The 160 vcpu limit is a KVM limit, so when booting without kvm, -no-kvm, then that limit no longer matters. Does the windows guest boot on qemu using TCG at all? If so, how many cpus can be configured and still boot? Does it work with 160?

(In reply to Andrew Jones from comment #1)
> The 160 vcpu limit is a KVM limit, so when booting without kvm, -no-kvm,
> then that limit no longer matters. Does the windows guest boot on qemu using
> TCG at all? If so, how many cpus can be configured and still boot? Does it
> work with 160?

For windows guest.
QE tested two scenarios.
1. /usr/libexec/qemu-kvm -M pc -no-kvm  -smp 1
2. /usr/libexec/qemu-kvm -machine pc,accel=tcg -no-kvm -smp 1

got the same result:
1. guest boot fail and show error code as below
error code:000000C4

For linux guest.
QE tested two scenarios.
1./usr/libexec/qemu-kvm -M q35 -no-kvm -smp 40 -m 4G
guest works

2./usr/libexec/qemu-kvm -M q35 -no-kvm -smp 50 -m 4G
guest kernel panic

Additional:
If remove -no-kvm option from command line for linux guest. then works with 160.

Fix included in qemu-kvm-rhev-2.6.0-11.el7

According to comment2. verified this bug with qemu-kvm-rhev-2.6.0-22.el7.

result:

for windows guest-PASS(guest works well)
1. /usr/libexec/qemu-kvm -M pc -no-kvm  -smp 1
2. /usr/libexec/qemu-kvm -machine pc,accel=tcg -no-kvm -smp 1


For linux guest-PASS(guest works well)
1./usr/libexec/qemu-kvm -M q35 -no-kvm -smp 50 -m 4G
guest kernel panic

So,Base on this testing result. this bug is fixed.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2016-2673.html