From 18045fb9f457a0f0cba2bd113c748a2dcb4ed39e Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 28 Jul 2014 17:34:16 +0200 Subject: [PATCH] pc: future-proof migration-compatibility of ACPI tables This patch avoids that similar changes break QEMU again in the future. QEMU will now hard-code 64k as the maximum ACPI table size, which (despite being an order of magnitude smaller than 640k) should be enough for everyone. Reviewed-by: Laszlo Ersek Tested-by: Igor Mammedov Signed-off-by: Paolo Bonzini Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/i386/acpi-build.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index ec86f1b..2178894 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -62,6 +62,8 @@ #define ACPI_BUILD_LEGACY_CPU_AML_SIZE 97 #define ACPI_BUILD_ALIGN_SIZE 0x1000 +#define ACPI_BUILD_TABLE_SIZE 0x10000 + typedef struct AcpiCpuInfo { DECLARE_BITMAP(found_cpus, ACPI_CPU_HOTPLUG_ID_LIMIT); } AcpiCpuInfo; @@ -1588,7 +1590,13 @@ void acpi_build(PcGuestInfo *guest_info, AcpiBuildTables *tables) } g_array_set_size(tables->table_data, legacy_table_size); } else { - acpi_align_size(tables->table_data, ACPI_BUILD_ALIGN_SIZE); + if (tables->table_data->len > ACPI_BUILD_TABLE_SIZE) { + /* As of QEMU 2.1, this fires with 160 VCPUs and 255 memory slots. */ + error_report("ACPI tables are larger than 64k. Please remove"); + error_report("CPUs, NUMA nodes, memory slots or PCI bridges."); + exit(1); + } + g_array_set_size(tables->table_data, ACPI_BUILD_TABLE_SIZE); } acpi_align_size(tables->linker, ACPI_BUILD_ALIGN_SIZE); -- 2.7.4