KVM: arm64: Implement the capability of DVMBM

virt inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I62Q2L


CVE: NA

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Implement the capability of DVMBM. Before each vcpu is loaded, we
re-calculate the VM-wide dvm_cpumask, and if it's changed we will kick all
other vcpus out to reload the latest LSUDVMBM value to the register, and a
new request KVM_REQ_RELOAD_DVMBM is added to implement this.

Otherwise if the dvm_cpumask is not changed by this single vcpu, in order
to ensure the correctness of the contents in the register, we reload the
LSUDVMBM value to the register and nothing else will be done.

Signed-off-by: Quan Zhou <zhouquan65@huawei.com>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Nianyao Tang <tangnianyao@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>