On Wed, 18 Aug 2021 20:21:29 +0000, Oliver Upton wrote:

The CPU_ON PSCI call requires careful coordination between vCPUs in KVM,
as it allows callers to send a payload (pc, context id) to another vCPU
to start execution. There are a couple of races in the handling of
CPU_ON:

 - KVM uses the kvm->lock to serialize the write-side of a vCPU's reset
   state. However, kvm_vcpu_reset() doesn't take the lock on the
   read-size, meaning the vCPU could be reset with interleaved state
   from two separate CPU_ON calls.

[...]

Applied to next, thanks!

[1/4] KVM: arm64: Fix read-side race on updates to vcpu reset state
      commit: 6654f9dfcb88fea3b9affc180dc3c04333d0f306
[2/4] KVM: arm64: Handle PSCI resets before userspace touches vCPU state
      commit: 6826c6849b46aaa91300201213701eb861af4ba0
[3/4] KVM: arm64: Enforce reserved bits for PSCI target affinities
      commit: e10ecb4d6c0761ca545b3946df1707a41f9f845e
[4/4] selftests: KVM: Introduce psci_cpu_on_test
      commit: cb97cf95c44021278b7637731bc0928026bc29ab

Cheers,

	M.
-- 
Without deviation from the norm, progress is not possible.