Comment 41 for bug 1832622

I think I found the missing kernel bit.

As reported it needs:
2b57ecd0208f KVM: PPC: Book3S: Add count cache flush parameters to kvmppc_get_cpu_char()

Which was brought into Bionic/Cosmic already as part of bug LP1822870.
This is only needed when I'd be on new HW/FW

Bionic: $ grep -Hrn KVM_PPC_CPU_CHAR_BCCTR_FLUSH_ASSIST *
arch/powerpc/kvm/powerpc.c:1949: KVM_PPC_CPU_CHAR_BCCTR_FLUSH_ASSIST;
arch/powerpc/kvm/powerpc.c:2014: cp->character |= KVM_PPC_CPU_CHAR_BCCTR_FLUSH_ASSIST;
arch/powerpc/kvm/powerpc.c:2021: KVM_PPC_CPU_CHAR_BCCTR_FLUSH_ASSIST;
arch/powerpc/include/uapi/asm/kvm.h:466:#define KVM_PPC_CPU_CHAR_BCCTR_FLUSH_ASSIST (1ull << 54)

Disco: the same grep finds nothing.

$ git tag --contains 2b57ecd0208f
v5.1
...
Disco is on 5.0.0.27.28, so it needs this commit.

Comparing git://kernel.ubuntu.com/ubuntu/ubuntu-bionic.git with git://kernel.ubuntu.com/ubuntu/ubuntu-disco.git confirms, this was lost on the path to Disco.

@IBM - can we release the qemu portion of this now and the kernel Team will include that on the next kernel SRU cycle? Or does the addition of this to Qemu without the related kernel change break anything. It didn't seem so to me in my DD 2.2 Tests.