On 07/25/13 15:23, Michael S. Tsirkin wrote: > On Thu, Jul 25, 2013 at 03:06:25PM +0200, Gerd Hoffmann wrote: >> Hi, >> >>> As table content is likely to change over time, >>> the following measures are taken to simplify >>> cross-version migration: >>> - All tables besides the RSDP are packed in a single FW CFG entry. >>> This entry size is currently 23K. We round it up to 64K >>> to avoid too much churn there. >> >> Does it need to be that way? I'd prefer to have one fw_cfg entry per table. >> >> cheers, >> Gerd >> > > It's better I think. The advantages are: > - when we add more tables we don't break cross-version > migration compatibility
New tables are a guest-visible change, so I think we have to turn them off for old machine types via compat properties anyway. This will also solve the migration issue. > - we have limited number of files, this way we won't > run out of them Anything which prevents us from raising that number? > what are advantages of file per table? You can look at the tables without doing a full linker pass first, so the firmware can easily initialize the hardware according to what it finds in specific acpi tables. Check FADT for pm_base. Check MCFG for mmconf xbar location. cheers, Gerd
