KVM: arm/arm64: fix races in kvm_psci_vcpu_on

Fix potential races in kvm_psci_vcpu_on() by taking the kvm->lock
mutex.  In general, it's a bad idea to allow more than one PSCI_CPU_ON
to process the same target VCPU at the same time.  One such problem
that may arise is that one PSCI_CPU_ON could be resetting the target
vcpu, which fills the entire sys_regs array with a temporary value
including the MPIDR register, while another looks up the VCPU based
on the MPIDR value, resulting in no target VCPU found.  Resolves both
races found with the kvm-unit-tests/arm/psci unit test.

Reviewed-by: Marc Zyngier <[email protected]>
Reviewed-by: Christoffer Dall <[email protected]>
Reported-by: Levente Kurusa <[email protected]>
Suggested-by: Christoffer Dall <[email protected]>
Signed-off-by: Andrew Jones <[email protected]>
Cc: [email protected]
Signed-off-by: Christoffer Dall <[email protected]>

0 files changed, 0 insertions, 0 deletions