qemu-system-x86_64 hard crashes when using `--accel hvf` on intel Mac
Description of problem:
The QEMU process hard crashes after a few minutes. The only message is:

```
vmx_write_mem: mmu_gva_to_gpa ffff990489fa0000 failed
```
Steps to reproduce:
1. Run QEMU with the above commandline
2. Do something to keep the VM busy - running `git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git` reliably crashes it for me
3. Wait a 3-5 minutes
Additional information: