On Fri Jun 14, 2024 at 9:36 AM AEST, Salil Mehta wrote:
> From: Jean-Philippe Brucker <jean-phili...@linaro.org>
>
> When a KVM vCPU is reset following a PSCI CPU_ON call, its power state
> is not synchronized with KVM at the moment. Because the vCPU is not
> marked dirty, we miss the call to kvm_arch_put_registers() that writes
> to KVM's MP_STATE. Force mp_state synchronization.
Hmm. Is this a bug fix for upstream? arm does respond to CPU_ON calls
by the look, but maybe it's not doing KVM parking until your series?
Maybe just a slight change to say "When KVM parking is implemented for
ARM..." if so.
>
> Signed-off-by: Jean-Philippe Brucker <jean-phili...@linaro.org>
> Signed-off-by: Salil Mehta <salil.me...@huawei.com>
> ---
> target/arm/kvm.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/target/arm/kvm.c b/target/arm/kvm.c
> index 1121771c4a..7acd83ce64 100644
> --- a/target/arm/kvm.c
> +++ b/target/arm/kvm.c
> @@ -980,6 +980,7 @@ void kvm_arm_cpu_post_load(ARMCPU *cpu)
> void kvm_arm_reset_vcpu(ARMCPU *cpu)
> {
> int ret;
> + CPUState *cs = CPU(cpu);
>
> /* Re-init VCPU so that all registers are set to
> * their respective reset values.
> @@ -1001,6 +1002,12 @@ void kvm_arm_reset_vcpu(ARMCPU *cpu)
> * for the same reason we do so in kvm_arch_get_registers().
> */
> write_list_to_cpustate(cpu);
> +
> + /*
> + * Ensure we call kvm_arch_put_registers(). The vCPU isn't marked dirty
> if
> + * it was parked in KVM and is now booting from a PSCI CPU_ON call.
> + */
> + cs->vcpu_dirty = true;
> }
>
> void kvm_arm_create_host_vcpu(ARMCPU *cpu)
Also above my pay grade, but arm_set_cpu_on_async_work() which seems
to be what calls the CPU reset you refer to does a bunch of CPU register
and state setting including the power state setting that you mention.
Would the vcpu_dirty be better to go there?
Thanks,
Nick
