied by the driver after device initialization. Note: Historically, drivers supplied an uninitialized buffer in the first buffer. Unfortunately QEMU does not seem to implement the recommendation even for the legacy interface. Cc: stable@vger.kernel.org Signed-off-by: Ladi Prosek Signed-off-by: Michael S. Tsirkin