Side channel execution mitigations were added to QEMU.
- qemu: Machine emulator and virtualizer
Ken Johnson and Jann Horn independently discovered that microprocessors
utilizing speculative execution of a memory read may allow unauthorized
memory reads via sidechannel attacks. An attacker in the guest could use
this to expose sensitive guest information, including kernel memory. This
update allows QEMU to expose new CPU features added by AMD microcode
updates to guests on amd64 and i386.
The problem can be corrected by updating your system to the following