qemu:handle_cpu_signal received signal outside vCPU context

[Tj (Elloe Linux)]

We're seeing this error on Ubuntu 20.04 amd64 host and aarch64
qemu-aarch64-static chroot when executing 'aptitude':

qemu:handle_cpu_signal received signal outside vCPU context
qemu:handle_cpu_signal received signal outside vCPU context

Research led us to an identical issue report against qemu-m68k [0] where
it is reported this issue is resolved in 5.0.0+.

Ubuntu 20.04 LTS currently ships v4.2 so I'm trying to identify the
commit(s) that resolved this issue so we can test a cherry-pick of the fix.

Do you know which commit(s) addressed this?

Some suggestions as to the responsible patch have been made but I've not
been able to find the patchwork patch [1] content in current upstream
which suggests its the wrong patch, it was never merged, or the code has
since changed so it is unrecognisable.


[0] https://github.com/vivier/qemu-m68k/issues/38

[1]
http://patchwork.ozlabs.org/project/qemu-devel/patch/1456850240-21096-1-git-send-email-peter.maydell@linaro.org/