Gautam Menghani [off-list ref] writes:

Running a L2 vCPU (see [1] for terminology) with LPCR_MER bit set and no
pending interrupts results in that L2 vCPU getting an infinite flood of
spurious interrupts. The 'if check' in kvmhv_run_single_vcpu() sets the
LPCR_MER bit if there are pending interrupts.

Applied to powerpc/fixes.

[1/1] KVM: PPC: Book3S HV: Mask off LPCR_MER for a vCPU before running it to avoid spurious interrupts
      https://git.kernel.org/powerpc/c/a373830f96db288a3eb43a8692b6bcd0bd88dfe1

cheers