KVM: arm64: Probe and configure DVMBM capability on HiSi CPUs

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


CVE: NA

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DVMBM is an virtualization extension since HIP09, which allows TLBI
executed at NS EL1 to be broadcast in a configurable range of physical
CPUs (even with HCR_EL2.FB set). It will bring TLBI broadcast optimization.

Introduce the method to detect and enable this feature. Also add a kernel
command parameter "kvm-arm.dvmbm_enabled" (=0 on default) so that users can
{en,dis}able DVMBM on need. The parameter description is added under
Documentation/.

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>