On Mon, Nov 17, 2025 at 11:50 AM Michael S. Tsirkin <[email protected]> wrote: > > On Fri, Nov 14, 2025 at 12:25:03PM +0100, Eugenio Perez Martin wrote: > > RCU is protecting that the address space pointer of the vq group is > > not modified concurrently with the access. Ideally, this should be a > > full lock, but just making sure that all accesses from the reader are > > coherent is enough. Userspace should expect nothing if it uses the map > > and modifies the vq group ASID at the same time anyway, but the kernel > > needs to be sure that it does not see intermediate states. TBH, we > > could move to a READ_ONCE / WRITE_ONCE, would that be more clear? > > generally rcu itself does not need ONCE macros. > these are for funky lockless things, and rcu can be > seen as a kind of lock, after all. >
Right, I meant to replace RCU by READ_ONCE / WRITE ONCE. But I also prefer RCU.
