KVM: arm64: Fix read-side race on updates to vcpu reset state

stable inclusion
from stable-5.10.68
commit 53921242cf995a6c9867154696ba9f07b6bd7957
bugzilla: 182671 https://gitee.com/openeuler/kernel/issues/I4EWUH

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=53921242cf995a6c9867154696ba9f07b6bd7957



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[ Upstream commit 6654f9df ]

KVM correctly serializes writes to a vCPU's reset state, however since
we do not take the KVM lock on the read side it is entirely possible to
read state from two different reset requests.

Cure the race for now by taking the KVM lock when reading the
reset_state structure.

Fixes: 358b28f0 ("arm/arm64: KVM: Allow a VCPU to fully reset itself")
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210818202133.1106786-2-oupton@google.com


Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Weilong Chen <chenweilong@huawei.com>

Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>