On 03/16/14 13:31, Michael S. Tsirkin wrote: > On Fri, Mar 14, 2014 at 11:22:52PM +0100, Laszlo Ersek wrote: >> Building on the previous patch, raise the maximal count of processor >> objects / NTFY branches / CPON elements from 255 to 256. This allows the >> VCPU with APIC ID 0xFF to be hotplugged. >> >> Signed-off-by: Laszlo Ersek <ler...@redhat.com> >> --- >> hw/i386/acpi-build.c | 16 +++++++++++----- >> 1 file changed, 11 insertions(+), 5 deletions(-) >> >> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c >> index 2bbefb5..51162fc 100644 >> --- a/hw/i386/acpi-build.c >> +++ b/hw/i386/acpi-build.c >> @@ -999,11 +999,15 @@ build_ssdt(GArray *table_data, GArray *linker, >> AcpiCpuInfo *cpu, AcpiPmInfo *pm, AcpiMiscInfo *misc, >> PcPciInfo *pci, PcGuestInfo *guest_info) >> { >> - int acpi_cpus = MIN(0xff, guest_info->apic_id_limit); > > Maybe just make this line > int acpi_cpus = guest_info->apic_id_limit; > and then the patch will be smaller.
I did think of that, but I didn't like the unchecked unsigned --> int conversion. The limit checks below cover that too. Also, the patch renders the function similar to the other acpi builder functions; there are a handful of loops that directly name "guest_info->apic_id_limit" in their controlling expressions. Anyway, would you be OK with a patch that did the assignment you suggest (rather than modifying the loops), and kept the BUILD_BUG and the g_assert below? Thanks Laszlo > >> int ssdt_start = table_data->len; >> uint8_t *ssdt_ptr; >> int i; >> >> + /* The current AML generator can cover the APIC ID range [0..255], >> + * inclusive, for VCPU hotplug. */ >> + QEMU_BUILD_BUG_ON(ACPI_CPU_HOTPLUG_ID_LIMIT > 256); >> + g_assert(guest_info->apic_id_limit <= ACPI_CPU_HOTPLUG_ID_LIMIT); >> + >> /* Copy header and patch values in the S3_ / S4_ / S5_ packages */ >> ssdt_ptr = acpi_data_push(table_data, sizeof(ssdp_misc_aml)); >> memcpy(ssdt_ptr, ssdp_misc_aml, sizeof(ssdp_misc_aml)); >> @@ -1029,7 +1033,7 @@ build_ssdt(GArray *table_data, GArray *linker, >> build_append_nameseg(sb_scope, "_SB_"); >> >> /* build Processor object for each processor */ >> - for (i = 0; i < acpi_cpus; i++) { >> + for (i = 0; i < guest_info->apic_id_limit; i++) { >> uint8_t *proc = acpi_data_push(sb_scope, ACPI_PROC_SIZEOF); >> memcpy(proc, ACPI_PROC_AML, ACPI_PROC_SIZEOF); >> proc[ACPI_PROC_OFFSET_CPUHEX] = acpi_get_hex(i >> 4); >> @@ -1042,7 +1046,8 @@ build_ssdt(GArray *table_data, GArray *linker, >> * Method(NTFY, 2) {If (LEqual(Arg0, 0x00)) {Notify(CP00, Arg1)} >> ...} >> */ >> /* Arg0 = Processor ID = APIC ID */ >> - build_append_notify_method(sb_scope, "NTFY", "CP%0.02X", acpi_cpus); >> + build_append_notify_method(sb_scope, "NTFY", "CP%0.02X", >> + guest_info->apic_id_limit); >> >> /* build "Name(CPON, Package() { One, One, ..., Zero, Zero, ... })" >> */ >> build_append_byte(sb_scope, 0x08); /* NameOp */ >> @@ -1052,8 +1057,9 @@ build_ssdt(GArray *table_data, GArray *linker, >> GArray *package = build_alloc_array(); >> uint8_t op = 0x13; /* VarPackageOp */ >> >> - build_append_int(package, acpi_cpus); /* VarNumElements */ >> - for (i = 0; i < acpi_cpus; i++) { >> + build_append_int(package, >> + guest_info->apic_id_limit); /* VarNumElements >> */ >> + for (i = 0; i < guest_info->apic_id_limit; i++) { >> uint8_t b = test_bit(i, cpu->found_cpus) ? 0x01 : 0x00; >> build_append_byte(package, b); >> } >> -- >> 1.8.3.1