d8b441a3fb
The number of slots per page being 511 (i.e. not a power of two) means that the (32-bit) read and write indexes going beyond 2^32 will likely disturb operation. The hypervisor side gets I/O req server creation extended so we can indicate that we're using suitable atomic accesses where needed, allowing it to atomically canonicalize both pointers when both have gone through at least one cycle. The Xen side counterpart (which is not a functional prereq to this change, albeit a build one) went in already (commit b7007bc6f9). Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Read the documentation in qemu-doc.html or on http://wiki.qemu-project.org - QEMU team