KVM: arm64: Implement the TRNG hypervisor call

mainline inclusion
from mainline-v5.12-rc1
commit a8e190cd
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4QOJF


CVE: NA

----------------------

Provide a hypervisor implementation of the ARM architected TRNG firmware
interface described in ARM spec DEN0098. All function IDs are implemented,
including both 32-bit and 64-bit versions of the TRNG_RND service, which
is the centerpiece of the API.

The API is backed by the kernel's entropy pool only, to avoid guests
draining more precious direct entropy sources.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
[Andre: minor fixes, drop arch_get_random() usage]
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210106103453.152275-6-andre.przywara@arm.com



 Conflicts:
	arch/arm64/include/asm/kvm_host.h
	arch/arm64/kvm/Makefile
	arch/arm64/kvm/hypercalls.c
[wangxiongfeng: fix conflicts caused by context mismatch.]
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>