+ Add xianglai Good catch.
In theory, it is logical id, and it can be not equal to physical id. However it must be equal to _UID in cpu dsdt table which is missing now. Can pptt table parse error be fixed if cpu dsdt table is added? Regards Bibo Mao 在 2023/8/20 18:56, Jiajie Chen 写道: > In hw/acpi/aml-build.c:build_pptt() function, the code assumes that the > ACPI processor id equals to the cpu index, for example if we have 8 > cpus, then the ACPI processor id should be in range 0-7. > > However, in hw/loongarch/acpi-build.c:build_madt() function we broke the > assumption. If we have 8 cpus again, the ACPI processor id in MADT table > would be in range 1-8. It violates the following description taken from > ACPI spec 6.4 table 5.138: > > If the processor structure represents an actual processor, this field > must match the value of ACPI processor ID field in the processor’s entry > in the MADT. > > It will break the latest Linux 6.5-rc6 with the > following error message: > > ACPI PPTT: PPTT table found, but unable to locate core 7 (8) > Invalid BIOS PPTT > > Here 7 is the last cpu index, 8 is the ACPI processor id learned from > MADT. > > With this patch, Linux can properly detect SMT threads when "-smp > 8,sockets=1,cores=4,threads=2" is passed: > > Thread(s) per core: 2 > Core(s) per socket: 2 > Socket(s): 2 > > The detection of number of sockets is still wrong, but that is out of > scope of the commit. > > Signed-off-by: Jiajie Chen <c...@jia.je> > --- > hw/loongarch/acpi-build.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/loongarch/acpi-build.c b/hw/loongarch/acpi-build.c > index 0b62c3a2f7..ae292fc543 100644 > --- a/hw/loongarch/acpi-build.c > +++ b/hw/loongarch/acpi-build.c > @@ -127,7 +127,7 @@ build_madt(GArray *table_data, BIOSLinker *linker, > LoongArchMachineState *lams) > build_append_int_noprefix(table_data, 17, 1); /* Type */ > build_append_int_noprefix(table_data, 15, 1); /* Length */ > build_append_int_noprefix(table_data, 1, 1); /* Version */ > - build_append_int_noprefix(table_data, i + 1, 4); /* ACPI Processor > ID */ > + build_append_int_noprefix(table_data, i, 4); /* ACPI Processor > ID */ > build_append_int_noprefix(table_data, arch_id, 4); /* Core ID */ > build_append_int_noprefix(table_data, 1, 4); /* Flags */ > }
