On Mon, Mar 17, 2014 at 11:08:46AM +0100, Laszlo Ersek wrote: > 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.
Make it unsigned acpi_cpus then? > 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. I'm fine with refactoring this if you feel it's more readable (I don't bit I wrote this so I know I'm biased), but let's make it a separate patch then. > 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 Yes, fine. > > > >> 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