Messages in this thread | | | From | "Tian, Kevin" <> | Subject | RE: [PATCH V4 07/11] vfio/pci: Update stale comment | Date | Fri, 28 Apr 2023 06:42:49 +0000 |
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> From: Chatre, Reinette <reinette.chatre@intel.com> > Sent: Friday, April 28, 2023 1:36 AM > > @@ -419,11 +419,9 @@ static int vfio_msi_set_vector_signal(struct > vfio_pci_core_device *vdev, > } > > /* > - * The MSIx vector table resides in device memory which may be > cleared > - * via backdoor resets. We don't allow direct access to the vector > - * table so even if a userspace driver attempts to save/restore > around > - * such a reset it would be unsuccessful. To avoid this, restore the > - * cached value of the message prior to enabling. > + * If the vector was previously allocated, refresh the on-device > + * message data before enabling in case it had been cleared or > + * corrupted since writing. > */ > cmd = vfio_pci_memory_lock_and_enable(vdev); > if (msix) {
What about keeping backdoor reset as an example, e.g.
"in case it had been cleared or corrupted (e.g. due to backdoor resets) ..."
otherwise one may doubt whether it is a more severe problem causing the corruption inadvertently w/o userspace driver's awareness and then whether just restoring the data is sufficient to move on.
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