Commit 4b5b47ab authored by Eduardo Habkost's avatar Eduardo Habkost Committed by Michael S. Tsirkin
Browse files

acpi: Use apic_id_limit when calculating legacy ACPI table size 



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: default avatarEduardo Habkost <ehabkost@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent d668fc4c

hw/i386/acpi-build.c

+1 −1
Original line number Diff line number Diff line
@@ -2860,7 +2860,7 @@ 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);