0824121660
zihpm is the Hardware Performance Counters extension described in chapter 12 of the unprivileged spec. It describes support for 29 unprivileged performance counters, hpmcounter3-hpmcounter31. As with zicntr, QEMU already implements zihpm before it was even an extension. zihpm is also part of the RVA22 profile, so add it to QEMU to complement the future profile implementation. Default it to 'true' for all existing CPUs since it was always present in the code. As for disabling it, there is already code in place in target/riscv/csr.c in all predicates for these counters (ctr() and mctr()) that disables them if cpu->cfg.pmu_num is zero. Thus, setting cpu->cfg.pmu_num to zero if 'zihpm=false' is enough to disable the extension. Set cpu->pmu_avail_ctrs mask to zero as well since this is also checked to verify if the counters exist. Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Message-ID: <20231023153927.435083-4-dbarboza@ventanamicro.com> Signed-off-by: Alistair Francis <alistair.francis@wdc.com> |
||
---|---|---|
.. | ||
meson.build | ||
tcg-cpu.c | ||
tcg-cpu.h |