Hi All:
This is a rework on the IRQ hardening for virtio which is done
previously by the following commits are reverted:
9e35276a5344 ("virtio_pci: harden MSI-X interrupts")
080cd7c3ac87 ("virtio-pci: harden INTX interrupts")
The reason is that it depends on the IRQF_NO_AUTOEN which may conflict
with the assumption of the affinity managed IRQ that is used by some
virtio drivers. And what's more, it is only done for virtio-pci but
not other transports.
In this rework, I try to implement a general virtio solution which
borrows the idea of the INTX hardening by re-using per virtqueue
boolean vq->broken and toggle it in virtio_device_ready() and
virtio_reset_device(). Then we can simply reuse the existing checks in
the vring_interrupt() and return early if the driver is not ready.
Note that, I only did compile test on ccw and MMIO transport.
Please review.
Changes since V4:
- use spin_lock_irq()/spin_unlock_irq() to synchronize with
vring_interrupt() for ccw
- use spin_lock()/spin_unlock() to protect vring_interrupt() for non
airq
- add comment to explain the ordering implications of set_status() for
PCI, ccw and MMIO
- various tweaks on the comments and changelogs
Changes since V3:
- Rename synchornize_vqs() to synchronize_cbs()
- tweak the comment for synchronize_cbs()
- switch to use a dedicated helper __virtio_unbreak_device() and
document it should be only used for probing
- switch to use rwlock to synchornize the non airq for ccw
Changes since V2:
- add ccw and MMIO support
- rename synchronize_vqs() to synchronize_cbs()
- switch to re-use vq->broken instead of introducing new device
attributes for the future virtqueue reset support
- remove unnecssary READ_ONCE()/WRITE_ONCE()
- a new patch to remove device triggerable BUG_ON()
- more tweaks on the comments
Changes since v1:
- Use transport specific irq synchronization method when possible
- Drop the module parameter and enable the hardening unconditonally
- Tweak the barrier/ordering facilities used in the code
- Reanme irq_soft_enabled to driver_ready
- Avoid unnecssary IRQ synchornization (e.g during boot)
Jason Wang (8):
virtio: use virtio_reset_device() when possible
virtio: introduce config op to synchronize vring callbacks
virtio-pci: implement synchronize_cbs()
virtio-mmio: implement synchronize_cbs()
virtio-ccw: implement synchronize_cbs()
virtio: allow to unbreak virtqueue
virtio: harden vring IRQ
virtio: use WARN_ON() to warning illegal status value
Stefano Garzarella (1):
virtio: use virtio_device_ready() in virtio_device_restore()
drivers/s390/virtio/virtio_ccw.c | 31 +
drivers/virtio/virtio.c| 24 +
drivers/virtio/virtio_mmio.c | 14
drivers/virtio/virtio_pci_legacy.c | 1 +
drivers/virtio/virtio_pci_modern.c | 2 ++
drivers/virtio/virtio_pci_modern_dev.c | 5 +++
drivers/virtio/virtio_ring.c | 32 +++---
include/linux/virtio.h | 1 +
include/linux/virtio_config.h | 47 +-
9 files changed, 145 insertions(+), 12 deletions(-)
--
2.25.1
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