The series is motivated by auditing the usage of CPUState::nr_cores and CPUState::nr_threads, which is motivated by [1].
The initial goal is to initialize nr_threads and nr_cores earlier for x86, which leads to patches [2] and [3]. Patch [2] touches all the ARCHes and patch [3] looks hacky. At last Igor suggested to audit nr_threads and nr_cores, and only set them in the pre_plug() callback for the ARCHes that really need them[1]. By audting nr_threads and nr_cores, I found nr_cores is only used by x86. So we can introduce a x86 specific one and initialize in x86_cpu_pre_plug(), then drop nr_cores totally. However for nr_threads, it's used by MIPS and PPC as well[4]. There are two options: 1. maintain separate substitute in X86/MIPS/PPS, so we can drop CPUState::nr_threads like for CPUState::nr_cores. 2. keep CPUState::nr_threads and find place (or introduce pre_plug()) to initialize them earlier for MIPS/PPC. I would like to seek for opinions for which one is prefered. This series implments the drop for CPUState::nr_cores. Though it doesn't help on the initial goal without the solution for nr_threads, I think it is still a good cleanup? BTW, by initializing nr_threads and nr_cores earlier than qemu_init_vcpu(), it also unblocks [5]. [1] https://lore.kernel.org/qemu-devel/20241125103857.78a23...@imammedo.users.ipa.redhat.com/ [2] https://lore.kernel.org/qemu-devel/5f8db586-cdda-4d00-be02-f9880a20e...@redhat.com/ [3] https://lore.kernel.org/qemu-devel/20241122160317.4070177-1-xiaoyao...@intel.com/ [4] https://lore.kernel.org/qemu-devel/045f9cb1-2b17-4b2c-985f-3c34e3626...@intel.com/ [5] https://lore.kernel.org/qemu-devel/20231128171239.69b6d...@imammedo.users.ipa.redhat.com/ Xiaoyao Li (4): i386/topology: Update the comment of x86_apicid_from_topo_ids() i386: Extract a common fucntion to setup value of MSR_CORE_THREAD_COUNT i386: Track cores_per_module in CPUX86State cpu: Remove nr_cores from struct CPUState hw/core/cpu-common.c | 1 - hw/i386/x86-common.c | 4 +++- include/hw/core/cpu.h | 2 -- include/hw/i386/topology.h | 5 +++-- system/cpus.c | 1 - target/i386/cpu.c | 2 +- target/i386/cpu.h | 16 ++++++++++++++++ target/i386/hvf/x86_emu.c | 3 +-- target/i386/kvm/kvm.c | 5 +---- target/i386/tcg/sysemu/misc_helper.c | 3 +-- 10 files changed, 26 insertions(+), 16 deletions(-) -- 2.34.1
