Add padding after the DSDT. Tables that vary depending on the
command-line arguments will have to be byte-equivalent across QEMU
versions >= 2.2, while fixed tables (including the DSDT) can be
changed freely.
This new algorithm will let us present smaller ACPI blobs to
the guest, which avoids bugs with -kernel/-initrd and 32-bit
RHEL5 guests. However, this patch does not change the size of
the blobs yet; for now, the values of the parameters are tuned
to have 2.1-compatible sizes.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
hw/i386/acpi-build.c | 11 +++++++----
hw/i386/pc_piix.c | 5 +++++
include/hw/i386/pc.h | 2 ++
3 files changed, 14 insertions(+), 4 deletions(-)
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 694ee91..48e7f2e 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -65,8 +65,6 @@
#define ACPI_BUILD_LEGACY_CPU_AML_SIZE 97
#define ACPI_BUILD_ALIGN_SIZE 0x1000
-#define ACPI_BUILD_TABLE_SIZE 0x20000
-
typedef struct AcpiCpuInfo {
DECLARE_BITMAP(found_cpus, ACPI_CPU_HOTPLUG_ID_LIMIT);
} AcpiCpuInfo;
@@ -1597,6 +1595,10 @@ void acpi_build(PcGuestInfo *guest_info, AcpiBuildTables
*tables)
acpi_add_table(table_offsets, tables->table_data);
build_fadt(tables->table_data, tables->linker, &pm, facs, dsdt);
+ if (guest_info->fixed_table_align) {
+ acpi_align_size(tables->table_data, guest_info->fixed_table_align);
+ }
+
ssdt = tables->table_data->len;
acpi_add_table(table_offsets, tables->table_data);
build_ssdt(tables->table_data, tables->linker, &cpu, &pm, &misc, &pci,
@@ -1681,14 +1683,15 @@ void acpi_build(PcGuestInfo *guest_info,
AcpiBuildTables *tables)
g_array_set_size(tables->table_data, legacy_table_size);
} else {
/* Make sure we have a buffer in case we need to resize the tables. */
- if (tables->table_data->len > ACPI_BUILD_TABLE_SIZE / 2) {
+ if (!guest_info->fixed_table_align &&
+ tables->table_data->len > guest_info->acpi_table_align / 2) {
/* As of QEMU 2.1, this fires with 160 VCPUs and 255 memory slots.
*/
error_report("Warning: ACPI tables are larger than 64k.");
error_report("Warning: migration may not work.");
error_report("Warning: please remove CPUs, NUMA nodes, "
"memory slots or PCI bridges.");
}
- acpi_align_size(tables->table_data, ACPI_BUILD_TABLE_SIZE);
+ acpi_align_size(tables->table_data, guest_info->acpi_table_align);
}
pc_set_acpi_data_size(tables->table_data->len);
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index ca9f07c..1ecb281 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -61,6 +61,8 @@ static const int ide_irq[MAX_IDE_BUS] = { 14, 15 };
static bool has_acpi_build = true;
static int legacy_acpi_table_size;
+static int fixed_table_align = 0;
+static int acpi_table_align = 131072;
static bool smbios_defaults = true;
static bool smbios_legacy_mode;
/* Make sure that guest addresses aligned at 1Gbyte boundaries get mapped to
@@ -164,6 +166,8 @@ static void pc_init1(MachineState *machine,
guest_info->has_acpi_build = has_acpi_build;
guest_info->legacy_acpi_table_size = legacy_acpi_table_size;
+ guest_info->fixed_table_align = fixed_table_align;
+ guest_info->acpi_table_align = acpi_table_align;
guest_info->isapc_ram_fw = !pci_enabled;
guest_info->has_reserved_memory = has_reserved_memory;
@@ -314,6 +318,7 @@ static void pc_compat_2_0(MachineState *machine)
* QEMU 1.7 it is 6414. For RHEL/CentOS 7.0 it is 6418.
*/
legacy_acpi_table_size = 6652;
+ acpi_table_align = 4096;
smbios_legacy_mode = true;
has_reserved_memory = false;
}
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 853829b..8b65b47 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -94,6 +94,8 @@ struct PcGuestInfo {
uint64_t *node_cpu;
FWCfgState *fw_cfg;
int legacy_acpi_table_size;
+ int fixed_table_align;
+ int acpi_table_align;
bool has_acpi_build;
bool has_reserved_memory;
};
--
2.1.0
