Re: [PATCH v5 08/14] iommufd/viommu: Add iommufd_viommu_report_event helper

On Wed, Jan 22, 2025 at 11:02:59PM -0800, Nicolin Chen wrote:

I made a change to duplicate the overflow node in the fetch() that is protected by the spinlock, which is used for copy_to_user. Then the other routine for vEVENT reporting, protected by the spinlock, can race-freely update the preallocated overflow node.

That seems like the right answer, copy the few bytes you need on the stack under the spinlock.

Jason