On Thu, Jun 17, 2010 at 02:17:20PM +0300, Michael S. Tsirkin wrote: > On Thu, Jun 17, 2010 at 08:03:08PM +0900, Isaku Yamahata wrote: > > This patch set allows seabios to initialize multi pci bus and 64bit BAR. > > > > Currently seabios is able to initialize only pci root bus. > > However multi pci bus support is wanted because > > - more pci bus is wanted in qemu for many slots > > - pci express support is commin in qemu which requires multi pci bus. > > those patches on Qemu part are under way, though. > > Not that I object, but - does it really require multi bus? Why?
I should have explained about pci express a bit more. Express defines root/upstream/upstream port. They are shown to software as pci-to-pci bride. Express slot to which express device is inserted is under a root or downstream port. That means multi bus. Native hot plug is implemented in root or downstream port. Again that means multi bus. I heard that some windows device driver checks pci-to-pci bridge existence. Perhaps others may know this better. -- yamahata
