On Fr, 2013-10-11 at 13:20 +0200, Igor Mammedov wrote: > On Thu, 10 Oct 2013 14:54:29 +0200 > Gerd Hoffmann <kra...@redhat.com> wrote: > > > We have a fw_cfg entry to pass e820 entries from qemu to the firmware. > > Today it's used to pass reservations only. This patch makes qemu pass > > entries for RAM too. > > > > This allows to pass RAM sizes larger than 1TB to the firmware and it > > will also allow to pass non-contignous memory ramges should we decide > > to implement that some day, say for our virtual numa nodes. > > > > Obviously this needs some extra care to not break existing firware. > > > > SeaBIOS loads the entries and happily adds them without looking at the > > type. Which is problematic for memory below 4g as this will overwrite > > reservations added for bios memory etc. For memory above 4g it works > > just fine, seabios will merge the entry derived from cmos with the one > > loaded from fw_cfg. > It will make amount of available memory in e820 table more than described > in smbios and could break MS's SMBIOS HCT test.
Happens only in case the installed amount of memory is larger than 1TB (which is the maximum the cmos can describe). Such a setup doesn't work correctly without the patch anyway, so it isn't a regression IMHO. And with an additional patch on the seabios side we can fix the smbios info even for the >1TB case. > Perhaps related smbios info > also should be picked up from QEMU. Worth investigating, but lets concentrate on the acpi table merge first. cheers, Gerd
