diff options
Diffstat (limited to 'hw/i386/acpi-build.c')
| -rw-r--r-- | hw/i386/acpi-build.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index 7d880bec4a..2e15f6848e 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -2512,6 +2512,34 @@ build_dmar_q35(GArray *table_data, BIOSLinker *linker) build_header(linker, table_data, (void *)(table_data->data + dmar_start), "DMAR", table_data->len - dmar_start, 1, NULL, NULL); } + +/* + * Windows ACPI Emulated Devices Table + * (Version 1.0 - April 6, 2009) + * Spec: http://download.microsoft.com/download/7/E/7/7E7662CF-CBEA-470B-A97E-CE7CE0D98DC2/WAET.docx + * + * Helpful to speedup Windows guests and ignored by others. + */ +static void +build_waet(GArray *table_data, BIOSLinker *linker) +{ + int waet_start = table_data->len; + + /* WAET header */ + acpi_data_push(table_data, sizeof(AcpiTableHeader)); + /* + * Set "ACPI PM timer good" flag. + * + * Tells Windows guests that our ACPI PM timer is reliable in the + * sense that guest can read it only once to obtain a reliable value. + * Which avoids costly VMExits caused by guest re-reading it unnecessarily. + */ + build_append_int_noprefix(table_data, 1 << 1 /* ACPI PM timer good */, 4); + + build_header(linker, table_data, (void *)(table_data->data + waet_start), + "WAET", table_data->len - waet_start, 1, NULL, NULL); +} + /* * IVRS table as specified in AMD IOMMU Specification v2.62, Section 5.2 * accessible here http://support.amd.com/TechDocs/48882_IOMMU.pdf @@ -2859,6 +2887,9 @@ void acpi_build(AcpiBuildTables *tables, MachineState *machine) machine->nvdimms_state, machine->ram_slots); } + acpi_add_table(table_offsets, tables_blob); + build_waet(tables_blob, tables->linker); + /* Add tables supplied by user (if any) */ for (u = acpi_table_first(); u; u = acpi_table_next(u)) { unsigned len = acpi_table_len(u); |