On Mon, Jul 28, 2014 at 05:34:16PM +0200, Paolo Bonzini wrote: > 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.
Famous last words :) So what worries me here, is that we are potentially breaking legal configurations for the benefit of the minority that cares about cross-version migration. So I'm inclined to apply everything except this patch, and instead, use the patches that I sent to make the ram block very large, something like 1 Megabyte. This localizes the pain to cross-version migration. > > Reviewed-by: Laszlo Ersek <ler...@redhat.com> > Tested-by: Igor Mammedov <imamm...@redhat.com> > Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> > --- > 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 a3d5822..25cf297 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; > @@ -1569,7 +1571,13 @@ 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); > -- > 1.8.3.1 >