Issue with qemu 2.12.0 + SATA

(first reported here: https://bugzilla.tianocore.org/show_bug.cgi?id=949 )

I had a Windows 10 VM running perfectly fine with OVMF UEFI, since I upgraded to qemu 2.12, the guests hangs for a couple of minutes, works for a few seconds, and hangs again, etc. By "hang" I mean it doesn't freeze, but it looks like it's waiting on IO or something, I can move the mouse but everything needing disk access is unresponsive.

What doesn't work: qemu 2.12 with OVMF
What works: using BIOS or downgrading qemu to 2.11.1.

Platform is arch linux 4.16.7 on skylake, I have attached the vm xml file.