The specific upstream commit is 20140a82c67467f53814ca197403d5e1b561a5e5 and is incorporated into qemu 1:3.1+dfsg-2ubuntu3.1 in disco-security (19.04) and 1:3.1+dfsg-2ubuntu4 in eoan-proposed. For backporting to cosmic and older, I believe it requires the infrastructure to support IA32_ARCH_CAPABILITIES in place.
The specific upstream commit is 20140a82c67467f 53814ca197403d5 e1b561a5e5 and is incorporated into qemu 1:3.1+dfsg- 2ubuntu3. 1 in disco-security (19.04) and 1:3.1+dfsg-2ubuntu4 in eoan-proposed. For backporting to cosmic and older, I believe it requires the infrastructure to support IA32_ARCH_ CAPABILITIES in place.