qemu-system-i386 runs slow after upgrading legacy project from qemu 2.9.0  to 7.1.0
Description of problem:
Using several custom serial and irq devices including timers.
The same code (after some customisation in order to compile with new 7.1.0 API and meson build system runs about 50% slower.
We had to remove "-icount 4" switch which worked fine with 2.9.0 just to get to this point.
Even running with multi-threaded tcg did not help.
We don't use the new ptimer API but rather the old QEMUTimer.
Any suggestions to why we encounter this vast performance degradation?