xchg may also cause the #AC for split-lock check.
This patch adds this emulation.
1. Kick other vcpus of the guest to stop execution
if the guest has more than one vcpu.
2. Emulate the xchg instruction.
3. Notify other vcpus (if any) to restart execution.
Tracked-On: #5605
Signed-off-by: Jie Deng <jie.deng@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>