Re: [PATCH v4 2/2] accel/tcg: Register a force_rcu notifier

2021-11-10 Thread Richard Henderson
On 11/9/21 7:35 PM, Greg Kurz wrote: A TCG vCPU doing a busy loop systematicaly hangs the QEMU monitor if the user passes 'device_add' without argument. This is because drain_cpu_all() which is called from qmp_device_add() cannot return if readers don't exit read-side critical sections. That is t

[PATCH v4 2/2] accel/tcg: Register a force_rcu notifier

2021-11-09 Thread Greg Kurz
A TCG vCPU doing a busy loop systematicaly hangs the QEMU monitor if the user passes 'device_add' without argument. This is because drain_cpu_all() which is called from qmp_device_add() cannot return if readers don't exit read-side critical sections. That is typically what busy-looping TCG vCPUs do