Comment 4 for bug 1832661

These 4 patches didn't apply cleanly and needed manual merging. Nothing too hairy though:

synchronize sync(2) against cgroup writeback membership switches
KVM: x86: Skip EFER vs. guest CPUID checks for host-initiated writes
arm64: cpu_ops: fix a leaked reference by adding missing of_node_put
crypto: vmx - ghash: do nosimd fallback manually