[Qemu-devel] [PATCH] qemu will core dump with "-smp 254, sockets=2, cores=3, threads=2"

[lijun <junmuzi@gmail.com>]

Hi all,

when set "-smp" more than 160, qemu will give the following warning:
Warning: Number of SMP cpus requested (161) exceeds the recommended cpus 
supported by KVM (160)
As the above warning, when set "-smp 160,sockets=2,cores=3,threads=2", 
but find that apic_id(hw/i386/acpi-build.c) is 259 not 159 and 
id(hw/acpi/piix4.c) is 259 not 159.

As the above warning, when set "-smp 254,sockets=2,cores=3,threads=2", 
but find that apic_id(hw/i386/acpi-build.c) is 513 not 253 and 
id(hw/acpi/piix4.c) is 513 not 253.

Based on above reasons, we have two methods to fix this issue.
1, Delete "assert(apic_id <= MAX_CPUMASK_BITS)" in file 
"hw/i386/acpi-build.c" and delete "g_assert((id / 8) < PIIX4_PROC_LEN)" 
in file "hw/acpi/piix4.c".
2, Detect the values of "sockets,cores,threads" when get them from 
command line. And modify smp_parse function in file vl.c to do some 
restrictions on these parameters when boot qemu.

I will submit the code patch later.

Best Regards,
Jun Li