On Fri, Nov 11, 2016 at 02:45:42PM -0200, Eduardo Habkost wrote: > The code that calculates the legacy ACPI table size for migration > compatibility uses max_cpus when calculating legacy_aml_len (the size of > the DSDT and SSDT tables). However, the SSDT grows according to APIC ID > limit, not max_cpus. > > The bug is not triggered very often because of the 4k alignment on the > table size. But it can be triggered if you are unlucky enough to cross a > 4k boundary. > > Change the legacy_aml_len calculation to use apic_id_limit, to calculate > the right size. > > Signed-off-by: Eduardo Habkost <ehabk...@redhat.com>
Does this affect migration in some way? > --- > This patch was submitted in 2014 and reviewed by Paolo. Only > today I noticed that it was never merged. > > Changes v1 -> v2: > * Use pcms->apic_id_limit, as guest_info doesn't exist anymore > --- > hw/i386/acpi-build.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c > index c02f408..bb66446 100644 > --- a/hw/i386/acpi-build.c > +++ b/hw/i386/acpi-build.c > @@ -2859,7 +2859,7 @@ void acpi_build(AcpiBuildTables *tables, MachineState > *machine) > */ > int legacy_aml_len = > pcmc->legacy_acpi_table_size + > - ACPI_BUILD_LEGACY_CPU_AML_SIZE * max_cpus; > + ACPI_BUILD_LEGACY_CPU_AML_SIZE * pcms->apic_id_limit; > int legacy_table_size = > ROUND_UP(tables_blob->len - aml_len + legacy_aml_len, > ACPI_BUILD_ALIGN_SIZE); > -- > 2.7.4
